US3001576A - Air directing apparatus - Google Patents

Description

A. BIBER EIAI.

AIR DIRECTING APPARATUS 2 Sheets-Sheet 1 Sept. 26, 1961 Filed Nov. 17, 1958 M a r m u A Sept. 26, 1961 A. BIBER ETAI.

AIR DIRECTING APPARATUS 2 Sheets-Sheet 2 AZJERI' 8/85? Eel/Ff 2. W415 .ATTO RIJEY United States Patent G t 2 3,001,576 v AIR DIRECTING APPARATUS H Albert Biber, Penn Hills Township, Allegheny County, and Bruce R. Walsh, Wilkinsburg, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware Filed Nov. 17, 1958, Ser. No. 774,418

9 Claims.- (Cl. 158-76) This invention relates to an air directing device for gun-type fuel oil burners and more particularly to a device for attachment to the nozzle end of the air blast tube of gun-type fuel oil burners. In gun-type fuel burners, liquid fuels are supplied to a combustion chamber generally in the form of a conical spray. Some means is necessary to provide a supply of air or oxygen to the atomized fuel in order to produce combustion of said fuel.

The present invention provides a novel device for mixing the atomized fuel and air to bring about more perfect combustion of the fuel.

The device of the invention is adapted for mounting over the nozzle and of the air blast tube of a gun-type fuel burner, and comprises a plate having a relatively large central orifice in which the fuel nozzle is located and a plurality of orifices surrounding said central orifice so oriented to direct jets of air into the fuel spray cone in order to insure maximum mixing of the air While combustion takes place.

The invention is illustrated in the drawingsaccompanying the specification and forming a part thereof and in which:

FIGURE 1 is a side elevation partially broken away of a gun-type fuel burner and shows the relative location of its various parts including the improved air injector of the invention.

FIGURE 2 is an end elevation of the improved air direction means of the invention when attached to the nozzle end of the air blast tube. i

FIGURE 3 is a sectional view of FIGURE 2 taken along the line IIIHI.

FIGURE 4 is a sectional view of FIGURE 2 taken along the line IVIV.

FIGURE 5 is a sectional view of FIGURE 2 taken along the line V-V.

FIGURE 6 is a modified structure of the air direction means of the invention when attached to the nozzle end of the air blast tube.

FIGURE 7 is a sectional view of FIGURE 6 taken along the line VII-VII,

Referring to FIGURE 1, the air directing means of this invention comprises a plate 11 which is adapted for mounting over the nozzle end of air blast tube 12 of guntype fuel burner 13. Plate 11 is adapted to be frictionally held in position within the air blast tube 12. Other fastening means, as for example, set screws can be employed for holding the plate in position. Fuel nozzle 14 with its fuel supply tube is located centrally of air blast tube 12 and is approximately flush with the front face of plate 11. The liquid fuel issues from fuel nozzle 14 as a conical spray as at 15. In the embodiment shown, the air blower 16 is located at the rear end of air blast tube 12 and projects the air through the blast tube into the combustion chamber as indicated by the arrows in FIGURE 1.

In FIGURE 2 numeral 11 again designates the entire air directing means of this invention. Numeral 17 designates the relatively large central circular opening in which fuel nozzle 14 is located. Openings 18 and 19 are provided to receive insulated electrodes (not shown) which serve the purpose of igniting the liquid fuel which is atomized and discharged into the combustion chamber.

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2 Located on each side of central orifice 17 are openings 20 and 21. As brought out in FIGURE 5, orifices 20 and 21 are disposed in plate 11 at an angle with respect to the axis of the center orifice, to direct converging jets of air toward the fuel spray cone so as to impinge upon and penetrate the fuel spray cone. The side orifices are preferably inclined inwardly at an angle of approximately 30 more or less to the axis of the center orifice 17.

