US1995047A - Stoker - Google Patents

Description

March 19, 1935. G. VON HAASE STOKER 4 Sheets-Sheet 1 Filed April 22, 1931 I lnuerz c f if March 19,1935. (5. VON HAASE STOKER Filed April 22, 1931 4 SheetsSheet 2 March 19, 1935. e. VON HAASE STOKER Filed April 22, 1931 March 19, 1935. G VON HAASE 1,995,047

STOKE'R Filed April 22, 1931 4 Sheets-Sheet 4 Patented Mar. 19, 1935 i rs P T Q,

George von Haase, Lakewood, Ohio, assignor to The American Ship Building Company, Cleveland, Ohio, a corporation of New Jersey Application April 22,1931, Serial No. 532,002

' 3 Claims. (Cl.,110--32) V Thisinventicn relates to mechanical stolsers; Fig. 12 is a partial sectional elevation showingf and more particularly to a device of this-kind of another form of gratebar support. i i improved and simplified form.

. V "In the drawings, to which detailed reference An object of this invention is toprovide a mewi l p e y b a e; v shown t e 5 chanical stoker'having a movable grate compris chanical- Stoker Of my invention s be ng asso- 5 ing interchangeable grate bars, and in which the a e a a e yp S t but b arrangement of structure is such as to permit o e proceeding w th this detailed description/it broken or burn d grate b g t b readily 1'9- willbe understood-of course, that my invention placed. j 7 may be embodied in various structural forms 10 Another object of this invention is to provide 'Q' h Q18 particular One 'hereini11ust a i 10 a mechanical stoker having grate actuating'and and y t ker may be, used withbth b i fuel feeding means so arranged as to permit, the e the P t i t e' ned. x i use of a hand4firifi door. I In the preferred form of my invention, as illus- Another object of this invention is to provide ire/Bed lf e drawings, Ihave Shown y St e a mechanical stoker embodying novel grate actu mechanism applied to a fire e l The 5 ating means i, boiler is shown as being provided with ac onstii1 another object of this invention is to prov t t u furnace?! which is uipiied vide a Stoker in which the fuel supplying means Wi m ej mnt 1 8. The furnace front is embodies novel means for distributing the fuel v qe i a a firing 1 9, and ii addie substantially uniformly upon the receiving end'of' E1011 @9 the "1 5 f n i e a e f m, 20 the grate. namely that of forming a closure for the outer A further object of this invention is to provide enflei the furnace; i l Constitutes a ppb a mechanical stoker in which novel means is eni-i 0 the fuel feeding means a for the grate ployed for selectively regulating the speed of the actuating means of my s okermechanis'm which 7 5 fuel feeding means and of the grate actuating etbemore fully d s ri ed hereinaftermeans. 1 As is usual in boilers of this type; the furnaces The invention may be further briefly sum- 17 r Ofacylindrical, o u ated f rmtaf Sh marized as consisting in' certain novel combina n l nd a d e d into the boiler shell tions and arrangements of parts hereinafter 63- between the front a thereof a d Li scribed and particularly set out in the'appended f Well. 21 h Secondary 00311015711011 Q1aims chamber. It will be understooiof course th at- In the accompanying sheets of drawings, a h leu'meeeis pped Wi y k l m ehm Fig.1 is a side elevational view, with parts nism, 0 mp the e p etailed thereof in section, showing a boiler furnace havreference w D i u n 1 h 'jfi r a 5; ing the stcker mechanism of my invention assounite A plurality 0 grate a 22 d. 0 5' ciategi t t gitudinally within the furnace in adjacent Fig. 2 is a longitudinal sectional elevation taken parallel relation to o a grate upon which the through cne of the boiler furnaces' and its stoker fuel d- T e bars are u p ted wi hi mechanism; 1 the furnaceat such a height as to providean air 40 Fig. 3 is a front el vation of one of the furnace pa 23 beneath the a e- The grate bars are fronts; all of the same form so as to be interchangeable, Fig. 4 is a sectionalplan view taken substan- $111.15 facilitating. h replacement of bars which tia11y n the line 4 4 f Fig 3; are burned or broken. At their forward end, or,

