CA2232805C - Pulverized fuel combustion burner - Google Patents
Pulverized fuel combustion burner Download PDFInfo
- Publication number
- CA2232805C CA2232805C CA002232805A CA2232805A CA2232805C CA 2232805 C CA2232805 C CA 2232805C CA 002232805 A CA002232805 A CA 002232805A CA 2232805 A CA2232805 A CA 2232805A CA 2232805 C CA2232805 C CA 2232805C
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- Prior art keywords
- pulverized fuel
- supply pipe
- fuel supply
- rich
- flow
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- 239000000446 fuel Substances 0.000 title claims abstract description 352
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 171
- 230000008859 change Effects 0.000 claims abstract description 34
- 238000002347 injection Methods 0.000 claims abstract description 19
- 239000007924 injection Substances 0.000 claims abstract description 19
- 230000004044 response Effects 0.000 claims abstract description 7
- 238000011144 upstream manufacturing Methods 0.000 claims description 17
- 239000000126 substance Substances 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 15
- 238000000926 separation method Methods 0.000 description 9
- 230000009471 action Effects 0.000 description 8
- 238000010276 construction Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 230000006872 improvement Effects 0.000 description 4
- 230000000717 retained effect Effects 0.000 description 3
- 230000002730 additional effect Effects 0.000 description 2
- 239000003245 coal Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C5/00—Disposition of burners with respect to the combustion chamber or to one another; Mounting of burners in combustion apparatus
- F23C5/02—Structural details of mounting
- F23C5/06—Provision for adjustment of burner position during operation
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D1/00—Burners for combustion of pulverulent fuel
- F23D1/02—Vortex burners, e.g. for cyclone-type combustion apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2201/00—Burners adapted for particulate solid or pulverulent fuels
- F23D2201/10—Nozzle tips
- F23D2201/101—Nozzle tips tiltable
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2201/00—Burners adapted for particulate solid or pulverulent fuels
- F23D2201/20—Fuel flow guiding devices
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Disintegrating Or Milling (AREA)
- Combustion Of Fluid Fuel (AREA)
- Pre-Mixing And Non-Premixing Gas Burner (AREA)
- Pressure-Spray And Ultrasonic-Wave- Spray Burners (AREA)
Abstract
ABSTRACT A pulverized fuel combustion burner applied to a boiler of a thermal power plant or chemical plant, a furnace of a chemical industry or the like is provided in which, even if the injection direction of the primary air nozzle changes upward or downward, a proper concentration distribution of the mixed flow of the pulverized fuel and the earner air can be obtained at the exit plane of the furnace side wall and leakage of a portion of the combustion auxiliary air into the furnace is not caused. The pulverized fuel combustion burner comprised a rich/lean flow separator provided at or near the jointed portion between the primary air nozzle and the pulverized fuel supply pipe. The rich/lean flow separator is enabled to change its direction in response to or independently of a change in an injection direction of the primary air nozzle. Thus, the rich/lean flow separator follows the change of the direction of the injection of the primary air nozzle and the mixed flow so separated rich and lean can be injected in the same direction as the primary air nozzle without any biasing.
Description
SPECIFICATION
TITLE OF THE INVENTION
Pulverized Fuel Combustion Burner BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a pulverized fuel combustion burner to be applied to a boiler of a thermal power plant or chemical plant, a furnace of a chemical industry or the like.
Related Art The technique of this kind of the prior art will be described with reference to Fig. 5. Figs. 5(a) to 5(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 5(a), 5(b) and 5(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward.
Reference numeral 1 designates a primary air nozzle, and numeral 2 designates a secondary air nozzle arranged outside of the primary air nozzle 1.
Numeral 3 designates a pulverized fuel supply pipe, and numeral 4 designates a combustion auxiliary fuel supply passage which is defined by the pulverized fuel supply pipe 3 and a windbox 5.. The pulverized fuel supply pipe 3 communicates at its terminal end with the primary air nozzle l, and the combustion auxiliary air supply passage 4 communicates with the secondary air nozzle 2.
i Reference numeral 10 designates a rich/lean flow separator which is arranged in the pulverized fuel supply pipe 3 so that a mixed flow 7 of the pulverized fuel and the carrier air, as flowing through the pulverized fuel supply pipe 3, may impinge upon the rich/lean flow separator 10 and may be separated by the action of the centriiPugal force into a relatively rich flow (as indicated by solid lines) to flow along the outer side and a lean flow 9 (as indicated by broken lines) to flow along the inner side.
Here, reference numeral 12 designates a clearance which is established between the furnace side end portion of the windbox 5 and the windbox side end portion of the secondary air nozzle 2 when the secondary air nozzle 2 is directed upward, as shown in Fig. 5(b), or downward, as shown in Fig. 5(c), by B degrees.
In the ordinary operations, the mixed flow 7 of the pulverized fuel and the carrier air is guided through the pulverized fuel supply pipe 3 into the primary air nozzle 1 so that it is injected into the furnace. On the other hand, the combustion auxiliary air is guided through the combustion auxiliary air supply passage 4 into the secondary air nozzle 2 so that it is injected into the furnace.
In order to satisfy the performances of a low Nox combustion etc.
demanded from the combustion aspect, both the relatively rich and lean flows 8 and 9 of the pulverized fuel, as separated after the mixed flow 7 is separated by the action of the rich/lean flow separator 10, have to be kept with a proper concentration distribution in the furnace side exit plane of the primary air nozzle 1.
Moreover, the combustion auxiliary air has to be injected as wholly as z possible through the secondary air nozzle 2 into the furnace thereby to make an effective contribution to the combustion.
Fig. 5(a) shows the state in which the mixed flow 7 and the combustion auxiliary air are injected horizontal!.ly into the furnace. In this burner of the prior art, the injection direction of the mixed flow 7 and the combustion auxiliary air into the furnace can be changed upward or downward by directing the primary air nozzle 1 and the secondary air nozzle 2 upward or downward, respectively, as shown in Fig. 5(b) or 5(c).
As a result, the position of tlhe flame to be held in the furnace ca.n be moved upward or downward of the furnace thereby to adjust the gas temperature distribution in the furnace and the gas temperature in the furnace exit plane.
In the burner of the prior art thus far described, the mixed flow 7 of the pulverized fuel and the carrier air can achieve the proper concentration distribution in the furnace side exit plane of the primary air nozzle 1 when it is injected horizontally into the furnace, as shown in Fig. 5(a). When the primary air nozzle 1 is directed upward or downward, respectively, as shown in Fig. 5(b) or 5(c), on the other hand, the relatively rich flow 8 of the pulverized fuel is biased to raise a, problem that the mixed flow 7 cannot establish the proper rich/lean distribution in the furnace side exit plane of the primary air nozzle 1 unlike the state shown in Fig. 5(a).
Moreover, the combustion auxili<~ry air has to pass as wholly as possible through the secondary air nozzle 2. When the secondary air nozzle 2 is directed upward or downward, however, the clearance 12 is established, as shown in Fig. 5(b) or 5(c), between the furnace side end portion of the windbox 5 and the windbox side end portion of the secondary air nozzle 2. As a result, a portion of the combustion auxiliary air bypasses the secondary air nozzle 2 from that clearance 12 and leaks into the furnace thereby to raise a problem that the combustion auxiliary air does not make the effective contribution to the combustion.
SUMMARY OF THE INVENTION
The invention contemplates to solve those problems of the prior art and has an object to provide a pulverized fuel combustion burner which can keep the concentration distribution of the pulv~°rized fuel and can eliminate the leakage of the combustion auxiliary air.
In order to achieve the above-specified object, according to an aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said nozzles including a primary air nozzle having a variable direction to inject the mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around the primary air nozzle, a pulverized fuel supply pipe for feeding the mixed flow to the primary air nozzle and a windbox arranging the pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around the pulverized fuel supply pipe, said windbox being constructed by arranging the unit wiondboxes in a separated or jointed relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, wherein the improvement comprises a rich/lean flow separator disposed at or near a jointed portion between the primary air nozzle and the pulverized fuel supply pipe, and wherein said rich/lean flow separator is enabled to change its direction in response to or independently of a change in an injection direction of the primary air nozzle.
Specifically, the rich/lean flow separator is arranged at or near the jointed portion between the primary air nozzle and the pulverized fuel supply pipe, and the rich/lean flow separator is enabled to change its direction in response to or independently of the change in the injection direction of the primary air nozzle. Thus, when the primary air nozzle changes its injection direction upward or downward, for example, the rich/lean flow separator follows the direction change so that the mixed air of the rich and lean flows separated thereby is injected without any biasing in accordance with the direction of the primary air nozzle.
According to another aspect of the invention, there is provided a pulverized fuel combustion burner further comprising another rich/lean air separator disposed upstream of the first-named rich/lean flow separator.
Specifically, upstream of the rich/lf;an flow separator disposed at or near the jointed portion between the primary .air nozzle and the pulverized fuel supply pipe, there is disposed another rich/lean flow separator. Thus, the rich/lean flow separation is made at first by the rich/lean flow separator positioned upstream, and then is further made, by taking over the separation effect, at or near the jointed portion which is near the injection port between the primary air nozzle and the pulverized fuel supply pipe while being followed by the direction changed in accordance with the upward and downward turn of the primary air nozzle.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, the air nozzles including a primary air nozzle having a variable direction to inject the mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around the primary air nozzle, a pulverized fuel supply pipe for feeding the mixed flow to the primary air nozzle and a windbox arranging the pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around the pulverized fuel supply pipe, said windbox being constructed by arranging the unit windboxes in a separated or jointE;;d relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, wherein tile improvement comprises a rich/lean flow separator disposed in the pulverized fuel supply pipe and wherein a flow straightener or a straightening plate disposed at least in any one of the primary air nozzle and the pulverized fuel supply pipe for keeping a concentration distribution, as established by the rich/lean flow separator, to an exit of the primary air nozzle.
That is, subsequent to the rich/lean flow separator disposed in the pulverized fuel supply pipe, more specifically, a flow straightener or a straightening plate is disposed at least in any one of the primary air nozzle and the pulverized fuel supply pipe. As a result, the separation result by the rich/lean flow separator is taken over by the flow straightener or the straightening plate so that the rich flow and the lean flow are carried in the separated state and injected through the primary air nozzle into the furnace.
