US2420598A

US2420598A - Liquid fuel burner

Info

Publication number: US2420598A
Application number: US620336A
Authority: US
Inventors: James H Jackson
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-10-04
Filing date: 1945-10-04
Publication date: 1947-05-13
Anticipated expiration: 1964-05-13

Description

May 13, 1947. J. H. JACKSON 2,420,598

LIQUID FUEL BURNER Filed Oct. 4, 1945 2 Sheets-Sheet l May 13, 1.947. J. H. JACKSON 2,420,593

LIQUID FUEL BURNER Filed Oct. 4, 1945 2 Sheets-Sheet 2 vg-9.5 5 @MMYLMZ L Patented May 13, 1947 UNITED STATES PATENT sies 10 Claims.

This invention relates to liquid fuel burning apparatus, and in particular to fuel oil burners.

One object of this invention is to provide a liquid fuel burner having an improved arrangement of air ducts whereby a superior distribution of the air is brought about, thereby bringing about better combustion.

Another object is to provide a liquid fuel burner having a single air conduit divided into two ducts by a longitudinal vane or partition so arranged as to admit air on opposite sides of the air mixing chamber and thereby bring about improved air distribution and superior combustion.

Another object is to provide a liquid fuel burner as set forthl in the preceding objects wherein the intake end of the air conduit is substantially aligned with the fuel spray nozzle, thereby facilitating installation and mounting.

Another object ls to provide a liquid fuel burner having an improved hearth or retort wherein a flat zone is provided centrally thereof so that the air emerging from the blast ring or central aperture is permitted to move outwardly for a short distance prior to encountering the more strongly curved side walls of the retort, thereby giving improved combustion andproviding a. layer of air between the inner walls of the retort and the fuel spray so as to maintain the lower portion of the hearth relatively cool and permit the use of a metallic hearth or retort.

Another object is to provide a liquid fuel burner with a bowl-shaped hearth or retort having an annular flange surrounding it near the top thereof, thereby strengthening the retort and serving as a girdle to protect lt against cracking due to rapid expansion under rapidly rising tempera tures.

Another object is to provide a liquid fuel burner having a bowl-shaped hearth or retort preferably of metallic material, and having an insulating coating on the outside thereof so as to prevent undue loss of heat by conduction and radiation through the retort.

Another object is to provide an improved air supply device for fuel burners consisting of a single air supply conduit curving around the air mixing chamber and divided into two ducts by a longitudinal vane or partition so arranged as to admit air on opposite sldesof the air-mixing chamber and thereby bring about improved air distribution and superior combustion.

Another object is to provide a fuel burner having an improved auxiliary air tube associated with the fuel supply nozzle and having improved means for adjusting the ilow of air therethrough.

Other objects and advantages will become apparent during the course of the following description of the accompanying drawings, wherein:

Figure 1 is a top plan view of a liquid fuel burner according to the preferred form of the invention, with the top partially broken away to disclose portions of the interior;

Figure 2 is a longitudinal section through the liquid fuel burner of Figure 1, taken along the broken line 2--2 therein;

Figure 3 is a. cross-section through the airmixing chamber taken along the line 3--3 in Figure 1;

Figure .4 is a cross-section through the air lintake conduit, taken along the line 4-4 in Fig-i `ure 2: i

Figure 5 is a cross-section through the auxillary air tube taken along the line 5-5 in Figure 2; and 4 Figure 6 is a top plan view of av modified form of liquid fuel burner with thetop partially broken away to disclose a portion of the interior.

Referring to the drawings in detail, Figure 1 shows a preferred form of the liquid fuel burner of this invention as including a casing l0 having an air supply conduit il with an intake portion it Whose axis is substantially aligned with a liquid fuel spray nozzle i3. The air supply con duit l l is provided with a central vane or parti tion it (Figure 4) dividing it into two ducts l5 and i6. The end of the partition I4 terminates in an inwardly bent portion Il' serving as an in wardly-directed baille and curved to prevent direct collision between the air stream entering the air-mixing chamber iii through the duct l and the air stream entering through, the duet l5, and bring about a smooth blending thereof. The bent portion Il also provides a full width oi the air duct l5 at its discharge opening le and prevents constriction thereof. IThe casing I El is provided with a partition 2! forming in effect a continuation of the wall 2 of the conduit l l and having. a bent portion 2i? serving as an inwardlydirected baffle in a. manner similar to the bent portion I1 on the end of the partition I4. The bent portion 22 likewise serves to prevent, direct collision between the yairstreams and brings about a smooth blending thereof. The intake end I2 of the conduit II is provided with an internal rib 23 to serve as an abutment for a pipe telescoped into the vestibule 24 thereof and conveying air from the blower of the power plant (not shown). The intake portion I2 is also provided with dampers 25 and 26 within the ducts I5 and I6 and secured to bolts 21 and 28 respectively. The bolts 21 and 28 are provided with spiral springs 29 for urging the dampers 25 and V2li toward their open positions. Adjusting