Fi 5 is a partial elevational view showing the n other Words, at the end o the bars a t means for regulating the speed of the grate actun from, I Provide t eible fl k nd, ating means and of the fuel feeding means; tiens' 2% Which fit relatively close og th r, $0 Fig. 6 is a plan view showing the fuel distribas t leave b a s r e a pa e w en uting member; the same and .to form a fuel receiving table or Fig. '7 is an end elevational view thereof; p xt n i g t an ve s y .Of the ra e- 7 Fig. 8 is an elevational view showing one pair TI' DDO h r t b 22 sovthat hes i 50 l of the grate bar supporting bridges; may be moved longitudinally within the furnace Fig. 9 is a plan view thereof; to thereby' progressively advance, the fuel being Fig. 10 is a. detail elevational View r the grate burned, I pr v d tpair o an ver e y nd operating cam; V ingmovablesupporting bars or bridge members Fig. llis an end elevation thereof; and adjacentthe ends of the grate, -At=the forward or fuel receiving end of the grate, this supporting means comprises the bridge members 25 and 26, and the supporting means at the rear or discharge end of the grate comprises the bridge members 27 and 28. As shown in Figs. 8 and 9, these bridge members extend transversely of the furnace, and at their ends are provided with Wedge-shaped bearing lugs or portions 29 engaging in V-shaped bearing recesses formed in the supporting members 30, which latter members are secured to the wall of the furnace. Along their longitudinal top edges, the bridge members are provided with spaced lugs 31 of rounded form constituting bearing projections which engage in similarly shaped bearing recesses 32 formed in the grate bars adjacent the ends thereof. This engagement of thebearing projections in the recesses of the grate bars affords a connection between these parts whereby tilting of the bridge members upon their supports fiil from the position illustrated in Fig. 2 to the position illustrated in Fig. 1, produces the desired longitudinal movement of the grate bars. 7 a

As stated above, the grate bars are'identical in form, and it should be noted, at this point, that two adjacent bearing recesses 32 are provided at both ends of each bar. Likewise, it should be notedthat thebearing projections 31 of each pair of bridge members are in staggered relation, as shown in Figs. 8 and 9. This arrangement of bearing projections and bearing recesses permits alternate grate bars to be supported upon the that the grate bars constitute two sets Which'are movable relative to each other. In other words,

the grate constitutes two sets of bars, one of which is'supported'upon the bridge members 26 and 28 and the other of which is supported upon the bridge-members 25 and 2'7, so that inclination of either of these sets of bridge members will cause longitudinal movement of one set of grate bars relative to the other set. V

Adjacent its inner end, the furnace 17 isprovided with a transversely extending rear wall 33 of suitable construction. This wall is spaced from the discharge end of the movable grate so as to form an ash pit 34 into which the ash and clinkers drop from the discharge end of the grate. The ash pit is separated from the air space 23 beneath the grate by means of a transversely extending plate member 35 and a damper 36 pivoted adjacent the platemember. The position of this damper may be adjusted from the front of the boiler bymeans of the rod 3'7to thereby vary the amount of air which is allowed to pass from the air space into the ash pit, or to permit the removal of ashes from the pit. It will be noted that the plate member 35 is so formed andarranged as to leave a transversely extending air passage 38' between this member and the grate. This air passage constitutes a by-pass for the damper whereby air may beadmitted to the ash pit from the air space 23 during such time that the damper is closed. The admission of air to the ash pit through the passage insures a proper supply of'secondary' air for'mixturewith the heated volatile gases distilled from the coal, at a grate bar'svcan be moved longitudinally within the furnace to advance the fuel being burned.

