US1132573A - Furnace. - Google Patents

Description

Patented Mar. 23, 1915.

BSHEETSWSHEBT 1.

G. FURUHOLMEN.

PURNACE.

APPLICATION MLM) JAN. 9. 101s,

Ur. FURUHOLMEN.

FURNACE.

APPLNANO Patented Mar. 23, 1816.

3 SEEETSSHEBT 2 Zzwesses @n L@ N 7d G. FURUHLMEN.

PURNACE.

APPLICATION FILED JAN. 9. w13.

1 ',1 82,573. Patented Mar. 23, 1915.

3 SHEETS'SHEETS.

LMJ

UNITED STATES .3ATENT OFFICE.

GEORGE FURUHOLMN. Of MNNEAPOLTS. MINNESOTA.

FURNACE.

Appiicaticn led January 9, 1913.

T0 all whom it may concern Be it known that I, GEORGE FURUHOLMEN, a subject of the King of Norway residing at. Minneapolis, in the county of llennepin and State of Minnesota, have invented cer tain new and useful Improvements in Furnaces, of which the following is a specification.

My invention relates to improvements in furnaces, and has for its object to provide a furnace havinnr an improved construction and arrangement of fuel-feeding` and sus taining mechanism in combination with mea-ns for directing and controllingr the fuel gases and air so that a colting effect is had upon the fresh coal fed into the furnace and the fuel gases are mixed with the air at a point where the temperature of the furnace is the highest, so that practically complete combustion immediately takes place and a smokeless, or nearly smokeless eonibustion results.

It is a further object of my invention to provide means for feeding the coal from the rear to the front of the furnace chamber and to provide mechanism for receiving the unconsumed material at the end of the feeding mechanism and pushing said unconsunred material forward at the same time that ashes and waste are permitted to drop through into the. ash pit.

lt is a further object of my invention to provide means for regulatingr thiI rate of feed of coal from the coal feeding chamber to the moving grate and the thicknesst of the body of coal upon said grate. and also to provide means for reirulatiney the extent of grate surface suhieeted to draft` all for regulating and varying the intensity of the fire in the furnace.

The. full objectsl and advantages of'my invention vcill appear in connection n ith the detailed description ther iof and are particularly pointed out in the claims.

ln the drawings, illustrating the application of my invention in one formrdfigurc 1 is a sectional lside elevation of a furnace embodying my improvements. Fig. is a transverse section on line '2-2 of Fig. l. Fig. fi is a view similar to Fig. l illustrating;r a modified means of forcing the coal from the primary feeder ,to the grate. Fig. fl is n Specification of Letters Patent.

Patented Mar. 23, 1915.

Serial No. 740.968.

longitudinal section of a part of a furnace showing my improvements applied to a different type of boiler. Fig. 5 is a. section on line.' 5*-5 of Fig. 4. Fig. 6 is a sectional view across the front grate taken through the main receiving part of the grate and outside of one of the movable forwarding members. Fig. 7 is a similar sectional view taken in part through one of the movable forwarding members. Fig. 8 is a Sectional view through a portion of the grate along the grate shaft taken on line 8--8 of F ig. 6. Fig. 9 is a plan view of a portion of the receiving grate. Fig. 10 is an enlarged sectional view of the front part of the receivY ing grate taken on line 10-10 of Fig. 6.

in the practice of my invention the pri maiv elements or features thereof are,- a feed chamber 11 located adjacent the rear part. of the fire box 12 opening thereinto through a passageway 13, a moving grate 14 having the rear turn thereof adjacent the opening 13 and the upper surface constantly moving toward the front of the furnace, a. coliing arch or baille 15 extending forwardly above the said moving grate to apoint above and a little short of the forward end of said grate, a damper plate 16 below the fuelreceiving portion of the grate for withholdingr air from a part of the fuel on said grate, and a combination dumping and fuelforwarding grate mechanism 17 at the front of said moving grate for receiving the unconsumed material from the grate and sifting and forwarding the same. to the front of the furnace or dumping, as desired.

