US2173883A - Mechanical stoker - Google Patents

Description

Sept- 26, 1939- H; E. PRESTON r-:r AL 2,173,883

MECHANICAL STQKER Filed April 14, 1936 5 Sheets-Sheet l ra @y y H. E. PRESTON Er AL 2.173.883

MECHANCAL sToKER Filed April 14, 1936 5 Sheets-Sheet 2 Sept. 26, 1939.

Sept. 26, 1939. H. E. PRESTON Er A1. 2,173,883

V l MECHANICAL sToKER Filed April 14, 1936 5 sheets-sheet 3` Sept. 26, 1939.

H. E I. PRESTON El' AL MECHANICAL STOKER Filed April 14, 1936 5 Sheets-Sheet 4 Sept. 26, 1939. H. E. PRESTON n AL MECHANICAL sTOKER Filed April 14, 1956 5 Sheets-Sheet 5 uw@ @FM /Z .5 @f5 fw, m TFM/4 w f 4/ Patented Sept. 26, 1939 UNITED STATESY PATENT oFFlci- MECHANICAL STOKE' Application April 14, 1936, Serial N0. 74,260

8 Claims.

This invention relates to mechanical stokers, and more particularly to stokers of the multiple retort underfeed type.

One object of the present invention is to provide a generally improved and simplified stoker of the stated character.

Another object to to provide each Stoker retort with an improved arrangement of fuel feeding and distributing elements.

A further object is to provide in'stokers of the stated character an improved and simplified front wall construction.

A still further object is to provide an improved mounting for the ram boxes of the stoker which house the main fuel feeding rams.

A still further object is to provide improved Stoker retort and ram box cap constructions.

Other and further objects will become apparent as the description of the invention progresses.

Of thedrawings:

Fig. 1 is a longitudinal sectional view diagrammatic in part taken through one of the retorts of an underfeed Stoker, showing various of the improvements comprising the present invention.

Fig. 2 is a sectional elevational view taken substantially along line 2 2 of Fig. 1.

Fig. 3 is a sectional elevational view taken substantially along line 3 3 of Fig. 1.

Fig. 4 isan elevational view, partly in section, and with certain parts removed to show the construction of the interior of the front wall of the stoker, said View being taken substantially along lines 4 4 of Fig. 1.

Fig. 5 is an elevational view, partly in section and with some of the parts removed, showing the structure of the exterior of the front wall of the stoker, said view being taken substantially along line 5 5 of Fig. 1.

Fig. `6 is an enlarged sectional View taken through the front wall of the stoker showing certain details of construction thereof.

Fig. 7 is a sectional plan view taken substantially along line 1 1 of Fig. 6.

Fig. 8 is a sectional View taken substantially along line 8 8 of Fig. V6.

Fig. 9 is a side elevational View taken through the Stoker, partly in section and with certain parts removed to show the structural framework of the stoker and the supports therefor.

Fig. 10 is a plan view of the structure shown in Fig. 9.

Fig. 11 is a sectional view taken substantially along line II I| of Fig. 9.

Fig. 12 is a sectional view taken substantially along line I2 I 2 of Fig. 9.

Fig. 13 is a fragmentary elevational view of the upper end of the Stoker, with certain parts broken away to show the general construction 'of the upper end of one of the tuyre chambers.

Fig. 14 is a sectional View taken substantially 5 along line I 4 I4 of Fig. 13.

