US1945225A - Furnace - Google Patents

Description

Jan. 30, 1934.

0. KELLY FURNACE Filed Sept. 3, 1929 5 Sheets-Sheet l Jan. 30, 1934. -o. KELLY 1,945,225

FURNACE Filed Sept. 3, 1929 5 Sheets-Sheet 3 ,IIIIIIIIIIIIIIIIITIIIIIIIIIIIIIIII/IIII I I I I f I f I f i 0 IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII Jaz a. 30, 1934- Q KELLY 1,945225 I FURNACE Filed Sept. 3. 1929 5 Sheets-Sheet 4 q I u! HHIHHHIHHHHH 85 Jan. 30, 1934. Q KELLY v 1,945,225

FURNACE Filed Sept. 5. 1929 5 Sheets-Sheet 5 flven or' Patented Jan. 30, 1934 UNITED STATES PATENT OFFICE 2 Claims.

My invention relates more particularly to furnaces of the self-stoking time.

One feature of my invention relates to the feeder mechanism for feeding the coal from a hopper, or the like, into the furnace. In this connection considerable difliculty has been experienced in feeders as hitherto provided when the coal contains an occasional relatively large lump which is often the case with so-called slack. In constructions of feeders of the plunger type the presence of large lumps of coal often results in such jamming of the lumps between the plunger and the throat through which the feeder mechanism feeds the fuel, which must be of rel- 5 atively small size to permit of proper feed control, that the driving means of the feeder mechanism is subjected to great stresses, requiring that all parts of the structure subjected to the stresses from such lodgment of lumps, be of heavy construction to resist the stresses to which they are subjected, with resultant large expense and oftentimes resulting in the stalling of the motor of the drive mechanism. In constructions of feeder mechanism of the straight bottom feeder-plate type the presence of such lumps results in the choking of the throat through which the coal is fed, and consequent interruption of the feeding operation, inasmuch as the feeder-plate slides back and forth under such lumps without breaking or displacing them.

One of my objects in this connection is to avoid the objections above noted and to provide a construction whereby the throat may be of relatively large cross-sectional area and the depth of feeding by the mechanism sufficiently small to permit of the proper feed control.

Another object in this connection is to provide a construction which will serve to reduce the lumps of coal lodging between the throat and feed member to such size that they will pass through the throat and with the exertion of less stress on the mechanism than in the case of the plunger type of apparatus as commonly provided.

Another feature of my invention relates to the 1 driving mechanism of the stoker apparatus, my

primary object, in this connection, being to provide a compact construction of such mechanism which may be provided as a self-contained enclosed unit adapting it to be run in oil and practically noiseless in operation.

Another feature of my invention relates to a coking chamber for the fuel wherein the fuel, before discharge to the main fire bed, is preliminarily heated, one of my objects in this connection being to provide an improved construction of floor and conveying mechanism for such a chamber.

Another object is to provide a construction of furnace whereby the fire-bed is rendered selfcleaning, even with the worst of clinker-forming coals or, as frequently happens, when tin cans, broken glass, crockery, or other non-combustible masses, are throw into the furnace.

Another object is to avoid the forcing of live coals into the ash pit by the action of the stoking mechanism, thereby economizing in the use of fuel; and other objects as will be manifest from the following description.

Referring to the accompanying drawings: 7 H

Figure 1 is a view in end elevation of a hot-air m furnace equipped with my improvements, the surrounding casing of the furnace being removed.

Figure 2 is a section taken at the irregular line 22 on Fig. 1 and viewed in the direction ofthe arrows.

Figure 3 is a broken enlarged vertical sectional view taken at the line 3 on Fig. 2 and viewed in the direction of the arrow.

Figure 4 is a broken plan sectional view-taken at the line 44 on Fig. 3 and viewed in the direc- 30 tion of the arrows.

Figure 5 is an enlarged section taken atthe line 5 on Fig. 1 and viewed in the direction of the arrow, showing a detail of the feed mechanism.

Figure 6 is a section taken at the line 6 on 5 Fig. 5 and viewed in the direction of the arrows.

Figure 7 is a broken section taken at the line '7 on Fig. 2 and viewed in the direction-of the-arrow, with certain parts of the mechanism omitted; and I Figure 8, a broken section taken at the line 8 on Fig. 2 and viewed in the direction of the arrow, with certain parts of the mechanism omitted.