ln the application of my invention shown in Figs. 1 and 3. the. feed chamber l1 may conveniently be located haelt of the wall 1S which supports the front. end of the boiler, while for the type of boiler Aillustrated in Fig. 4 the chamber 11 may be formed at a suitable point beneath the boiler by a specially devised brick-work structure 1S). ln either event the coal or other fuel passes by gravity or is forced through the opening 13 by automatic stolting mechanism upon the rear end of endless grate 14. At once upon passing to the grate 14 the coal is subjected to -heat and .vill begin to emit gases. lf, howeverVthese gases were allowed to escape directly into the combustion .mi and to iioiv thence toivould enter the corn-A a low temperature Where chamber itself was at a lov.Y tempcinture and a seriously :end otnuigviousl-v smokeproducing Iumpiiou would result. l provide,

fi baille arch 1.7 extending forhin [he lire box 12 from above on passage 13 to a point at con of the moving grate. .All from the fuel upon the grate w into the tire box 1i over the figc Q of the baille 15. This i cctlv above 'the hottest part of 1. the batiic arch l5 at its front edge vv; be heated red or White hot, so that the gas emitted fronrthc incoming fuel swap'. vto tbe fire box al: the hottest point lirzco, biowmef'. if: -1i.. .wtwl to "l hem of the furnace from we ive .im below and will neceslei-conn- .rv bot. The gases from the lowiag alongthis bot surbig; lv heated before escap- .fz'iniicsccnt edge 20 of the ifi-ans ol tl e damper 16 air o pues: rbrougl. only the forfthe grate. so that. a large A the grate beneath the no ...ctefl to heat such as i gases therefrom and t fue? before actual cour` place as the fuel reaches the i de. The air draft 'tgl'. the timivard portion of nim'in trato 1l. and through thc forwarding and dumping grate l. not only' provides the hottesty combustion of the fuel end of baliie arch 15, but also the sa..

. 3 fuel -fl adm ,led smul pori lon 0 pari; of the but baille arch lf3 is bfi-"vv 'the and tl of the bai e r; Where both and air are hosted to a very high temperature, Which insults in .web complete oxidation of the fuel gases that. the prodnrts of combustion are pract ally smokeless.

'Profi sentit or deer d: 'fr :it the to: Tl. a

.urtare exposed to 1 'ft of moving grate will hereinafter be described. sn the formV of niv device shown in Fig. 1.. which is a highiv useful and satisfactmv feeding method. the rear por Aon of moving grate Mextcnds beneath tite omini-gf 13 and the bottom of feed chan r 1l, so that it iS noir Vf to lf: i the chamber ll .'ti'vla-eii n" in orde.- 'hat the moving $9 grate `l tiniiallr sed forward the desired amount of f'- o ver;y the thickfed upon moving of changing the .i provide a vertical slidihc Ientire baille arch previouslv liberated diminish the thickness of the sheet of fuel fed forward by the'endless Fig. 3 a mechanical Stoker pusher. type is shown for forcing the fuel from feed chamber 11 through passageway 13 and upon endless feeder 14. lWhen the mechanical Stoker is used the endless feed grate 14 will not extend so far rearwardly as in the form shown in Fig. 1, and a guido plate 28 will carry the coal to the top of the endless feeder. Another forni of mechanical distributing mechanism is shown in Figs. 4 and 5 in which fuel is dis tributed from a side hopper 29 into the feed chamber 11, and from thence forced upon' the endless feed belt 14 by means of a spiral conveyor 30, preferably of diminishing diametrical dimensions as shown, in which case a guide plate 31 similar to the guide plate 28 may be arched around and above the spiral conveyor so as to direct the fuel forced upon said plate by the said spiral conveyer through the passageway 13 and upon the moving grate 14. The mechanical stokers shown are referred to as typical of different mechanical operating devices for the purpose. lVhen such devices are used the suppl) of fuel to the moving grate may be regulated by varying the rate of opera tion of the. mechanical Stoker.

It is to be noted that the modifications shown in Figs. 3 and 4 relate onl \7 to the means of supplying the'sheet of fuel to the movin grate. As shown in Fig. 3, a mechanical stokcr involving reciprocating pushers below hopper 11 is employed, which pushers force the fuel upon moving grate 1-l. As shown in Fig. 4, the same result is obtained by an endless screw 30 which may project from a hopper 29 at one side of the furnace, as shown in Fig. 5. In either of these last mentioned forms the fuel is positively forced upon the moving grate by the mechanical means shown which require a motor for operating the same; While in the form shown in Figs. l and'Q, the moving grate 14 extends below the mouth of hopper 11 and the feed of the fuel to said grate is effected bygravitv.