thumb screws

30 and 3| for the dampers 25 and 26 are threaded through the side walls of the casing II (Figure 1), and engage the dampers 25 and 26 respectively. By turning the thumb screws 38 and 3I inwardly, the dampers 25 and 26 are caused to move in directions tending to close the ducts I and I6, and this adjustment can be xed by means of lock nuts 32. By adjusting the thumb screws 30 and 3i, and consequently the dampers 25 and 26, the air entering the vestibule 24 is proportioned between the ducts I5 and I6 in any desired amount, thereby controlling the relative amounts of air entering the air mixing chamber I8 through the discharge openings I9 and 33 of the ducts I5 and I6 respectively, and the air-mixing chamber I8 is thereby supplied with streams of air from diametrically opposite locations.

The fuel spray nozzle I3 is mounted substantially centrally in the air-mixing chamber I8 and has a spray head 34 threaded into the upper end of a fuel supply stem 35, the lower end of which (Figure 3) is threaded as at 36 and passed through a bore 31 in the bottom wall 38 of the casing I0. Nuts 39 and 40 secured on opposite sides of the bottom wall 38 hold the stem 35 rigidly in position. The stem 35 at its lower end is internally threaded to receive the threaded end 4I 0f an elbow 42 having a threaded union 43 connecting it to a liquid fuel supply pipe 44 (Figure 2). Surrounding the stem 35 and spaced from it by the spider-like centering member 45 (Figure'l) is an auxiliary air tube 46 having its upper end immediately below the level of the spray head 34 and its lower end resting upon the bottom wall 38. The lower portion of the auxiliary air tube 46 is provided with ports 41 distributed around the periphery thereof and cooperating with an air adjusting sleeve 48 having similar ports 49 therein. A set screw 50 threaded into a boss 5I on the air adjusting sleeve 48 provides for an adjustment of the air passing through the

cooperating ports

41 and 49. The sleeve 48, when rotated to a, position where the air passages provided by the

cooperating ports

41 and 49 are of suitable width, is locked in position by tightening the set screw 50.

The bottom wall 38 is provided with bosses 52 on opposite sides of the bore 31, these being internally threaded as at 53 to receive the threaded ends 54 of ignition plugs 55 having insulators 56 and terminals 51 attached to central electrodes 58 passing into the air mixing chamber I8 through insulating tubes 59. The electrodes 58 are bent at right angles so that their ends 66 form a spark gap (Figure l). To the terminals 51 are connected wire cables 6I which pass through insulating tubes 62 (Figure 2) mounted in bores 63 in a downwardly extending bracket 64 forming a part of the casing IU. The latter is supported upon leveling studs 65 (Figures 2 and 4) threaded into the bores 66 in the casing IIJ and secured thereto by the lock nuts 61. Threaded upon the lower ends of the studs 65 are conical supports 68 locked in position by the lock nuts 69. The supports 68 may thus be moved upwardly or downwardly upon the studs 65 to level the apparatus and to adjust it to irregularities in the floor, grates or other portion of the furnace upon which the device rests.

The top of the casing I0 is provided with a corneal flange 10 providing a circular outlet 1I around the spray nozzle I3. Resting' upon the flange 10 is a conical adapter ring 12 having a stepped portion 13 of approximately the same thickness as the flange 1I! so that the inner surfaces of the flange 10 and the adapter 12 form a. substantially continuous cone. Resting upon the upper annular shoulder 14 of the adapter 12 is a bowl-shaped hearth or retort 15 having a relatively iiat or shallowly curved annular zone 18 extending approximately to the boundary circle 11 from the edge circle 16 of the aperture in the center of the hearth 15. Beyond the boundary circle 11 of the iiat zone 16, the hearth 15 is provided with a more strongly curved side wall 19.