In the stoker mechanism herein disclosed, I provide actuating means presently to be described in detail, whereby the sets of grate bars are moved simultaneously in the fuel advancing direction, or,in other words, away from the furnace front,

and are retracted or moved toward the furnace front in succession independently of each other. During their fuel advancing movement, both sets of grate barsare moved at the same time, and

consequently they advance the fuel bed as a whole. After the sets of bars have completed their fuel advancing movement, one set of bars is retracted beneath the fuel bed while the other set remains stationary. After the retracting movement of the first set of grate bars has been completed, this set remains stationary whilethe second set of bars is retracted under the fuel bed. Upon completion of the retracting movement of the second set of bars, both sets of bars are then ready for another cycle of operation beginning with the fuel advancing movement just described. a

For actuating the grate bars to carry out the cycle of operation just described, I provide a cross-head guiding member 40 which is supported upon the furnace front 18 just below the handfiring door 19, and in which is reciprocably mounted a plurality of cross-heads'el and 42.

The cross-heads 41 are twoin number, and are connected with the bridge member 26 by means I:

of pairs of linkslB, so that upon reciprocating movement of these cross-heads the bridge members 26 and 28 will be given a tilting movement and the set of grate bars supported thereby will be moved longitudinally. The cross-head 42, which is arranged intermediate the'pair of crossheads 41,.isprovided with a connecting rod 44 which extends through an opening provided in the bridge member 26 and has a loose connection with the bridge member 25. This loose connection, as herein shown, constitutes a rounded bearing 'member 45 mounted upon the end of the rod for engagement in a similarly shaped bearing recess provided in the bridge member 25. As clearly shown in Fig. 2 of the drawings, this loose connection serves to actuate the set of grate bars carried by the bridge members 25 and 2'7 intheir retracting direction, but does not impart motion to this set of grate bars in the opposite or fuel advancing direction. a this arrangement that when the cross-heads 41 are actuated in the direction to advance the set of grate bars carried by the bridge members 26 and 28, the latter members engage the bridge members 25 and 27 and cause the set of grate bars carried by the latter to be simultaneouslyam vanced. Upon movement of the cross-heads 41 in the retracting direction, the bridge members 26 and 28 are tilted, and the grate bars carried thereby are retracted while the bridge members 25 and 27 remain stationary. Upon movement of the cross-head 42 in the retracting direction, the rod 44 tilts the bridge member 25, causing the set of grate bars carried thereby to be retracted. a

To actuate the cross-heads in timed relation to produce the grate bar movement described, I provide a rotary cam member 46 which is keyed or otherwise secured to an actuating shaft 4-7. The cross-heads 41 and 42 are preferably of the same form of construction, which, as clearly shown in Fig. 2, is substantially U-shaped. The cross-heads are supported within the cross-head guide 40 with the spaced legs 48 and 49 forming bearing portions, and with those legs straddling It will be seen from theactuating cam-46 Thelegs 48-and 49 are provided, respectively, with integral lug portions 50and 51 which are formed with inclined contact surfaces adapted to be engaged by radially projecting cam portions 52 and 53 provided-on the member 46. The cam portions 52 are two in number to correspond with the number of crossheads 41, and are arranged in alignment with each other axially of the member 46. The cam portion 53, which cooperates with the contact surfaces of the cross-head 42, is located on the member 46 at a point intermediate the cam portions 52 and is also spaced from the latter circumferentially of the member 46 approximtely 60", so that as the member is rotated the camportion 53 will always lag behind the cam portions 52.

As viewed in Fig. 2 of the drawings, the rotation of the cam member 46 is in a clockwise direction, and with the parts in the relative positions shown in this figure, the cam portions 52 have just engaged the contact lugs 50 of the crossheads 41. Further rotary movement of the member 46 causes the cross-heads 41 to'be moved toward the boiler, and, as explained above, all of the grate bars are thereby moved simultaneously in the fuel advancing direction until the cam portions 52 disengage the contact lugs 56. Continued rotary movement of the member 46 causes the cam portions 52 to engage the contact lugs 51 of the cross-heads 41 to retract the set of grate bars carried by the bridge members 26 and 28. This retracting'movement continues until the member 46 is rotated sufiiciently' to cause the cam portions 52 to disengage the contact lugs 51. Thereafter, the cam portion 53 engages the contact lug 51' of the cross-head 42, causing this cross-head, and the rod 44 connected thereto, to be moved in a direction to retract the set of grate bars carried by the bridge members 25 and 27.