According to a further aspect of the invention, there is provided a Ei pulverized fuel combustion burner further comprising a combustion auxiliary air flow straightener disposed in the windbox for guiding the combustion auxiliary air into an entrance of the secondary air nozzle. Specifically, the leakage of the combustion auxiliary air at the entrance of the secondary air nozzle can be drastically prevented not only by devising the primary air nozzle for guiding the mixed flow of the pulverized fuel and the carrier air preferably but also by guiding the combustion auxiliary air to the entrance of the secondary air nozzle by the combustion auxiliary air flow straightener disposed in the wi ndbox.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner, wherein the primary air nozzle is disposed at a corner portion of the side wall of 1'.he furnace. Specifically, the burner is devised to separate the mixed flow of the pulverized fuel and the carrier air into the rich flow and the lean flow by the pulverized fuel supply pipe and the primary air nozzle and to keep the sE;paration effect, and is arranged at the corner portion of the furnace side wall so that the preferable injection may be effected from the corner portion into t:he furnace.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner, wherein the windbox comprises a plurality of unit windboxes, each having a square front section and each having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, said unit windboxes being arranged in a separated or jointed relation between each other, and the unit windbox has an upward and downward directional length of one and a half(1.5) times or less of its lateral directional length.
Specifically, the unit windbox is constructed by housing the primary air nozzle, which is devised to separate the mixed flow of the pulverized fuel and the earner air by the pulverized fuel supply pipe and the primary air nozzle and to keep the separation effect, and the secondary air nozzle which prevents the leakage of the combustion auxiliary air at its entrance, and the unit windbox has an upward and downward directional length of one and a half (1.5) times or less of its lateral directional length, thereby to make the entire construction compact without lowering the performance.
Accordirig to another aspect of the invention, there is provided, a pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including: a primary air nozzle having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle, and a windbox comprising a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle, wherein said pulverized fuel supply pipe extends through said windbox such that a combustion auxiliary air supply passage is formed around said pulverized fuel supply pipe, wherein a rich/lean flow separator is disposed in said pulverized fuel supply pipe, and a flow straightener or a straightening plate is disposed at least in any one of said primary air nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining a concentration distribution as established by said rich/lean flow separator to an exit of said primary air nozzle.
According to another aspect of the invention, there is provided a pulverized fuel combustion burner and furnace arrangement comprising a plurality of air nozzles arranged on a side wall of the furnace for injecting a mixed flow of pulverized fuel and carrier air to establish a flame into the furnace, said plurality of nozzles comprising a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace;
a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe along a centerline of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe, said pulverized fuel supply pipe having an unseparated mixed flow of pulverized fuel and carrier air upstream of said rich/lean flow separator, and such that as the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established including a fuel-rich flow at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow at an inner part inside of said pulverized fuel supply pipe inside of the rich flow and along said centerline of said pulverized fuel supply pipe; and a flow-straightening member disposed and positioned in at least one of said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining the rich/lean flow concentration distribution established by said rich/lean overflow separator to said exit of said primary nozzle.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner and furnace arrangement comprising a plurality of air nozzles arranged on a 8a side wall of the furnace for injecting a mixed flow of pulverized fuel and carrier air to establish a flame in the furnace, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit: a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace;
a windowbox, said pulverized fuel supply pipe extending through said window, and said windowbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside of the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and flow straightening plates including plates disposed and positioned in said primary nozzle and plates disposed and positioned in said pulverized fuel supply pipe downstream of said rich/lean flow separator so as to maintain the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
According to another aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles injecting a mixed flow of pulverized fuel 8b and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow, a windowbox, said pulverized fuel supply pipe extending through said window, and said windowbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe along a centerline of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe, said pulverized fuel supply pipe having an unseparated mixed flow of pulverized fuel and carrier air upstream of said rich/lean flow separator, and such that as the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established including a fuel-rich flow at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow at an inner part of said pulverized fuel supply pipe, said inner part being inside of the pulverized fuel supply pipe inside of the rich flow and along center line of said pulverized fuel supply pipe; and a flow straightening member disposed and positioned in at least one of said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
According to another aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles for injecting a mixed flow of pulverized 8c fuel and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace; a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and flow straightening plates including plates disposed and positioned in said primary nozzle and plates disposed and positioned in said pulverized fuel supply pipe downstream of said rich/lean flow separator so as to maintain the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles for injecting a mixed flow of pulverized fuel and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle 8d for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow; a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and means, disposed in both said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator, for maintaining the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle even when said primary nozzle is pivoted and a direction for injecting the mixed flow changes.
BRIEF DESCRIPTION OF THE DRAWINGS
Of Figs. 1 (a), 1 (b) and 1 (c) schematically showing a pulverized fuel combustion burner according to a first embodiment of the Invention: Fig. 1 (a) is an explanatory diagram showing 8e the case in which a mixed flow of a pulverized fuel and carrier air is injected horizontally; Fig.
1(b) is an explanatory diagram showing the case in which the mixed flow is injected upward; and Fig. I(c) is an explanatory diagram showing the case in which the mixed flow is injected downward;
Of Figs. 2(a), 2(b) and 2(c) schematically showing a pulverized fuel combustion burner according to a second embodiment of the Invention: Fig. 2(a) is an explanatory diagram showing the case in which a mixed flow of a pulverized fuel and carrier air is injected horizontally; Fig. 2(b) is an explanatory diagram showing the case in which the mixed flow is injected upward; and Fig. 2(c) is an explanatory diagram showing the case in which the mixed flow is injected downward;
Of Figs. 3(a), 3(b) and 3(c) schematically showing a pulverized fuel combustion burner according to a third embodiment of the Invention: Fig. 3(a) is an explanatory diagram showing the case in which a mixed flow of a pulverized 8f fuel and carrier air is injected horizontally; Fig. 3(b) is an explanatory diagram showing the case in which the mixed flow is injected upward; and Fig.
3(c) is an explanatory diagram showing the case in which the mixed flow is injected downward;
Of Figs. 4(a), 4(b) and 4(c) schematically showing a pulverized fuel combustion burner according to a fourth embodiment of the Invention: Fig. 4(a) is an explanatory diagram showing the case in which a mixed flow of a pulverized fuel and carrier air is injected horizontally; Fig. 4(b) is an explanatory diagram showing the case in which the mixed flow is injected upward; and Fig. 4(c) is an explanatory diagram showing the case in which the mixed flow is injected downward: and Of Figs. 5(a), 5(b) and 5(c) schematically showing a pulverized fuel combustion burner of the prior art: Fig. 5(a) is an explanatory diagram showing the case in which a mixed flow of a pulverized fuel and carrier air is injected horizontally; Fig. 5(b) is an. explanatory diagram showing the case in which the mixed flow is injected upward.; and Fig. 5(c) is an explanatory diagram showing the case in which the mixed flow is injected downward.
Of Fig. 6 is an explanatory view showing an example of arrangement of a pulverized fuel combustion burner in a furnace with respect to each of the embodiments according to the present invention.
Of Fig. 7 is an explanatory view showing an outline of a unit windbox constructed by the pulverized fuel combustion burner with respect to each of the embodiments according to the present invention.
DESCR I PT I ON OF THE PREFERRED E14BOD I II~NT S
s One embodiment of the present invention will be described with reference to Figs. 1(a) to 1(c). Figs. 1(a) to 1(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 1(a), 1(b) and 1(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward.
Here, the portions identical to those of the prior art are designated by the common reference numerals, and their overlapped description will be omitted.
In this embodiment, at the jointed portion between the primary air nozzle 1 and the pulverized fuel supply pipe 3, there is arranged the rich/lean flow separator 6 which is connected to the primary air nozzle 1 by a suitable joint mechanism so that its direction may be changed as the primary air nozzle 1 changes its injection direction.
Incidentally, the rich/lean flow separator 6 can also be given a structure separate from the primary air nozzle 1 and can act by itself so that it can detect the motion of the primary air nozzle 1 to change its direction according to the motion detected.
Reference numeral 11 designates a dispersing device which is arranged at the outer side in the bent portion where the pulverized fuel supply pipe 3 is curved upstream, so that a rich mixture flow having a tendency to diverge by the centrifugal force may impinge upon the dispersing device and may be homogeneously dispersed in the pulverized fuel supply pipe 3.
In this embodiment, the rich/lean flow separator 6 is constructed to follow the change in the direction of the primary air nozzle l, as described above. While the primary air nozzle :l is directed horizontally, as shown in io Fig. 1(a), the rich/lean flow separator 6 is also directed horizontally. When the primary air nozzle 1 is directed upward, as shown in Fig. 1(b), the rich/lean flow separator 6 is accordingly directed upward. When the primary air nozzle is directed downward, as shown in Fig. 1(c), the rich/lean flow separator 6 is accordingly directed downward. Thus, the rich/lean flow separator 6 acts to introduce the flow of the mixed flow 7 in the same direction as that of the injection into the furnace by the primary air nozzle 1.
Thus, according to this embodiment, both the rich flow 8 and the lean flow 9 of the pulverized fuel to be prepared by the rich/lean flow separator 6 can establish a flow which maintains a concentration distribution equivalent to that of the case in which the mixed flow 7 is being injected horizontally.
Even if the direction for the primary air nozzle 1 to inject the mixed flow 7 changes from the horizontal to upward and downward directions, the concentration distribution, as demanded from the combustion efficiency of the fuel, can be kept and retained without establishing any biased flow in the exit plane of the primary air nozzle 1.
Here, the primary air nozzle (burner nozzle) thus constructed is arranged at each corner portion of the furnace side wall (furnace wall), as shown in Fig. 6 schematically, so that the mixed flow of the pulverized fuel.
as separated rich and lean, and the carrier air may be efficiently injected from the corner portion into the furnace.
Also, as shown in Fig. 7, a unit windbox having a square front section is made of at least one pulverized fuel supply pipe and one combustion auxiliary air supply pipe , and a plurality of these unit windboxes are i~
arranged either separately or by jointing them. This construction is made compact as a whole by making the upward and downward directional length of the unit windbox one and a half(1.5) times or less of the lateral directional length of the windbox. It is to be noted that, in Fig. 7, a coal burner which is constructed by the pulverized fuel supply pipe, the combustion auxiliary air supply passage, etd. and an oil burner are shown, but when no oil fuel is supplied, the oil burner may be used as an air port for supplying the auxiliary ai r.
A second embodiment of the present invention will be described with reference to Figs. 2(a) to 2(c). Like Figs. 1(a) to 1(c) showing the first embodiment, Figs. 2(a) to 2(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 2(a), 2(b) and 2(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward. Here, the portions identical to those of the prior art or the first embodiment are designated by the common reference numerals, and their overlapped description will be omi tted.
