US1691373A - Underfeed stoker - Google Patents

Description

Nov. 13, 1928. A

l R. L. BEERS UNDERFEED sToKER Filed June 16. 1922 5 Sheets-Sheet 1 Vw y Zyce Beez@ Nov. 13, .1928.

R'L BEERS UNDERFEED s'rolmn Filed .June 16. 1922` 5 sheets-,sheet 2 S/ZM Nov. 13, 1928, 1,691,373

R. L. BEERS UNDERFEED s'roxn- Filed June 16. 1922 5 Sheets-Sheet 5 Nov. 13, 1928.

R. L. BEERs UNDERFEED STOKER Filed June is. 1922 5 sheets-sheet 4 4 Zz?? zeugs;

N0v.'13`. 192a l 1,691,373

R. BEERS UNDERFEED STOKER Filed June 16. 1922 5 Sheets-Sheet 5 Patented Nov. A13., 1928.

UNITED STATES PATENT" oFFicE.

:ROYCE I.. Bnnns, or nnrnorr, MICHIGAN, 'AssIGNoIa BY IIESNE ASSIGNMENTS, To

RILEY STOXER CORPORATION, O FVWOBCESTER, MASSACHUSETTS, A CORPORATION F MASSACHUSETTS.

UNDEBIEED s'roxnn.

Application led June 16, 1922. Serial 1.10. 568,797.

The present invention in underfeed stokers rela-tes moreparticularly, in some of its features, to what are now sometimes called lat- -eral branch retort stokers, that is to say,

constructions in which 'the fuel is initially introduced into a main retort running in one direction, and whence part of the fuel is distributed to other etorts that extend laterally, or generally transversely to the direction of the main retort, with their fuel-receptive ends toward the main retort. Structures of the general type referred to are known,

as in Klefel Patent 1,270,171, dated June 18,

1918 (Reissue 14,747), and Armstrong and Blackburn, No. 1,333,696, issued March 16,

Some of the features of my present invention relate more particularly to installations of stokers of the character described in which .thelateral retorts are located at one side only of the main retort, and in this regard an object of my invention is to provide improved and advantageous structure for properly maintaining desired combustion conditions along the blank side of the fire-box, effectively free from disadvantageous clinkerin'g, and in a manner desirable to promote effective distribution of the fuel through the combustioii area. served by the lateral retorts.

ln other aspects my invention has further to do with a means for feeding fuel in a Stoker of the eneral character described, and v has for its o ject to provide advantageous and cooperating retort structure and feeding means to aid in securing and maintaining efficient/combustion conditions throughout the eective areaof the fire-box or combustion chamber floor, and also in the movement and disposition of ash or refuse of combustion.y

Further, my invention has to do with the mechanical construction of stokers of the general character described, with the yobject of attaining greater simplicity, economy of manufacture and use, ruggedness, durability, and facility in manufacture and installation of such Stoker construction.

tVith a view to attaining these and other objects which will become apparent to those skilled in the art from the following descrip- 'tion taken in conjunction with the accompanying drawings, m .invention consists in the combinations an features of construction hereinafter set forth by exemplification in a single embodiment, as to which embodiment it will be understood that numerous changes in details of construction and arrangement may be made without departure from the spirit of my invention and within the scope of the claims hereto appended.

In the drawings, Fig. 1 is a front elevation of a furnace e uipment embodyin my invention; Fig. 2 1s a vertical longitudinal section on .the plane 2 2 of Fig. 1, looking in the direction of the arrows; Fig. 3 is a plan view, with parts in section on line 3-3 of Fig. 2; Fig. 4 is a transverse section on line 4 4 of Fig. 3; Figs. 5 and 6 are details in side and front elevations of tuyre plate construction; Fig. 7 is a detail section on the line 7-7 of Fig. 4; Figs. 8 and 9 are sections through a corner-tu re, Fig. 8 being taken on the line 8-8 of ig. 9 and Fig. 9 on the line `99 of Fig. 8; and Fig. 10 is a perspective view of a corner-tuyre.

It will be understood that in the drawings, for clarity of illustration, working scale has not been observed, pertinent stoker parts be- `ing generally shown exa geratedly, and auxiliary` structures reduce in size.

In general, it will be understood, that green fuel lfrom a supply hopper 10 is fed throu h a front-wall throat 11 into a main longitu inal retort 12 by the reciprocation of a suitable ram 13, suitably driven in any way as by ram-engine 14.

