US3799734A

US3799734A - Combustion device

Info

Publication number: US3799734A
Application number: US00356803A
Authority: US
Inventors: J Bailey
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-05-03
Filing date: 1973-05-03
Publication date: 1974-03-26
Anticipated expiration: 1991-03-26

Abstract

A combustion device having a chamber for passage of the products of combustion therethrough and having a surrounding wall for heat transfer through said wall to external media. The combustion chamber has inlet and outlet means at opposite ends thereof with orifice plates extending transversely of the combustion chamber, which orifice plates have their peripheries secured directly in circumferentially spaced segments to the inner face of the surrounding wall, leaving minute segments between the secured segments for small amounts of combustion particles or gases to leak therethrough into the particles or gases passing through the orifice plates, thereby materially increasing the efficiency of the combustion of the burning gases.

Description

United States Patent [1 1 Bailey [4 1 Mar. 26, 1974 COMBUSTION DEVICE John J. Bailey, 1701 N. Ashland Ave., Chicago, Ill. 60622 [22] Filed: May 3, 1973 [21] Appl. No.: 356,803

[76] Inventor:

5/1967 Reba et a1 431/353 X Primary ExaminerEdward G. Favors Attorney, Agent, or Firm-Burns, Doane, Swecker &

Mathis [5 7] ABSTRACT A combustion device having a chamber for passage of the products of combustion therethrough and having a surrounding wall for heat transfer through said wall to external media. The combustion chamber has inlet and outlet means at opposite ends thereof with orifice plates extending transversely of the combustion chamher, which orifice plates have their peripheries secured directly in circumferentially spaced segments to the inner face of the surrounding wall, leaving minute segments between the secured segments for small amounts of combustion particles or gases to leak therethrough into the particles or gases passing through the orifice plates, thereby materially increasing the efficiency of the combustion of the burning gases.

9 Claims, 3 Drawing Figures SUMMARY OF THE INVENTION This invention relates to improvements in fuel bumers or combustion devices, and more particularly to the type of burner disclosed in US. Pat. No. 2,722,180, Nov. 1, 1955, and in US. Pat. No. 2,907,382, Oct. 6, 1959.

The fuel burner disclosed in the aforesaid patents was provided with a combustion chamber having transverse orifice plates therein spaced along the length of the chamber between the inlet and outlet thereof, with a burner and air supply means at one end and with a surrounding wall for effective heat transfer to a surrounding medium. Each of the orifice plates was secured about its periphery to the inner face of the surrounding 7 wall.

I have found that the securing of the entire periphery of each orifice plate to the inner face of the surrounding wall resulted in a lower combustion efficiency than can be achieved by intermittently securing the periphery of each orifice plate to the surrounding wall.

The object of this invention is to improve the efficiency of the burner and combustion chamber.

I have discovered that a great improvement in efficiency can be obtained by securing the surrounding edge of each orifice plate to the inner face of the wall at circumferentially spaced zones and leaving zones unsecured so as to leave minute passages for leak-by of a small amount of the burning gases which pass around the peripheral edge of each plate into the flow of combustion gases through the orifices thereof. The secured zones can be provided by a segmental row of circumferentially spaced spot welding or tack welding at each of severalcircumferential segments on the periphery of the orifice plate.

BRIEF DESCRIPTION OF DRAWINGS One embodiment of the invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view of a burner and combustion chamber;

FIG. 2 is a detail longitudinal section through a portion of the combustion chamber at one of the orifice plates, illustrating diagrammatically the flow of combustion gases therethrough; and

FIG. 3 is a transverse section through the combustion chamber.

DETAILED DESCRIPTION OF DISCLOSURE Turning now to a detailed description of the drawings, the numeral designates a combustion chamber casing or housing, which may be of circular cross section, as shown, but it is understood that it may be of any shape in cross section without deviating from the spirit of my invention.

The combustion chamber 10 is provided with a plurality of baffle plates 11 spaced longitudinally therein and provided with orifices or restricted apertures 12 substantially centrally disposed within the baffles. These baffle plates are preferably conical with the apex turning downstream. The orifices 12, preferably, should be in longitudinal axial alignment.

