US2019942A - Stoker for furnaces - Google Patents

Description

NOV. 5, 1935. G, E, VALENTINE 2,@994-Z lSTOKER FOR FURNAGE S Filed Aug. 9, 1954 4 Sheets-Sheet 1 ATTORNEY 5, W35 G. E, VALENTINE Zwg sToKER FOR FURNAGES Filed Aug. 9, 1954 n 4 Sheets-811391, '2

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ATTRNEv Nov., 5, 1935. G, E, VALENTINE STOKER FOR FURNACE S www Filed Aug. 9, 1934 4 Shetsfsheet 5 m E N k amm e u H1 .INN QN l w Q l I Lal F m l. 8%. S wl Nw n NNW ATTORNEY E m T N E L A v E G.

STOKER FOR FURNACE'S Filed Aug. '9, 1934 .4 Sheets-Sheet 4 INVENTOR lATTDRNEY Za-argef yale/zh@ Patented Nov. 5, 1935 UNirED STATES PATENT OFFIC s'roKER FOR FURNACES George E. Valentine, Schuylkill Haven, Pa.

Application August 9, 1934; Serial No. I739,151

8 Claims.

The present invention relates to an improved stoker forv furnaces, and a purpose of the invention is to provide an apparatus for facilitating the burning of rice and other small gauge coal.

Another purpose is to provide, in an apparatus of this kind, means for screening the coal, a hopper for receiving the coal and means for intermittently feeding the coal from the hopper to the fire and providing a direct constant draft lthrough the bed of coal on the fire.

Another purpose is to provide an air drum having an upper perforated wall forming a fuel supporting plate on which the re bed rests, an air and coal feed pipe communicating with the in- 15,A terior of the drum and having a coal outlet above the fuel supporting plate, and means for distributing the coal from said outlet over the surface of said plate.

The invention comprises further features and combination of parts to be hereinafter set forth,

shown in the drawings and claimed.

In the drawings:-

Figure 1 is a view in perspective of Stoker mechanism constructed in accordance with the invention and applied to a furnace.

Figure 2 is a View in side elevation of the Stoker mechanism showing the air drum and its cornmunicative connections with a combined coaland air feed pipe in section. Y

Fig. 3 is a sectional view taken on the line 3--3 of Fig. 2 showing means for feeding the coal from a container into the hopper, the screening means, and parts of the means for intermittently feeding coal from the hopper.

A Fig. 4 is a sectional View taken on the line 4 4 of Fig. 3, showing an oscillatory valve associated with the hopper and forming part of the intermittent feeding means and an opening in the valve in communication with the hopper.

4()` Figure 5 is a detail sectional view of the oscillatory valve and its casing, showing the opening in the valve out of communication with the hopper and out of communication with an outlet from the oscillatory valve casing. Y Figure 6 is a sectional View through the oscillatory valve and its casing showing the opening in the Valve in communication with the outlet from the valve casing.

Figure 7 is a cross sectional View through a wire fabric screen tube on one end of the coal feed pipe from the container, and taken on line 'II-l of Figure 3.

Figure 8 is a detail view in elevation of one end of the oscillatory valve casing. Figure 9 is a View in elevation of the opposite Figure 13 is a bottom plan View of the air drum 10 showing supporting bars therefor.

Fig. 14 is a plan view, Apartly in section, of an arm and sleeve associated with the air and coal feed pipe, and

Figure 15 is a sectional view on line I-I of 15 Figure 2.

Referring to the drawings I identifies a base including a frame 2, on one end of which a conventional type of change speed mechanism as shown in dotted lines in Figure 3, is mounted, a 20 housing 3 enclosing said mechanism. A shaft @i connecting with a conventional type of motor 5 is connected operatively with the change speed mechanism within the casing 3.