The hearth 15 near its upper edge 80 is provided with an integral annular flange 8I. The latter serves as a strengthening member or girdle to prevent the hearth 15 from cracking under the high and uneven temperatures generated by the combustion within the hearth 15. The annular flange 8I also vserves as a support for the struc- .ture connecting the hearth 15 to the side walls of the furnace or rebox in which the apparatus is installed. The outer wall 82 of the hearth 15 is surrounded by an insulating layer 83 of asbestos or other fire resisting material. The insulating layer 83 prevents the escape and loss of heat by conduction through the hearth 15, thereby conserving fuel.

The modification shown in Figure 6 is generally similar to the preferred form shown in Figure 1 except that the intake portion II2 of the air supply conduit'l II is offset relatively to the spray nozzle II3, so that the air duct IIS is substantially straight and the air duct I I5 is approximately in the form of a letter J. In the principal form of the invention (Figure 1), the air duct I5 is approximately in the form of a question mark, (2), due to the substantial alignment of the lntake portion I2 with the spray nozzle I3. The remaining features of the modification of Figure 6 are substantially the same as those of the form shown in Figure 1 and are similarly designated by reference numerals.

In the operation of the invention, the vestibule 24 is connected to the conduit from the blower associated with the usual power plant (not shown) and a stream of air supplied thereto. The air enters the vestibule 24 and is divided by the partition or vane I4 into two streams. One stream passes through the duct I6 directly into the air mixing chamber by way of the discharge opening 33, whereas the other stream passes through the air duct I5 along a path shaped substantially like a question mark or sickle and enters the air mixing chamber I8 through the intake opening I9 on the opposite side thereof. The

end portions I1 and 22 serve as bailles to prevent the two air streams from colliding abruptly and causes them to blend evenly so as to eliminate dead air spots and insure even combustion in the hearth 15.

The liquid fuel such as fuel oil, is supplied through the pipe IIII to the spray nozzle I3 and ignited by a spark passing between the electrede ends 80 (Figure 1). The adjusting ring IIB is turned relatively to the auxiliary air tube 46 so that a proper amount of air passes through the

ports

41 and 49. Meanwhile, the proportionate amounts of air passing through the ducts I 5 and I6 have been adjusted by changing the position of the dampers 25 and 26 by means of the thumb screws 3|] and 3| (Figure 1) so that the correct air mixture is obtained in the hearth without dead air spots or areas. The air passing upward from the outlet 'II throughthe circle 3d shoots outward over the iiat zone 5E before encountering the curved inner wall i9 of the hearth 15, thereby providing a, cushion of air in the vicinity of the zone 'I6 and lower portions of the hearth l5. By this means, combustion takes place largely in the upper portions of the hearth 'l5 so that the lower portions thereof are relatively cool. This construction enables a metallic hearth to be employed, for example cast ironfthereby eliminating the fragility of hearths of refractory materials, such as re clay. The latter are diilicult to ship without breakage and also frequently fail during use, ythe resulting cracks admitting air and interfering with satisfactory combustion.

While I have shown and described my invention in detail, it is to be understood that the same is to be limited only by the appended claims, for many changes may be made Without departing from the spirit and scope of my invention.

What I claim is:

1. In a liquid fuel burner, a casing having therein an air chamber with an outlet, a. liquid fuel spray nozzle mounted in said chamber and directed toward the outlet thereof, an air supply conduit connected to said chamber, said conduit having an internal longitudinal partition therein dividing said conduit into outer and inner air supply ducts, said ducts discharging into said chamber at locations remote from =each other and on opposite sides of said outlet and means in said conduit for constricting the flow` of air through one of said ducts whereby to proportion the air passing through said ducts into said chamber.

2. In a liquid fuel burner, a casing having therein an air chamber with an outlet, a liquid fuel spray nozzle mounted in said chamber and directed toward the' outlet thereof, an air supply conduit connected to said chamber, said conduit having an internal longitudinal partition therein dividing said conduit ,into outer and inner air supply ducts, one of said ducts extending around said chamber and said ducts discharging into said chamber at locations remote from each other and on opposite sides of said outlet and means in said conduit for ccnstricting the flow of air through one of said ducts whereby to proportion the air passing through said ducts into said chamber.

