US2933259A - Nozzle head - Google Patents

Description

F. J. M. RASKIN NOZZLE HEAD April 19, 1960 3 Sheets-Sheet 1 Filed March 3, 1958 NW Finn: J.H. RASKI/V deemed Ap i 1960 F. J. M. RASKIN 2,933,259

NOZZLE HEAD Filed March 3, 1958 3 Sheets-Sheet 2 a4 a5 gym-1% J n t o g o o o o o o o o o o o o o o o o a 8 o o o o o o o 0 o o 0 o o O o O fig 9 nwnvmn Franz .m RASK/IV detected April 19, 1960 F. J. M. RASKIN NOZZLE HEAD 3 Sheets-Sheet 3 Filed March 3, 1958 N UI IH Q on w 3m 3 Qgwmm Q m G sh hm mm mm mm QQ mum H00: 1!! RASKIN dreamed ,Y F6

. g 2,933,259 Patented Apr. 19, 1960 NOZZLE HEAD Application March 3, 1958, Serial No. 718,599

Claims. (Cl. 239-405) The present invention relates to a nozzle head for discharging under pressure a mixture of two or more gases, or a spray of liquid or pulverized solid.

The nozzle head in accordance with the present invention is more particularly applicable for use in burner equipment 'for atomizing a liquid fuel or for mixing a gaseous fuel with air or other combustive.

The nozzle head of the present invention can also be used to produce a spray of any liquid such as a fine water spray,-or a spray of fine solid material such as pulverized coal;

In some conventional oil spray burners, the oil is mixed with steam or air to form an atomized mixture which is discharged as a single jet of relatively large capacity. However, this mixture is very often nonhomogeneous in both the size variation of the liquid particles of the atomized liquid and also the distribution of said liquid particles in the carrier gas.

To obviate this disadvantage, it has been suggested to replace the single discharge opening of the spray plate by a plurality of smaller sized discharge openings and to associate each discharge opening with individual steam or air and oil supply tubes so that a plurality of atomized oil jets combine to form the spray issuing from the nozzle. A more homogeneous mixture results from such a noule and also the modulating capacity of the nozzle is increased; however, in such nozzles, the individual oil feeding tubes communicate with. one side only of the air or stream feeding tubes so that the spray issuing from each discharge opening is nonhomogeneous. Also, such nozzles are very difiicult to manufacture because of the necessity of correctly aligning small bores arranged in pairs and which communicate at an angle to each other. The design of an oil atomizer for an oil burner should be such that with one basic design, variations-in the size 7 and proportions of the parts of the oil atomizer will give control over the following characteristics:

(a) The quality 'of atomization, in other words, atomization from coarse to extremely fine;

(b) Theshape of the oil spray, such as a rectangular flat spray of any size, a fiat spray of fan tail shape, a conical spray of any included angle and solid or hollow;

and

g (0 The capacity which may be required from a single atomizer. J

' Characteristics (b) and (0) apply also to a mixer for mixing gaseous fuel with air; furthermore, such a mixer should be so designed that the enclosed volume of the.

neity of the particle size and distribution of the" atomized liquid. 'Antither important object of the present invention is the provision of a nozzle head of the character described in which the atomized or mixed jet issuing from the head is composed of a plurality of individual atomized or mixed small jets of substantially uniform concentration and homogeneity.

' Still another important object of the present invention is the provision of an atomizer of the character described which can be proportioned to obtain the desired degree of atomization.

Yet another important object of the present invention is the provision of an atomizer and/ or mixer head of the character described in which the individual jet openings may be so disposed as to provide any desired shape for the overall jet or spray.

Yet another important object of the present invention is the provision of a nozzle head of the character described in which the capacity can be varied at will by varying the number of individual jets and, within certain limits, the size of said individual jets.

Yet another important object of the present invention is the provision of a mixer of the character described which is so arranged that, when used as a gas burner, the

gas fuel is mixed with the air only in small volume chambers whereby the danger of explosive flashbacks is eliminated.

Another object of the present invention is the provision: of a nozzle head of the character described which is very simple and easy to manufacture and in which the individual bores may be formed with the optimum size and shape for utmost atomization and/or mixing efiiciency.

Yet another important object of the present invention: is the provision of a device of the character described which may be used to atomize liquids other than fuel, such-as, for atomizing-water to produce a water spray.