The grate mechanism 1s supported upon a frame comprising side bars 32 and end bars 33, said side bars having rollers 34 journaled thereon so that if desired the frame may be dropped upon tracks 35 and grate 14. ln 0H t of a common withdrawn from the furnace through an 'opening in the front wall thereof provided for that purpose. Normally thc front end of the frame is sustained upon posts 36, and the rear end upon screw members 3T in a position sloping frpm the front to the rear,

the screw members 3T providing means forl adjusting the rear end of the frame. Upon a rear shaft 3S, journaled between side members 32, is a solid roller 39, and similarly journaled between side pieces 32 near the front end thereof, is a shaft 40, preferably supplied with a series of narrow roller-ssl. The endless grate 14 consists of achain grate formed of transverse bars having draft openings through the same and extending over roller 39 and the sets of rollers 41. Both shafts 3S and 40 may be provided with worm wheels 4Q, with which mesh a pair of worms 43 upon a shaft 44 constantly driven from any desired source of power by which the roller 39 and rollers `rl1 are rotated at a uniform speed and the endless chain grate 24 continuously and automatically moved from the rear toward the front of the fire box.

The damper 16 comprises a ined plate 45 supported upon cleats on side pieces 32 and a crossbar 4G adjacent roller 39, said plate 45 hap-fing the end if thereof in close proximity to the periphery of roller .-lfl so as to close dra ft communication from below damper plate, 15 through the grate 14. Secured to crossbar 476 and another crossbar 4S toward'the forward portion of grate bar 14, are longitudinal bars 49 upon which slide a movable, damper plate 50, said plate being provided on the under side thereof with racks 5t, which are engaged by pinions 52 on a shaft journaled in side pieces 32, said shaft 53 extending vbeyond side/piece 3Q between worm wheels 42 on shafts 38 and 40, and having on the extended end thereof a hand wheel By turning the hand provided with circular apertures 64, through which extends loosely a squared, ,hollow shaft (i5 having the corners round-:d so that the same may rotate in the said apertures C4. The upper front portions of ribs 61 are formed as indicated at G6 so as to engage the fixed grate member and preventthe forward portion of plate 59 from Contact ing with the curved portion of moving chain grate l section 5S and the fixed section are conjointly formed so as to provide a hollow or depressed portion, 6T, extending rearwardly in a curved ascending plane into close proxunity with the descending portion of mov-4 ing grate 14. Back of apron 59 and between rilis 61 are positioned a series of grate bars fast on shaft 65 and movable in unison by such shaft. It is noted that the grate bars 68 are formed with a. curved wheel 54 the movable damper member() will he slid backward 0r forward relative to baffle arch 15, opening more or less of the fuel supporting portion of lmoving grate 1t to draft of air .from beneath.

The front receiving and forwarding grate l? comprises a stationary portion 55 held in fixed position at the front of the furnace. said portion .fi-3' being formed 'with draft openings 56 and 5T'. Between the fixed grate portion 55 and the peripheral curve of moving grate 14, wherel thev same goes over rollers 41. is located a grate section 58. said section comprising a front apron 59 formed with a series of draft openings (if) therein Vand a series of depending ribs 61, crossbars or webs G2 at the rear of said ribs, and a crosshar (i3 at the front thereof operating to bind the same rigidly together at the lower portion thereof. The ribs 61 are upper surface corresponding to that of the ribs G1, and also each of said grate bars is provided with transverse draft apertures (S9 and longitudinal draft apertures 70, formed between pairs of forwardly extended ribs 71 which come' into proximity to projecting portions of fixed grate 55 and are adapted to engage and crush c linkers or other obstructions which may get on to the grate bars 68. The rear portion of the grate bars v(it is formed as an extended arcuate flange 72, as bcstshown in Figs. G and 7. Maferial upon the grate and within the depressed portion (37 will be pushed in a forward direction when the grate sections (3S. are rocked upwardly'; and material upon the apron 59 will be restrained from falling through between ribs 61 by aforesaid fianges 72.

From the above it will be seen thatthe grate bars GS are secured 'to move together lupon and with the shaft 65. On one of said grate bars is formed a forwardly projecting crank arm 73, to the farther end of which is connected an operating link or har 74 which projects through the front of the furnace and is pivotally connected to Yan operating lever 75. By this means t-he'shaft 65 may be rocked in a direction to cause the grate bars G8 to rise between the adjacent ribs 61, the operative portions 76 of said bars moving upwardly and forwardly so as to push the ma* rial resting above thehollow portion (i7 of the grate toward the front ofthe fire box, the loose ashes and clinkers dropping through'between the rear Aportions of ribs (51. Clinkers that are too large to pass between said ribs G1 will be engaged between the ends of ribs 71 and portions of the fixed grate 55, and by operative portions 76, said clinkers thereby being broken so that they will fall through. One of the .depending ribs G1 is provided with an integral downwardly and forwardly projecting crank arm Itis to he noted that the grate' the. baille arch.