The green fuel thus fed into the main retort 12 is, in part, ultimately consumed in the combustion area directly above the main retort, but-other portions of fuel, more or less affected by the passage through the main retort, will be distributed to lateral retorts 15 for consumption in the further area served by these retorts. Of these lateral retorts generally arranged side by side and extending in a direction transverse to that of the main retort, a suitable plurality may be provided dependent in number on the length of the main retort and the desirable width of the lateral retorts. 4 A

These retort structures form part of a firebox floor, generally indicated at 16, which, as a whole, extends from the front wall 17 to the bridge wall 18 and from one side wall 19 to the other side wall 20 of the boiler setting, the Iretorts proper being supplemented in this floor formation, b suitable eXtension surfaces and by aSh-dIumping surfaces paralleling the outer or delivery ends of the lateral retorts. The space 21 above the floor may, as a whole, be called the combustion space, while belowthe floor division is made 4asbya artition structure 22 into an ash pit 23 be ow the ash dump 24, and a windx 25 into which air under pressure is constantly introduced from a. suitable source of supply. Air from the wind-box kfinds emission/through the tuyre openings, generically indicated at 26, around the margins of the retort structure to support combustion in the chamber 21, and if desired a dampered orifice -27 tothe ash pit may permit a regulated supply. of airto flow to the dump plate, both to cool the latter and to complete the combustion of any partly consumed matter that may lodge on the dump plate in the forcing of the stoker operation, as under boiler-overload. v

With the very widespread area of active: combustion that may be fed from a single source of supply of fuel, and a single main retort, it is feasible and oftentimes desirable to construct the stoker with lateral retorts along one side only of the main retort, thus locating the main retort near one side of the boiler-setting, and such a construction I have specifically illustrated in the drawin s. The main retort 12 'is relatively close to t e sidewall 20, and lateralpdistribution of fuel dis only toward the right (Fig. 4),/ toward the single dump mechanism 24. It is usually desirable that the mouths of the lateral retorts have a distinct down-slope from receiving end to delivery end, so that the dump structure 24 is considerably lower than the mouth of the main retort, and therefore the hi h point of the fuel bed is apt to, be near t ef lank side of the retort and adjacent the wall 20. Further it is my preference that the mouth offthe main retortY be substantially horizontal, and since the feed of the combustible in this locality longitudinal or par-y allel with the furnace side-wall, I space the blank side of the main retort'smewhat away from the side wall and provide tuyre structures spanninfg1 from the blank wallof the retort 'to the mace side wall of such character and construction as to prevent or minimize' possibility of clinker-adhesion that might` interfere with the feeding. action.-

Further, although distribution of combusti- -bles from the main retort to the lateral reforts may' variously be accomplished, it is my preference that the inner or receptive ends o f the lateral retorts shall be in open communi- Acation throughout all, or a large portion of,

' Thus, in. the c construction shown'. each of the latenlltldrtszl, opens directly main retort, and its appurtenances, I prefer ahl provide structure for aiding in the d1s tri u'tionof combustible from the mainretort t0 the lateral retort.

- several plates if side Wall is surmounted by an upright edge plate 29 bolted thereto' and having along its. uppe` edge an outwardly turned flan e 30. Surmounting this extension-piece o the main retort through the right-hand side' wall of the latter, and the left-hander blank the blank side wall of the retort is a nonclinker 'locked in position between the ange 29 and 1 the furnace side-wall and spanning the space between the two. vThis multiple plate struc-- ture preferably provides, as portlons of the fire-box floor, one inclined surface-Q32 contacting with the side wall at a point high' enough above the topmost point of the tuyre blocks for the lateral retorts to include the normal zone of clinker-formation and sloping downwardly, inwardly, or toward,the axial vertical plane of the main retort, to a -line preferably above but between the edges ofthe main-retort mouth, andanother surface, roundedly merging with the first, that extends downwardly but back toward the side wall ,of the retort to aline of juncture with the edge plate 29. Thus, as shown in Fig. 4, the upward extension of the retorts blank wall, afforded by these surfaces, pro-l vides a re-entrant or overhangin shoulder against which the upthrust of 'fue may take effect to 4divert its force laterally toward the laterally extending retor 4In specific constructiorl? I preferably form I each unit 34 of the stated structure 31 in they mannen' specifically indicated in Figs. 5 and 6, that is to say, to provide a plate body orthin lweb 37 having a -marginal flange 38 bordering all but its bottom edge.` Notches 39 and 39 through Asuch borden-in appro'-A priate positions, will-afford tuyere openmgs 39 through surface ,33 and small a1r ports '39 at the to of surface 32 to cool the furbelow leach of the nace-wall. ediateliy)1 backwardly and vupwardly 'alongvthe'p ate to l tures slould be burned olf,- the closely spacedl body webs would prevent the fuel from fallesima. It wi11be`1woted 4that even if the Ysurfaces of these plate-structhrough to any serious extent, and the y webs also serve to minimizethe danger of burning out, by carrying away' the heat. In the construdzion of lateral retort stakers it is now known practice to dispose the bottom of the main retort at one level, arrange the lateral retorts with their bottoms at a level lower than this, and to provide channels, below the bottom level of the main retort and opening into the lateralretorts, in which to locate cross-feed mechanism for the lateral retort to supplement the fuel-feeding action of the feeding devices associated with the main retort. I find that in a stoker so characterized efficacy in fuel-.distribution and in fuel consumption and ash disposal are aided,