An exhaustport 13 is provided at one end of the combustion chamber 10that connects to aflue conduit 14, preferably helical in form, that passes through a 2 fluid tight jacket 15 and extends substantially throughout the length of chamber 15. The conduit 14 has an outlet 16 from the jacket 15 that conducts the burned gases to a suitable stack or chimney. Fluid openings 17 and 18 are provided in the jacket 15, as shown in FIG. 1, for inlet and outlet respectively of. the media to be heated, such as gaseous fluid or air, or a liquid.

A fuel pipe 19 with a nozzle 19', including any desired means for ignition, is located at the inlet end of the combustion chamber 10 and may be of conventional design adapted to operate on either liquid or gaseous fuel for combustion. An aperture plate 20, similar to the baffle plates 11, is provided at the inlet end of chamber 10. The nozzle 19 is located so that the spray pattern of the fuel generally passes through the orifice 21 in plate 20 into the chamber 10.

According to this embodiment of the invention, air is admitted into a nozzle housing 22 by means of a conduit 23. The air flow is provided by any conventional type of air pump, such as a rotary or turbine type blower. The air flow is divided into three parts after entering the housing 22. The flow of the primary air to the burner nozzle 19 is shown at 24. A secondary flow of air at 25 is directed between two cylindrical sleeves 26 and 27 spaced apart by a helical vane 28 that imparts a rotational spin to air flow 25 as it is directed about the nozzle axis. The tertiary air flow 29 passes through annular opening 30 between the plate 20 and sleeve 27 so that this tertiary air provides a wiping action as it flows across the plate 20 and through the orifice 21.

The baffle plates llproduce a turbulent flow of the burning gases by virtue of the fact that they cause the direction of movement thereof to change approximately every time a baffle plate is reached. As the hot burning gases pass the length of the combustion chamber 10, they are forced through the restricted openings or orifices 12. This will cause a change in velocity of the gases in the chamber .10, and again a further turbulence will take place along the baffles 11 as well as on the inside wall of the chamber 10. This process is repeated through each successive baffle 11 until the maximum efficiency of the combustion of the burning gases is obtained and the products of combustion are exhausted through the port 13 and through the helical flue conduit 14, giving up heat to the fluid medium 31 in the jacket 15, thereby utilizing the heat of the combustion for heating that fluid, either air, water or other fluid.

The surrounding wall of the combustion chamber 10 is made of sheet metal with a smooth inner surface. Each of the baffle plates 11 has its periphery shaped to fit the inner wall surface of the combustion chamber 10. This forces the burninggases from the burner nozzle 19" to pass through the orifice l2 ineach of the baffle plates 11 substantially in the manner illustrated by the arrows in FIG. 2. The forced flow of burning gases that is directed through the orifices 12 of the several baffle plates 11 will cause the gases to sweep alongthe inner surfaces of the expansion chamber formed between each adjacent pair of baffle plates and to change direction after passing through the orifices thereof, as also indicated in FIG. 2, until the column of spent gases or products of combustion under this forcedfeed is directed through the outlet 13. The directionaland velocity changes through the orifice 21 of the baffle plate 20 are identical in function to those in the baffle plates 1 l.

Each of the baffle plates 11 is secured in circumferentially spaced segments thereof to the inner face of the surrounding wall of the combustion chamber 10, preferably by segments of tack welding, generally indicated at 32 in FIGS. 2 and 3 or by overlapping segments or other suitable means. Each of these segments of tack welding or otherwise extends only for a small segment of the circumferential length of the baffle plate 11 with gaps of unsecured segments 33 therebetween which, however, are not materially spaced from the inner face of the surrounding wall 10. It has been discovered that this relationship provides a materially increased efficiency of the combustion. It is believed that this relationship in the mounting and securing of the baffie plates to the inner surface of the surrounding wall has two effects.

When the orifice plates 11 are secured at spaced segments 32 to the combustion chamber wall 10, the heat absorbed from the burning gases transfers more slowly through the orifice plates to the combustion chamber wall because of the smaller total combined linear length of the intermediate or spaced areas of tack welding and thus does not provide as much direct conduction surface between the plates and the wall. Therefore, the orifice plates will function at a higher temperature because they do not release heat as quickly as the surrounding wall. Thus, the burning gases are directed or deflected by the higher temperature plate surfaces and thereby continue at a more efficient combustion temperature as they pass through the combustion chamber.

