US2000702A - Domestic type stoker - Google Patents

Description

May 7, 1935. w KAY 2,000,702

DOMESTIC TYPE STOKER Original Filed Nov. 5, 1928 2 Sheets-Sheet l May 7, 1935. F. w. KAY 2,000,702

DOMESTIC TYPE STOKER Original Filed Nov. 5, 1928 2 Sheets-Sheet 2 5 ri s, Ada/a511 Patented "May 7,

DOMESTIC TYPE STOKE]! Frank w. Kay, Philadelphia, Pa, assignor to American Engineering Company, Philadelphia, Pa., a corporation of Pennsylvania Original application November 3, 1928, Serial No.

Divided and this application March 14, 1930, Serial No. 435,856

- 3 Claims. (01. 110-109) My invention relates to stokers, and it has for one object the provision of a relatively small stoker particularly applicable for domestic use, such, for example, as apartment houses and the like.

Another object of my invention is to provide a stoker 'unit of the character described which may be readily installed in existing furnaces with a minimum alteration.

Still another object of my invention is to provide a stoker comprising means whereby the fuel may be automatically fed through the usual firing door and subsequently automatically discharged through the usual ash door.

A still further object of my invention is to provide a fuel-feeding plunger with a detachable head portion positioned in spaced relation thereto, the head portion being formed to exert a feeding as well as a spreading action on the fuel.

A still further object of my invention is to provide in combination with a fuel-feeding passage, means whereby the fuel may be spread over a desired portion of the width of the stoker.

Other objects and applications of my invention, as well as details of construction and operation, whereby my invention may be practiced, will be apparent more fully hereinafter, when taken in connection with the accompanying drawings, wherein Fig. 1 is a vertical, longitudinal sectional view through a domestic type furnace embodying my invention;

Figs..2 and 3 are detail, top plan and rear elevational views, respectively, of the fuel-spreading means;

Figs. 4 and 5 are similar views of the extension means for use in connection with the structure of Figs. 2 and 3;

Figs. 6 and 7 are transverse, sectional views taken on the lines 6-6 a- .i 1-1 of Figs. 2 and 4, respectively.

This application is a division of my copending application Serial 1'). 317,065, filed November 3, 1928.

Referring to Fig.' the structure therein shown comprises a domestic type furnace I having a front wall 2 provided with an upper opening 3 enclosed by a firing door 4 and also a lower opening 5 enclosed by an ash door 6. A removable 50 stoker unit 1 for the furnace comprises broadly a-fuel passage 8 which extends through the firing door 4 and opening 3; a grate structure 9 which extends rearwardly from the fuel passage 8 and terminates in spaced 55 relation to a rear wall ll of the furnace as shown in Fig. 1.

to form an ash pocket l2; an ash crusher 3; a drag or conveyor |4 positioned in a passage l5 for removing the ashes in the pocket l2 from the furnace I through the ash door 6 and the opening 5 in the furnace front wall 2; and common 5 driving apparatus I6 for the stoker positioned Just in front of the furnace wall 2. I

Considering the stoker unit embodied in my invention in greater detail, a hopper I1 is provided with an open upper end |8 for the receipt of the fuel. A lower end portion IQ of the hopper is provided with converging sides 22 and a vertical side 23. The side 23 at the lower pointed end portion thereof is provided with an opening 24 through which the fuel may move into an offset vertical passage 25, controlled by a horizontally-positioned valve 26. The removal of the fuel through the vertical side 23 rather than through one of the angled sides 22, as well as the offsetting of the passage 25 tends to prevent the arching of the fuel in the bottom of the hopper and the consequent closing of the opening 24.

The valve controlled passage 25 is connected to an upper end 21 of.a passage 28 which is formed in a. ram casing 29. The passage 28 opens into a horizontal passage 3| in the casing 28 intermediate front and rear ends 32 and 33. Fuel in the passages 28 and 3| may be moved rearwardly by means of a ram plunger 34 which extends through the open end 32 of the casing 3\ 23. The portion of the casing 29 forming the passage 3| is of rectangular cross section and is provided with a removable bottom wall 35, permitting replacement in the event 01' damage thereto. The portion of the passage 3| between the rear end 33 thereof and the passage 28 is slightly flared vertically, affording the plunger 34 a loose fit when positioned therein. Experience has shown that such construction tends to prevent the pulverizing of the fuel and the subsequent blocking of the passage 3|.

The movement of the fuel, as well as the subsequent spreading thereof, is facilitated by the mounting of a ram or plunger head portion 36 in spaced relation to the main body portion of 4 plunger 34 on a rod 31 extending therebetween,

The plunger head portion ,38 is of block-like'form and is provided with a lower side 38 which slidably engages the bottom wall of the passage 3|; vertical side walls 39 and 4| which are positioned in spaced relation to vertical side walls 42 and 43 of the ram casing 29, Figs. 1 and 2; and front and rear walls 44 and 45. The-front wall 44 is so beveled that when the ram extension or, head portion 36 is moved 55 forwardly, the fuel in passage 29 moves readily over the same with a minimum retarding force. The rear wall 45 is so formed that when the head portion 36 is actuated in a rearward direction, a scoop-like effect is exerted on the fuel, causing not only a forward bodily movement thereof, but also an upward movement of that portion of the fuel which is directly in engagement with the bottom side 35 of the passage 3|. As a result of this upward movement of the fuel, a force is exerted on the head portion 36 tending to maintain the same in sliding engagement with the bottom wall 35. The rear side 45 is also so formed as to exert not only a lifting but also a spreading effect on the fuel.