The foregoing and other important objects of the present invention will become more apparent during the following disclosure and by referring to the drawings in which:

Figure 1' is a longitudinal section of a first embodiment of the nozzle head in accordance with the present invention, said section being taken along line 11 of Figure 2.

Figure 2 is a front view of the embodiment of Figure 1;

Figure 3 is a partial longitudinal section of the first em- 'bodiment taken'along line 33 of Figure 2-;

"Figure 4 is a partial longitudinal section of a second embodiment;

Figure 5 is a partial longitudinal section of a third embodiment;

Figure 6 is a front view of the embodiment of Figure 5; QFigure 7 is a longitudinal section of still another embodiment of a nozzle headin accordance with the present invention;

Figure 8 is an enlarged cross-section of a modified shape of an individual nozzle;

Figure 9 is an enlarged longitudinal section of still another modified form of an individual nozzle;

Figure 10 is.,a perspective view of the sleeve-like insert used in-Figure 9; and

Figure 11 is an enlarged cross-section taken on line 11TH of Figure 9.

Referring now more particularly to the drawings in hich like reference characters indicate like elements throughout, the nozzle head, in accordance with the present invention, essentially consists of an inner and an outer plate-like element maintained in spaced relationship so as to provide a gap therebetween of substantially uniform width, said two elements being provided with a plurality of through bores arranged in axially aligned pairs, that is, the bores of one element register with an associatedbore of the other element; said elements being associated with me'ans to admit a-first fluid substance under pressure to the inlets of the through bores ,of the inner element and a second fluid substance under pressure end portion 3 to be secured to an inner pipe 4'adapted to supply a first substance under pressure, such as air, steam or gas. The frusto-conical member 1 is provided with a plurality of cylindrical throughbores 5 which are circu larly arranged about the axis of the skirt 2 and which are disposed at right-angles to the frusto-conical member 1.

' The skirt 2 is further provided with a radially outwardly projecting peripheral flange 6' which is perforated with a plurality of through bores 7. A cylindrical sleeve 8'Iis slidably fitted over the outer cylindrical surface of the flange 6 and is provided at its rear end portion with inner threads 9 to threadedly engage a nipple 10 adapted to be connected to an outer pipe (not shown) for supplying a second substance under pressure, such as a liquid or gas fuel. v I

' The forward end of the sleeve 8 forms an inwardly directed lip 11 engageable with a shoulder 12 made at the periphery of. the outer element or face plate of the nozzle head which consists of a second frusto-conical member 13. The latter has the same included angle as the first fr-usto-conical member 1. The two members 1 and 13 are maintained ata predetermined distance apart by means of a spacer sleeve 14 engageable between the flange 6 of the skirt 2 and the peripheral portion of the inner face of the-member 13. Thus a gap 15 of substantially uniform width is formed'between the two frusto- conical members 1 and 13. This gap is in communication at the periphery of the two frusto-conical members with a pressureequalizing chamber 16 surrounding the skirt 2, and said chamber 16 is -in turn in communication with the nipple 10 through the axial bores 7 made in the flange 6. 1

The second'frusto-conical member 13 is provided with alplurality of cylindrical through bores 17 respectively axially aligned with the throughbores 5 of the inner frusto conicalmember 1 and of a diameter slightly greater than said through bores 5.

said gap 15. The through bores 5 and 17 are very easily machined: they canbe made inexact alignment and,

furthermore, they can be finished to the exact required diameter because the two members 1 and 13 are detachable. Also, the skirt 2 may be made of such a length as to clear a tool inserted through the inlet end of the through bores 5'.

With the embodiment 1 of Figures 1, 2 and 3, there results a hollow substantially conically shaped flame haV? 1 However, it is ing a rather restricted included angle. possible to vary. the shape of the flame due to the simple design in accordance with the present invention.