In this embodiment, another rich/lean flow separator 10 is arranged upstream of the rich/lean flow separator 6 which is disposed at the jointed portion between the primary air nozzle 1 and the pulverized fuel supply pipe 3.
Of these rich/lean flow separators 6 and 10, the downstream one 6, as disposed at the jointed portion between the primary air nozzle 1 and the pulverized fuel supply pipe 3, is of such a variable type as to act according to the action of the primary air nozzle 1, as in the first embodiment, to iz change the flow direction so that the relatively rich and lean flows 8 and 9 may be established in the same direction in which the pulverized fuel is injected into the furnace. On the other hand, the other rich/lean flow separator 10, as arranged upstream, may be either of a fixed type or a variable type in which it is not especially restrained by the action of the primary air nozzle 1.
In this embodiment, the mixed flow 7 is separated at first into the rich and lean flows by the upstream rich/lean flow separator 10 and is then guided into the downstream rich/lean flow separator 6 and the primary air nozzle 1.
Next, as in the first embodiment, the downstream rich/lean flow separator 6 is constructed to follow the change in the direction of the primary air nozzle l, as described above. While the primary air nozzle 1 is directed horizontally, as shown in Fig. 2(a), the rich/lean flow separator 6 is also directed horizontally. When the primary air nozzle 1 is directed upward, as shown in Fig. 2(b), the rich/lean flow separator 6 is accordingly directed upward. When the primary air nozzle is directed downward, as shown in Fig. 2(c), the rich/lean flow separator 6 is accordingly directed downward. Thus, the rich/lean flow separator 6 acts to introduce the flow of the mixed flow 7 in the same direction as that of the injection into the furnace by the primary air nozzle 1.
By this action, the pulverized fuel, as prepared by the rich/lean flow separators 6 and 10, is enabled to establish the flows keeping a concentration distribution equivalent to that of the case in which both the rich flow 8 and the lean flow 9 are injected horizontally, as shown in Fig. 2(a).
Even if the direction for the primary air nozzle 1 to inject the mixed flow 7 changes from the horizontal to upward and downward directions, with the 1 .3 additional action of the rich/lean flow separator 10, the concentration distribution, as demanded from the combustion efficiency of the fuel, can be kept and retained in the exit plane of the primary air nozzle 1.
Further, a third embodiment of the present invention will be described with reference to Figs. 3(a) to 3(c). Like the first and second embodiments.
Figs. 3(a) to 3(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 3(a), 3(b) and 3(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward. Here, the portions identical to those of the prior art or the first and second embodiments are designated by the common reference numerals, and their overlapped description will be omitted.
This embodiment is provided with a first straightening plate 13 which is disposed in the primary air nozzle 1 and changes its direction in accordance with the change in the direction of the primary air nozzle 1, and a second straightening plate 14 which is disposed in the pulverized fuel supply pipe 3 downstream of the rich/lean flow separator 10.
In this embodiment, the mixed flow 7 of the pulverized fuel and the carrier air is injected horizontally from the primary air nozzle 1, as shown in Fig. 3(a), and the primary air nozzle 1 changes its direction to inject the mixed flow 7 upward or downward, as shown in Fig. 3(b) or 3(c).
Before this injection, this mixed flow 7 is separated into rich and lean flows by the rich/lean flow separator l0 arranged at the upstream side, and is then introduced into the primary air nozzle 1.
First of all, as shown in Fig. 3(a), the second straightening plate 14 r 4 in the pulverized fuel supply pipe 3 acts to keep the concentration distribution, as determined by the rich flow 8 and the lean flow 9 of the pulverized fuel, at a stage before tree rich flow 8 and the lean flow 9 reach the primary air nozzle 1. The first straightening plate 13 in the primary air nozzle 1 acts to direct the rich flow 8 of the pulverized fuel toward the inner face of the primary air nozzle 1.
When the primary air nozzle 1 is directed upward or downward by 8 degrees, as shown in Figs. 3(b) or 3(c), too, the pulverized fuel is enabled to keep the concentration distribution of the rich flow 8 and the lean flow 9, as established by the rich/lean flow separator 10, by the straightening actions of the second straightening plate 14 in the pulverized fuel supply pipe 3 and the first straightening plate 13 in the primary air nozzle 1.
By the actions of these first and second straightening plates 13 and 14, the rich flow 8 and the lean flow 9 of the pulverized fuel are enabled to establish the flows which keep the concentration distribution equivalent to that of the case in which the mixed flow 7 is injected horizontally, as shown in Fig. 3(a). Even if the direction for the primary air nozzle 1 to inject the mixed flow 7 changes from the horizor,~tal to upward and downward directions, with the additional action of the rich/lean flow separator 10, the concentration distribution, as demanded from the combustion efficiency of the fuel, can be kept and retained in the exit plane of the primary air nozzle 1.
Further, a fourth embodiment of the present invention will be described with reference to Figs. 4(a) to 4(c). Like the first, second and third embodiments, Figs. 4(a) to 4(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 4(a), 4(b) and 4(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward. Here, the portions identical to those of the prior art on the first, second and third embodiments are designated by the common reference numerals, and their overlapped description will be omitted.
In this embodiment, there is disposed in the combustion auxiliary air supply passage 4, a combustion auxiliary air flow straightener 15 which is arranged inside of the windbox 5 and in the vicinity of the jointed portion between the secondary air nozzle 2 and the combustion auxiliary air supply passage 4. Here, reference numeral 16 designates the combustion auxiliary air to be injected from the combustion auxiliary air supply passage 4 through the secondary air nozzle 2 into the furnace. Numeral 17 designates the combustion auxiliary air which bypasses the secondary air nozzle 2 from the combustion auxiliary air supply passage 4 and leaha around the secondary air nozzle 2 into the furnace.
In this embodiment, the mixed flow 7 of the pulverized fuel and the carrier air is dispersed by the dispersing device 11 and separated into the rich and lean flows by the rich/lean flow separator 10 until it is guided into the primary air nozzle 1.
The combustion auxiliary air flow straightener 15 acts to change the flow direction of the combustion auxiliary air so positively that the combustion auxiliary air having passed the vicinities of the upper inner wall face and the lower inner wall face of the combustion auxiliary air supply passage 4 may pass through the inside of the secondary air nozzle 2.
it As shovm in Figs. 4(b) and 4(c), too, the combustion auxiliary air flow straightener 15 acts to change the flow direction of the combustion auxiliary air so positively that the combustion auxiliary air having passed the vicinities of the upper inner wall face and the lower inner wall face of the combustion auxiliary air supply passage 4 may pass through the inside of the secondary air nozzle 2.
By the action of this combustion auxiliary air flow straightener 15, almost all the combustion auxiliary air can be the combustion auxiliary air 16 to be injected into the furnace through the secondary air nozzle 2, while minimizing the amount of the air 17 which might otherwise bypasses the secondary air nozzle 2 and leaks into the furnace.
Although the invention has been described in connection with the shown embodiments, it should not be limited thereto but can naturally be variously modified in its specific structure within the scope thereof.
The pulverized fuel combustion burner according to the invention is constructed to comprise a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including a primary air nozzle having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle.
a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle and a windbox arranging said pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe, said windbox being constructed by arranging the unit windboxes in a separated or jointed relation between each other, each unit windbox having m at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, wherein the improvement comprises a rich/lean flow separator disposed at or near a jointed portion between said primary air nozzle and said pulverized fuel supply pipe and wherein said ric~~lean flow separator is enabled to change its direction in response to or independently of a change in an injection direction of said primary air nozzle. As a result, the rich/lean flow separator varies following the change in the injection direction of the primary air nozzle so that the mixed flow can be injected as a reliable and stable flow without any biasing in the direction off' the primary air nozzle from the primary air nozzle into the furnace, thereby to provide a highly reliable pulverized fuel combustion burner.
The pulverized fuel combustion burner according to the invention of Claim 2 is constructed to further coimprise another rich/lean air separator disposed upstream of the first-named rich/lean flow separator. As a result, the flow separation is made at first by the rich/lean flow separator, as positioned upstream, and the mixed flow can be guided by taking over the separation effect without any biasin;; in the same direction as that of the primary air nozzle and injected into the furnace, thereby to provide a highly reliable pulverized fuel combustion burner.
The pulverized fuel combustion burner according to the invention of Claim 3 is constructed to comprise a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including a primary air nozzle having a variable direction to inject: said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary is air nozzle, a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle and a windbox arranging said pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe, said windbox being constructed by arranging the unit windboxes, in a separated or jointed relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, wherein l:he improvement comprises a rich/lean flow separator disposed in said pulverized fuel supply pipe and wherein a flow straightener or a straightening plate disposed at least in any one of said primary air nozzle and said pulverized fuel supply pipe for keeping a concentration distribution, as established by said rich/lean flow separator, to an exit of said primary air nozzle. As a result, the flow straightener or straightening plate takes the separation result by the rich/lean separator so that the mixed flow of the pulverized fuel and the carrier air can be conveyed while keeping separate in the rich flow and the lean flow and injected for the preferable combustion from the primary air nozzle into the furnace, thereby to enhance the reliability as the pulverized fuel combustion burner.
The pulverized fuel combustion burner according to the invention of Claim 4 is constructed to further comprise a combustion auxiliary air flow straightener disposed in said windbox for guiding said combustion auxiliary air into an entrance of said secondary air nozzle. As a result, the mixed flow of the pulverized fuel and the carrier air can be injected in a preferable situation from the primary air nozzle, and the combustion auxiliary air can be guided in a preferable state from the outer side into the entrance of the secondary air nozzle by the combustion auxiliary air flow straightener disposed in the windbox, thereby to prevent the leakage of the combustion auxiliary air drastically at the entrance of the secondary air nozzle.
The pulverized fuel combustion burner according to the invention of Claim 5 is constructed such that said primary air nozzle is disposed at a corner portion of the side wall of the furnace. As a result, the burner is devised to separate the mixed flow of the pulverized fuel and the carrier air into the rich flow and the lean flow by the pulverized fuel supply pipe and the primary air nozzle and to keep the separation effect, and is arranged at the corner portion of the furnace side wall so that the preferable injection can be effected from the corner portion into i:he furnace, thereby to retain the proper combustion.