In Fig. 12 of the drawings, I have shown another form of support for the discharge end of the sets or grate bars which may be used to advantage instead of the rocking bridge members 27 and 28. This support comprises a stationary bridge bar 27 extending transversely of the furnace adjacent the discharge end of the grate. The bridge bar is appropriatelyshaped to have the requisite strength to support the discharge ends of both sets of movable grate bars. As clearly shown in this figure, the top portion of the bridge bar forms a platen or table 28 having a top surface which is dished'or concave. The width of this table 28, or in other words its dimension in the direction of the longitudinal axis of the furnace is preferably somewhat greater than the extent of the longitudinal movement of the grate bars so that the grate bar portions which engage the concave table surface will not overtravel the edges of the latter.

When the bridge bar 2'7 is employed, all of the grate bars are provided, adjacent their discharge ends, with one or more rounded bearing lugs or projections which frictionally engage, and

ride in the concavity of the table 28' as the grate bars are reciprocated. The provision of concave bearing means for the discharge end of the sets of grate bars, causes the bars of one set to have a' dipping movement in the vertical plane relative to the other set of bars, and this dipping of the sets of bars as they are reciprocated greatly facilitates the advancement of the fuel being burned.

For supplying fuel to the furnace, I provide fuel feeding mechanism which is supported on the furnace front at a point above and in the clear of the hand-firing door'l9 so as not to in: terfere with the latter during hand-firing opera-, tions. This fuel feeding means includes a hollow fitting 55 having a passage 56 leading through the furnace front and communicating with the interior of the furnace. The fitting 55 is provided with a hopper 57 of. suitable shape, which is arranged to feed fuel into the passage 56. The fuel may be advanced within the passage 56 toward the furnace, as by means of a plunger 58 which is reciprocably mounted in the fitting Y55 and actuated by the crank 59 of the drive shaft 60 through the connecting rod 61. f

In order to properly distribute the fuel supplied through the passage 56, so that the same will be delivered substantially uniformly across the receiving end of the grate, I provide a distributing member 62 which is of peculiar shape, and which is arranged to cooperate with the inner. end of the fuel supply passage 56.. This distributing member is formed with a substantially horizontally disposed table portion 63 which, as shown in Figs. 2, 6, and '7, is slightly dished, or, in other words, has a semi-circular edge or lip 64 elevated somewhat above the bottom portion 65 which is substantially flush with'the bottom wall of the passage 56. This raised semi-circular edge 64 forms a sloping Weir-like barrier which affords some resistance to the fuel being delivered upon the table portion from the passage 56. As the fuel is pushed upon the table portion 63 by the action of the plunger 58, it travelsup the sloping barrier and over the semi-circular edge 64 dropping down upon the receiving end of the grate. In order to-obtain proper distribution of the'fuel as it drops from the table portion, I provide the dis-' tributing member with a depending portion 66 which is flared or inclined downwardly and outwardly relative to the table portion. This dependin portion of the distributing member, as shown in Figs. 6 and 7, is part of the surface of a cone.

This inclined flaring surface represents that partthe fuel, which is pushed over theedge 64 of the :4

table, to be distributed substantially uniformly across the receiving end of the grate, because as the particles of fuel are pushed over the edge of the table, they fall by gravity along lines representing elements of the frusto-conical surface and 4 are thereby caused to diverge or fan out to produce the desired distribution. The fuel descends along the frusto-conical surface 66, as just explained, and continues to travel along lines representing elements of that surface until the particles reach the sheared edge 6'? from which they drop downwardly in a vertical direction upon the receiving end of the grate.

It should be noted that the inverted U-shape formation, given to the depending frusto-conical portion 66, straddles the opening for the handfiring door 19, and thus aifords clearance for hand-firing operations so that the distributing member need not be removed to perform these operations or to replace broken grate bars.

If desired, a transversely extending plate 69 may be provided to prevent fuel from dropping off the receiving end of the grate. This transversely extending plate also serves as an abutment for preventing the fuel from moving toward the furnace' front with the grate bars as the latter are being retracted.

