US2387600A

US2387600A - Combustion apparatus

Info

Publication number: US2387600A
Application number: US435647A
Authority: US
Inventors: Donald J Mosshart
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1942-03-21
Filing date: 1942-03-21
Publication date: 1945-10-23
Anticipated expiration: 1962-10-23

Description

GOMBUSTION APPARATUS Filed. March 21, 1942 2 Sheets-Sheet l WITNESSES:

ATTORNEY Douma' J. Mossunm Oct- 23, 1945- u D. .LMo'ssHRT 2,387,600

COMBUSTION APPARATUS Filed March 2l, 1942 2 Sheets-Sheet 2 mvENToR DoNnLD J. MossHnnT.

BY OWPDLM.;

I ArroRNEY Patented Oct. 23, 1945 S PATENT N y.artistaN `OFFIGIE COMBUSTION APPARATUS Donald J. Mosshart, Ardmore, Pa., assignor to) u Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 21, 1942, Serial No. 435,647 claims.A ,(cl. 11o-3s) `'I'his invention relates to furnaces, more pare ticularlyto those `of the stoker-red type, and has for an object to provide novel and improved apparatus of this character.

A further object of theinvention is to provide a ASpreader-fed Stoker wherein' fuel is deposited on a central portion of the fuel-supporting grate surface, where itis partially coked and ignited and then `is fed laterally in opposite directions over side rportions of the grate surface where it is consumed. M 4

, Another object ofthe invention is to provide a progressive-feed grate structure wherein a plurality of bars ofinverted-V configuration extend transversely of the Stoker inside by side relation, a number'of thefbars being stationary, and the remainderbeing reciprocatory and interspersed among the stationary bars.' y

4 Yet another object of the invention'is the provision, in a spreaderefed'progressive feed stocker,

or pressure responsive means for maintaining a predetermined ratio between rate of feed of fuel tothe grateand rate of flow of air to the fuelfed portion of the grate.

. These and other objects are 4effected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of .this application, in which:

g Fig. l is a' longitudinal sectional View taken along the line I-I of Fig. 3, looking in the direction of the arrows; t

Fig.' 2 is a horizontal sectional view, taken along the line II-II of Fig. 1, looking in the direction of the arrows;

Fig. 3` is a transverse sectional view taken along the line III--III of Fig. 2, looking in the direction ofthe arrows; 'A ili'ig.' 4 is a view in perspective of one ofthe movinggrate bars;'and, 1 l Fig.`5 is a side elevational view of one of the stationary grate bars. Referring now to the drawings more in detail, there is shown, at l0, a furnace comprising front andire'ar walls Il and l2, respectively, and side wallsV I3. Positioned within the lower portion of the furnace' l0 is a s'toker I4, comprised'by a row of :alternate moving and stationary grate bars I5 and IE, respectively.

^ A plurality of lwall members 20, together with structural steel members 2| and 22, carriedv thereby, extend lfrom front to rear ofthe fur.- nace and constitute supports for theY row of grate bars.

`The moving bars I5` are provided at their lower sideswith supporting surfaces adapted to slidably engage the upper surfaces of the supporting mem-` bers 2| and 22, the stationary bars I6 also having flat supporting surfaces at their under sides for similar engagement with the supporting members.

In order to impart transverse reciprocatory motion to the moving bars l5, the latter are each provided with a depending yoke member 24 adapted to receive a pin 25projecting upwardly from a drive shaft 26, the latter extending longitudinally of the row of grate bars from front to rear of the furnace, the forward end of the shaft 26 projecting forwardly through the front wall Il of the furnace and being equipped with suitable linkage 21 through which oscillatory motion may be imparted thereto by suitable means,-

not illustrated.

In order to prevent any transverse reciprocatory motion of the stationary bars I6, the latter are provided with a plurality of depending

lugs

29 and 30 adapted to engage laterally against the sides of the top flanges of the supporting members 2l and 22.

A desirable feature of the grate bar construction just described is that both types of bars, that is, reciprocatory and stationary, may 'be removed and replaced by a simple vertical movement and without the disengagement of any fastening means, such as bolts, clamps, etc.