The pulverized fuel combustion burner according to Claim 6 is constructed such that said windbox comprises a plurality of unit windboxes, each having a square front section and each having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, said unit windboxes being arranged in a separated or jointed relation between each other, and said unit windbox has an upward and downward directional length of one and a half(1.5) times or less of its lateral directional length. As a result, the unit windbox is constructed by housing the primary air nozzle, which is devised to separate the mixed flow of the pulverized fuel and the carrier air by the pulverized fuel supply pipe and the primary air nozzle and to keep the separation effect, and the secondary air nozzle which prevents the leakage of the combustion auxiliary air at its entrance, and the unit windbox has an upward and downward directional length of one and a half(1.5) times or less of its lateral directional length, so that the entire construction can be made compact without lowering the performance.
TITLE OF THE INVENTION
Pulverized Fuel Combustion Burner BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a pulverized fuel combustion burner to be applied to a boiler of a thermal power plant or chemical plant, a furnace of a chemical industry or the like.
Related Art The technique of this kind of the prior art will be described with reference to Fig. 5. Figs. 5(a) to 5(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 5(a), 5(b) and 5(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward.
Reference numeral 1 designates a primary air nozzle, and numeral 2 designates a secondary air nozzle arranged outside of the primary air nozzle 1.
Numeral 3 designates a pulverized fuel supply pipe, and numeral 4 designates a combustion auxiliary fuel supply passage which is defined by the pulverized fuel supply pipe 3 and a windbox 5.. The pulverized fuel supply pipe 3 communicates at its terminal end with the primary air nozzle l, and the combustion auxiliary air supply passage 4 communicates with the secondary air nozzle 2.
i Reference numeral 10 designates a rich/lean flow separator which is arranged in the pulverized fuel supply pipe 3 so that a mixed flow 7 of the pulverized fuel and the carrier air, as flowing through the pulverized fuel supply pipe 3, may impinge upon the rich/lean flow separator 10 and may be separated by the action of the centriiPugal force into a relatively rich flow (as indicated by solid lines) to flow along the outer side and a lean flow 9 (as indicated by broken lines) to flow along the inner side.
Here, reference numeral 12 designates a clearance which is established between the furnace side end portion of the windbox 5 and the windbox side end portion of the secondary air nozzle 2 when the secondary air nozzle 2 is directed upward, as shown in Fig. 5(b), or downward, as shown in Fig. 5(c), by B degrees.
In the ordinary operations, the mixed flow 7 of the pulverized fuel and the carrier air is guided through the pulverized fuel supply pipe 3 into the primary air nozzle 1 so that it is injected into the furnace. On the other hand, the combustion auxiliary air is guided through the combustion auxiliary air supply passage 4 into the secondary air nozzle 2 so that it is injected into the furnace.
In order to satisfy the performances of a low Nox combustion etc.
demanded from the combustion aspect, both the relatively rich and lean flows 8 and 9 of the pulverized fuel, as separated after the mixed flow 7 is separated by the action of the rich/lean flow separator 10, have to be kept with a proper concentration distribution in the furnace side exit plane of the primary air nozzle 1.
Moreover, the combustion auxiliary air has to be injected as wholly as z possible through the secondary air nozzle 2 into the furnace thereby to make an effective contribution to the combustion.
Fig. 5(a) shows the state in which the mixed flow 7 and the combustion auxiliary air are injected horizontal!.ly into the furnace. In this burner of the prior art, the injection direction of the mixed flow 7 and the combustion auxiliary air into the furnace can be changed upward or downward by directing the primary air nozzle 1 and the secondary air nozzle 2 upward or downward, respectively, as shown in Fig. 5(b) or 5(c).
As a result, the position of tlhe flame to be held in the furnace ca.n be moved upward or downward of the furnace thereby to adjust the gas temperature distribution in the furnace and the gas temperature in the furnace exit plane.
In the burner of the prior art thus far described, the mixed flow 7 of the pulverized fuel and the carrier air can achieve the proper concentration distribution in the furnace side exit plane of the primary air nozzle 1 when it is injected horizontally into the furnace, as shown in Fig. 5(a). When the primary air nozzle 1 is directed upward or downward, respectively, as shown in Fig. 5(b) or 5(c), on the other hand, the relatively rich flow 8 of the pulverized fuel is biased to raise a, problem that the mixed flow 7 cannot establish the proper rich/lean distribution in the furnace side exit plane of the primary air nozzle 1 unlike the state shown in Fig. 5(a).
Moreover, the combustion auxili<~ry air has to pass as wholly as possible through the secondary air nozzle 2. When the secondary air nozzle 2 is directed upward or downward, however, the clearance 12 is established, as shown in Fig. 5(b) or 5(c), between the furnace side end portion of the windbox 5 and the windbox side end portion of the secondary air nozzle 2. As a result, a portion of the combustion auxiliary air bypasses the secondary air nozzle 2 from that clearance 12 and leaks into the furnace thereby to raise a problem that the combustion auxiliary air does not make the effective contribution to the combustion.
SUMMARY OF THE INVENTION
The invention contemplates to solve those problems of the prior art and has an object to provide a pulverized fuel combustion burner which can keep the concentration distribution of the pulv~°rized fuel and can eliminate the leakage of the combustion auxiliary air.
In order to achieve the above-specified object, according to an aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said nozzles including a primary air nozzle having a variable direction to inject the mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around the primary air nozzle, a pulverized fuel supply pipe for feeding the mixed flow to the primary air nozzle and a windbox arranging the pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around the pulverized fuel supply pipe, said windbox being constructed by arranging the unit wiondboxes in a separated or jointed relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, wherein the improvement comprises a rich/lean flow separator disposed at or near a jointed portion between the primary air nozzle and the pulverized fuel supply pipe, and wherein said rich/lean flow separator is enabled to change its direction in response to or independently of a change in an injection direction of the primary air nozzle.
Specifically, the rich/lean flow separator is arranged at or near the jointed portion between the primary air nozzle and the pulverized fuel supply pipe, and the rich/lean flow separator is enabled to change its direction in response to or independently of the change in the injection direction of the primary air nozzle. Thus, when the primary air nozzle changes its injection direction upward or downward, for example, the rich/lean flow separator follows the direction change so that the mixed air of the rich and lean flows separated thereby is injected without any biasing in accordance with the direction of the primary air nozzle.
According to another aspect of the invention, there is provided a pulverized fuel combustion burner further comprising another rich/lean air separator disposed upstream of the first-named rich/lean flow separator.
Specifically, upstream of the rich/lf;an flow separator disposed at or near the jointed portion between the primary .air nozzle and the pulverized fuel supply pipe, there is disposed another rich/lean flow separator. Thus, the rich/lean flow separation is made at first by the rich/lean flow separator positioned upstream, and then is further made, by taking over the separation effect, at or near the jointed portion which is near the injection port between the primary air nozzle and the pulverized fuel supply pipe while being followed by the direction changed in accordance with the upward and downward turn of the primary air nozzle.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, the air nozzles including a primary air nozzle having a variable direction to inject the mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around the primary air nozzle, a pulverized fuel supply pipe for feeding the mixed flow to the primary air nozzle and a windbox arranging the pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around the pulverized fuel supply pipe, said windbox being constructed by arranging the unit windboxes in a separated or jointE;;d relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, wherein tile improvement comprises a rich/lean flow separator disposed in the pulverized fuel supply pipe and wherein a flow straightener or a straightening plate disposed at least in any one of the primary air nozzle and the pulverized fuel supply pipe for keeping a concentration distribution, as established by the rich/lean flow separator, to an exit of the primary air nozzle.
That is, subsequent to the rich/lean flow separator disposed in the pulverized fuel supply pipe, more specifically, a flow straightener or a straightening plate is disposed at least in any one of the primary air nozzle and the pulverized fuel supply pipe. As a result, the separation result by the rich/lean flow separator is taken over by the flow straightener or the straightening plate so that the rich flow and the lean flow are carried in the separated state and injected through the primary air nozzle into the furnace.
According to a further aspect of the invention, there is provided a Ei pulverized fuel combustion burner further comprising a combustion auxiliary air flow straightener disposed in the windbox for guiding the combustion auxiliary air into an entrance of the secondary air nozzle. Specifically, the leakage of the combustion auxiliary air at the entrance of the secondary air nozzle can be drastically prevented not only by devising the primary air nozzle for guiding the mixed flow of the pulverized fuel and the carrier air preferably but also by guiding the combustion auxiliary air to the entrance of the secondary air nozzle by the combustion auxiliary air flow straightener disposed in the wi ndbox.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner, wherein the primary air nozzle is disposed at a corner portion of the side wall of 1'.he furnace. Specifically, the burner is devised to separate the mixed flow of the pulverized fuel and the carrier air into the rich flow and the lean flow by the pulverized fuel supply pipe and the primary air nozzle and to keep the sE;paration effect, and is arranged at the corner portion of the furnace side wall so that the preferable injection may be effected from the corner portion into t:he furnace.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner, wherein the windbox comprises a plurality of unit windboxes, each having a square front section and each having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, said unit windboxes being arranged in a separated or jointed relation between each other, and the unit windbox has an upward and downward directional length of one and a half(1.5) times or less of its lateral directional length.
Specifically, the unit windbox is constructed by housing the primary air nozzle, which is devised to separate the mixed flow of the pulverized fuel and the earner air by the pulverized fuel supply pipe and the primary air nozzle and to keep the separation effect, and the secondary air nozzle which prevents the leakage of the combustion auxiliary air at its entrance, and the unit windbox has an upward and downward directional length of one and a half (1.5) times or less of its lateral directional length, thereby to make the entire construction compact without lowering the performance.
Accordirig to another aspect of the invention, there is provided, a pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including: a primary air nozzle having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle, and a windbox comprising a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle, wherein said pulverized fuel supply pipe extends through said windbox such that a combustion auxiliary air supply passage is formed around said pulverized fuel supply pipe, wherein a rich/lean flow separator is disposed in said pulverized fuel supply pipe, and a flow straightener or a straightening plate is disposed at least in any one of said primary air nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining a concentration distribution as established by said rich/lean flow separator to an exit of said primary air nozzle.