On one end of a shaft 6 of said change speed 25 mechanism a sprocket wheel 1 is mounted, the sprocket wheel being in turn operatively connected by a sprocket wheel chain 8 to a sprocket 9 on a cylindrical feedtube I0, which in turn is rotatably mounted at one end in a bearing on 30 the upper end of an upright II rising from the base l the other end of the tube having a bearing in a support 43. A suitable chain tightener I2 is operatively supported' on the upright ii and adapted to engage one side of the chain 8 for 35 retaining the chain suitably tightened. This coal feed tube I extends. into a coal container i3. One end of the coal feed pipe has a cut away por- Y tion or notch I`3a, through which the fuel, such as rice coal or the like may pass and enter the 40 tube I0, said coal gradually feeding through the tube in an inclined direction toward the other end of the feed tube. This other end carries a short section of wire fabric forming a coal discharge element I4, which is secured on the end 45 of the feed tube Il) by a suitable band I5.

A casing I6 for an oscillatory valve I'I is provided. This casing has an upstanding hopper I8 and a depending portion I9, into which a coal and air feed pipe or tube 2U is secured at 2I. Also 50 fastened securely by any suitable means in the other end of the depending portion I9 of the valve casing I6 is a tapered lateral portion 22 carried by one side .of a conventional type of blower casing 23, the blower fan 23a therein 55 generating sufficient velocity of air to feed coal approximately the size of rice through the air and coal feed pipe 2U. The blower fan is operatively carried by the other end of the motor shaft 5 4, the operation of the motor furnishing power to the blower as well as to the change speed mechanism.

The shaft 6 of the change speed mechanism carries on its end opposite the sprocket 1 a disc 10 24, eccentrically to which at 24a a connecting rod 25 is pivotally secured. The connecting rod 25 passes through a sleeve 26 carried at the lower end of a tubular element 21, which is pivotally mounted at 28 on an arm 29, which is fixed at 30 to one end of the oscillatory valve I1. A detent plug 3| tensioned by a spring 32 is mounted in the tubular element 21, and its nose 33 normally engages an annular groove 34 in the connecting rod 25. The spring 32 is held in place by a screw 34a, which isthreaded into the tubular element 21. A second connecting rod 35 is connected to the arm 2Q by a pivot 28a. The second connecting rod 35 in turn is operatively pivw oted to an arm 36 carried by a sleeve 55 rockable on a sleeve 63 integrally depending from the center of the bottom of an air drum 5i] presently described.

The oscillatory valve proper I1 oscillates in i Athe casing I6, the valve I 1 being in tubular form, and its wall has an elongated opening 38. Where `the hopper I8 joins the casing I5 a port 39 is provided, and where the depending portion l5 of the valve casing joins the casing I5 an opposite port 40 is provided. The opening 38 in the valve I1 proper is so elongated and of such a size that when the valve is in one position partly and sufficiently registering with the port 39 coal from the hopper may enter the valve and when the valve is rocked sufficiently in the opposite direction the 40 opening 38 may register with the port 55, in which case the coal in the valve will drop through the depending portion I9 of the valve casing and enter the coal and feed pipe 20, it being understood that the velocity of the air in the latter is sufficient to carry or feed the coal through the tube or pipe 20 and into its vertical portion to the air drum 5). When the oscillatory valve I1 is in a position where the opening 38 is positioned between the ports'39 and 53, said ports 39 and 40 are closed. The construction and operation of the valve I1 are such that the opening 3B in the valve I1 cannot register with the ports 39 and 40 at the same time. Also at no time can coal pass straight through the valve and straight through the depending portion I9 of the valve casing.

In the event any hard particle of coal or other foreign substance lodges between one edge of the opening 38 and one Wall of the port 39 the valve I1 proper ceases movement for the time being until it either loosens and falls down into the valve or breaks. While the valve proper l1 remains still for such a period of time, the pressure action is sufficient at this point to overcome the pressure of the spring 32 and cause the nose 33 of the detent element 3l to escape from the groove 34 in the connecting rod 25, in which event the rod 25 will move back and forth through the sleeve 25 without imparting any movement to the valve.

