US2329272A - Combustion chamber - Google Patents

Description

COMBUSTION CHAMBER n Clttorpeg Sept. 14, 1943. E. w. JOROLEMON coMBUsTIoN CHAMBER Z'Sheets-Sheet 2 Filed July l, 1940 Patented sept. 14, 1943 COMBUSTION CHAMBER Earl W. Jorolemon, Rochester, N. Y., assignor to General Motors Corporation, Detroit, Mich., aA corporation oi' Delaware vApplication July 1, 1940, Serial No. 343,336

(Cl. 158-4). t

Claims.

'I'his invention relates generally tov improvements in the construction of water heaters which vide a universal type of water heater which is v highly eillcient in operation and relatively low in cost and which is especially suitable for either large domestic hot water supply systems or small steam or hot Water heating systems.

One of the principal features ofthey invention is the construction of the combustion chamber, which is preferably of relatively thin sheet metal, for use with a conventional gun or pressure atomizing type of burner, -to provide a 'relatively confined space to promote combustion and afford an efficient radiant heat transfer to the heatabsorbing walls of the water heater. I

A further feature vof the invention resides in the provision of a vertical sheet metal target and baiile plate within the combustion chamber between a horizontal side opening for the burner tube and an outlet opening adjacent the bottom of the combustion chamber.

A further feature of the invention is the provision of a bafile between the combustion chamber and outlet flue which causes a more intimate contact between the combustion gases and the heatabsorbing walls of the water heater.

Other objects and features of the invention, such asthe location and mounting of the combustion chamber and the burner in the water heater and the novel arrangement, construction and combination of parts together with the advantages thereof, will be apparent from, or specifically pointed out in the following description and accompanying drawings in which:

Fig. 1 is a vertical sectional view, with parts in elevation, of a water heater or `boiler embodying Fig. 5 is 'an enlarged fragmentary perspective view of a modification of the securing means for and supported and secured as by means such as brackets III, on a base ring I2. The water tank is preferably enclosed by the casing or jacket I4 and the space between the tank and jacket is preferably filled with insulating material such as rock-wool which may be blown under vpressure into this space.

Within the outer shell 2 of the water tank is an inner combustion shell I6 consisting of the vertical cylindrical portion I8 andthe upper end 2li and lower end 22 welded thereto. This inner shell I6 is spaced from the outer shell both at the sides and top and bottom to form therewith a I `furthermore provide or deilne the combustion space 24.

The'upper ends B and 20 of shells 2 and I6, respectively, are provided with vertically aligned.

openings to receive `the flue pipe 26 which is welded to such ends and serves to connect the combustion space 24 to the stack or smoke pipe 28. Adjacent its lower end the yshell 2 is provided with a drain valve 30 and a. water return or inlet 32 and the upper end 6 of shell 2 is provided with the hot water or steam outlet pipe 34.

A water temperature control unit 3B and stack mounted burner control unit 38, may be located as shown in Fig. 1. Such controls do not comprise a part of my invention and may be of any conventional type. It should also be understood that, depending upon the d esired function and operation of the complete unit as either a domestic water heater or asteam or hot water boiler,

lcertain other conventional controls would be employed such as a watertemperature limit control, a steam pressure control and a pressure relief valve, together with any desired indicating gages such as a. pressure gage and water level column.

42 which is welded to theshells and serves to support the burner and combustion chamber and provide an opening or passage into the combustion shell I6. It will be here noted that except for the space occupied by the sleeve 42 and the flue pipe 26, the combustion shell I6 is entirely surrounded by the water space between the shell I6 and tank shell 2 and a portion atleast of the flue pipe `26 is also surrounded by the water space to thereby provide an emcient heatexchange. A

The outer end of the sleeve 42 is adapted to be substantially entirely closed by the burner mounting plate 44 secured to the sleeve asby hook bolts 46 extending around therinner end of the sleeve as shown in detail in Fig. 3 and a suitable gasket .or packing 48 may be provided between the plate 44 and the outer end of sleeve 42. The mounting plate 44 is provided with a suitable opening to receive'the burner tube 50 oi! the oil burner indicated generally at 52 which may be secured to such plate'as by bolts 54. The oil burner 52 has not been shown in detail but it will be understood that the same is generally of the pressure atomizing type in which liquid fuel is discharged under pressure through an atomlzing nozzle inthe burner tube 50 and adapted to mix with air supplied through such tube to form the combustible mixture.