According to another aspect of the invention, there is provided a pulverized fuel combustion burner and furnace arrangement comprising a plurality of air nozzles arranged on a side wall of the furnace for injecting a mixed flow of pulverized fuel and carrier air to establish a flame into the furnace, said plurality of nozzles comprising a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace;
a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe along a centerline of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe, said pulverized fuel supply pipe having an unseparated mixed flow of pulverized fuel and carrier air upstream of said rich/lean flow separator, and such that as the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established including a fuel-rich flow at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow at an inner part inside of said pulverized fuel supply pipe inside of the rich flow and along said centerline of said pulverized fuel supply pipe; and a flow-straightening member disposed and positioned in at least one of said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining the rich/lean flow concentration distribution established by said rich/lean overflow separator to said exit of said primary nozzle.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner and furnace arrangement comprising a plurality of air nozzles arranged on a 8a side wall of the furnace for injecting a mixed flow of pulverized fuel and carrier air to establish a flame in the furnace, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit: a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace;
a windowbox, said pulverized fuel supply pipe extending through said window, and said windowbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside of the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and flow straightening plates including plates disposed and positioned in said primary nozzle and plates disposed and positioned in said pulverized fuel supply pipe downstream of said rich/lean flow separator so as to maintain the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
According to another aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles injecting a mixed flow of pulverized fuel 8b and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow, a windowbox, said pulverized fuel supply pipe extending through said window, and said windowbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe along a centerline of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe, said pulverized fuel supply pipe having an unseparated mixed flow of pulverized fuel and carrier air upstream of said rich/lean flow separator, and such that as the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established including a fuel-rich flow at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow at an inner part of said pulverized fuel supply pipe, said inner part being inside of the pulverized fuel supply pipe inside of the rich flow and along center line of said pulverized fuel supply pipe; and a flow straightening member disposed and positioned in at least one of said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
According to another aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles for injecting a mixed flow of pulverized 8c fuel and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace; a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and flow straightening plates including plates disposed and positioned in said primary nozzle and plates disposed and positioned in said pulverized fuel supply pipe downstream of said rich/lean flow separator so as to maintain the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
According to a further aspect of the invention, there is provided a pulverized fuel combustion burner comprising a plurality of air nozzles for injecting a mixed flow of pulverized fuel and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle 8d for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow; a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and means, disposed in both said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator, for maintaining the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle even when said primary nozzle is pivoted and a direction for injecting the mixed flow changes.
BRIEF DESCRIPTION OF THE DRAWINGS
Of Figs. 1 (a), 1 (b) and 1 (c) schematically showing a pulverized fuel combustion burner according to a first embodiment of the Invention: Fig. 1 (a) is an explanatory diagram showing 8e the case in which a mixed flow of a pulverized fuel and carrier air is injected horizontally; Fig.
1(b) is an explanatory diagram showing the case in which the mixed flow is injected upward; and Fig. I(c) is an explanatory diagram showing the case in which the mixed flow is injected downward;
Of Figs. 2(a), 2(b) and 2(c) schematically showing a pulverized fuel combustion burner according to a second embodiment of the Invention: Fig. 2(a) is an explanatory diagram showing the case in which a mixed flow of a pulverized fuel and carrier air is injected horizontally; Fig. 2(b) is an explanatory diagram showing the case in which the mixed flow is injected upward; and Fig. 2(c) is an explanatory diagram showing the case in which the mixed flow is injected downward;
Of Figs. 3(a), 3(b) and 3(c) schematically showing a pulverized fuel combustion burner according to a third embodiment of the Invention: Fig. 3(a) is an explanatory diagram showing the case in which a mixed flow of a pulverized 8f fuel and carrier air is injected horizontally; Fig. 3(b) is an explanatory diagram showing the case in which the mixed flow is injected upward; and Fig.
3(c) is an explanatory diagram showing the case in which the mixed flow is injected downward;
Of Figs. 4(a), 4(b) and 4(c) schematically showing a pulverized fuel combustion burner according to a fourth embodiment of the Invention: Fig. 4(a) is an explanatory diagram showing the case in which a mixed flow of a pulverized fuel and carrier air is injected horizontally; Fig. 4(b) is an explanatory diagram showing the case in which the mixed flow is injected upward; and Fig. 4(c) is an explanatory diagram showing the case in which the mixed flow is injected downward: and Of Figs. 5(a), 5(b) and 5(c) schematically showing a pulverized fuel combustion burner of the prior art: Fig. 5(a) is an explanatory diagram showing the case in which a mixed flow of a pulverized fuel and carrier air is injected horizontally; Fig. 5(b) is an. explanatory diagram showing the case in which the mixed flow is injected upward.; and Fig. 5(c) is an explanatory diagram showing the case in which the mixed flow is injected downward.
Of Fig. 6 is an explanatory view showing an example of arrangement of a pulverized fuel combustion burner in a furnace with respect to each of the embodiments according to the present invention.
Of Fig. 7 is an explanatory view showing an outline of a unit windbox constructed by the pulverized fuel combustion burner with respect to each of the embodiments according to the present invention.
DESCR I PT I ON OF THE PREFERRED E14BOD I II~NT S
s One embodiment of the present invention will be described with reference to Figs. 1(a) to 1(c). Figs. 1(a) to 1(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 1(a), 1(b) and 1(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward.
Here, the portions identical to those of the prior art are designated by the common reference numerals, and their overlapped description will be omitted.
In this embodiment, at the jointed portion between the primary air nozzle 1 and the pulverized fuel supply pipe 3, there is arranged the rich/lean flow separator 6 which is connected to the primary air nozzle 1 by a suitable joint mechanism so that its direction may be changed as the primary air nozzle 1 changes its injection direction.
Incidentally, the rich/lean flow separator 6 can also be given a structure separate from the primary air nozzle 1 and can act by itself so that it can detect the motion of the primary air nozzle 1 to change its direction according to the motion detected.
Reference numeral 11 designates a dispersing device which is arranged at the outer side in the bent portion where the pulverized fuel supply pipe 3 is curved upstream, so that a rich mixture flow having a tendency to diverge by the centrifugal force may impinge upon the dispersing device and may be homogeneously dispersed in the pulverized fuel supply pipe 3.
In this embodiment, the rich/lean flow separator 6 is constructed to follow the change in the direction of the primary air nozzle l, as described above. While the primary air nozzle :l is directed horizontally, as shown in io Fig. 1(a), the rich/lean flow separator 6 is also directed horizontally. When the primary air nozzle 1 is directed upward, as shown in Fig. 1(b), the rich/lean flow separator 6 is accordingly directed upward. When the primary air nozzle is directed downward, as shown in Fig. 1(c), the rich/lean flow separator 6 is accordingly directed downward. Thus, the rich/lean flow separator 6 acts to introduce the flow of the mixed flow 7 in the same direction as that of the injection into the furnace by the primary air nozzle 1.
Thus, according to this embodiment, both the rich flow 8 and the lean flow 9 of the pulverized fuel to be prepared by the rich/lean flow separator 6 can establish a flow which maintains a concentration distribution equivalent to that of the case in which the mixed flow 7 is being injected horizontally.
Even if the direction for the primary air nozzle 1 to inject the mixed flow 7 changes from the horizontal to upward and downward directions, the concentration distribution, as demanded from the combustion efficiency of the fuel, can be kept and retained without establishing any biased flow in the exit plane of the primary air nozzle 1.
Here, the primary air nozzle (burner nozzle) thus constructed is arranged at each corner portion of the furnace side wall (furnace wall), as shown in Fig. 6 schematically, so that the mixed flow of the pulverized fuel.
as separated rich and lean, and the carrier air may be efficiently injected from the corner portion into the furnace.
Also, as shown in Fig. 7, a unit windbox having a square front section is made of at least one pulverized fuel supply pipe and one combustion auxiliary air supply pipe , and a plurality of these unit windboxes are i~
arranged either separately or by jointing them. This construction is made compact as a whole by making the upward and downward directional length of the unit windbox one and a half(1.5) times or less of the lateral directional length of the windbox. It is to be noted that, in Fig. 7, a coal burner which is constructed by the pulverized fuel supply pipe, the combustion auxiliary air supply passage, etd. and an oil burner are shown, but when no oil fuel is supplied, the oil burner may be used as an air port for supplying the auxiliary ai r.
A second embodiment of the present invention will be described with reference to Figs. 2(a) to 2(c). Like Figs. 1(a) to 1(c) showing the first embodiment, Figs. 2(a) to 2(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 2(a), 2(b) and 2(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward. Here, the portions identical to those of the prior art or the first embodiment are designated by the common reference numerals, and their overlapped description will be omi tted.
In this embodiment, another rich/lean flow separator 10 is arranged upstream of the rich/lean flow separator 6 which is disposed at the jointed portion between the primary air nozzle 1 and the pulverized fuel supply pipe 3.
Of these rich/lean flow separators 6 and 10, the downstream one 6, as disposed at the jointed portion between the primary air nozzle 1 and the pulverized fuel supply pipe 3, is of such a variable type as to act according to the action of the primary air nozzle 1, as in the first embodiment, to iz change the flow direction so that the relatively rich and lean flows 8 and 9 may be established in the same direction in which the pulverized fuel is injected into the furnace. On the other hand, the other rich/lean flow separator 10, as arranged upstream, may be either of a fixed type or a variable type in which it is not especially restrained by the action of the primary air nozzle 1.
In this embodiment, the mixed flow 7 is separated at first into the rich and lean flows by the upstream rich/lean flow separator 10 and is then guided into the downstream rich/lean flow separator 6 and the primary air nozzle 1.
Next, as in the first embodiment, the downstream rich/lean flow separator 6 is constructed to follow the change in the direction of the primary air nozzle l, as described above. While the primary air nozzle 1 is directed horizontally, as shown in Fig. 2(a), the rich/lean flow separator 6 is also directed horizontally. When the primary air nozzle 1 is directed upward, as shown in Fig. 2(b), the rich/lean flow separator 6 is accordingly directed upward. When the primary air nozzle is directed downward, as shown in Fig. 2(c), the rich/lean flow separator 6 is accordingly directed downward. Thus, the rich/lean flow separator 6 acts to introduce the flow of the mixed flow 7 in the same direction as that of the injection into the furnace by the primary air nozzle 1.
By this action, the pulverized fuel, as prepared by the rich/lean flow separators 6 and 10, is enabled to establish the flows keeping a concentration distribution equivalent to that of the case in which both the rich flow 8 and the lean flow 9 are injected horizontally, as shown in Fig. 2(a).
Even if the direction for the primary air nozzle 1 to inject the mixed flow 7 changes from the horizontal to upward and downward directions, with the 1 .3 additional action of the rich/lean flow separator 10, the concentration distribution, as demanded from the combustion efficiency of the fuel, can be kept and retained in the exit plane of the primary air nozzle 1.
Further, a third embodiment of the present invention will be described with reference to Figs. 3(a) to 3(c). Like the first and second embodiments.
Figs. 3(a) to 3(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 3(a), 3(b) and 3(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward. Here, the portions identical to those of the prior art or the first and second embodiments are designated by the common reference numerals, and their overlapped description will be omitted.