Suitable guide pins 4l are mounted in a lateral portion 42 of the hopper and carry a support 43, which in turn receives and supports one end of the coal feed tube Ill. The guide pins 4I slide through the lateral oortion 42 of the hopper I8,

there being a screw 44 mounted in the lateral portion 42, so that by rotating the screw the support 43 may be raised and lowered, for the purpose of regulating the inclination of the coal feed tube or pipe I3. By inclining the coal feed tube I slightly upwardly a more gradual feed of the coal will be provided, and by lowering the tube or pipe slightly downwardly, it is obvious that the feed of the coal will pass therethrough more rapidly. The upper end of the screw 44 10 has a rotary connection at 45 with the support 53. Suitable oil cups 4B are carried by the casing of the oscillatory valve I1 proper in order to permit the valve to more easily rock in the casing. A guide element 41 is mounted in the 15 hopper to guide the coal into the hopper as it is screened through the Wire fabric tubular element at one end of the feed tube I0.

Mounted in the re box 43 of a conventional type of furnace on supporting bars 49 is an air 20 drum 5B, the top plate of which supports the fuel and is perforated as at 16 for a purpose presently seen. The supporting bars 4S rest upon a flange 5i of the interior of the re box. The bottom of the air drum 50 is composed of three sections, 25 an intermediate section 52 and opposed side sections 53. The intermediate section 52 has integral transverse ribs 54, the ends of which overlie the adjacent edges of the outer side sections 53, the transverse bars 43 being secured at 55 to 30 the ribs 5G. The sections 52 and 53 forming the bottom to the air drum are secured at 55 to the lower edge of the cylindrical side wall of the air drum.

The coal and air feed pipe 23 at its end near- 35 est the center of the air drum carries a T union 51 held in place by a screw 58, there being a plug 59 secured at 53 in said T. The inner end of the plug has a curved deflecting wall 6I, to cause the coal and air to more readily follow through 40 the interior tubular section 31 of the upright portion of the coal and air feed tube, the lower end of which rotatably ts into the T 51. The intermediate section 52 of the bottom of the air drum has depending from its center and integral 45 therewith a sleeve 63, which has a loose t of substantially ,-16 of an inch more or less and is coaxial with the inner tube 31. Welded, shrunk or otherwise made fast to the inner tube 31, is a ratchet wheel 64, and mounted to rock on said 50 sleeve 53 depending from the intermediate section 52 of the bottom of the air drum is the sleeve G5, which integrally carries said arm 35, to which said connecting rod 35 is pivoted. The arm 35 of the sleeve 65 has three apertures 51, into any 55 one of which a pivot pin 68 may engage, so as to regulate the pivot point of the connecting rod 35, and thereby increase or decrease the throw of the arm 35 and hence increase or decrease the rocking movement of the ratchet wheel 64. The 60 arm 35 has pivoted thereto at 69 a pawl 10, which is spring tensioned at 1I to retain the pawl in engagement with the teeth of the ratchet. As the connecting rod 35 is pulled through the mef dium of the movement of the connecting rod 25 65' and the disc 23 which also operates the valve I1, an intermittent or step by step movement is imparted to the inner tube 31, in the direction of the arrow as shown in Figure 14.

The inner tube 31 approximately where it 70 passes through the air drum is provided with diametrically opposite openings 12, and made fast in any suitable manner to the inner tube 31 at 14 is the inner endrof a spiral feed band 15 with the lower edges of the coils of said band rotatably 75' I resting on the bottom of the air drum, so that such coal dust or the like as may pass through the perforations 16 in the topl plate ofthe drum, may fall on the bottom of the drum, and be picked up by the free end 11 of the feed band and fed back toward the center of the drum and through the beveled opening 18, which communicates with the approximate le of an inch of space between the depending sleeve 63 and the inner tube 31 as shown at 19. At right angles to where the arm 3S is integrally connected with the sleeve 65,'said sleeve is provided with diametrically opposite cut away portions or notches Sil. The depending stationary sleeve G3 is provided with similar diametrically opposite cut away portions or notches 8l. These notches register so as to permit small particles of coal or coal dust that may pass through the space 19 to fall out upon the surface of the ratchet and thereby be fed to the outer periphery of the ratchet and then into the ash pit. This dust or the like that so passes away into the ash pit is of small quantity. However, the greater portion of the dust or the like that is fed toward the center of the air drum by the spiral head feeds through the beveled opening 13and then through the diametrically opposite openings 12 of the inner tube 31, to the interior or" said pipe, so that with the oncoming coal and air feed, this dust or the like will be carried upwardly through the inner tube 31 and hence through the nozzle 83. This nozzle 83 has opposite frustro-conical portions 8S and S5, the smaller ends of the tapered portions joining at a suitable point substantially between the larger ends. This nozzle rests within the seat t6 at the upper end of the inner tube 31, there being diametrically opposite screws 81 and 81a. The screw 81 is threaded through the wall of the upper end of the inner tube 31 and also into the nozzle, holding the nozzle xed tothe tube. The screw 81a is threaded through the wall of a head 83, the inner portion 239 of said wall of the head 88 fitting exteriorly of the upper end of the inner tube 31. The interior surface of the wall 89 of the head 83 as shown at 911 is beveled over toward the marginal edge of the smaller tapered end of the nozzle, as shown in Figure 2, thereby preventing any coal `or coal dust entering between the nozzle and the wall.