Referring to Figure 4, the inner element 19 is in the form of a semi-spherical member which is concentric with a semi-spherical member 20 which constitutes the outer element. The members 19 and 20 are provided with a the liquid fuel pipe. The outer member Ztlismaintained in fixed relation with respect to the inner member 19 by means of the spacer sleeve 25. This embodiment will form a solid conical fire having a wider included angle than the embodiment of Figure 1. i

The ernbodimentof Figures 5 and dis designed to produce a rectangular. fiat spray which may have any width and/or thickness. In this embodiment the outer element 26 and the inner element 27 areeach in the form a of a rectangular plate of V shaped cross-section having equal included angles. The twoelements 26 and 27 are provided with ,two rows of aligned through bores 28 and 29 respectiyely. The inner element 27 has flat side walls 30 and flat end walls 30', which form an elongated rectangular chamber 31 provided at the middle thereof with a circular nipple 3 2 in threaded engagement with a As shown in Figure 3, the inner and outer frusto-conical members land 13 are maintained by means of dowel pins 18, in a fixed angular relationship and against rotation with-respect to each'other, so that the through bores 5 and 17 are always maintained in exactaxial alignment.

'When the nozzle head, in accordance with the first embodiment, is used to atomize a liquid fuel, steam air of the'fuel into the pressure-equalizing anti-chamber 36;

which communicates with the gap 37 between the inner and .out erlelements 27 and26. The anti-chamber 36 exor any other suitable gas such as n'atural gas atthe con-.

ventional pressure is supplied by :the inner pipe 4, while the fuel oil is supplied by the outer pipe connected to nipple 10. The steamer gas under pressure passes at high velocity through the aligned bores 5 and 17, while the liquid fuel normally under pressure although said pressure may be very s'mall or nonexistant for small capacity atomizers completely fllls the gap 15 and is drawn by and mixes' with the steam or air jet from around the entire periphery of said jet for each individual pair of through A r a mixing tube wherein the liquid would b'e supplied from one. side only. The through bore 17 has a slightly larger diameter than the through bore 5 toprevent the production of, a, counter pressure in the gap 15 to produce a. Yenturi effect creating suction of the fuel from tends around the entire periphery; of the inner element 27.. A spacer member 38 of rectangular shape abuts 6s Theouter element '26 is removably retained in position by meaus ofthe retainin'g member 39.. having the form of a rectangular box withoutbottom and top and having aninward lip 40 at its forward end engageable with. a houlder 41' extending around the entire periphery of the outer element 26. The retaining member 39 is provided at thencentre thereof with opposite top and. bottom seg-' mental flanges'42 adapted to be removablysecuredbymeans of bolts 43 to the flange 44' of a flanged collar 45 which is threadedly connected toa liquid supply outer pipe 46 decreased. 1

V I'thasbeen found that very wide nozzles can be manufactured in accordance withthe present invention, and

stiILtheQfueland the air or steam will be supplied to the.

individual'nozzles at a substantially uniform pressure,"

therebyobtaining individual jets of combustible mixture of;{un;ifiorn1 comp05iti.0n and of uniform atomization.

Thus a long single row of holes 28 may be provided to produce a thin, rectangular, even spray of any width required, which is highly desirable for some installations such as an open hearth furnace, or by providing more rows of holes, it is possible to have a thick rectangular spray. Obviously, the capacity of the entire spray can be varied by varying the number of component jets.

Figure 7 shows still another embodiment of the nozzle head, in accordance with the present invention, in which both the inner and outer elements are detachable for ease of machining the through bores thereof.

As shown in Figure 7, a sleeve 47 is threadedly connected at its inlet end 48 to an inner pipe 49 for the supply of a first substance, such as steam or air under pressure. The sleeve 47 is part of and forms an inner annular projection at the forward end of an elongated nipple 50 which spacedly surrounds the inner pipe 49 and is in threaded engagement at its inlet end 51 with an outer pipe for the supply under pressure of the second substance such as liquid fuel. 1

The nipple 50 has at its forward end an externally threaded portion of reduced outside diameter, as shown at 53, which is in threaded engagement with a sleeve-like retaining member 54 provided at its forward end with an inwardly directed lip 55 engageable with a shoulder 56 of the outer element 57 of the nozzle head.

The inner element 58 of the nozzle head is detachable and is sandwiched between the outer element 57 and the sleeve 47. Thus, the two elements 57 and 58 are maintained in secured position by means of the retaining member.

The inner element 58 is provided at the periphery of its outer face with an outwardly projecting rib 59 engageable with the peripheral portion of the inner face of the outer element 57 so as to maintain between elements 57 and 58, a cap 60 ofrequired width. Radially inwardly of the rib 59, there is provided a peripheral groove 61 serving as means for distributing the oil within the gap 60; the groove 61 is continuous around the periphery of the element 58 and is in communication with a groove 62 at theinner face of the element 58 by means of a plurality of passages or holes 63.