In 'the construction herein illustrated, both moving and stationary barsare shown as beineJr ofY composite constructionfeach -bar comprising a pair of identical bars joined together rigidly by suitable means,'such as the bolts 32. to provide forthe desired ow of air between the adjacent grate bars, the side surfaces of the barsv It will be apparent from consideration of Fig. 3

that the supporting members 20, 2| and 22 serve the added function of dividing the space beneath the row of grate bars into a central plenum chamberv35 and a pair of side plenum chambers `36. A plurality of

ducts

38, 39 and 40 serve to conduct air under `pressure to the plenum chambers from a suitable source, for example, the blower 4l.

In order to control the supply of air to thecentrai-plenum chamber 35, there is provided in the duct 38 a metering orice 42 followed by a damper 43. kPressure-responsive apparatus, at 44, provides for variation `in the flow of air ,to the chamber l35 In order in direct proportion to variations in the quantity of fuel fed to the grate, as will be more fully explained hereinafter. Coal from the hopper body 45 is fed, by means of a plurality of rams 46, through the opening 41 in the furnace front wall Il, where the spreader 48 sprinkles the coal over a central portion of the great-surface which is in communication with the plenum 'chamber 35, .this central portion extending from front -to rear of the furnace.

A variable speed motor` 50, driving through belts and 52, operates both the ram 46 and the spreader 48.

In order that the supply of air tothe central. plenum chamber 35 may be varied' inv direct pro.-Y portion to changes in rate of feedI of fuel to that portion of the grate surface overlying the plenum chamber 35, the motor 50 is directly connected to a tachometer blower 52a which supplies air under pressure to a bellows 53, the latter being connected through the compression spring 54to one end of the lever 55, pivotally mounted intermediate its ends on a fixed support, at 56. The compression spring 54, whose tension may be adjusted by the screw 51, urges the right-hand end of the lever 55 upwardly with respect to the bellows 53. The left-hand end of the lever 55. is connected through the rod 58' to a pair of spaced' bellows 60 and 6|, the former being in communi cation with the upstream side of the metering orifice 42 and the latter being in communication with the downstream side thereof. The lever 55 is also connected through the stem 62 with the valve 63 controlling flow of pressure medium through the conduit 64, the latter being in communication with the expansible chamber 65, en closed in part bythe movable piston or abutment 61, which is connected by the rod 681 with the bell crank 69', iixedly secured to the damper 43 in the passage 38. A compression spring TI exerts force in the piston orl abutmentin opposition to the force of fluid pressure acting thereon.

In operation, it will be apparent that any increase in the rate of feed of fuel to the grate surface will result in increased speedV ofthe tachometer blower 52a and increased` pressure within the bellows 53. This in turn will produce upward movement of the right-hand end of the lever 55 and opening of the valve 63. As a result, the pressure within the chamber 65 will be increased, causing downward movement ofthe piston 61 and rod 68 carried thereby, thereby further opening the damper 43, resulting in increased flow of air to the central plenum chamber 35. As the` chamber opens, the differential pressure across the metering orifice 42 decreases, resulting in upward force and movement applied to the left-hand end of the lever 55. The lever will moveuntil equilibrium of forces acting thereon is restored with thev valve 63 adjusted for the increased fuel feed rate. If the rate of fuel feed is decreased, the contrary operation takes place. By adjusting the spring 54, the relation of fuel feed' rate to air flow rate to the central duct 38 and plenum chamber 35 maybe varied.

- fuel bed adapted to be fed laterally-of the stoker as; thel result of reciprocation of the movable grate bars l5, the fuel being consumedV as it passes over the side portions of the fuel supporting grate surface overlying the side plenum chambers 36. Ash and unconsumed refuse leaving the lower ends of the grate bars may be received upon ash dump plates 'l0 and periodically discharged into the ash pits 'll provided at each side of the furnace.