To this end, I provide the front wall 45 with a pair of beveled side portions 46 and 41, as shown in Fig. 2, which terminate in a centrally positioned rear edge 48. When the head 36 is moved rearwardly, the rear side portions 46 and 41 cause a desired spreading of the fuel. Each of the side portions 46, 41 is provided with an upper vertically-extending portion 49 and a lower curved portion 5|. The portions 49 afford the principal fuel-abutting surface, causing a rearward movement of the fuel, while the portions 5|, in combination with the portions 49, tend to exert the desired scoop-like effect on the fuel. fuel is not only moved rearwardly during the working stroke of the ram 34 and head portion 36, but also upwardly from the bottom wall 35, as well as laterally into engagement with the adjacent portions of the side walls 42 and 43.

The ram casing 29 is mounted in the firing door 4 and extends into the wall passage 3. In order to cause the further spreading. of the fuel, a spreader casing 52 is mounted on the rear end 33 of the ram casing 29, thereby forming an end portion for the fuel passage 3|. The spreader casing 52 comprises flaringside walls 53 and 54, a bottom wall 55 and a removable top wall 56. The bottom and top walls 55 and 56 are slightly flared, as shown in Fig. 1, so that the end portion of the passage 3| may also increase in depth. The spreading of the fuel is increased by providing the bottom wall 55 with rear corner portions 51 and 58 which are beveled to a greater extent than a central portion 59.

The fuel leaving the flared end of the passage 3| moves onto a spreader extension 6 I, comprising a bottom wall 62 and side walls 63 and 64. inner sides and 66 of the walls 63 and 64 are contiguous to the corresponding sides of the walls 53 and 54, respectively, thereby forming a continuous inclined deflecting surface. A front flange 66 extends forwardly from the spreader extension 6| and it is offset, as shown in Fig. 1, so as to provide a supporting shoulder for the rear edge portion of the spreader casing 52. The flange 66' is supported on a cross beam 68, while the ends of flanges 61 are mounted in side walls 69 and 1| of the stoker unit. A relative movement between the spreader extension 6| and the spreader casing 52 is prevented by a pair of centering lugs 12 and 13 which flt complementary recesses 14 and 15 formed in a front edge portion 16 of the extension 6|. The offset flanges 61 may be extended parallel to the flaring side walls 65 and 66. Rear end portions 11 and 18 of the side walls 65 and 66 are respectively mounted on the stoker side walls 69 and 1|, as shown in Fig. 4.

The bottom wall 62 of the spreader extension 6| is provided with a central, rearwardly inclined portion 19 constituting a continuation of the inclined central portion 59 of the spreader Thus, the r casing 52, and also inclined side portions and 8| constituting continuations of the spreader casing wall portions 51 and 58, respectively. The side walls 63 and 64 are preferably hollow, providing air chambers 82 which extend slightly above the upper level of the fuel bed. Apertures 83 and 84, near the upper sides of the chambers 82, permit the escape of air so as to prevent the formation of dead air pockets. The spreading effect of the plunger head portion 46, the spreader casing 52 and the spreader extension 6| may be increased by means of a spreader member 85, Figs. 1, 2 and 3. The member 85 is provided with a pair of beveled sides 86 and 81 terminating in a vertical front-edge 88 which is in the same vertical plane with the rear edge 48 of the ram extension 36. The member 85 is also formed with a beveled rear side 89 which extends from a transverse rear edge portion 9| forwardly and upwardly, as shown in Fig. 1. As a result of the several spreading means, just described, the fuel as it finally passes over a rear edge portion 92 of the spreader extension 6| is of substantially uniform depth across the width of the stoker.

The grate structure 9 extends from the spreader extension 6| rearwardly to a supporting cross beam 93 positioned in a front wall 94 of the ash pocket I2. The stoker 1 comprises a plurality of series of grate plates 95, as shown in Fig. l of the drawings. Each of the intermediate series of grate plates comprises alternate stationary and movable plates 96 and 91, respectively. The stationary plates 96 of each intermediate series are mounted in spaced relation on horizontal steplike portions 98 of spaced longitudinally extending supporting beams 99, the front ends of which are secured to flange portions IIII of a supporting front beam 68, while rear end portions are secured to the cross beam'93. Intermediate projections of the longitudinal beams 99 rest on a cross beam I02 which extends between the stoker side walls.

The passage of siftings between the upper, front row of movable grate plates and the rear edge portion 92 of the spreader extension 6| is prevented by means of a bar I45 which is loosely mounted in a recess I46 formed in a lower side I41 of the edge portion 92. As shown in Fig. 1, the bar I45 slidably engages the upper sides of the movable grate plates forming the upper row, thereby preventing not only the passage of siftings but also constituting a wind seal preventing air from entering the adjacent portion of the fuel bed and the consequent burning of the edge portion 92 of the spreader extension 6|.