and results improved, by structure which I l will now describe.. Both the main and the lateral retorts are made quite shallow. The bottom of each lateral retort preferably has its inner portion flat and arranged horizontally, but toward its outer or delivery end it up-slopes as at 47 to a marginal flange 48. The horizontal portion 46 finds effective continuation in the bottom wall 49 of the channel 50 transversely traversing the bottom portion of the main retort. p a. feed block 51, having a fin 52 extending down through a slot 53 in the channel-bottom 49 and carrying guide rollers 54 that act on the margins of the slot. This block is preferably of such length that at all times itcovers the slots and it is reciprocable from rock shaft 55 through lever arm 56 and link 57, the latter connectible to the arm at varying distances from the axis of oscillation of the shaft to vary the length of throw of the feed block. At its active end (or at both ends if Fused in a furnace having two sets of lateral retorts) 'this feed block is preferably formed for both horizontally moving and up-thrusting the fuel, preferably bythe provision of an upper shoulder 58, approximately vertical in position, and therebelow a protruding beveled nose 59 that slopes from the shoulder downwardly and outwardly to the bottom of the block, or at an inclination opposite to slope 47 of t-he retort-bottom. Feeding o-f the fuel longitudinally of the main retort is effected primarily by the operation of the ram 13, but may be furthered by the provision of a. reciprocable feed plate 61 extending through the throat and along the flat bottom of the main retort, preferably from side to side thereof, and provided with one or more upstanding feed blocks 62. I preferably employ two feed blocks 62 and 62', the rear block 62 being the deeper and having a substantially vertical rear end 63 and a top surf-ace 64 gradually inclined downwardly to its front end. The other, shallower block 62 preferably has its rear end 63 steeply inclined to project at its bottom and its top-surface 64 gradually down-sloped to the front. The plate 61, running over and covering the transverse feed blocks 51, is guided in brackets 65 on the retort-walls and is reciprocated by a lost-motion connection at its outer end With In each of these channels is arranged the ram, a pendant arm 66 of the ram engaging between adjustable stop p-ins 66 of the plate extension. A check plate 67 secured in the throat extends over and guides the feed plate 61 and its abrupt shoulder stops any tendency of the fuel to follow the feed plate into the throat. For operating the rock shaft by which all of the lateral feed blocks are reciprocated, a lever 68 is provided on the end of the rock shaft and is suitably vibrated by an engine 69, suitably controlled in operation-periodicity.

I find ,that with the lateral retorts relatively shallow, and having the inner portions of their bottoms horizontal and the delivery portions thereof up-sloped, the horizontally traveling feed blocks both propel and lift the fuel with an efficacy that gives most excellent distribution of the fuel and at the same time tends most strongly to prevent clinker-formation by adequately breaking up the fire, keeping the live fuel-bed actively stirred and properly distributed for the full and effective action of the air which is emitted to the bed through the tuyres. The flat feed plate, pusher-block equipped, tends to carry fuel rearward to sonne extent, while upon its retracting action the inclined surfaces of the pusher-blocks have a lifting and loosening action with respect to the coal that is very beneficial in preparing it to be fed either.

along the main retort or into the lateral retorts.

vThe mouths of the lateral retorts may be located with their outer edges somewhat removed from the dumping zone, and the intelmediate space from the retort ends to the dump plate may be'bridged by end plates 70, either somewhat 'perforated or dead-plates. At the front and rear of the fire-box structure air-cooled dead plates may steeply upslope from the margins of the extreme lateral retorts which are respectively proximate to the furnace front wall and to the bridge wall, to meet these furnace walls at a high enough level to protect them, as best shown4 inA Fig. 2, the under sides of these plates being open to the wind-box so as to be kept cooled by the air therein. These plates may be imperforate but are otherwise of substantially the construction of plate-tuyres 31.