As shown also in FIGURE 5, the rear portions of orifices 20 and 21 are flared as at 22 to present a relatively large air intake area and a somewhat more restricted discharge outlet. This structure tends to impart greater velocity to the jet of air leaving the orifices and assists the air in penetrating the fuel spray cone and interminglingwith the atomized fuel. Numeral 23 designates a relatively elongated slot positioned above the central orifice 17 through which a relatively broad stream of air is discharged into the combustion zone. As shown in FIG- URE 3, deflector 24 extends outwardly from plate 11 above slot 23 for the purpose of directing the air stream which is'discharged through slot 23. The deflector 24 is provided with a downwardly projecting tip as at 25 which structure insures that the air stream emerging from slot 23 does not diverge upwardly from the fuel cone.v Numeral 26 designates another somewhat smaller elongated slot located below the central orifice 17 through which a portion of the air is discharged. As shown also in FIG- URE 3, lip 27 extends from plate 11 below slot 26 and is inclined upwardly to define with the face of plate 11 an angle of approximately 30 in order to direct a stream of air upwardly into the fuel cone. A distinctive feature of this arrangement is that the air is directed through the various orifices in a manner to penetrate the fuel cone at a plurality of points thus insuring that a supply of air is available throughout the fuel spray cone. In addition; by means of the described arrangement a curtain of air is supplied above the flame which causes the fiarne to be confined and provides an additional supply of air to insure more complete combustion.

The over-all size of the plate comprising the air direct ing device of the invention will depend upon the size of the air blast tube of the gun burner in which it is to be used. For example with a gun-type burner having a blast tube 4 inches in diameter the plate 11 will be constructed so as to have a diameter of slightly less than 4 inches to permit it to be inserted and held within the discharge end of the blast tube. The size of the various orifices provided in plate .11 will vary with the volume of the combustion space and with the amount of oil to be burned. By way of example, the following size orifices have proved feasible for use in a gun-type burner equipped with a fuel nozzle delivering gallon of fuel per hour. The center orifice 17 is made large enough the accommodate a conventional fuel nozzle and will be for example, approximately inch in diameter and the side orifices 20 and 21 approximately /8 inch in diameter. The lower elongated slot 26 is approximately inch by 1 /4 inches and the upper elongated slot 23 is approximately inch by 1% inches. When burning larger amounts of oil the air supply will, for proper combustion be greater and the size of the orifices will be correspondingly increased.

In FIGURES 6 and 7, there is shown a preferred em' bodiment of the invention wherein the side inwardly projecting orifices are carried in a strip 28 which is attached to the front face of plate 11 by means of screws 29. In this embodiment of the invention the side orifices 20 and 21 are disposed in plate 11 parallel with the axis of the central orifice 17, thus simplifying manufacture of the plate 11. To obtain the effect of the side air streams converging toward the fuel cone, strip 28 is provided with two inwardly projecting side orifices 30 and 31 .ment of the invention, it is a simple matter to replace the .strip member 28 with one in which the side orifices are of larger size to compensate for any change in the amount of fuel being supplied to the combustion chamber as would occur upon substitution of a fuel nozzle of greater capacity.

In operation of the air directing device of the invention, air from blower 16 travels down air blast tube 12 to plate 11. The relatively large stream of air is broken up at this point into a number of air jets of shapes corresponding to the configuration of the various orifices in the plate. A minor portion of the air passes through center hole '17 around fuel nozzle 14 and performs the function of creating an initial spray of oxygen for the combustion of the atomized fuel emerging from nozzle 14. A larger blast of air passes through the lower slot- Iike opening 26 and. is directed upwardly by lip 27 to encounter the fuel cone at a point relatively near the fuel nozzle. The . side orifices 29 and 21 deliver 'two high velocity jets of air which 'impinge'upon the fuel cone at a point farther away from the fuel nozzle to support a later stage of combustion. The upper elongated slot 23 discharges a relatively broad sheet-like curtain of air over the flame which supports further combustion and in addition causes the flame 'to be confined. Thus, by means of the air directing device of the invention, air is caused to surround and penetrate the fuel cone and a thorough intermingling of the fuel and air is insured. Moreover, substantially all of the air comes into contact with the burning oil and gases during com bustion so that it is unnecessary to provide an excessive amount of air which will tend to reduce the temperature and efliciency in order to secure clean and complete combustion.

Asis apparent, a gun-type fuel burner equipped with the; air directing device of the invention can be utilized to supply a mixture of fuel and air toany conventional combustion chamber. The principal advantage produced by this invention is that of improved combustion efficiency. Tests have proven that the use of the air directing device of this invention results in a blue fiame within the combustion chamber and combustion products having low smoke numbers and'high carbon dioxide content.