Each of the upper movable grate plates is connected with the next lower movable grate plate in its series by means of a pair of links I48, Fig. 1. pivotally mounted thereon. A pin I49 extends between these links and fits in a recess I5I formed in an end portion I52 of a lever I53 extending upwardly between the links I48 and mounted on a cross shaft I54. Shaft I54 is connected by crank arms I58 to a longitudinally-extending link I59 passing outwardly of the stoker through a bearing |6| positioned at the front end thereof.

A rear end of the link I59 is pivotally connected to a second link I62 carried by a rod I63 journaled in a bearing I64. The bearing I64 constitutes one part of a cross plate I65 which forms in a connection with the cross beam 93, the end wall 94. The rear end of the rod I 63 is connected by a link I66 to a pivotally-mounted ash crusher I61 which extends across substantially the full width of the stoker. The motion thus imparted to the upper pair of connected grate plates in each series may be imparted to the next movable grate plate by means of an adjustable lost-motion connection I68, and from the last-mentioned grate plate to the lower, rear movable grate plate by means of an adjustable lost-motion connection I69. In this way, the alternate movable grate plates of each series may be reciprocated and the movement thereof relatively adjusted to effect the desired rate of fuel travel.

Inasmuch as it is desirable to have a continuous flow of air through the side walls, a series of apertures I86 may be formed in the upper portion thereof. The air may be supplied to the airbacks in the stoker side walls, as well as to the underside of the grate structure 9, through an air passage I8! leading from a fan I88 through the ash door 6. The air passage I 8Imay comprise an outer section I89 and an inner section I90. The outer section is connected to the fan I88 while the inner section extends through the ash door and opens into the air chamber formed directly beneath the grate structure 9. An outer end of the section I90 serves to support the bearing plate I6I.

A bottom wall I9I of the air chamber formed under the grate structure 9 comprises a plurality of cross plates I92 the ends of which are connected by filler plates to the lower side wall sections. The plates I92 are mounted in spaced relation to the floor level I16 so as to form the ash-discharge passage I 5. The wall thus formed extends from the rear end wall 94 to a removable bottom wall I94 of the air passage I 81. Air is thus prevented from blowing into the ashdischarge passage I5 and is confined to the region immediately below the grate structure 9. The ash discharge passage I5 is provided with the ash conveyor I4, the inner end of which extends into the ash pocket I2, while the outer end passes through the ash door 5 and is connected by a passage I95 to an exteriorally-positioned ash-receiving receptacle I95. The conveyor I4 constitutes the subject matter of a patent to Herbert E. Preston, No. 1,837,994, granted December 22, 1931 and assigned to American Engineering Company.

In accordance with my invention, common driving apparatus I9 is provided for the several movable parts of the stoker unit I. This apparatus, as well as the fan I88, is driven by a main driving motor '96.

While I have shown only one' form of embodiment of my invention, for the purpose of describing the same and illustrating its principles of construction and operation, it is apparent that various changes and modifications may be made therein, without departing from the spirit of my invention. I desire, therefore, that only such limitations shall be imposed thereon, as are indicated in the appended claims and as are demanded by the prior art.

I claim: 1. In apparatus of the character set forth,

the combination with a passage having a horizontally flared discharge end portion, the bottom of said end portion inclining downwardly toward the side walls from the central portion thereof, a stationary distributing element located within saidend portion and substantially centrally thereof, said element comprising deflecting side surfaces converging inwardly toward the fuel receiving end of the passage and decreasing in height toward said discharge end, and means for feeding material through said passage toward said discharge end portion, said feeding means comprising a ram substantially fitting said passage at its fuel receiving end and having a head portion secured in advance of the working face of the ram and constituting supplemental feeding means and means for transversely distributing the fed material in the said flaring end portion forwardly of said ,end thereof in substantially the same vertical plane with said wedge-shaped extension to cooperate therewith to spread the fuel in said passage, the bottom wall of the flared portion of said passage inclining downwardly toward the side walls from the central portion thereof for further spreading the fuel in said passage, and means for operating said ram.

3. Ina stoker, the combination with a fuel supporting grate and a hopper, of a passage communicating with said hopper at its forward end and abutting said grate at its rearward end, a ram provided in said passage for feeding fuel discharged from said hopper through said passage, a wedge-shaped extension secured to said ram in spaced relation therewith forfeeding and spreading the fuel in said passage, said passage having top, bottom and side walls, the rear portion of said passage flaring horizontally, stationary spreading means onthe bottom of said passage adjacent the rear end thereof in substantially the same vertical plane with said wedge-shaped extension andcooperating therewith to effect spreading of the fuel in said passage, the bottom wall of said passage having a substantially fiat central surface and side surfaces which incline downwardly therefrom to the side walls thereof, for further spreading the fuel in said passage, and means for operating said ram.

FRANK W. KAY.

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