The fuel mixture issuing from the,b'urner nozzle and tube 50is projected into the sheet metal combustion chamber indicated generally at 56 in which practically complete combustion occurs before the combustion gases escape into the combustion shell- I6. The chamber 66 is made of relatively thin sheet metal of' such material as certain chrome steel alloys which have been found to withstand the high temperatures encountered and attain a maximum temperature and become practically incandescent almost immediately upon starting the burner to transmit radiant heat directly to the walls of the combustion shell `I6 from which the heat is efficiently absorbed by the water surrounding such shell.

' As shown generally in Fig. 1 and in detail in Fig. 4, the combustion chamber 56 may be readily constructed with a cylindrical body portion 58 and substantially conical upper and lower end portions 60 and 62, respectively. The lower end portion 62 is preferably welded to the body portion 58 and such parts may be inserted as a unit into the combustion space 24 through the opening. provided by the sleeve 42. Such opening is not sufliciently large, however, to permit of the insertion of the complete combustion chamber and to facilitate the assembly thereof within the combustion space, the upper end portion 60 is provided with spaced openings or slots 64 adapt# ed to receive the upwardly extending clips 66 on portion 58 which may be bent over the periphery of the upper end portion to secure the same in position. g

The cylindrical body portion 58 of the combustion chamber is provided at one side with a circular inlet opening and with an external cylindrical sleeve 68 secured thereto at such opening which is adapted to fit around the burner tube 50 and provided with spaced projecting tongues 'l0 which are adapted to be bent outwardly as shown in Fig. 2 and clamped with' a suitable gasket 12 between a flange 14 on the burner tube 58 and an offset portion of the mounting plate 44. As shown in Fig. 4, thetongues 'l0 may be formed as extensions on angle brackets which connect the sleeve 68 to the combustion chamber portion 58, or as shown in Fig. 5, the tongues indicated at I6 may be'separately formed and welded to the sleeve 68 independently of the anglebrackets 18 which connect thesleeve to the chamber portion 58. The combustion chamber 56 is adapted to be primarily supported by this connection to the mounting plate 44 but to properly position the same within the combustion shell I6 and also support the same to .some extent, the cylindrical portion I8 of the shell may have welded thereto spaced inwardly extending brackets such as indicated in Fig. 1 at 88 which are inclined or have an inclined surface to engage the conical lower end portion 62 of the combustion chamber.

Both the upper and lower end portions of the combustion chamber 56 are closed except for a relatively restricted outlet opening indicated at 82 in Fig. 1 in the lower end portion 62 adjacent the side opposite the burner inlet opening. As shown in Figs. 1 and 4, a transverse, sheet metal target and baille vplate 84 is provided within the combustion chamber intermediate the inlet and outlet openings and preferably closely adjacent the latter. This plate 84 extends vertically into the path of some of the fuel mixture from the burner and is preferably made of special heatresistingl chrome steel to withstand the intense heat to which the same is subjected. To stiilen the plate against permanent distortion it is formed with a top flange 86 and to permit repeated expansion and contraction on heating and cooling without buckling, it is preferably secured The combustion chamber 56 provides a relatively confined space in which practically complete combustion occurs before the combustion gases or products of combustion escape through.

the relatively restricted outlet 82 into the combustion space 24, the relative dimensions of the chamber 56, the location and dimensions of the target and baille plate 84" therein, and the dimensions of the outlet 82 be such that this desirable result is attained without any appreciable resistance to the escape of the combustion gases or the development of any appreciable combustion pressure within the chamber 56. 1