For actuating the fuel feeding means and the grate mechanism, I provide a bell crank fitting 74 which is arranged adjacent the furnace front and is adapted to be oscillated as by means, of a vertical link '75 adapted to be reciprocated by any suitable driving means. The fitting '74 is supported in suitable bearings 76 carried by the furnace front, and actuates the fuel feeding means and the grate mechanism through the links '77 and 78. This fitting is formed with a crank arm '79 to which the upper end of the link '75 is pivoted and is also provided with angularly disposed lever arms 80 and 81 which are operably connected, respectively, with one end each of the links 77 and '78. The opposite end of the link '77 is pivoted to an arm 82 which is journaled upon the crankshaft 60. A ratchet pawl 83 is associated with the arm 82 for engagement with a ratchet wheel 84 which is keyed to the shaft 60. By this arrangement, it will be seen that oscillation of the fitting 74 will cause oscillation of the lever 82 which, in turn, drives the crankshaft 60 through the ratchet mechanism to cause reciprocation of the fuel feeding plunger 58. The link 78 is similarly connected through a ratchet mechanism 85 to a pinion 86 which meshes with a gear 87. This latter gear is keyed to the shaft 47 upon which the cross-head actuating cam 46 is mounted.

For selectively varying the speed of operation of the fuel feeding means and of the grate actuating means, I provide the lever arms 80 and 81 with adjustable pivotal connections for the links 77 and 78. These adjustable connections are of similar construction, each comprising a block 88 which is slidable in a slot 89 provided in the lever arm. The block 88 has pivotal connection with its link and is adapted to be actuated in its slot by means of a screw 90 extending through the block. The screw 90 is preferably provided with a readily accessible squared portion 91 at the end there-' sired speed. It will be noted, of course, that-the means for adjusting thespeed of the fuel feeding mechanism is entirely independent of the.

means for adjusting the grate actuating mechanism, so that the speed of operation of these mechanisms, can be selectively regulated as desired to produce the most efficient operation of the stoker mechanism.

It will now be readily understood that I have provided an improved and simplified form of stoker mechanism which embodies novel means for distributing the fuel to the fuel receiving end of the movable grate substantially uniformly, un-' der all conditions of operation, and. which also embodies novel grate actuating means. It will also be readily seen that I have provided simple and eflicient means for controlling the speed of operation of the fuel feeding means, and of the grate actuating mechanism, so that these functions can be regulated independently of each other for most efficient operation. Moreover, it will be seen that the arrangement of my stoker mechanism is such as to permit broken grate bars to be readily replaced, and such that hand-firing may be resorted to if desirable or necessary.

Having thus described my invention, I claim:

1. In a stoker, the combination of a furnace having a hand-firing door and a longitudinally movable grate, means for delivering fuel to said furnace at a point located above and in the clear of said door, means disposed below and in the clear of said door for actuating said grate, and defleeting means adapted to receive fuel from said delivering means and to distribute the same substantiallyv uniformly upon the receiving end of said grate, said deflecting means comprising a member having a table portion formed with an upwardly sloping wall and having an arcuate edge and a frusto-conical' deflecting portion depending from said arcuate edge, the latter portion of said deflecting means being of substantially inverted U-shape and arranged to straddle the opening for said door.

2. In fuel feeding apparatus, the combination with a combustion chamber having a door-con-- trolled opening, of a fuel supply conduit disposed above said opening and communicating with said combustion chamber, and distributing means associated with the delivery end of said conduit, said distributing means comprising a member having a table portion formed with an upwardly sloping wall and having an arcuate edge, and a frusto-conical deflecting port-ion depending from said arcuate edge, said frusto-conical portion having an opening through the wall thereof substantially in line with the door-controlled opening.

3. In fuel feeding apparatus, the combination of a fuel supply conduit, distributing means associated with the delivery end of said conduit, said distributing means comprising a member having an approximately horizontally disposed concave fuel-receiving table provided with an elevated arcuate edge and a substantially frusto-conical deflecting portion formed integral with said table and depending from said arcuate edge, and fuel advancing means operable in said conduit for gradually pushing the fuel across said table and over said elevated arcuate edge whereby the fuel descends by gravity along said deflecting portion.

GEORGE VON I-IAASE.

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