Fig. 15 is a perspective view of one of the ram box cap brackets, and

Figs. 16 and 17 are perspective views, showing the structure of one of the ram box caps. 0

Referring to the drawings, the numeral I indicates generally an inclined grate underfeed Stoker, comprising a sexies of alternately disposed retorts 2 and tuyre rows .3. As shown in Figs. 1 and 9, the stoker is secured to and inclines downwardly 5 from the stoker front and furnace wall 4', and is supported at the lower end thereof upon a transverse I-beam 5. Fuel is supplied to the stoker I from the usual hoppers 6, mounted exterior of the front wall, and supported upon ram boxes l, the fuel gravitating into the inner ends of the cylinders 8 thereof being fed to the stoker through openings or passages 9 provided in the front wall 4 between the adjacent tuyre rows by a series of rams Ill. Each inlet opening or passage 9 is bounded at the bottom by a supporting casting l l having a beveled end I2 forming the bottom of the upper end of the retort 2, at the top by a ram box cap I 3 detachably secured to a bracket I4 and at the sides by a pair of wear plates I5. The side walls of each retort 2 comprise a pairof spaced beams it extending from front to rear of the stoker upon eachy of which is supported a series of air cooled supporting plates Il for the tuyres 3, while the bottom wall consists of a series of alternately disposed secondary fuel feeding elements or pushers i8 and dead plates I9'.

The under side of the uppermost pusher I8' is provided with a transverse slot 20 in which is secured a downwardly extending bar 2l in which is loosely mounted a rod 22. One end of rod 22 is pivotally secured at 23 to the second pusher |82, while its other end has secured thereto an extension 24 to the free end of which is pivotally connected the upper end of a lever 25. .Lever 25 is pivoted on a shaft 2E mounted in a pair of 45 brackets 21, secured to'extensions 28 'depending from beams I5, as. shown in Figs. 1, 2 and 9. The lower end of lever 25 is pivotally connected to one end of a link 29, the other end of the latter being pivotally attached to the upwardly extending portion of a collar 30 mounted on a reciprocating rod 3|. Secured to rod 22 at spaced points on either sideof bar 2l by any suitable means, such as by shearing pins, are a pair of collars 32.

Between collars 32 and bar 2l are a series of removable washers 33 which provide a lost motion connection, if desired, between the first and second pushers I8 and |82. By this arrangement it is seen that upon reciprocation of rod 22 the first two pushers will be actuated. The third pusher I83 has pivotally connected to the front end thereof a link 34, the free end of which having two or more apertures 35 provided therein adapted for reception of a pin extending through the upper end of a lever 36. The lower end of lever 36 is operatively connected to a second reciprocating rod SI2. By providing two or more apertures 35 in link 34 proper adjustment of the pusher may be effected. 'I'he third pusher I83 also has a bar 2 I 3 depending from the lower side thereof through which extends a rod 223 pivotally connected to the fourth pusher |84. Rod 223 is also provided with spaced collars 323 and washers 333 to permit relative movement of the third and fourth pushers |83 and |84, if it is so desired. The fth pusher I is operated independently through a link and lever mechanism indicated at 31, and operatively connected to a third pusher rod 3I3.

The sixth pusher I86 in the present instance is also provided with a link and lever mechanism 38 similar in construction and operation to those associated with the pushers I 813 and I85 previously described, and is connected by a link 39 to a pusher rod 40' disposed beneath pusher rods 3|. The sixth and seventh pushers |86 and I8'I are also interconnected for operation by a bar 2 I6 and a rod 226, similar in construction to those previously described. The lowermost pusher I8s in the present instance operates independently through a link and lever mechanism indicated at 4|, operatively connected to a .pusher rod 402. The extension grates 42 disposed at the lower end of the stoker have each operatively connected thereto a rod 43 to the forward end of which is pivotally connected the lower end of a lever 44 pivoted intermediate its ends on a rod 45, suitably secured to a pair of brackets 461 extending'rearwardly from the lower end of front wall 4. The upper end of lever 44 is pivotally connected to one end of a link 41, the other end of the latter being pivoted to the depending portion of a collar 48, secured to a rod 403. `Rods 3| and 40 are mounted in suitable bearings 49 and 50 respectively, secured at one end to the front wall and at the other end to lateral supports 5| provided in brackets 46, by bolts 5|', as shown in Figs. 2 and 5. The forward ends of rods 3| and 40 are connected by means of extension rods 52 and 53 respectively to the lower arm 54 of a multi-armed lever 55 pivoted to an extension bracket 56 Secured kto ram box 1. 55 has pivotally connected thereto the lower end of a link 58, the upper end of which is connected to a crank 59 on shaft 59, driven by the power mechanism indicated at 60 in a Well known manner. A third arm of lever 55 has pivotally connected thereto one end of a link 62, the other end of said link being pivotally connected to the interior of ram I0. Suitable removable washers 63 may be provided on the extension rods 52 and 53 to provide an adjustable lost motion connection betweensaid rods and arm 54, whereby the strokes of pushers I8 may be varied as desired. The specific construction of this connecting means forms no part of the present invention, and therefore need not be described in detail. For a complete disclosure of this construction A second arm 51 of lever reference may be had to United States Patent No. 2,005,005.