The particular illustrated construction of furnace, shown as a hot air furnace, compriseshol- 95 low and heads 9 and 10, flue pipes 11 and 12 for the products of combustion communicating with the interiors of the heads 9 and 10, an arched member 13 interposed between said heads, a

lower frame member 14 and a casing 15 for the 1011.

circulation therethrough ofthe air to be heated surrounding the above described parts in' spaced relation thereto, the casing 15 containiing an inlet 16 for the air to be heated and outlets 1'7 for the heated air. 105

The rear head 9 which rests at its sides on the frame. 14 is provided with a horizontal partition 18 dividing the space Within the head into upper and lower compartments'19 and 20, respectively, opposite side portions of this head being aligned with the side walls 21 of the member 13, the forward wall of the head 9 at its lower portion being open as represented at 22, and the side wall of the compartment 19 containing an outlet 23 for communication with a stack (not shown). I

The front head 10 which also rests at its sides on the frame 14 contains a partition 24 which aligns with the upper portion of the member 13 and divides the space within the head 10 into upper and lower compartments 25 and 25, respectively.

The flue pipe 11 connects at its opposite ends with the interiors of the upper compartment 19 of the head 9 and the upper compartment 25 of the head 10, and the flue pipes 12, arranged at opposite sides of the furnace, connect at their opposite ends with the interiors of the lower compartment 20 of the head 9 and with the upper compartment 25 of the head 10, the lower compartment 20 of the head 9 communicating at the opening 22 with the lower portion of the space within the member 13.

By the arrangement described a combustion chamber, indicated at 27 and comprising the heads 9 and 10 and the member 13, and fed with air through the open side of the casing 15 is provided, the products of combustion generated therein passing from this chamber rearwardly into the lower compartment of the head 9 and thence upwardly, in divided streams, into the rear ends of the flue pipes 12 and forwardly in the latter into the compartment of the head 10 from which they pass rearwardly through the flue pipe 11 into the compartment 19 of the head 9 and then discharge to the stack.

The furnace shown comprises mechanical stokingmeans for feeding fuel to the fire bed, these means also comprising the grate portion on which the fire bed is supported. The combined grate-forming and stoking mechanism shown comprises a series of stationary grate sections 28 extending entirely across, and forming the bottom of, the combustion chamber 27, these grate sections being spaced apart vertically and arranged in the form of steps as shown.

Interposed between adjacent ones of the stationary grate sections 28 are grate sections 29 mounted to be reciprocated lengthwise of the furnace and operating to advance the fire bed toward the rear end of the furnace and replenishing the fire bed with fuel delivered thereto at the .front end of the furnace as hereinafter described.

The movable grate sections 29, together with a plunger 30 located directly above the uppermost stationary grate section 28, are rigidly connected together by brackets 31 and 32 and rods 33. The brackets 31 and 32 are duplicated at opposite sides of the furnace and each of the brackets 31 is provided on its underside with a rack 34, these racks meshing with gear segments 35 rigid on the ends of a rock-shaft 36 having an arm 37 pivoted at 38 to one end of a link 39 the opposite end of which is pivotally connected at 40, with an arm 41 rigid on a shaft 42 and oscillated by the mechanism hereinafter described. A

The furnace structure also comprises a plate 100 which extends across the rear end of the combustion chamber 2'7 and is pivotally supported at its ends in U-bearings 101 (one only of which is shown) extending inwardly from the opposite sides of the chamber 27, the plate 100 having a weight 102 extending to one side of the axis aboutjwhich this plate is swingable. Located to the rear of the one of the grate sections 28 nearest the rear end of the furnace is a plate 103 which extends rearwardly beyond the rearward travel of the lowermost one of the reciprocabie grate sections 29, but spaced from the wall of the combustion chamber 27, whereby an open-. ing therebctween to the ash pit of the furnace and represented at 27 is provided; the plate 100 and plate 103 being so relatively positioned, as shown, that the plate 100 normally inclines downwardly in a forward direction under the action of the eccentrically disposed weight 102.

The top portion of the arch member 13 forms the top and sides of a coking chamber 43, the bottom of which is formed of a series of alternating stationary and sliding sections 44 and 45, respectively, which are arranged in the form of steps but reach short of the forward end of the furnace thereby to provide an opening 46 at the forward end of this coking chamber, through which the coal to be consumed in the furnace and preliminarily heated by the heat generated in the fire bed below it, discharges to the grateforming and stoking mechanism above described. The bottom of this coking chamber contains slots through. which the fine particles of coal may drop upon the hot fire bed below. In the construction shown one only of the bottom-forming sections, namely, one of the sections 44, is represented as containing slots, these slots being shown at 47, but it will be understoodthat if desired others of the bottom-forming sections may be slotted.

The sections 44 and are each of a length substantially equal to the width of the coking chamber 43, as shown in Fig. 3, the stationary sections 44 being supported at their ends on lugs 43 provided on the inner surfaces of the side walls of the member 13 and the sliding sections 45 resting on the upper surfaces of the adjacent sections 44 and guided by upwardly extending flanges 49 on the sections 44.