While in the embodiment herein illustrated, thegfurnace has been shown as .containing only onestoker, it will be apparent that; the invention is not limited to this arrangement but may include the provision of two or more stokers disposed in side by side relation and extending from front to rear of the furnace, together with a corresponding number of fuel feeding and spreading devices associated therewith.

While-the invention has been shown in but one form, it Vwill be obvious to those skilled in the art that itis notso limited, but is susceptible of variouschanges and modifications without departing from the spirit thereof, and it is desired, therefore, thatl only such limitations shall be placed` thereupon as are specifically set forthin the-appended claims.

What is claimed is: K Y

1. A furnace having front', rear and sidewalls; a stoker disposed in the lower portion of saidV furnace and comprising a row of transversely-disposed grate bars, which row extends from front to rear of the furnace and comprises a plurality of reciprocatory bars interspersed among a plurality of stationary bars and provides a fuel`supporting surface of inverted-V shape in transverse section having a central portion adjacent the apex'of.` the inverted-V flanked by two side portions at the-legs of the inverted-V; means forfeeding coal through the furnace front wall a material distance above the fuel-supporting surface and spreading it-over the central portion thereof from front to rear of the furnace; and means for imparting transverse reciprocatory' motion to the reciprocatory bars to feed the coal from said'central portion latierally in opposite directions over the si'de portions.

2'. A furnace having front, rear and si'de Walls; a stoker disposed in the lower portion ofs'aid'furnace and comprising a row of transversely-disposed grate bars, which row extends from front to` rear ofthe furnace and comprises a numbery of reciprocatory bars interspersedt among a number of stationary bars, saidV row of" bars providing a fuel-supporting surfaceV of inverted-V shape in transverse sectionv having a central portion adjacent the apex of the inverted-V andsside p0r= tions at the legs of the" inverted-V,` means'for feeding coal through the furnace front wall and spreading it over said central portion of the fuelf supporting surfacefrom frontl t 0V rear 'off the furnace for partial coking and ignition' thereon, a first means carried by each reciprocatory bar, and second means extending longitudinally-of the row of grate bars and engaging: said, first means, said first and second meansg being adaptedto impart transverse reciprocatory motion to the reciprocatory bars to feed the partially coked and ignited coal from the central portion laterally over they side portions for consumption at saidf side portions.

3. Structure as specified in claim 2, wherein the row of transversely-disposed grate bars comprises alternate reciprocatory and stationary bars:

4. Apparatus of the character described! comprising a furnace; grate' structure withintheffurgnace; fuel-feeding mechanismA of the sprinkler 'or spreader type for sprayingfuel freely'overa ceri--v tral portion of the grate, which portion extends' from front to rear of the' furnace and is;l spaced from the side walls thereof, whereby a substantial portion of combustion takes place while the fuel is in suspension; and means for imparting movement to the grate structure to feed the fuel transversely of the furnace along the grate from the central portion to the sides of the furnace.

5. Apparatus of the character described comprising a furnace; grate structure within the furnace providing a fuel-supporting` surface of inverted-V shape in transverse section having a central portion adjacent the apex of the inverted- V anked by two side portions of the legs of the inverted-V; fuel-feeding mechanism of the sprinkler or spreader type for spraying fuel freely over said central portion of the grate, which portion extends from front to rearl of the furnace, whereby a substantial portion of combustion takes place while the fuel is in suspension; and means for imparting movement to the grate structure for feeding the fuel from said central portion laterally 10 in opposite directions over said side portions.

DONALD J. MossHART'. p

CERI'IFICA'I'E.` 'OF CORRECTION.

Patent No, 2,587,600. october 25. 1915.

DONALD J. MossHART.

It is hereby certified thatlerror .appears in the printed specification of the above numbered patent requiring correction as "follows: Page l, first column, line 2l, for 'or pressure read --oi pressure page V2, firstl column, line Y, forY ugreatu readl --grate--g and that the said Letters Patent' should be read with this correction therein that the same may' conform t0` the record of the oase in the Patent Office.

Signed and sealed this 22nd day of January, A. D. 19h61.

Leslie Frazer `(Seal) First Assistant Commissioner of Patents.