From the foregoing description ofthe rams I0, pushers I8 and extension grates 42, and of the various operating connections between these elements and the power mechanism 60, it is seen that upon rocking of lever 55 by said power mechanism, reciprocatory movement is imparted to said elements. By providing relatively thin dead plates I9 between adjacent pushers I8, groups of said pushers may be interconnected for simultaneousl operation if it is so desired. These relatively thin dead plates also enable a larger number of pushers to be provided in each retort, and as a result eicient feeding and distribution of the fuel are eiected.

Referring to Figs. 2, 3 and 9 to 11, it is seen that each beam I6 comprises a pair of spaced, longitudinally extending plates 69, 69. The dead plates I9 and the supporting plate 65 for casting II extend between and are secured to the adjacent plates 69 of beams I6 of each retort 2 by any suitable means, such as by welding. By providing welded seams as indicated at 66, between the dead plates and the retort side walls,air leakage intol the retorts from the plenum chamber 89 disposed beneath the stoker, is materially reduced. The dead plates I9 are each provided with an enlarged recess 61 at the forward end thereof to accommodate the operating means for the pushers I8, the portions 68 of said dead plates at the sides of these slots providing extended bearing surfaces for said pushers.

As shown more particularly in Figs. 2, 9, 10 and 11, the -plates 69 and 69' of each beam I6 are 10, 1|, 12 and 13, secured to said plates by a series of bolts 14. The upper edge of each plate 69 extends above the upper edge of plate 69 and has provided therein a series of apertures 15. As illustrated in Figs. 1 and 2, ,the lower edges of the tuyre supporting plates I1 rest upon the upper edge of plate 69, while laterally extending anges 16 of said supporting plates rest upon the upper edge of plate 69. A series -of bolts 'I1 extending through apertures provided in plates I1 and the apertures 15 of plates 69 rigidly retain said supporting plates in position in such a manner that the vertical faces 18 thereof. are ilush with the retort side of plates 69. The plates I1 are also held together by means of tie plates 19. A bracket 80, having an extension 8|, is secured to the lower end of each plate 69. The extensions 8| of the brackets 80 in line with the walls of adjacent retorts are secured by means of bolts 82 to hollow rectangular bearing blocks 83, which rest upon rollers 84 mounted in roller brackets 85 secured by bolts 86 to I-beam 5. The rollerse84 provide an anti-friction support for the lower end'of the stoker permitting said stoker to expand and contract due to the variable temperature conditions under which it operates.

The stoker front 4 is supported upon a transverse I-beam 90, and comprises a series of spaced columns 9| and 92, extending from I-beam 90 to substantially the lower-end of the brickwork 93 forming the front wall 4 of the furnace. The columns 9| may be of. I-beam construction, while columns 92 comprise pairs of channel irons 94 having iller plates 95 disposed therebetween. The webs of adjacent channel irons 94 are se cured by the bolts 96, or by any other suitable fastening means. This construction enables the stoker to be constructed in units of any desired -held in spaced relation by means of spacer bars number of retorts. The columns 9| and 92 are machined at the upper ends 91 thereof to conform with the interior configuration of a transversely disposed channel iron 98, Fig. 6. A `transversely extending plate 99 rests upon the web of channel iron 98 and has lsecured thereto a pair of longitudinally extending angle irons4 |00 and IOI. One leg ofangle iron is secured to channel iron 98 by bolts |02 or by any other suitable means.I