3. In a liquid fuel burner, a casing having therein an air chamber with an outlet, a liquid fuel spray nozzle mounted in said chamber and directed toward the outlet thereof, an air supply conduit connected to said chamber, said conduit having an internal longitudinal partition therein dividing said conduit into outer and inner air supply ducts, said ducts discharging into said chamber at locations remote from each other and on opposite sides of said outlet, and a damper in one of said air ducts arranged to constrict the flow of air therethrough for proportioning the distribution. of the air between said ducts.

' sectional area thereof whereby to vary the proportionate amounts of ducts to said chamber.

5. In a liquid fuel burner, a casing having therein an air chamber with an outlet, a liquid fuel spray nozzle mounted in4 said chamber and directed toward the outlet thereof, an air supply conduit connected to said chamber, said conduit having an internal `longitudinal partition therein dividing said conduit into outer and inner airl supply ducts, said ducts discharging into said chamber at locations remote from each other and on opposite sides of said outlet, and an inwardly-directed baille at the end of said parti tion whereby to prevent direct collision between and evenly blend the air streams discharged from said outer and inner ducts into said chamber.

6. In a liquid fuel burner, a casing having therein an air chamber with an outlet, a liquid fuel spray nozzle mounted in said chamber and directed toward the outlet thereof, an air supply conduit connected to said chamber, said conduit having an internal longitudinal partition therein air distributed by said ldividing said conduit into outer and inner air supply ducts, said ducts discharging into said chamber at locations remote from each other and on opposite sides of said outlet, and `an inwardly-directed baille at the end of said partition and a second inwardly-directed baille at the location of entry of said inner air duct into said chamber whereby to prevent direct collision between and evenly blend the air streams discharged from said outer and inner ducts into said chamber.

7. In a liquid fuel burner, a casing having therein an air chamber with an outlet, a liquid fuel spray nozzle mounted in said chamber and directed toward the outlet thereof, and an air 4 supply conduit assembly connected to said chamber, said conduit assembly having a plurality of air supply ducts discharging into said chamber at remotely separated locations on opposite sides of said outlet, one of said ducts being approxi mately sickle-shaped and partially encircling said chamber.

8. In a liquid fuel burner, a casing having therein an air chamber with an outlet, a liquid fuel spray nozzle mounted in said chamber and directed toward the outlet thereof, an air supply conduit assembly connected to said chamber, said conduit assembly having a. plurality of air supply ducts discharging into said chamber at remotely separated locations on opposite sides of said outlet, one of said ducts being approxiu mately sickle-shaped and partially encircling said chamber, and air proportioning mechanism extending into said ducts for varying the proportionate amounts or air distributed by said ducts to said chamber.

9. An air supply casing for fuel burners com-a prising a housing having therein an air chamber with an outlet, and an air supply conduit connected to said chamber, said conduit having an internal longitudinal partition therein dividing asesores said conduit into outer and inner supply ducts, one of said ducts partially encircling said chamber and said ducts discharging into said chamber at locations remote from and on opposite sides of said outlet.

l0. An, air supply casing for fuel burners comprising a housing having therein an air chamber with an outlet, an air supply conduit connected to said chamber, said conduit having an internal longitudinal partition therein dividing said conduit into outer and inner supply ducts, one of saisi. ducts partially encircling said chamber and said ducts discharging into said chamber at locations remote from and on opposite sides of said outlet, and valve means in said conduit arranged to vary the cross-sectional area of each duct for proportionately distributing the air supplied thereto between said ducts.

JAMES H. JACKSON.

REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Ogilvy May 15, 1928 Fletcher June 19, 1928 Sundstrand Feb. 18, 1930 Jackson Nov. 28, 1939 Jackson Jan. 13, 1942 Donley et al Dec. 30, 1930 Ewing May 4, 1926 Meyers Feb. 5, 1924 Tyrrell May 20, 1924 White Mar. 2, 1915 Reid June 7, 1921 Kerrick June 2, 1942 Robinson Oct. 30, 1888 Udesen Sept. 1, 1936 Couch Mar. 31, 1925 Ross Dec. 1, 1936