This embodiment is provided with a first straightening plate 13 which is disposed in the primary air nozzle 1 and changes its direction in accordance with the change in the direction of the primary air nozzle 1, and a second straightening plate 14 which is disposed in the pulverized fuel supply pipe 3 downstream of the rich/lean flow separator 10.
In this embodiment, the mixed flow 7 of the pulverized fuel and the carrier air is injected horizontally from the primary air nozzle 1, as shown in Fig. 3(a), and the primary air nozzle 1 changes its direction to inject the mixed flow 7 upward or downward, as shown in Fig. 3(b) or 3(c).
Before this injection, this mixed flow 7 is separated into rich and lean flows by the rich/lean flow separator l0 arranged at the upstream side, and is then introduced into the primary air nozzle 1.
First of all, as shown in Fig. 3(a), the second straightening plate 14 r 4 in the pulverized fuel supply pipe 3 acts to keep the concentration distribution, as determined by the rich flow 8 and the lean flow 9 of the pulverized fuel, at a stage before tree rich flow 8 and the lean flow 9 reach the primary air nozzle 1. The first straightening plate 13 in the primary air nozzle 1 acts to direct the rich flow 8 of the pulverized fuel toward the inner face of the primary air nozzle 1.
When the primary air nozzle 1 is directed upward or downward by 8 degrees, as shown in Figs. 3(b) or 3(c), too, the pulverized fuel is enabled to keep the concentration distribution of the rich flow 8 and the lean flow 9, as established by the rich/lean flow separator 10, by the straightening actions of the second straightening plate 14 in the pulverized fuel supply pipe 3 and the first straightening plate 13 in the primary air nozzle 1.
By the actions of these first and second straightening plates 13 and 14, the rich flow 8 and the lean flow 9 of the pulverized fuel are enabled to establish the flows which keep the concentration distribution equivalent to that of the case in which the mixed flow 7 is injected horizontally, as shown in Fig. 3(a). Even if the direction for the primary air nozzle 1 to inject the mixed flow 7 changes from the horizor,~tal to upward and downward directions, with the additional action of the rich/lean flow separator 10, the concentration distribution, as demanded from the combustion efficiency of the fuel, can be kept and retained in the exit plane of the primary air nozzle 1.
Further, a fourth embodiment of the present invention will be described with reference to Figs. 4(a) to 4(c). Like the first, second and third embodiments, Figs. 4(a) to 4(c) are side sections showing a construction of a pulverized fuel combustion burner schematically. Figs. 4(a), 4(b) and 4(c) show the cases, respectively, in which a mixed flow of a pulverized fuel and carrier air is injected horizontally, in which the mixed flow is injected upward, and in which the mixed flow is injected downward. Here, the portions identical to those of the prior art on the first, second and third embodiments are designated by the common reference numerals, and their overlapped description will be omitted.
In this embodiment, there is disposed in the combustion auxiliary air supply passage 4, a combustion auxiliary air flow straightener 15 which is arranged inside of the windbox 5 and in the vicinity of the jointed portion between the secondary air nozzle 2 and the combustion auxiliary air supply passage 4. Here, reference numeral 16 designates the combustion auxiliary air to be injected from the combustion auxiliary air supply passage 4 through the secondary air nozzle 2 into the furnace. Numeral 17 designates the combustion auxiliary air which bypasses the secondary air nozzle 2 from the combustion auxiliary air supply passage 4 and leaha around the secondary air nozzle 2 into the furnace.
In this embodiment, the mixed flow 7 of the pulverized fuel and the carrier air is dispersed by the dispersing device 11 and separated into the rich and lean flows by the rich/lean flow separator 10 until it is guided into the primary air nozzle 1.
The combustion auxiliary air flow straightener 15 acts to change the flow direction of the combustion auxiliary air so positively that the combustion auxiliary air having passed the vicinities of the upper inner wall face and the lower inner wall face of the combustion auxiliary air supply passage 4 may pass through the inside of the secondary air nozzle 2.
it As shovm in Figs. 4(b) and 4(c), too, the combustion auxiliary air flow straightener 15 acts to change the flow direction of the combustion auxiliary air so positively that the combustion auxiliary air having passed the vicinities of the upper inner wall face and the lower inner wall face of the combustion auxiliary air supply passage 4 may pass through the inside of the secondary air nozzle 2.
By the action of this combustion auxiliary air flow straightener 15, almost all the combustion auxiliary air can be the combustion auxiliary air 16 to be injected into the furnace through the secondary air nozzle 2, while minimizing the amount of the air 17 which might otherwise bypasses the secondary air nozzle 2 and leaks into the furnace.
Although the invention has been described in connection with the shown embodiments, it should not be limited thereto but can naturally be variously modified in its specific structure within the scope thereof.
The pulverized fuel combustion burner according to the invention is constructed to comprise a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including a primary air nozzle having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle.
a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle and a windbox arranging said pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe, said windbox being constructed by arranging the unit windboxes in a separated or jointed relation between each other, each unit windbox having m at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, wherein the improvement comprises a rich/lean flow separator disposed at or near a jointed portion between said primary air nozzle and said pulverized fuel supply pipe and wherein said ric~~lean flow separator is enabled to change its direction in response to or independently of a change in an injection direction of said primary air nozzle. As a result, the rich/lean flow separator varies following the change in the injection direction of the primary air nozzle so that the mixed flow can be injected as a reliable and stable flow without any biasing in the direction off' the primary air nozzle from the primary air nozzle into the furnace, thereby to provide a highly reliable pulverized fuel combustion burner.
The pulverized fuel combustion burner according to the invention of Claim 2 is constructed to further coimprise another rich/lean air separator disposed upstream of the first-named rich/lean flow separator. As a result, the flow separation is made at first by the rich/lean flow separator, as positioned upstream, and the mixed flow can be guided by taking over the separation effect without any biasin;; in the same direction as that of the primary air nozzle and injected into the furnace, thereby to provide a highly reliable pulverized fuel combustion burner.
The pulverized fuel combustion burner according to the invention of Claim 3 is constructed to comprise a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including a primary air nozzle having a variable direction to inject: said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary is air nozzle, a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle and a windbox arranging said pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe, said windbox being constructed by arranging the unit windboxes, in a separated or jointed relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, wherein l:he improvement comprises a rich/lean flow separator disposed in said pulverized fuel supply pipe and wherein a flow straightener or a straightening plate disposed at least in any one of said primary air nozzle and said pulverized fuel supply pipe for keeping a concentration distribution, as established by said rich/lean flow separator, to an exit of said primary air nozzle. As a result, the flow straightener or straightening plate takes the separation result by the rich/lean separator so that the mixed flow of the pulverized fuel and the carrier air can be conveyed while keeping separate in the rich flow and the lean flow and injected for the preferable combustion from the primary air nozzle into the furnace, thereby to enhance the reliability as the pulverized fuel combustion burner.
The pulverized fuel combustion burner according to the invention of Claim 4 is constructed to further comprise a combustion auxiliary air flow straightener disposed in said windbox for guiding said combustion auxiliary air into an entrance of said secondary air nozzle. As a result, the mixed flow of the pulverized fuel and the carrier air can be injected in a preferable situation from the primary air nozzle, and the combustion auxiliary air can be guided in a preferable state from the outer side into the entrance of the secondary air nozzle by the combustion auxiliary air flow straightener disposed in the windbox, thereby to prevent the leakage of the combustion auxiliary air drastically at the entrance of the secondary air nozzle.
The pulverized fuel combustion burner according to the invention of Claim 5 is constructed such that said primary air nozzle is disposed at a corner portion of the side wall of the furnace. As a result, the burner is devised to separate the mixed flow of the pulverized fuel and the carrier air into the rich flow and the lean flow by the pulverized fuel supply pipe and the primary air nozzle and to keep the separation effect, and is arranged at the corner portion of the furnace side wall so that the preferable injection can be effected from the corner portion into i:he furnace, thereby to retain the proper combustion.
The pulverized fuel combustion burner according to Claim 6 is constructed such that said windbox comprises a plurality of unit windboxes, each having a square front section and each having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, said unit windboxes being arranged in a separated or jointed relation between each other, and said unit windbox has an upward and downward directional length of one and a half(1.5) times or less of its lateral directional length. As a result, the unit windbox is constructed by housing the primary air nozzle, which is devised to separate the mixed flow of the pulverized fuel and the carrier air by the pulverized fuel supply pipe and the primary air nozzle and to keep the separation effect, and the secondary air nozzle which prevents the leakage of the combustion auxiliary air at its entrance, and the unit windbox has an upward and downward directional length of one and a half(1.5) times or less of its lateral directional length, so that the entire construction can be made compact without lowering the performance.
Claims (22)
1. A pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including a primary air nozzle having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle, a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle and a windbox provided with said pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe, said windbox being constructed by arranging unit windboxes in a separated or jointed relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, characterized in that a rich/lean flow separator is disposed at or near a jointed portion between said primary air nozzle and said pulverized fuel supply pipe and said rich/lean flow separator is enabled to change its direction in response to or independently of a change in an injection direction of said primary air nozzle.
2. A pulverized fuel combustion burner as set forth in claim 1 characterized in that another rich/lean flow separator is disposed upstream of the first-named rich/lean flow separator.
3. A pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including a primary air nozzle having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle, a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle and a windbox provided with said pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe, said windbox being constructed by arranging unit windbox in a separated or jointed relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, characterized in that a rich/lean flow separator is disposed in said pulverized fuel supply pipe and a flow straightener or a straightening plate is disposed in one of said primary air nozzle and said pulverized fuel supply pipe for keeping a concentration distribution, as established by said rich/lean flow separator to an exit of said primary air nozzle.
4. A pulverized fuel combustion burner as set forth in any one of claims 1 to 3, characterized in that a combustion auxiliary air flow straightener is disposed in said windbox for guiding said combustion auxiliary air into an entrance of said secondary air nozzle.
5. a pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including a primary air nozzle being disposed at a corner portion of the side wall of the furnace and having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle, a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle and a windbox provided with said pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe, said windbox being constructed by arranging unit windboxes in a separated or jointed relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, characterized in that a rich/lean flow separator is disposed at or near a jointed portion between said primary air nozzle and said pulverized fuel supply pipe and said rich/lean flow separator is enabled to change its direction in response to or independently of a change in an injection direction of said primary air nozzle.