The oute` facing of the stoker front comprises f a sheet metal closing plate |03 which is secured to the flanges 9|' and 94' of I-beams- 9| and channel` irons 94, respectively, by rivets |05, or by any ther suitable securing means, as shown more particularly in Fig.5. The upper end of closing plate |03 is also secured to angle iron I04| by bolts |06. 'As shown in` Fig. .6, the front portion of brickwork 93 is supported upon plate 99, while the inner portion thereofis supported -upon the upper\surface of alternately `disposed bolts |09 to the front closing plate |03 in such a manner that the ram cylinders 8 thereofcom- "municate with the inlet openings 9 o f the stoker front 4. Some of the bolts |09 extend through the flanges 9|' and 94 of columns 9| and 92, thereby affording a rigid support for the ram boxes 1.'

Closing plate |03 has provided opposite each-retort 2 of the stker aA pair of vertically spaced apertures I I0 and I I, Figs. 5 and 6, the apertures I|0 being `shaped to conform with the in er end of ram cylinders 8. The apertures provide openings for the reciprocating rods for the pushers I8 and extension grates 42. A pair of bearing brackets ||2 and II3, in which are mounted the bearings 49 and 50, respectively, for the reciprocating rods are secured to closing plate I 03 and to the flanges 9|' and 94 of lcolumns 9| and 92 by bolts ||2' and-H3'.

The lower ends of columns 9| and 92 are secur'ed by welding to the base flange of a transversely extending angle iron |I4, the lower, outwardly disposed'sides of said columns being cut upper end of plate I|6 and the vertical flange ofangle iron I I4ware secured to thelower-end of closing plate |03 by bolts I1. *l

Referring more particularly to Figs; 2, 4, '7, 9 and 10, it is seen that the .upper ends of plates 69 are securedby rivets II 8, or by any other suitable securing means, to the rearwardly exftending anges |,I9 of angle irons |20, which in turn are secured to the rear flanges |2| and |22 respectively, of'columns 9| and 92 by bolts |23.

The upper end of the Stoker is thus rigidly secured directly to the stoker front, and the use of intermediate brackets is entirely eliminated.

The brackets 46' provided near the lower inner end of stoker wall 4 are welded or otherwise secured to the` rearwardly extending flanges of angle irons |25 which in turn are secured by bolts |26 to the rear f|anges|2| and |22 of columns 9| and 92, respectively. Thev wear plates I constituting the side wal of the ,inlet openings 9 are secured by bolts |21 to vertical supporting plates |28, as shown more particularly in Figs. 2, 4 and '1. Plates |28 ex- 1 tend beyond the upper and lower extremities oi' plates I5 and are secured by bolts |29 to ears |30 integral with columns 9| and 92. Supporting plates |28 are each provided with a vertical ange |3| at the forward end thereof against which the forwardly disposed ends of wear plates I5 abut. As shown in Fig. 7, the inner walls of wear plates I5 converge slightly from front to rear, as indi-r cated at |32, whereby the fuel fed through openings 9 is introduced to the retorts in a compact mass.

The castings II forming the bottom walls of openings 9, are each provided with an open transverse slot |35 at the forward end thereof which receives a tongue |36 projecting rearwardly from closing plate |03, Figs. 1, 6 and 7. 'I'he forward ends of castings are4 thus held against vertical movement. A stud bolt |31 engaging in a tapped recess in supporting plate 65 prevents vertical,

as well as transverse movement of the other end of said casting. Castings are thus rigidly held in position, while the securing means therefore permits ready installation or removal thereof in the, event they should become Worn or damaged during operation of the stoker.