'Thosemodifications and variations which fall within the spirit of the invention and the scope ofthe appended claims are to be considered part of the invention.

We claim: 1. An air directing device for use in fuel burners comprising a plate having a relatively large central orifice through which a substantially conical spray of fuel is delivered to a combustion zone, said plate having an elongated horizontally extending slot-like opening located above said central orifice and means in said plate including a plurality of orifices adjacent said central orifice having their axes disposed at an angle .to the axis of said central orifice for delivering a plurality of forwardly converging streams of air which'irnpinge'upon the said fuel spray.

2. An air directing device forum in fuel burners comprising a plate having .a relatively large central orifice through which .a substantially conical spray of-fuel .is delivered to a combustion zone, said plate having an elongated horizontally extending slot-like opening located above said central orifice through which a stream of airis delivered above said fuel spray, said plate having asecond elongated horizontally extending slotlike opening 10-- cated below said cenual orifice through which a stream of air is supplied for combustion of the fuel, a lip member extending outwardly and upwardly from below said last mentioned opening to direct the air emerging therefrom so that it impinges upon the .said fuel spray, said plate having openings located on opposite .sides of said central orifice and disposed at an angle to the axis thereof for .de; livering a plurality of forwardly converging streams of air which impinge upon the said fuel spray.

3. An air directing device for use in fuel burners comprising a plate having .a relatively large central orifice through which a substantially conical spray of fuel is delivered to .a combustion zone, said plate having an elongated horizontally extending slot-like opening located above said central orifice and axially paralled thereto through which a stream of air is delivered above said fuel spray, a deflector memberlocated above said elongated opening and extending outwardly from the face of said plate and being provided with a downwardly projecting tip, said plate having a second elongated horizontally extending slot-like opening located below said central orifice through which a stream of air is supplied for combustion of'said fuel, a lip member extending outwardly and upwardly from below said last-mentioned opening to direct thelair stream emerging therefrom so that it impinges upon said fuel spray, said plate having openings located on opposite sides of said central orifice and disposed at an angle to the axis thereof to deliver a plurality of forwardly converging streams of air which impinge upon said fuel spray. 7

4. An air directing device for use in fuel burners com prising a plate having a relatively large central orifice through which a substantially conical spray of fuel is delivered to a combustion zone, said plate having an elongated horizontally extending slot-like opening located above said central orifice and axially parallel thereto through which a relatively broad sheet-like stream of air is delivered above said fuel spray, said plate having a second elongated horizontally extending slot-like opening located below said central orifice through which a stream ofairissupplied for combustion of said fuel, a lip membeiextending outwardly and upwardly from below said last-mentioned opening to direct the air emerging there from so that it impinges upon the said fuel spray at a point relatively near the face of said plate, said plate having two openings located on opposite sides of said central orifice and disposed at an angle to the axis thereof to deliver two forwardly converging streams of air which impinge upon the said fuel spray at a point spaced for wardly from the face of said plate. g

5. An air directing device for use in fuel burners com-f prising a plate having a relatively large central orifice through which a substantially conical spray of fuel is delivered to a combustion zone, said plate having an elongated horizontally extending slot-like opem'ng located above said central orifice and axially parallel thereto through which a stream of is delivered above said 'fuel spray, a deflector member located above said elongated opening and extending outwardly from the face of the said plate and being provided with a downwardly projecting tip, said plate having a second elongated hori zontally extending slot-like opening located below said; central orifice through which a stream of air is supplied for the combustion of said fuel, a lip member extending outwardly and upwardly from below said last-mentioned opening to direct the air stream emerging therefrom so that it impinges upon said fuel spray, said platehaving two circular openings located on opposite sides of the said central orifice and axially parallel thereto, a strip member extending transversely across the front face of said plate and removably attached thereto, said strip member having a central orifice matching said central: orifice in said plate, said .strip member having also two orifices disposed on opposite sides of the central orifice and spaced tomatch :thetwo circular side :openingswith-i in said plate, the side orifices within said strip member being disposed at an angle to the axis of the central orifice of said plate, to deliver two forwardly converging streams of air which impinge upon said fuel spray at a point spaced forwardly from the face of said plate, said strip member having also a recess in the inner face thereof extending laterally from the central orifice to the side orifices therein.