6. A pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including a primary air nozzle having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle, a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle and a windbox provided with said pulverized fuel supply pipe therethrough for forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe, said windbox being constructed by arranging unit windboxes in a separated or jointed relation between each other, each unit windbox having at least one pulverized fuel supply pipe and one combustion auxiliary air supply passage, and having an upward and downward directional length of one and a half (1.5) times or less of its lateral directional length, characterized in that a rich/lean flow separator is disposed at or near a jointed portion between said primary air nozzle and said pulverized fuel supply pipe and said rich/lean flow separator is enabled to change its direction in response to or independently of a change in an injection direction of said primary air nozzle.
24 A pulverized fuel combustion burner comprising a plurality of air nozzles arranged on a side wall of a furnace for injecting a mixed flow of a pulverized fuel and carrier air to establish a flame, said air nozzles including: a primary air nozzle having a variable direction to inject said mixed flow into the furnace, a secondary air nozzle for feeding combustion auxiliary air to around said primary air nozzle, and a windbox comprising a pulverized fuel supply pipe for feeding said mixed flow to said primary air nozzle, wherein said pulverized fuel supply pipe extends through said windbox such that a combustion auxiliary air supply passage is formed around said pulverized fuel supply pipe, wherein a rich/lean flow separator is disposed in said pulverized fuel supply pipe, and a flow straightener or a straightening plate is disposed at least in any one of said primary air nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining a concentration distribution as established by said rich/lean flow separator to an exit of said primary air nozzle.
8. A pulverized fuel combustion burner as set forth in claim 7, wherein a combustion auxiliary air flow straightener is disposed in said windbox for guiding said combustion auxiliary air into an entrance of said secondary air nozzle.
9. A pulverized fuel combustion burner as set forth in claim 7 or 8 wherein said primary air nozzle is disposed at a corner portion of the side wall of the furnace.
10. A pulverized fuel combustion burner as set forth in any one of claims 7 to 9, wherein said windbox comprises a section and each having at least one said pulverized fuel supply pipe and one said combustion auxiliary air supply passage, said unit windboxes being arranged in a separated or jointed relation between each other, and each said unit windbox has an upward and downward directional length (h) of one and a half (1.5 times) or less of its lateral directional length (w).
11. A pulverized fuel combustion burner and furnace arrangement comprising a plurality of air nozzles arranged on a side wall of the furnace for injecting a mixed flow of pulverized fuel and carrier air to establish a flame into the furnace, said plurality of nozzles comprising a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace;
a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe along a centerline of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe, said pulverized fuel supply pipe having an unseparated mixed flow of pulverized fuel and carrier air upstream of said rich/lean flow separator, and such that as the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established including a fuel-rich flow at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow at an inner part inside of said pulverized fuel supply pipe inside of the rich flow and along said centerline of said pulverized fuel supply pipe; and a flow-straightening member disposed and positioned in at least one of said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining the rich/lean flow concentration distribution established by said rich/lean overflow separator to said exit of said primary nozzle.
a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe along a centerline of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe, said pulverized fuel supply pipe having an unseparated mixed flow of pulverized fuel and carrier air upstream of said rich/lean flow separator, and such that as the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established including a fuel-rich flow at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow at an inner part inside of said pulverized fuel supply pipe inside of the rich flow and along said centerline of said pulverized fuel supply pipe; and a flow-straightening member disposed and positioned in at least one of said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining the rich/lean flow concentration distribution established by said rich/lean overflow separator to said exit of said primary nozzle.
12. The pulverized fuel combustion burner and furnace arrangement of claim 11, wherein said primary nozzle is disposed at a corner portion of the furnace.
13. The pulverized fuel combustion burner and furnace arrangement of claim 11 wherein said windbox comprises a plurality of unit windboxes, each of said unit windboxes having a rectangular front section, one of said unit windboxes having said pulverized fuel supply pipe extending through the one of said unit windboxes and forming said combustion auxiliary air supply passage around said pulverized fuel supply pipe, and each of said unit windboxes having a height of no more than one-and-a-half times the width of each of said unit windboxes.
14. A pulverized fuel combustion burner and furnace arrangement comprising a plurality of air nozzles arranged on a side wall of the furnace for injecting a mixed flow of pulverized fuel and carrier air to establish a flame in the furnace, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace;
a windowbox, said pulverized fuel supply pipe extending through said window, and said windowbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside of the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe;
and flow straightening plates including plates disposed and positioned in said primary nozzle and plates disposed and positioned in said pulverized fuel supply pipe downstream of said rich/lean flow separator so as to maintain the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
a windowbox, said pulverized fuel supply pipe extending through said window, and said windowbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside of the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe;
and flow straightening plates including plates disposed and positioned in said primary nozzle and plates disposed and positioned in said pulverized fuel supply pipe downstream of said rich/lean flow separator so as to maintain the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
15. The pulverized fuel combustion burner and furnace arrangement of claim 14 wherein said straightening plates are disposed in said pulverized fuel supply pipe so as to be spaced inward of inside walls of said pulverized fuel supply pipe and outward of a centerline of said pulverized fuel supply pipe.
16. The pulverized fuel combustion burner and furnace arrangement of claim 14 wherein said straightening plates are disposed both upstream and downstream of said jointed portion.
17. A pulverized fuel combustion burner comprising a plurality of air nozzles injecting a mixed flow of pulverized fuel and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow, a windowbox, said pulverized fuel supply pipe extending through said window, and said windowbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe along a centerline of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe, said pulverized fuel supply pipe having an unseparated mixed flow of pulverized fuel and carrier air upstream of said rich/lean flow separator, and such that as the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established including a fuel-rich flow at an outer part of said pulverized fuel supply pipe, said outer part being inside of the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow at an inner part of said pulverized fuel supply pipe, said inner part being inside of the pulverized fuel supply pipe inside of the rich flow and along center line of said pulverized fuel supply pipe; and a flow straightening member disposed and positioned in at least one of said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator for maintaining the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
18. The pulverized fuel combustion burner of claim 17, wherein said windbox comprises a unit windbox having a rectangular front section, said pulverized fuel supply pipe extending through said unit windbox and forming said combustion auxiliary air supply passage around said pulverized fuel supply pipe, and said unit windbox having a height of the width of said unit windbox.
19. A pulverized fuel combustion burner comprising a plurality of air nozzles for injecting a mixed flow of pulverized fuel and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow into the furnace;
a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and flow straightening plates including plates disposed and positioned in said primary nozzle and plates disposed and positioned in said pulverized fuel supply pipe downstream of said rich/lean flow separator so as to maintain the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and flow straightening plates including plates disposed and positioned in said primary nozzle and plates disposed and positioned in said pulverized fuel supply pipe downstream of said rich/lean flow separator so as to maintain the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle.
20. The pulverized fuel combustion burner of claim 19, wherein said straightening plates are disposed in said pulverized fuel supply pipe so as to be spaced inward of inside walls of said pulverized fuel supply pipe and outward of a centerline of said pulverized fuel supply pipe.
21. The pulverized fuel combustion burner of claim 19, wherein said straightening plates are disposed both upstream and downstream of said jointed portion.