The sections 45 are connected together for simultaneous reciprocation, to effect the feeding of the coal supplied thereto as hereinafter described, through the coking chamber 43, by means of bars 50 at opposite ends of the lowermost section 45 which are extended rearwardly at portions represented at 51 where they terminate in racks 52.

The feed mechanism also comprises a hopper 53 for receiving the fuel, the rear wall of the hopper represented at 54, extending below the front wall thereof and depending into a trough-like feed member 55 reciprocable in an opening 56 in the rear head 9 of the furnace and an opening 15 in the casing 15, the forward end of the trough member 55 lapping the uppermost stationary section 44. The space between the lower edge of the front wall 57 of the hopper and the bottom of the feed member 55 constitutes a throat 135 through which the coal delivered to the hopper 53 is intermittently fed by reciprocating the member 55, it being understood that in the movement of the member 55 to the left in Fig. 2 coal flows from the hopper 53 into the member 55 and is 140 advanced with the latter, and upon the movement of the member 55 to the right in Fig. 2 the member 55 slides along the body of coal therein, the coal being held against movement with the member 55 by abutment with the stationary plate 145 54 thus depositing the coal upon the uppermost bottom-forming section 44 from which latter it is fed to the sections below it by the next advancing movement of the feeder member 55, the coal being progressively moved through the coking 15o chamber 43 and discharged through the outlet 46, by the member and the reciprocating sections 45.

The member 55 and sections 45 are reciprocated simultaneously by mechanism comprising a pair of gear segments 58 rigid on a shaft 59 journalled in bracket arms 60 and gear segments 61 rigid on a shaft 62 journalled in these bracket arms, the gear segments 58 meshing with racks 63 depending from the member 55 and the gear segments 61 meshing with the racks 52. The shaft 59 is provided with an arm 64 connected with an arm 65 rigid on the shaft 62 by a link 66 pivoted to these arms. The shaft 62 is also provided with an arm 6'7 pivotally connected at 68 with the upper end of a link 69 pivoted at 70 to an arm '71 rigid on the shaft 42.

It will be understood from the foregoing that rotation of the shaft 42 operates to simultaneously oscillate the gear segments 35, 58 and 61 for reciprocating the grate members 29, the sections 45 and the feed member 55.

The mechanism for rotating the shaft 42 may be of any desirable construction. That shown is in the form of a fiuid-pressure-operated piston and cylinder mechanism represented at 72, the cylinder of which is shown at '73, and may be of any suitable construction, it having a valve mechanism the casing of which is represented at '74 and the stem of the valve at '75 which serves in oscillating to control the inlet of fluid pressure to the opposite ends of the cylinder 73 and the exhaust therefrom for effecting reciprocation of the piston (not shown) therein which is provided with a piston rod 76.

The piston rod '76 is shown as carrying a member 7'7 of angular shape, the lower, horizontal, arm '78 of which is provided with a pair of spaced pins '79 between which the upper end of an arm fixed on a shaft 81, extends. The shaft 81 is journalled in the sides of a casing 82 and has secured thereto a pair of spaced disks 83 equipped with pawls 84 and 85 pivoted thereto as represented at 86 and 87, respectively. The pawls 84 and 85 are provided for cooperation with a ratchet wheel 88 located within the casing 82 and fixed on the shaft 42 journalled in the sides of the casing 82, the ends of the shaft 42 being provided with the cranks 41 and '71 as above set forth.

It will be understood from the foregoing that by reason of the provision of the pawl-andratchet mechanism just described, the oscillatory movement of the shaft 81, produced by the reciprocations of the piston of the mechanism '72, is converted into rotary movement of the shaft 42, for oscillating the gear segments 35, 58 and 61 by reason of the above described connections therebetween.

In the arrangement shown the valve device for automatically reversing the flow of fluid pressure into the ends of the cylinder '73, is automatically operated at substantially the ends of the piston strokes, through the medium of a slide bar 89 provided with stops 90 spaced apart and located at opposite sides of an arm 91 secured to the upper end of the valve stem 75, coil springs 92 being interposed between the stops 90 and the arm 91. The slide rod 89 is also provided with spaced-apart tappets 93, the upwardly ex tending arm 94 of the member 77 being positioned between these tappets and cooperating therewith to effect the shifting of the rod 89 for controlling the position of the valve mechanism,

. as will be readily understood. As the piston of the mechanism '72 nears the limits of its movement to the leftin Fig. 2 the arm 94 strikes the left-hand tappet 93 turning the valve stem '75 to permit actuating fluid pressure to enter the cylinder '73 at the left-hand end thereof in Fig. 2 and the exhaust pressure to exhaust from the opposite end of the cylinder; and as the piston nears the limit of its movement to the right in Fig. 2 the arm 94 strikes the right-hand tappet 93 to open the righthand end of the cylinder '73 to the force of fluid pressure and open the opposite end of the cylinder to the exhaust.