In the particular construction shown, the body casting for each branch retort is sepavrately made, and flanged as at along its receptive end which is to be connected With the main retort structure. These castings may be all alike and of any desired length. The main retort is formed of a plurality of longitudinally adjoining sections, one for each lateral-retort position, these sections being flanged as at 77 at their abutting edges, to be suitably secured together as by bolts. Each such section has atits forward and rear edges respective halves of two side wall posts 78, and the outer margin of the post casting i channel andthis plate may be recessed `or apertured as at 81 to receive the end 0f the S into pieces meeting in ahorizontal plane `side-margins of said retort castings,

between two lateral retort-s.

84, 84d and marginally feed plate 61. To reduce casting-size, each main-,retort section may be further dividecll anc bolted together to form a section-unit, but this is not always desirable. v

The tuyre blocks 82, spanning the airtrunk` 83 between the side walls of adjoining lateral retorts, and mounted on the flanged may be of plate form, disposed in generally upright arrangement side by side, supplemented by suitable corner tuyres 84 forming the tops of the side wall posts. v

These corner-tuyeres are especially subject to hard usage and are preferably specially constructed for facility of replacement, at minimum expense, for efficacy in air-distribution in all directions, and to hold up the lire even when partly burned away. In detail I construct each such corner-tuyre of a plurality of complemental thin-sections interlocking to give a firm assembly and shaped in the aggregate to present in their upper portion a rounded contour, nearly quarterspherica-l-in effect, for exposure to the fire,

with tuyre openings in all directions of such surface, and in their lower portion to make up a stem for insertion into the air-trunk space In detailfive sections or layers are shown, although more or less may be used, these sections 84", 84", 84, having each a head portion (85a to 85), and a stem portion (86 to 86). Each section has a plate-web (87*v to 87e),

j bordered throughout the exposed head part by a flange-run (88a to 88e) hrough which ian es the tuyre openings are made, each leadlng to an interspace between body-webs. `The stem portions have interlocking and spacing lugs (89a to 89e) thereon to position the layers in assembled relation, and all stems may be notched as at 90 to engage the flangesof the lateral retorts.

The planes of severance between the layers are preferably nearly parallel between the stem portions 'but through the heads sweep on curves of progressively shorter radius for uniform distribution of the tuyre openings and stronger interlock.

To afford support for the metallic structure forming the fire-box floor, the partition 22 may in part be composed' of a partition plate casting 92 having suitable footings and brackets for sustaining the associated parts. In this plate the dampered or1fice 27 may be formed, and on the plate may be supported the rock shaft 93 for the ash dump platform 24, such shaft (as shown in Fig. 1) running through the front of the furnace for manual operation by a detachable crank not shown. Cross-beams 94, extending from lsuitable footings on said partition plate t0y the wall 19, aii'ord support for the main retort casting and may be supplemented by a longitudinal beam 95 to support the outer ends of the downwardly-inclined lflanges of the lateral retort castings. On these crossbeams 94 is supported the rock shaft 55 of thel feed mechanism for the lateral retorts.

The ash dumpplatform 24 is preferably madein rather narrow sections for easy replacement, each being shaped for detachable engagement at its inner end with the square rock-shaft 88, and near its outer end provided at opposite sides with a tongue 97 Aand a tongue-receptive locked. lAlso the plates are preferably perforated for air-passage therethrough, each -plate having a side edge notched as at 99 for notched lug 98 so that a' lseries of these duplicate pla-tes may be intersaid combustion space, said floor structureV comprising a main retort spaced from and running substantially parallel to one wall of the furnace, a plurality of lateral retorts extending across toward the'opposite furnace wall, such lateral retorts being spaced apart from each other and having marginal tuyres that are highest adjacent to the main retort, and a tuyre-structure spanning the space between the first-mentioned furnace. wall and the adjacent side of the main retort and open to the wind-box space, said tuyre structure extending up materially above the level of the highest tuyres for the lateral retorts to include, at a lower level than the top lines of said highest tuyres for the lateral retorts, the normalfgzone of clinker formation, and said tuyre structurehaving its tuyre opening near the level of vthe highest tuyres of said lateral retorts.