Referring more particularly to Figs. 14, 6, and 13 to l' inclusive, each ram box cap extension bracket I4 is of a hollow substantially triangular boxlike construction having an upwardly and rearwardly inclined wall |33 terminating at its upper end in a detachable, vertically disposed fuel, abutting portion |34, a substantially vertical forward wall |35, and substantially vertical side walls |36 and |31. The top wall |38 of bracket I4 l comprises a pair of substantially flat parallel portions |39 and |40 connected by an inclined portion |4I, forming a depression |42 at the forward end thereof into which extend the flanges of channel iron 98. Portion |39 is disposed somewhat beneath the upper edge of fuel portion |34, the purpose of which will be hereinafter described. The inclined wall |33 is provided with a pair of apertures |43 and |44, near the lower end thereof for receiving a pair of locking lugs |45 and |46 respectively provided near the lower end of ram box cap I3, Figs. 6, and 13 to 17. The portion of' the wall |33 of bracket I4 disposed forwardly of apertures |43 and |44 provides a pair of tongues |41 which, in assembly, engage the lugs |45 and |46, thereby effectively holding the forward end of the ram box cap in position. Inclined wall |33 has also provided therein an yenlarged opening |48, which in assemblyv may be closed by a plate, not shown, to prevent air leakage into the retorts, and a pair of bolt receiving recesses I 49 and |50. Recesses |49 and |50 each comprises an enlarged portion I5I and a reduced portion |52 communieating therewith. The enlarged portions I5I of apertures |49 and |50 are f suiiicient size to accommodate the heads of bolts |53. The inner wall |54 of recesses |49 and |50 is spaced suiilciently from the inner surfaces of the flanges |54' adjacent reduced portions |52 to permit` the heads of bolts |53 to pass therebetween, as shown in Fig. 6. The upper end of ram box cap extension I3 is provided with apair of'apertures |55 adapted to receive bolts |53. A pair of guide lugs |56 k sembly engagethe side walls |51 of recess |48.

' 1 `'lo assemblethe caps v.I3 on brackets I4, the lugs .|45 and |46 are y rst inserted in apertures |43 and |44, after bolts |53 have been inserted in `'recesses |49 and |50, as shown in Fig. 6. Extension |3 is then swung upwardly, causing the shank of bolts |53 to enter apertures |55. Nuts |58 are then secured to bolts |53 and extension I3 is then drawn tightly into engagement with bracket I4. The fuel engaging portion |59 of each rambox cap extension I3 in the present instance is offsub# stantially arcuate construction, although it may.` be flat or angular, asdesired, while the side walls |60 thereof are substantially flat and in assembly lie substantially in abutting relation with the retort sidewalls. v

` As shown more particularly in 4V and 15,` the side walls |36 and I 31 of each bracket I4 are provided near the upper ends thereof with flat, outwardly projecting portions .|6| .and |62l respectively, the lower edgesA |63 of which, in

assembly, rest upon the upper vhorizontal edges |63' of the upper tuyre-supporting ,plates |64, thereby affording a support for the disposed ends of said brackets.

The rearwardly disposed end ofeaeh bracket I4 is also supported'at either side thereof by a .pair of bars |65, Figs. 4, 6, 13 and 14. 'Ihese bars extend through aligned apertures I 66 and |61 provided respectively in the side Walls |36 and |31 of each bracket |4 and in the upper tuyre supporting plates |64 of the stoker. surfaces of bars |65 lie in substantially abutting relation with the lower surface of a flange v|68 integral with and extending forwardly of the inner surface of wall |33 of bracket |4. Bolts |69 passing through apertures provided in flange |68 and bars |65 rigidly secure said bars to the bracket. The bars I 65 engaging the upper tuyre supports |64 thus also form effective supports for the rearwardly disposed ends of brackets I4.