The groove 62*is opposite a groove 64 made in the front face of the sleeve 47. The grooves 62 and 64 form a pressure equalizing chamber around the element 58 for the oil supplied thereto by means of axial passages 65 made in the sleeve 47 and communicating with the annularchamber 66 defined between the inner tube 49 and the nipple; 5 0. l j I Theoutenand inner elements57 and 58 are provided with pairs of axially aligned through bores 67 and 68 respectively, both having a cylindrical shape, and the outer bores 67 having a slightly greater diameter than the inner bores 68.

When the nozzle arrangement, in accordance with the present invention, is used as a gas burner, the combustion air may be supplied through the central pipe and the gas through the outer pipe or vice versa. The individual jets will thoroughly mix the two different gases for combustion to any desired proportions, so as to produce the exact type and shape of flame required. Because the combustible mixture is formed in individual, small capacity mixing tubes, which are bores of the outer element, there is at no time any large volume of combustible mixture which, in conventional gas burners, often causes accidents when a flashback occurs. Also, it has been found that the individual jet arrangements, in accordance with the present invention, produce very eflicient mixing of the combustible gas and combustive air.

It is possible due to the simple design of the outer element in all the embodiments, and both the outer and inner elements in the embodiment of Figure 7, to make said elements of refractory material, thereby making it possible to have a very hot and very short flame without damaging the burner.

1 In all the embodiments described hereinabove, the component jetshave been shown as cylindrical bores, the bores of the inner element acting as jet tubes, and the bores of the outer element acting as mixing tubes. How ever, it will be noted that, due to the simple detachable construction of the inner and outer elements, the design lends itself to the economical machining of accepted forms of expanding nozzles for the most eflicient type ofjets, as well as shaping the mixing tubes to obtain the most eflicient induction of the fuel and the desired discharge characteristic of the'mixture.

The embodiment of Figure 8 shows one preferred form of an individual component jet in which the air or steam under pressure enters the jet tube 69 which has a restricted throat 70 and an expanding portion 71, while the mixing tube 72 has a throat 73 and two flaring portions 74 and 75, the flaring portion 74 having a maximum diameter greater than the maximum diameter of the jet tube 69. Thus, the liquid fuel is induced from the gap 76, as shown by the arrows, and the throat 73 produces a very thorough and uniform mixing and atomizing of the liquid fuel in the air or steam jet issuing from the jet tube69. Instead of inducing the liquid fuel or the gas through a Venturi effect it is also possible, in accordance with the present invention and referring to Figures 9 to 11 inclusive, to feed the fuel as jets with kinetic energy. This is achieved by inserting in the jet tube or through bore 77 of cylindrical shape and provided with an enlarged portion 78 at its outlet portion, a cylindrical insert 79 extending across the gap 80 and abutting against the inner face of the outer element 81 and having an inside diameterslightly less than the diameter of the mixing tube 82. r

The insert 79 is provided with a plurality of square notches 83 directed tangentially to the cylindrical inner surface of said insert 79; thus the liquid fuel enters the aligned through bores or tubes tangentially and at high velocity so as to effect a whirling action on the fuel. The combination of the kinetic energy of fuel and the kinetic energy of the atomizing gaseous substance, plus the whirling action of the fuel, results in a very thorough mixing and atomizing of the fuel in the gaseous substance.

The notches 83 may be semi-circular or square in crosssection so as to have in practice, as far as possible, a profile of which the ratio of the circumference to the surface is a minimum to provide for minimum clogging of the opening by liquid fuel as it has been found that liquid fuel normally tends to deposit sediments on the edge of an orifice.

From the foregoing, it will be clear-that the atomizer and/ or mixer nozzle, in accordance with the present invention, clearly fulfills the requirements noted above: its basic design can be adapted for varying the quality of atomization, varying the shape of the atomized oil spray and varying the capacity of the oil spray.

As to the shape of the spray, several embodiments of nozzles, in accordance with the present invention have already been described.

The capacity, of the spray may be varied by varying the number of component jets.