As will be noted the head 88 on the upper end of the inner tube 31 is eccentrically mounted, and as it intermittently rotates the coal is deected by the curved surface 92 of the cover S3 (which is secured in place at 965) down through the eccen tric part 95 of the head and out through the opening 96 upon the perforated top plate of the air drum 50. As previously stated the coal dust and thelike that may pass through the perforations 16 will be fed by the spiral toward the center of the drum and through the opening 12 and then blown up through the tube 31 and through the nozzle 83 and back upon the surface of the drum. The various convolutions of the spiral 15 are held in place by the radial pieces 91. A collar S8 secured at S9 on the inner tube 31 retains the spiral 15 in place with the lower edges of the convolutions scraping against the upper surface of the bottom of the air drum.

The coal passes through the coal and air feed pipe upwardly through the inner tube 31, through the nozzle 83, through the head 38 and is turned downwardly by the surface 92 through the eccentric portion of the head and then out through the opening 96. Obviously as the head 38 is rotating in the direction of the arrow b, as shown in Figure 11, the outer surface at |00 of the ecthedrum is slightly beveled at lill a slight re- 5 tardation of the coal is afforded, thereby preventing the coal from feeding off the periphery of the drum too freely. Obviously since the air passes through the feed pipe 2Q with considerable velocity, a substantial quantity of the air will pass 10 laterally out through the openings 12 and up through the perforations 16 of the upper wall of the drum, the tendency being to facilitate the burning of the coal. Therefore it is obvious that the ash at the bottom of the re bed will feed 15 off the periphery of the drum. A certain portion of the ash together with some coal dust will pass through the perforations 15, and then be fed back through the opening 12, then vupwardly through the tube 31 and back upon the fire bed 20 g by way of the passage through the head 88.

The clearance of l1-S of an inch between the sleeves 51 and 63 is to permit the sleeve to freely rotate, and it is not the purpose to supply any lubrication into this clearance, for the reason 25j that any coal dust in being fed through the diarnetrically opposite openings 12 that may pass through this clearance would mix with the lubrication and therefore tend to clog up this clearance and prevent free rotation of the sleeve 31. 30':

The clearance may vary according to circumstances, namely can be any size suitable to allow such coal dirt that may not pass through the openings 12 to easily pass through the clearance and discharge at its lower end upon the surface 35 1 of the ratchet and finally fall from the periphery of the ratchet to the iioor.

The air and coal in passing through the restricted portion of the passage through the Venturi nozzle creates a back pressure down through 40 the sleeve or tube 31 and is fed laterally through the openings 12, the air passing upwardly through the perforations 16, thereby facilitating the burning of the coal on the air drum. The coal or coal dust that does not pass upward through the 45 periorations 16 will fall back upon the lower Abottom of the air drum and be picked up and fed spirally toward the center of the drum and thence through the opening 12 or 29 and downwardly through the sleeve 31, and through the medium 50 of air again fed upwardly and through the restricted opening of the Venturi nozzle or tube and then upon the surface of the fire bed.

In Figure 2 of the drawings the radial pieces or arms 91 are secured to the upper edges of 55 the convolutions of the spiral band 15, through the medium of pins 91a. However, said arms 91 may be directly -connected to said band 15, if desired, as shown in Fig. 12.