6. In combination with a fuel burner having an air blast tube and burner nozzle which delivers a fuel spray, an air directing device comprising a plate which is adapted for mounting over the discharge end of said air blast tube, said plate having a relatively large circular orifice located centrally of said plate in axial alignment with said nozzle, said plate having an elongated horizontally extending slotlike opening located above said central orifice and means within said plate including a plurality of orifices surrounding said central orifice having their axes disposed at an angle to the axis of said central orifice for delivering a plurality of forwardly converging streams of air which impinge upon the said fuel spray.

7. In combination with a fuel burner having an air blast tube and burner nozzle which delivers a fuel spray, an air directing means comprising a plate mounted over the discharge end of said air blast tube, said plate having a relatively large circular orifice located centrally of said plate in axial alignment with said nozzle, said plate having an elongated horizontally extending slot-like opening located above said central orifice through which a stream of air is delivered above said fuel spray, said plate having a second elongated horizontally extending slot-like opening within said plate located below said central orifice through which a stream of air is supplied for combustion of the fuel, a lip member extending outwardly and upwardly from said plate below said last-mentioned opening to direct the air emerging therefrom so that it impinges upon the said fuel spray, said plate having openings located within said plate on opposite sides of said central orifice and disposed at an angle to the axis thereof for delivering a plurality of forwardly converging streams of air which impinge upon the said fuel spray.

8. In combination with a fuel burner having an air last tube and burner nozzle which delivers a fuel spray, an air directing means comprising a plate mounted over the discharge end of said air blast tube, said plate having a relatively large circular orifice located centrally of said plate in axial alignment with said nozzle, said plate having an elongated horizontally extending slot-like opening located above said central orifice and axially parallel thereto through which a stream of air is delivered above said fuel spray, a deflector member located above said elongated opening and extending outwardly from the face of said plate and being provided with a downwardly projecting tip, said plate having a second elongated horizontally extending slot-like opening within said plate located below said central orifice through which a stream air is supplied for combustion of said fuel, a lip member extending outwardly and upwardly from below said last-mentioned opening to direct the air stream emerging therefrom so that it impinges upon the said fuel spray, said plate having openings located said plate on opposite sides of said central orifice and disposed at an angle to the axis thereof to deliver a plurality of forwardly converging streams of air which impinge upon said fuel spray.

9. in combination with a fuel burner having an air blast tube and burner nozzle which delivers a fuel spray, an air directing means comprising a plate mounted over the discharge end of said air blast tube, said plate having a relatively large circular orifice located centrally of said plate in axial alignment with said nozzle, said plate having an elongated horizontally extending slot-like opening within said plate located above said central orifice and axially parallel thereto through which a stream of air is delivered above said fuel spray, a deflector member located above said elongated opening and extending out wardly from the face of the said plate and being provided with a downwardly projecting tip, said plate having a second elongated horizontally extending slot-like opening within said plate located below said central orifice through which a stream of air is supplied for the combustion of said fuel, a lip member extending outwardly and upwardly from said plate below said last-mentioned opening to direct the air stream emerging therefrom so that it impinges upon said fuel spray, said plate having two circular openings located on opposite sides of the said central orifice and axially parallel thereto, a strip member extending transversely across the front face of said plate and removably attached thereto, said strip member having a central orifice matching said central orifice in said plate, said strip member having also two orifices disposed on opposite sides of the central orifice and spaced to match the two circular side openings Within said plate, the side orifices within said strip member being disposed at an angle to the axis of the central orifice of said plate, said strip member having also a recess in the inner face thereof extending laterally fiom the central orifice to the side orifices therein.

References Cited in the file of this patent UNITED STATES PATENTS 1,911,488 Blatter May 30, 1933 1,976,097 Sharp Oct. 9, 1934 2,253,414 Arnold Aug. 19, 1941 2,500,787 Lelgemann Mar. 14, 1950 2,694,444 Oldenkamp Nov. 16, 1954 FOREIGN PATENTS 47,814 Denmark Sept. 25, 1933

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