The quality of atomization may be varied by changing any one or any combination of the following three variables:

(a) The diameters of the jets, smaller diameter jets producing fine atomization and larger diameter jets producing coarser atomization;

(b) The width of the gap between the outer and inner elements, a narrower gap producing finer atomization and a wider gap producing coarser atomization;

(c) The difference of diameters of the jet and mixing tubes.

From the foregoing it will also be seen that absolute uniformity of all component sprays is insured because all the jet tubes are similar, all the mixing tubes are similar,

.7 all the fuel entry rings are similar and the atemizing pressure and distribution mall the jets-is-uniformkahd the fuel oil'supply toiall the jets is also'unitormwith respect to pressure and distribution, thus a very high degree of homogeneity of the spray is obtained.

Also the nozzle has an extensive turn-down ratio or modulating range while still maintaining substantially complete combustion. The nozzle head, in accordance with the present inven tion, can easily be taken apart for cleaning.

Obviously, the head in accordance with the ,present invention, may be used to vapourize other liquids than fuel oil and may be found useful, for instance, for vapourizing or atomizing water to produce a fine spray. Such a water spray could be used, for example,for firefighting as it is now known that a water spray or fine water droplets is much more efiicient for fighting fires than a water jet. 7

The nozzle head of the present invention may-also be used to produce a jet'of fine solids such as pulverized coal. t T f In actual tests carried with the nozzle head of Fig 1 it has been found a very good atomization of No. 6 (bunker C) oilwas obtained with a'gap-of about between the two plate-like elements. When the burner was operated on a 'stop and start jetsjsleeve-like members extending across said gapin basis it was found desirable to purge at each stop the oil remaining in the nozzlehead by providing a relief valve, not shown, on the inner tube 4 toadmit purging air or steam into the outer pipe 10 in order to prevent carbonization within the gap 15. t

While preferred embodiments in accordance with the present invention have been illustrated and described,

it is understood that various modifications may be resorted to without departing from the spirit'and scope of the appended claims. 1

1. A nozzle head comprising aninner and an-outer plate-like element'spaced'from each other to define a continuous gap therebetween extending over amajorportion of said elements, saidouter element constituting the face plate of said nozzle head, said elements'having'a plurality of through bores, each through bore of one element being axially aligned with a through bore of the other element to'd'efine pairs of through bores, means to admit a first'fluid substance under pressure to themlets of the through bores of said inner element and 'means to admit a second fluid'under pressure to said gap whereby saidfirst'substance will be discharged as jets passing through said pair of bores and said second substance will enter said jets through said gap to be mixedwith said alignment withthe bores of each pairof bores to establish communication between said bores across said gap; said sleeve-like members having apertures made -therlethrough to communicate-the interior of said sleeves with 'said' p- I Y a =2. A nozzle head as claimed in claim 1, wherein said bores and said sleeve-like members have a cylindrical shape. I

3. A nozzle head asclaimed in claim 2, wherein said apertures open in the interior of said sleeve members tangentially to the inner surface of the latter.-

4. A nozzle head-for burners andthe like comprising an inner casing having an inlet for admission of a; first fluid under pressure and having a wall thereof -perforated with a plurality of'bores through which said}fluid escapes in the form of jets, an outer casing having-an inlet opening for admission of a second fluid under pres sure and having a wall thereof disposed in spaced rela-" tionship with the wall of said inner casing to provide a gap between said-walls, thewall of said outercasing-having a plurality of boresyeach axially aligned with abore of the wall of said innercasing, whereby said second fluid enters said outer casing, fills said gap and contacts and mixes with said jets from points around theiperiphery of the same as said jets escape from the bores of the wall of the'inner casing, the mixing continuing as said jets pass through the bores of the wall of said outer.

casing to issue therefrom, said bores'having a cylindrical shape and the bores in the wall of said outer casing having a slightly greater'diarneter than the diameter of the bores of the wall of the inner casing; the bores in the wall of said inner casing having enlarged end portions adjacent said gap and further including sleeve-like members inserted in said enlarged endportions and projecting across said gap to join with the inlet ends of the bores of the outer casing and each sleeve-like member further having notches made in the end thereofdisposed within said gap to'establishcommunication between the interior of said sleeve-like memberand said gap.

SPA nozzlelhead asclaimed in claim 4, wherein said":

notches have a square cross section and open with saidi sleeve-like members tangentially to the inner surface Simonin Mar, 2, 1937

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