Y The invention having been set forth, what is 60 claimed is:

1. The combination with a furnace havinga fire box, of a drum mounted in the fire box and including an upper perforated fuel supporting plate, said drum having a vertical central open- 65 ing therein, a fuel feed tube rotatably mounted in said opening and having an eccentrically mounted head above said plate for distributing fuel over the latter, pneumatic means for feeding coal upwardly through said tube to said head, 70 and means for rotating said tube.

2. The combination with a furnace having a re box, of a drum mounted in said re box and including an upper perforated fuel supporting plate, said drum having a vertical central open- 75 ing therein, a fuel feed tube rotatably mounted in said opening and having fixed thereon above said plate an eccentrically mounted head for distributing fuel over said plate, said tube being 5 provided with apertures communicating with the interior of said drum for the passage of dust deposits in said drum back into said tube, pneumatic means for feeding fuel upwardly through said tube to said head, means for intermittently rotating said tube, and means in said drum rotated by said tube to feed the deposits in the drum toward said apertures.

3. The combination with a furnace having a re box, of a drum mounted in the fire box and "including an upper perforated fuel supporting plate, said drum having a vertical central opening therein, a fuel feed tube rotatably mounted in said opening and having fixed thereon above said plate an eccentrically mounted head for distributing fuel over the plate, pneumatic means for feeding fuel upwardly through said tube to said head, and means for intermittently rotating said tube.

4. The combination with a furnace having a fire box, of a drum mounted in the fire box and including an upper perforated fuel supporting plate, said drum having a vertical central opening therein, a fuel feed tube rotatably mounted in said opening and having fixed thereon above said plate an eccentrically mounted head fo-r distributing pneumatic means for feeding fuel upwardly through said tube to said head, and means for intermittently rotating said tube.

5. The combination with a furnace having a fire box, of a drum mounted in the fire box and including an upper perforated fuel supporting plate,

said drum having a vertical central opening therein, a fuel feed tube mounted in said opening and having thereon ab-ove said plate a head for distributing fuel over said plate, and means for feeding fuel upwardly through said tube to said head and comprising a combined coal and air feed pipe, a hopper for supplying fuel to said pipe, an oscillatory valve for intermittently feeding fuel from the hopper to the pipe, a motor, operating connections between said motor and valve and including a lost motion connection permitting operation of the motor in the event that operation of the valve is blocked, and a blower for creating an air blast through said pipe and operated by said motor.

6. The combination with a furnace having a fire box, of a drum mounted in the re box and including an upper perfo-rated fuel supporting plate, said drum having a vertical central openmotor, and operating connections between said motor and said tube valve and blower respectively, the connection between the motor and valve including a lost motion connection permitting operation of the motor in the event that operation of the valve is blocked.

'7. The combination with a furnace having a fire box, of a drum mounted in said nre box and including an upper perforated fuel supporting plate, said drum having a vertical central opening therein, a fuel feed tube rotatably mounted in said opening and having fixed thereto and above said plate, an eccentrically mounted head for distributing fuel over said plate, and` means for feeding coal upwardly thro-ugh said tube to said head and including, a combined fuel and air feed pipe, a hopper for supplying fuel to said pipe, an oscillatory valve in said hopper for intermittently feeding fuel from the latter to said pipe, a fuel supply container, a rotatable feed pipe between said container and hopper for feeding coal from the former to the latter said pipe having a cylindrical screening portion located over said hopper and being adjustable to different angular positions to vary the feed of coal into the hopper, a blower for directing a blast of air into the combined fuel and air feed pipe, and means for rotating said tube and rotatable pipe and operating said valve and blower, and including an intermittent drive for said tube.

8. The combination with a furnace having a fire box, of a drum mounted in said fire box and including an upper perforated fuel supporting plate, said plate having a vertical central opening therein, a fuel supply tube rotatably mounted in said opening and having fixed thereon above said plate an eccentrically mounted head for distributing fuel over said plate, said tube being provided with apertures therein communicating with the interior of said drum for the passage of dust deposits from the drum into said tube, pneumatic means for feeding fuel upwardly through said tube to said head, means for intermittently rotating said tube, and means in said drum for feeding dust deposits therein toward said apertures and including a convolute spiral member rotated by said tube and engaging the bottom of said drum.

GEORGE E. VALENTINE.

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