77 jivhich is positioned adjacent the crank arm 73. To the lower end of crank arm 77 is connected an operating har or lifnl. which projects forwardly through the front side of the furnace and is pivotally connected to an operating` lever, 79. By operating the lever 79 the grate plate 5S may be swung upvvardly and forwardlyg dumping the contents thereon into the. ash pit. Preferably in accomplishing the dmnpinpr action the grate and the grate hars G8 will be operated simultaneously through levers '73 and 77.

The grate section 58 and the sha1-ier bars (3S taken together constitutenot only means for shaking or dumping the ashes, but a true grate havingr a multiplicity of draft spaces for providing complete and effectual drafttothe material loeat-ediipon this grate. The fixed grate section '55 also provides ample draft spaces. The purpose of this arrangement, therefore, is to provide a proper grate surface for receiving and retaining unconsumed material from the moving grate l-l; and supplying the requisite drafts of air to ellect proper combustion of suc-h material7 as well as shaking and dumping mechanism. lfloreover, the shaking device has a peculiar land novel function, namely-to move the material on the grate from the rear thereof toward the front so that the most fully consumed fuel and ashes will be contiiunzlly pushed to the frontof the grate adjacent the furnace opening and farthest from the boiler, Where, for convenience of operation and from the standpoint of practical economy, it is desirable to have a relatively loiv temperature.

It is to be noted that my entire organization provides a fuel distributing and draft mechanism not only efficient in a high degree for producing practically smokeless combustion, but also of unusual convenience tothe fireman or operator, who always Will-have a clear view of the fire hed and has convenient and ready access to all operating parts of my device. It is also true that the arrangement of moving grate, fuel supply, hopper or box admission, passage-way to the moving grate and balle arch above the .moving grate are assembled in a relative position such as to give the best possible results.

The baille arch must be spaced sufficient distance above the coal upon the moving gratefto permit ready movement of gases freed from said' coal toward the end 20 of Preferably also. as shown, the baille arch should be inclined upwardly. This baille arch Will not prove effective for the purpose if made .too long, and for this reason it is impracticable to use a baille arch and a movingr grate vvhere said arch and grate extend to the lrcar'iend of a. boiler of any considerable length. The draft controlling apparat-11s below the moving grate'is absolutely essential to draft regulation "o that the hot part of the fire `will be. at the foriva rd end of the moving grate and he'low the end 20 of the baille arch. lf a. thin sheet of (foal is to be fed for keeping a comparatively lon' fire, and no damper mechanism avere provided. the lire would creep back beneath the baille arch to the. coal admission point, and even might finally reach the fuel in the supply hopper'. The same result ,vonld follow to a degree if a tliicln-,r .sheet oi" fuel were fed. A combustion onthe moving grate beneath the. baille arch at a point much to the rear of the end 20 thereof is not desirable, since it, voulil he wasteful and he liable to canse smoking.

l claim: i

l. A. furnace comprising a tire box and a grate therein continuously movingr from the rear to a point near the front of the fire box, means forcontinuously delivering fuel upon the rear 5nd of said moving grate, means above the grate for causing the gases liberated from the fuel to be delivered into the eomluistion chamber near the forward end of the grate, means hel-ow the grate for limiting the delivery of air through the g ate to a point approximately below the point of delivery of said and a. 'normally stationary grate at the front of and Within the fire box positioned to receive and hold material from the moving grate for further combustion at a point which is close to the hottest, portions of said combustion chamber.

2. A furnace comprising a fire box and a grate therein continuously moving from the rear to a point near the front of the. lire box, means for continuously delivering fuel uponv the rear end of said moving,r grate, ay bafllc arch above said moving grate extending forwardly so that the gases released from the fuel on the `frate will be delivered into the combustion chamber at a Ipoint approximately above the .forward end of the moving gratea draft plate below the moving,

grate for limitingair draft through the front portion only of the same to produce the hottest combustion area. in the fire lion at the front of the moving grate and belofvi7 the end of said baille arch, and a normallystationary grate at the front of and Within.

the firebox positioned to receive and Ahold. i material from the moving.; grate for further y combustion at a point which is close to the hattest portions of said combustion chamber. l i

3. A fiirnaee comprisingr rear to the front of the tire-box and coma fire-box,a solid roller outside of the rear of said tire-box, av

prising a (lished surface, said receiving grate including movable gratte bars for engaging und fox'waldingfuel on the receiving grate, Said movable bars having arcuate flanged rear portions to prevent material falling through the receiving grate al', the rear part thereof when said bars are operated.

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