As the turning gases are forced through the axial openings 12 in the baffle plates 11, these gases are de flected around the peripheries of the plates, as shown at 34. If there were no space for some of the gases to leak through at the peripheries of the plates, there would be a suction effect created around the plates which would reduce the flow of the gases out to the periphery of the combustion chamber in each of the expansion chambers provided between a pair of spaced plates and thus slow down the passage of the gases through the combustion chamber. However, the lack of continuous welding around the periphery of each of the plates provides minute leak-by passages through which small amounts of the burning gases at 34 may pass from one expansion chamber to another without passing through the central orifice, thereby permitting the larger mass of the gas flowing through the orifices to continue on in a generally smooth forward flow without curling back upon itself and disrupting its flow pattern.

Thegases thus passing through the unsecured segments 33 of the orifice plates 11 do not function as air for purpose of combustion, but instead are products of combustion or burning gases. This produces a controlled turbulance of the burning gases which provides for maximum combustion efficiency.

While the invention has been illustrated and described in one embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in claims.

I claim:

1. A fuel burner comprising a combustion chamber having a surrounding wall and an inlet at one end a an outlet at the opposite end, an intermediate plate therein spaced from the inlet and outlet, said plate extending transversely to the surrounding wall of the combustion chamber and defining with said surrounding wall enlarged expansion chambers, said plate having a substantially central orifice therein and having a surrounding edge substantially abutting against the surrounding wall of the combustion chamber, and means for securing said surrounding edge of the plate to the inner face of the surrounding wall along circumferentially spaced segments of the surrounding edge.

2. A fuel burner according to claim 1, wherein the securing means comprises welding extending along circumferential segments of the surrounding edge and spaced from adjacent segments of the surrounding edge.

3. A fuel burner according to claim 1, wherein a plurality of intermediate plates are provided spaced from each other along the length of the combustion chamber, each having a substantially central opening and with a surrounding edge substantially abutting against the surrounding wall of the combustion chamber and secured thereto along spaced segments.

4. A fuel burner according to claim 3, wherein the intermediate plates are frusto-conical and the central orifices are restricted and aligned.

5. A fuel burner according to claim 1, wherein the spaces between the securing means provide minute leak-by passages for small amounts of combustion gases to pass from one expansion chamber to the next.

6. A fuel burner according to claim 1, including burner means at the inlet end of the combustion chamber having means for supplying air and fuel thereto and whereby burning gases pass through the orifice in the transverse plate from one expansion chamber to another, the spaces between the securing means providing minute leak-by passages for small amounts of combustion gases to pass from one expansion chamber to the next.

7. A fuel burner comprising a combustion chamber having a surrounding wall and having an inlet at one end and an outlet at the opposite end, a plurality of intermediate plates therein spaced from the inlet and outlet and from each other, said plates extending transversely to the surrounding wall and defining with said surrounding wall enlarged expansion chambers, each of said plates having a substantially central orifice therein and having a surrounding edge extending along the inner surface of the surrounding wall of the combustion chamber, means for securing the surrounding edge of each plate along spaced segments in substantially airtight relation and with the spaces between the segments unsecured and providing substantially minute leak-by passages for small amounts of combustion gases to pass from one expansion chamber to another.

8. A fuel burner according to claim 7, including burner means at the inlet end of the combustion chamber having means for supplying air and fuel thereto under pressure whereby burning gases at high velocity pass through the first orifice into the first expansion chamber, are reduced in pressure and increased in velocity and changed in direction againto pass out through the next orifice plate with consequent exit velocity, the small amounts of gases passing through the leak-by passages being directed into the burning gases after passage through the orifice in the plate.

9. A fuel burner according to claim 7, wherein the plates are frusto-conical and have constricted orifices in axial alignment.

Claims

8. A fuel burner according to claim 7, including burner means at the inlet end of the combustion chamber having means for supplying air and fuel thereto under pressure whereby burning gases at high velocity pass through the first orifice into the first expansion chamber, are reduced in pressure and increased in velocity and changed in direction again to pass out through the next orifice plate with consequent exit velocity, the small amounts of gases passing through the leak-by passages being directed into the burning gases after passage through the orifice in the plate.