2. In a furnace having walls laterally enand the adjacent side of the main retort and tort; and means for feeding fuel along the main retort;

3. In'a furnace having wallsy enclosing a combustion space and a wind-box therebelow, a Stoker floor-structure separating said windbox from said combustion space, said Hoor- 'structure comprising a main retort spaced from and running substantially parallel to one wall. of theI furnace, a plurality of lateralretorts adapted and arranged to receive fuel fromsaid main retort at their inner ends and extending across toward the opposite furnace wall, these lateral retorts being spaced apart from each other and having marginal tuyres communicating with the wind-box, and a structure bridging the space between the firstmentioned furnace wall and the adjacent side of the main retort, shapedto provide near its `bottom a portion bulging inwardly over the main retort and to provide thereabove a portion out-sloping to the furnace wall 'to meet the latter at a height that will include below its upper level the normal zone of clinker formation, and parts of such inwardly bulging portion being disposed directly opposite the fuel-receptive inner ends of said lateral retorts.

4. In a furnace of the character described, the combination with the furnace walls of a main retort extending. parallel and adjacent to one furnace Wall, said main retort having a blank side toward said wall and having openings through its opposite side, lateral retorts communicating with said main retort openings and extending across toward the opposite wall of the furnace, means for feeding fuel longitudinally of the main retort, and a structure surmounting the blank side of the mainvretort and overhanging the latter, at places directly opposite the openings to the lateral retorts for directing fuel,upthrust by the feeding means for the main retort, toward the lateral retorts.

5. In a Stoker structure of the character described, the combination of a plurality of lateral retorts arranged side by side, a main retort crossing the inner ends of said lateral retorts in arrangement to deliver fuel thereto,

said main retort having along its side at places directly opposite the said lateral retorts overhanging portions disposed to direct ilp-thrust fuel toward the respective lateral retorts, and means for feeding fuel longitudinally of the main retort and causing up-thrust kof fuel.

6. In astoker ofthe class described, thel combination of a main longitudinal retort, lateral branch retorts to receive fuel from the main retort and each having a substantially horizontal bottom portion at its fuel-receptive end, a feed ram for the main retort, and

laterally reciprocable pushers'in the branch retorts, each said pusher being located in the horizontal fuel-receptive portion of its .lateral retort and each having a` projecting nose providing a surface inclined to present its lower edge in advance of its upper edge in the direction of feeding movement.

7. In an underfeed furnace, a main retort having its bottom at one level, lateral branch retorts having their bottoms at a lower level, the bottom of each lateral retort having a horizontal portion adjacent the main retort and an 11p-sloped portion adjacent the other end of the lateral retort, and a vpusher blockA horizontally*reciprocable along the bottomV of each lateral retort and providing a prol jecting nose sloped oppositely to the end slope I of the retort.

8. In an underfeed lStroker having a main retort-and lateral retorts `at one side only of the main retort, a'tuyreplate structure providing a portion to overhang the blank side of the retort and comprisinpfa body web, a

marginal flange thereonto provide la downwardly and inwardly sloping upper surface. and a downwardly and outwardly sloping overhang surface having tuyre notches.

9. Inan underfeed stolzer having a main retort and lateral retorts at one side only of the main retort, a tuyre plate structure providing a portion to overhang the blank side of the retort and comprising a body web, a marginal flange thereon to provide a. downwardly and inwardly sloping upper surface, and a downwardly and outwardly sloping overhang surface having tuvre notches, and

said plate having at its bottom a hook to interlock with'a portion of the main retort.v

10. In a stoker of the character described, the combinationof the longitudinal main retort, lateral retorts extending transversely thereto and each having an opening in its bottom, respective pusher blocks in the lateral retorts each having a depending portion extending through the respect-ive opening in the retort bottom, a rock shaft. levers on said rock shaft, and respective Alinks connected' with the depending portions of the severalpusher blocks and each having independently adjust-able connect-ion with a corresponding lever'of therock shaft.

l d ROYCE L. BEERS.

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