The upper fuel abutting portion |34 of each bracket I4 is detachably secured in position by means of stud bolts |10 engaging in tapped recesses provided in a flange |1| depending from the upper wall portion |39. Other securing means may also be provided if it is so desired. Thus, in the event any of the portions |39 should become damaged during operation of the furnace, it may be readily removed without disturbing 'adjacent parts.

The wall brackets 81 disposed between adjacent brackets I4 are also of hollow construction and each comprises a substantially flat top wall |12 upon which the brie'kwork 931s supported, a front wall |13, vertical side walls |14, and a substantially fiat bottom wall |15, Figs. 4 and 13. Each side wall |14 of brackets 81 has provided thereon an extended lateral projection |16 which in assembly rests upon the upperportion |39 of an adjacent bracket I4. The upper end of each tuyre support |64 is provided with a longitudinally extending flange I 11 projecting into the associated tuyre chamber. The bottom wall of each bracket 81 extends forwardly of 'front wall |13, and terminates on a line substantially midway between the front and `rear ends of said bracket. In assembly bottom wall |15 rests .upon the anges |11 of a pair of tuyre supporting yplates .|64 and is secured thereto by bolts I 18.

The brackets 81 are thus rigidly held in position.

The upper-tuyres |19 of each vrow are held against vertical displacement byadjustable lockrearwardly The upper pair of vertical slots |8I through which extend a pair of bolts |82. Bolts |82 also extend through apertures provided in the vertical flanges |84 disposed in vertical alignment with the front wall |13 of bracket 81. Bars |80 may thus be adjusted vertically until the lower ends thereof engage tuyres |19 when the nuts |85 at the end of said bolts are tightened, thereby securing said lbars in locking engagement with said tuyres.

From the foregoing description it will be observed that ahighly improved stoker"has been provided. -The.structural framework of the retort and front wall is not only rugged, but involves a simplified construction'. The elements of the Stoker whichl arejsubject to wear, such as the tuyre supports,l the ram box caps, the wear plates and the wall brackets, are so mounted that installation thereof may not only be readily made,

,While the embodiment herein shown' is admirlably kadapted to fulfill the objects primarily stated, it is to be understood that the invention isnot to be limited thereto, since it maybe embodied in other forms, all coming within the scope of the claims which follow.

What is claimed is:

1. In a stoker, the combination witha series o f alternately disposed retorts and tuyre rows,

each of saidretorts comprising a pair of spaced,

longitudinally extending beams, of a series of alternately disposed pushers and dead plates providedat the bottom of each of said retorts, a stoker front comprising a series of spaced columns in line with said tuyre rows, flanges provided at the forwardly and rearwardly disposed sides of said columns, means for securing said beams to the flanges provided at the rearwardly disposed sides of said columns, a front closing plate having a pair of vertically spaced openings therein opposite each of said'retorts and secured to the flanges at the forwardly disposed sides of said columns, ram boxes secured to said closing i plate in alignment with the upper of said openings, operating means for saidpushers extending through the lower of said openings in said closing plate, bearings for said operating means, means for securing one end of each of said bearings to said closing plate, extension brackets provided on said columns, and means for securing the other end of said bearings to said extension brackets. Y

2. In a stoker, the combination with a series of alternately disposed retorts and tuyre rows, of a furnace wall, a. stoker front adapted to support said furnace wall, said stoker front comprising a series of spaced columns lhaving flanges at the forwardly and rearwardly `disposed sides thereof, meansfor securing said retorts to the flanges provided at the rearwardly disposed sides of said columns, a front closing plate secured to the flanges provided at the forwardly disposed sides of said columns, a transverse channel beam secured to the upper ends of said columns, means provided on Asaidlchannel beam for supporting the outer portionof said furnace wall, an angle iron secured tothe lower ends of said columns, a rigidvsupport for said columns, means for securing said angle iron to said rigid support, and a transverse sealing plate secured to'the lower end of said closing plate and engaging said rigid support.