22. A pulverized fuel combustion burner comprising a plurality of air nozzles for injecting a mixed flow of pulverized fuel and carrier air to establish a flame, said plurality of nozzles comprising: a primary nozzle for injecting the mixed flow into the furnace, said primary nozzle having an exit; a secondary nozzle positioned around said primary nozzle for feeding combustion auxiliary air around said primary nozzle; a pulverized fuel supply pipe for feeding the mixed flow to said primary nozzle, wherein said primary nozzle and said pulverized fuel supply pipe are joined at a jointed portion at which said primary nozzle can be pivoted to change a direction for injecting the mixed flow; a windbox, said pulverized fuel supply pipe extending through said windbox, and said windbox forming a combustion auxiliary air supply passage around said pulverized fuel supply pipe; a rich/lean flow separator disposed in a middle portion of said pulverized fuel supply pipe such that said rich/lean flow separator is spaced from opposite inner walls of said pulverized fuel supply pipe and such that when the mixed flow flows around said rich/lean flow separator, a rich/lean flow concentration distribution is established in which a fuel-rich flow is created at an outer part of said pulverized fuel supply pipe, said outer part being inside the pulverized fuel supply pipe and adjacent to said opposite inner walls and a fuel-lean flow is created at an inner part of said pulverized fuel supply pipe, said inner part being inside the pulverized fuel supply pipe inside of the rich flow and along a center line of said pulverized fuel supply pipe; and means, disposed in both said primary nozzle and said pulverized fuel supply pipe downstream of said rich/lean flow separator, for maintaining the rich/lean flow concentration distribution established by said rich/lean flow separator to said exit of said primary nozzle even when said primary nozzle is pivoted and a direction for injecting the mixed flow changes.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9080206A JP2995013B2 (en) | 1997-03-31 | 1997-03-31 | Pulverized fuel combustion burner |
| JP9-080206 | 1997-03-31 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2232805A1 CA2232805A1 (en) | 1998-09-30 |
| CA2232805C true CA2232805C (en) | 2001-08-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002232805A Expired - Lifetime CA2232805C (en) | 1997-03-31 | 1998-03-23 | Pulverized fuel combustion burner |
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| US (2) | US6145449A (en) |
| EP (2) | EP0869313B1 (en) |
| JP (1) | JP2995013B2 (en) |
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Families Citing this family (43)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3686250B2 (en) * | 1998-03-26 | 2005-08-24 | 三菱重工業株式会社 | Pulverized coal burner |
| KR100325948B1 (en) * | 1999-04-22 | 2002-02-27 | 김병두 | nozzle tip assembly of boiler for suppling of pulverized coal |
| US6260491B1 (en) | 1999-09-13 | 2001-07-17 | Foster Wheeler Corporation | Nozzle for feeding combustion providing medium into a furnace |
| WO2002012791A1 (en) * | 2000-08-04 | 2002-02-14 | Babcock-Hitachi Kabushiki Kaisha | Solid fuel burner and combustion method using solid fuel burner |
| US6439136B1 (en) * | 2001-07-03 | 2002-08-27 | Alstom (Switzerland) Ltd | Pulverized solid fuel nozzle tip with ceramic component |
| US6726888B2 (en) * | 2002-01-25 | 2004-04-27 | General Electric Company | Method to decrease emissions of nitrogen oxide and mercury |
| CA2515923A1 (en) * | 2005-08-05 | 2007-02-05 | Mark A. Dupuis | Nozzle |
| US7739967B2 (en) | 2006-04-10 | 2010-06-22 | Alstom Technology Ltd | Pulverized solid fuel nozzle assembly |
| CN1920382B (en) * | 2006-09-04 | 2011-07-20 | 东方锅炉（集团）股份有限公司 | Rotational flow pulverized coal burner |
| EP2068078A1 (en) * | 2006-09-04 | 2009-06-10 | Vitro Global, S.A. | Method and burner for burning solid fuels |
| JP5021999B2 (en) * | 2006-10-20 | 2012-09-12 | 三菱重工業株式会社 | Flame retardant fuel burner |
| US7717701B2 (en) * | 2006-10-24 | 2010-05-18 | Air Products And Chemicals, Inc. | Pulverized solid fuel burner |
| JP4898393B2 (en) * | 2006-11-09 | 2012-03-14 | 三菱重工業株式会社 | Burner structure |
| US8210111B2 (en) * | 2008-02-27 | 2012-07-03 | C.L. Smith Industrial Company | Method and system for lining a coal burner nozzle |
| US8701572B2 (en) | 2008-03-07 | 2014-04-22 | Alstom Technology Ltd | Low NOx nozzle tip for a pulverized solid fuel furnace |
| US8082860B2 (en) * | 2008-04-30 | 2011-12-27 | Babcock Power Services Inc. | Anti-roping device for pulverized coal burners |
| US8104412B2 (en) * | 2008-08-21 | 2012-01-31 | Riley Power Inc. | Deflector device for coal piping systems |
| US20100192817A1 (en) * | 2009-02-04 | 2010-08-05 | Shekell Lawrence G | Burner nozzle for pulverized coal |
| US20110114763A1 (en) * | 2009-11-13 | 2011-05-19 | Briggs Jr Oliver G | Pivot pin for furnace side removal |
| US8561553B2 (en) * | 2009-12-17 | 2013-10-22 | Babcock Power Services, Inc. | Solid fuel nozzle tip assembly |
| CN102235666B (en) * | 2010-04-27 | 2014-11-26 | 烟台龙源电力技术股份有限公司 | Pulverized coal burner and pulverized coal fired boiler comprising same |
| CN101865463B (en) * | 2010-06-21 | 2011-12-28 | 华南理工大学 | Petroleum coke power combustor |
| US20120103237A1 (en) * | 2010-11-03 | 2012-05-03 | Ronny Jones | Tiltable multiple-staged coal burner in a horizontal arrangement |
| US20120174837A1 (en) * | 2011-01-06 | 2012-07-12 | Jiefeng Shan | Tiltable nozzle assembly for an overfire air port in a coal burning power plant |
| EP2995857B1 (en) * | 2011-04-01 | 2019-05-08 | Mitsubishi Heavy Industries, Ltd. | Combustion burner |
| CN102297425B (en) * | 2011-06-27 | 2013-07-31 | 中国科学院过程工程研究所 | Pulverized coal decoupling combustor and decoupling combustion method thereof |
| SE536195C2 (en) * | 2011-10-12 | 2013-06-18 | Ecomb Ab Publ | Supply device for combustion chamber and method therefore |
| JP5658126B2 (en) | 2011-11-16 | 2015-01-21 | 三菱重工業株式会社 | Oil burning burner, solid fuel burning burner unit and solid fuel burning boiler |
| GB201202907D0 (en) * | 2012-02-21 | 2012-04-04 | Doosan Power Systems Ltd | Burner |
| CN102809146A (en) * | 2012-08-24 | 2012-12-05 | 哈尔滨工业大学 | Oscillating type over-fire air device of on-wall arrangement boiler |
| US9513002B2 (en) * | 2013-04-12 | 2016-12-06 | Air Products And Chemicals, Inc. | Wide-flame, oxy-solid fuel burner |
| CN103438447B (en) * | 2013-08-16 | 2016-05-18 | 武汉华尔顺冶金工程技术有限公司 | Water-cooled petroleum coke power combustor |
| US9709269B2 (en) | 2014-01-07 | 2017-07-18 | Air Products And Chemicals, Inc. | Solid fuel burner |
| WO2016100544A1 (en) * | 2014-12-16 | 2016-06-23 | Babcock Power Services, Inc. | Solid fuel nozzle tips |
| CN105351921A (en) * | 2015-12-09 | 2016-02-24 | 江苏东方电力锅炉配件有限公司 | Firing stabilizer |
| JP6925817B2 (en) * | 2017-02-13 | 2021-08-25 | 三菱パワー株式会社 | Pulverized coal burner, pulverized coal burner control method and boiler |
| EP3438529B1 (en) * | 2017-07-31 | 2020-04-22 | General Electric Technology GmbH | Coal nozzle assembly comprising two flow channels |
| CN109237465B (en) * | 2018-10-30 | 2024-03-19 | 北京巴布科克·威尔科克斯有限公司 | Cyclone burner and cyclone burner ventilation air methane spraying system |
| CN111256109B (en) * | 2020-02-20 | 2022-02-22 | 苏州西热节能环保技术有限公司 | Method for relieving temperature deviation of tube wall of opposed coal-fired boiler |
| CN111256110B (en) * | 2020-02-20 | 2022-02-22 | 苏州西热节能环保技术有限公司 | Method for preventing and treating high-temperature corrosion of side wall water-cooled wall of hedging coal-fired boiler |
| CN111998336B (en) * | 2020-09-14 | 2022-07-26 | 哈尔滨锅炉厂有限责任公司 | Direct-flow pulverized coal burner with thick outer part and thin inner part |
| US20230038688A1 (en) * | 2021-08-03 | 2023-02-09 | General Electric Technology Gmbh | Pulverized solid fuel nozzle tip assembly with carbon tip portion |
| US11859813B1 (en) * | 2022-12-16 | 2024-01-02 | General Electric Technology Gmbh | Pulverized solid fuel nozzle tip assembly with low contact frame |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2895435A (en) * | 1954-03-15 | 1959-07-21 | Combustion Eng | Tilting nozzle for fuel burner |
| US4252069A (en) * | 1979-04-13 | 1981-02-24 | Combustion Engineering, Inc. | Low load coal bucket |
| US4304196A (en) * | 1979-10-17 | 1981-12-08 | Combustion Engineering, Inc. | Apparatus for tilting low load coal nozzle |
| US4356975A (en) * | 1980-03-07 | 1982-11-02 | Combustion Engineering, Inc. | Nozzle tip for pulverized coal burner |
| US4611543A (en) * | 1981-12-17 | 1986-09-16 | Combustion Engineering, Inc. | Restrictor application for in line gas entrained solids redistribution |
| US4539918A (en) * | 1984-10-22 | 1985-09-10 | Westinghouse Electric Corp. | Multiannular swirl combustor providing particulate separation |
| JP2638040B2 (en) * | 1988-02-23 | 1997-08-06 | バブコツク日立株式会社 | Pulverized coal combustion equipment |
| US4930430A (en) * | 1988-03-04 | 1990-06-05 | Northern Engineering Industries Plc | Burners |
| JP2776572B2 (en) * | 1989-07-17 | 1998-07-16 | バブコツク日立株式会社 | Pulverized coal burner |
| US5215259A (en) * | 1991-08-13 | 1993-06-01 | Sure Alloy Steel Corporation | Replaceable insert burner nozzle |
| US5535686A (en) * | 1992-03-25 | 1996-07-16 | Chung; Landy | Burner for tangentially fired boiler |
| GB2272755B (en) * | 1992-11-20 | 1996-05-15 | Northern Eng Ind | Pulverised fuel flow re-distributor |
| GB9322016D0 (en) * | 1993-10-26 | 1993-12-15 | Rolls Royce Power Eng | Improvements in or relating to solid fuel burners |
| US5392720A (en) * | 1994-06-07 | 1995-02-28 | Riley Stoker Corporation | Flame retaining nozzle tip |
| CA2151308C (en) * | 1994-06-17 | 1999-06-08 | Hideaki Ohta | Pulverized fuel combustion burner |
| US5605103A (en) * | 1995-09-11 | 1997-02-25 | The Babcock & Wilcox Company | Internal pitch impeller for a coal burner |
| ES2162680T3 (en) * | 1996-07-08 | 2002-01-01 | Alstom Power Inc | TOWEL TIP FOR SPRAY SOLID FUEL. |
-
1997
- 1997-03-31 JP JP9080206A patent/JP2995013B2/en not_active Expired - Lifetime
-
1998
- 1998-03-19 DK DK00118421T patent/DK1054212T3/en active
- 1998-03-19 EP EP98105045A patent/EP0869313B1/en not_active Expired - Lifetime
- 1998-03-19 ES ES98105045T patent/ES2166572T3/en not_active Expired - Lifetime
- 1998-03-19 PT PT00118421T patent/PT1054212E/en unknown
- 1998-03-19 DK DK98105045T patent/DK0869313T3/en active
- 1998-03-19 DE DE69831355T patent/DE69831355T2/en not_active Expired - Lifetime
- 1998-03-19 EP EP00118421A patent/EP1054212B1/en not_active Expired - Lifetime
- 1998-03-19 ES ES00118421T patent/ES2246783T3/en not_active Expired - Lifetime
- 1998-03-19 AT AT00118421T patent/ATE302925T1/en active
- 1998-03-19 PT PT98105045T patent/PT869313E/en unknown
- 1998-03-19 DE DE69802736T patent/DE69802736T2/en not_active Expired - Lifetime
- 1998-03-19 AT AT98105045T patent/ATE210264T1/en active
- 1998-03-23 CA CA002232805A patent/CA2232805C/en not_active Expired - Lifetime
- 1998-03-23 RO RO98-00761A patent/RO117869B1/en unknown
- 1998-03-26 PL PL325576A patent/PL191766B1/en unknown
- 1998-03-26 PL PL377649A patent/PL193795B1/en unknown
- 1998-03-27 TW TW087104672A patent/TW358149B/en not_active IP Right Cessation
- 1998-03-27 SK SK407-98A patent/SK282933B6/en not_active IP Right Cessation
- 1998-03-30 HU HU9800714A patent/HU222468B1/en active IP Right Grant
- 1998-03-30 HU HU0203395A patent/HU222996B1/en active IP Right Grant
- 1998-03-31 CZ CZ1998978A patent/CZ292268B6/en not_active IP Right Cessation
- 1998-03-31 CZ CZ20024137A patent/CZ293654B6/en not_active IP Right Cessation
- 1998-03-31 KR KR1019980011176A patent/KR100295608B1/en not_active IP Right Cessation
- 1998-03-31 US US09/052,025 patent/US6145449A/en not_active Expired - Lifetime
-
2000
- 2000-09-19 US US09/665,072 patent/US6367394B1/en not_active Expired - Lifetime
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