The plate 84 has been referred to heretofore as a target and baille plate. As will be apparent, such plate is positioned partly in the path of some of the fuel mixture from the burner to function as a target and not only thereby provide for increased turbulence of the burning mixture but also attain an extremely high temperature and assist in the vaporization of any unatomized oil from the burner nozzle. The plate 84 also functions as a baille to prevent' the fuel mixture or burner flame from passing directly to the outlet 82 and by Vthus increasing the length of flame travel within the chamber 56, it tends to retain the burner llame in the chamber 56 until complete combustion of the fuel mixture therein. In actual practice it has been found that very little, if any, ilameever issues from the outlet 82 and the entire chamber 56- reaches a state of incandescence within a period of less than two minutes .space 24 around the combustion chamber `56 to However, it is preferable that the flue pipe 26 where further heat 'is extracted v tially dome shaped baille 90 is preferably suspended as by a transverse rod 92 directly beneath the lower end of thel flue pipe 26. Asiwill be readily apparent from 'the showing thereof in Fig. 1, thisbailie 90 intercepts the direct passage of combustion gases from the centralportion of the combustion space into the flue pipe and permits the gases to enter the flue pipe only after passing around the baille through the relatively restricted space between the baille and the adjacent side and upper walls of the combustion shell I6. As is indicated in Fig. 1 the baille 90 pref' erably co'nsists of a circular head 94 and depending cylindrical skirt 96 with an open bottom to thereby cause eddy currents in the combustion gases to reduce the velocity thereof and also absorb some heat from the gases and radiate the same to the adjacent heat absorbing surfaces of the shell I6.

It has been found desirable under certain conditions of combustion to` admit a small quantity of secondary air to the combustionspa'ce24 to prevent a condition known in the artas pufilng For this purpose the burner mounting plate 44 is provided with an inspection opening adapted to be normally substantially closed by a hinged door 98 which is spaced however from the plate 4 4 as shown in Fig. 1 at |00 to provide for communication between the combustion space 24 and the atmosphere. As will be understood this inspection door 98 is provided to permitexamination, when desired, of combustion conditionswithin the combustion space 24 and'the character of the combustion gases therein.

It will be apparent that many changes and modifications may be made in the detailed construction and arrangement of parts within the scope of my invention and that -many advantages of the several novel features thereof in addition to those mentioned herein will be obvious to those skilled in the art.

I claim:

1.l In a heating apparatus, a heat exchange unit including lheat absorbing and transmitting walls defining a hollowlcombustion space, a combustion chamberwithin said space having top, bottom and side walls, said combustion chamber having an inlet opening in the sidewall thereof at one side of said chamber andan outlet opening in the bottom wall adjacent the side opposite said inlet opening, a liquid fuel burner lassociated with said inlet opening. and a bame member in.

said combustion chamber between said inlet and outlet openings.

2. In a heating apparatus, a heat exchange unit including heat absorbing and transmitting walls defining a hollow combustion space, a combustion chamber within said space having top, bottom and side walls, said combustion chamber having an inlet opening in the side wall thereof at one side of said chamber and an outlet opening in the bottom wall adjacent the side opposite said inlet opening, a liquid fuel burner associated with said inlet opening, and a baiile member in said combustion chamber between said inlet and outlet openings having a -portion thereof located in the direct path of a portion of the fuel mixture from said burner.

3. In. a heating apparatus, a heat exchange unit including heat absorbing and transmitting walls deilning a hollow combustion space, a combustion chamber within lsaid space having top, bottom and side walls, said combustion chamber having an inlet opening in the side wall thereof at one side of said chamber and an outlet opening in the bottom wall adjacent the side opposite said inlet opening, a liquid fuel burner associated with said inlet opening, a baille member extending transversely within said combustion cham ber between said inlet and outlet openings, and means to rigidly secure said baille member adjacent its ends to said combustion chamber adapted toprovide for expansion and contraction of said member intermediate the ends thereof on changes of temperature.

4. In a heating apparatus, a heat exchange unit including heat absorbing and transmitting walls defining a hollow combustion space, a combustion chamber within said space having top, bottom and side walls, said combustion chamber having an inlet opening in the side wall thereof at one side of said chamber and an outlet opening in the bottom wall adjacent the side opposite said inlet opening, a liquid fuel burner associated with said inlet opening, and abaille member in said chamber between said inlet and outlet openings and providing 'compartments therein which communlcate only adjacent the upper part of said chamber.

5. In a heating apparatus, a heat exchange unit including heat absorbing and transmitting walls defining a hollow combustion space, and a combustion chamber within said space comprising a substantially frusta-conical closed upper end portion, an intermediate substantially cylindrical portion having an inlet opening in one side adapted to receive a burner tube, and a substantially frusto-conical lower end portion having an outlet opening into said combustion space adjacent vthe side opposite said inlet opening.

l EARL W. JOROLEMON.

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