v|83 of tuyre supports |64 and in a retaining bar- 3. In a Stoker, the combination of a series'of I6 inclined alternately disposed retorts and tuyre rows, each of said retorts consisting of a pair of spaced, longitudinally extending beams, la row of tuyre supporting plates mounted 4on each of said beams, each of the uppermost of said tuyre Asupporting plates having a vertical ange extending laterally fromone end thereof, adjustable bars mounted adjacent the flanges of pairs of said last mentioned tuyre supporting plates and adapted to engage the uppermost tuyres of said rows to prevent vertical displacement thereof, and means for securing said adjustable bars in position.

4. In a mechanical stoker, the combination with a series of inclined, alternately disposed retorts and tuyre rows, each of said retorts comprising a pair of spaced beams, of a stoker front, comprising a series of spaced columns having flanges at the forwardly and rearwardly disposed sides thereof, means for securing said beams to the anges at the rearwardly disposed sides ofl said columns, a front closing plate secured to the flanges provided at the forwardly disposed sides of said columns, ram boxes secured to said closing plate and in alignment with said retorts; a series of spaced ram box cap brackets, means for securing the forwardly disposed end of each ofsaid brackets to said closing plate, ram box caps mounted on said brackets, tuyre supporting plates secured to said beams, means for securing the rearwardly disposed end of each of vided on a ram box cap, said top wall comprising a pair of fiat parallel portions-arranged in offset relation, and connected by an inclined portion, supporting means for said bracket projecting laterally from each of said side walls, and a detachable, fuel abutting portion secured to one end of said bracket and forming Aan extension of the said inclined wall thereof.

6. In a stoker, the combination with a series of alternately disposed retorts and tuyre rows, each of said retorts `comprising a pair of spaced, longitudinally extending beams, of a plurality of alternately disposed pushers and dead plates provided in the bottom of each of said retorts, tuyre supporting plates mounted on said beams, a stoker front, comprising a series of spaced columns having laterally extending anges at the forwardly and rearwardly disposed sides thereof, means for securing said beams to the flanges at said rearwardly disposed sides of said columns, a

front closing plate having vertically spaced pairs of openingsprovided therein in alignment with said retorts, secured to the flanges at the forwardly disposed sides of said columns, ram boxes secured to said closing plate in alignment with the upper of said openings provided therein, operating means for said pushers extending through the lower of said openings in said closing plate,

bearing brackets for said operating means secured to said closing plate, and said Stoker front having passages communicating with said retorts and in line with the upper of said openings in said closing plate, said passages being bounded at the bottoms thereof by fuel supporting castings, at the top by ram box caps, and at the sides by Wear plates.

7. In a stoker, the combination with a series of alternately disposed retorts and tuyre rows, of a furnace wall, a stoker front for supporting said furnace Wall, said stoker front comprising a series of spaced columns having anges at the forwardly and rearwardly disposed sides thereof, means for securing said retorts to the flanges provided at the rearwardly disposed sides of said columns, a front closing plate secured to the flanges provided at the forwardly disposed sides of said columns, a transverse channel beam secured to the upper ends of said columns, means provided on said channel beam for supporting the outer portion of said furnace wall, a series 0f brackets supporting the inner portion of said furnace wall, and means for supporting said brackets in position.

8.V In a mechanical stoker, the combination with a s eries of inclined, alternately disposed retorts and tuyre rows, each of said retorts comprising a pair of spaced beams, of a stoker front. comprising a series of spaced columns having flanges at the forwardly and rearwardly disposed sides thereof, means for securing said beams to the flanges provided at the rearwardly disposed sides of said columns, a front closing plate secured to the flanges provided at the forwardly disposed sides of said columns, ram boxes secured to said closing plate and in alignment with said retorts, a series of spaced ram box cap brackets,

ram box caps mounted on said brackets, each of said brackets being secured at one end to said closing plate, tuyre supporting plates secured

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