It will be understood from the foregoing that in the movement of the coal along the bottom of the coking chamber 43 the coal is subjected to the heat generated by the fire bed on the grate and comprising the sections 28 and 29, causing it to become heated with the result of drying the coal and at least partially coking it, the finer particles of coal dropping through the apertures 4'7 and upon the hot fire bed below and, being in dried and heated condition, these finer particles readily ignite, very much the same as in the case of gas, with almost complete combustion.

The coal in passing through the coking chamber will give off more or less of the volatile matter therein which, together with air entering this chamber at the rear end thereof and which becomes heated in this chamber, travels, under the action of the draft in the stack along the coking chamber to the front end thereof and thence into the combustion chamber 2'7 above the fire bed where it will be burned without waste or smoke.

The coal which is thus delivered to the grate sections is in dried and at least partially coked condition thereby eliminating the production of smoke and ensuring practically complete combustion of the coal supplied to the furnace.

In accordance with one of the features of my invention the rear end of the feeder member 55 is formed with an upwardly offset bottom portion 95 presenting a forwardly facing shoulder 96 in front of which such lumps of coal as may discharge from the hopper 53, become disposed in the movement of the member 55, with the result that should the lump be too large to discharge through the throat hereinbefore referred to it will be subjected to attrition by reason of the Q,

shearing or rolling effect produced thereon by the upper edge of the shoulder 96, resulting in the reducing of the lump to such size or the breaking of it into such small pieces that it may readily pass through the throat, with much less stress on the mechanism than in the case of a construction of the full plunger type of feed. Furthermore, it will be noted that whereas the throat above referred to is of relatively large cross sectional area to permit of the feeding therethrough of I relatively large lumps of coal, the effective depth of the fuel bed as fed into thecoking chamber is the distance from the raised portion 95 of the feeder member 55 to the top of the throat which distance is relatively small and thus permits of 1.;

regular feed control.

The arms 64 and 65 are preferably provided with series of pivot-receiving holes as for example as shown to adapt the apparatus for adjustment to vary, as desired, the length and speed of 1' travel of the reciprocable sections 45 and the feed member 55.

Furthermore, it will be noted that the driving mechanism of the apparatus is provided as a small, self-contained, unit and by being enclosed in a casing as shown may be run in oil and is practically noiseless in operation.

The feature of the feed for the fuel in the coking chamber comprising the alternating station ary and movable sections is of advantage as the feed is thereby rendered positive and the mechanism simple.

By providing the pivot plate 100 and the stationary plate portion 103 associated therewith as stated, the fire bed on the grate is caused, by the resistance offered by the plate 103, to bunch up at the rear portion of the fire bed against the plate 100 forming a thicker bed at this point than otherwise would be produced; the pushing action of the movable grate sections 29 being horizontal and the plate 108 presenting frictional resistance to the sliding of the fire bed across it, the partially burned out coals are crowded on top of the fire bed at this point by the movement of the forward grate sections 29, while the rear grate section pushes the ashes, clinkers, and such noncombustible masses, such as tin cans, broken glass, and crockery, which may have been thrown into the furnace, against the plate 100 which swings rearwardly and permits the ashes, clinkers, and such other masses, to drop into the ash pit; thus the fuel is entirely consumed before being dumped into the pit and the fire bed. is rendered self-cleaning.

The bunching of the fire bed against the plate 100 also serves to effectually seal the cleansing spaces at the ends of this plate thereby aiding the draft through the grate.

While I have illustrated and described a particular construction embodying my invention and shown it as embodied in a particular kind of furnace, I do not wish to be understood as intending to limit it thereto as the same may be variously modified and altered and the invention embodied in other types of furnaces without departing from the spiritof the invention.

What I claim as new, and desire to secure by Letters Patent, is:

1. In a furnace, the combination of a grate, a coking chamber directly above said grate, and means for feeding fuel along said coking chamber for discharge to said grate comprising a series of alternating stationary and reciprocable members forming the bottom of said chamber, certain of said members being apertured to permit fine particles of the fuel to discharge to the fire bed on said grate, and means for actuating the movable ones of said members.

2. In a furnace, the combination of a grate comprising a reciprocable feed section, an oscillatory gear segment for reciprocating said section, a coking chamber above said grate, the bottom of said coking chamber comprising a reciprocable feed section, an oscillatory gear segment for reciprocating said second named section and a singl power device for actuating said gear segments.

ORIN KELLY.

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