US2163370A - Stoker mechanism - Google Patents

Description

June 20, 1939;,

R. E. BRESSLER STOKER MECHANISM Filed Feb. 13; 2937 2 Sheets-Sheet l June 1939- R. E. BRESSLER mm rmcmmxsu 2 Sheets-Sheet 2 Filed Feb. 13, 1937 Patented June 1939 P TENT OFFICE STOKER MECHANISM Robert E. Bressler, Oregon, 111., assignor to Kol- Master Corporation, Oregon, 111., a corporation of Illinois Application February 13, 1937, Serial No. 125,583

2 Claims.

This invention relates to improvements 'in stoker mechanism, and it consists of the matters hereinafter described and more particularly pointed out in the appended claims. The present invention relates more particularly -to the means for feeding solid fuel from the fuel hopper to the feed screw duct for conveying the solid fuel to the retort.

In my prior Patent No. 1,956,789 granted May 1, 1934, is shown a structure for a similar purpose wherein the disk at the bottom of the hopper has peripheral teeth meshing with the helical blade or flight of the feed screw so as to be rotated or driven thereby, the present invention being an improvement thereon.

One of the objects of the present invention is to provide means independent of the feed screw which will insure a positive feed of solid fuel from the fuel hopper to the screw conveyor duct and at the same time eliminate arching or packing of the fuel in the hopper in the vicinity of its outlet end where it communicates with the duct.

A further object of the invention is to provide a mechanism for feeding solid fuel from the '25 hopper to the conveyor duct, the parts being so arranged as to insure a substantial filling of the v duct and to cause less wear on the parts involved, so that the mechanism will have a longer period of usefulness without requiring service attention. I

The above mentioned objects of the invention, as well as others, together with the several advantages thereof .will more fully appear as I proceed with my specification. i

In the drawings: 2 Fig. 1 is a perspective view of an underfeed stoker embodying the preferred form of the invention. Fig. 2 is a plan view of the drive box end of the conveyor duct and associated parts with the hopper removed from its bottom better to show the structure involved.

Fig. 3 is a detail vertical sectional view through apart of the hopper bottom and drive box on an enlarged scale as taken on the'line 33 of Fig. 2.

Fig. 4 is a detail the drive box of the stoker mechanism as taken on the line 4-4 of Fig. 3. r

Fig. 5 is a view similar to Fig. 2 illustrating a modified form of the invention and which will be more fully referred to later. I

Referring now in detail to Lthat embodiment of the'invention illustrated in the drawings: ID indicates the retort or tuyere basinof the stoker vertical sectional view through and H indicates a section of a fuel tube or duct. Said tube or duct opens at one end into the bottom of the retort at one end thereof and it is through this tube that solid fuel is fed to the fuel bed in the retort from below. The other end of said section II is operatively connected to one end of a second section l2 of the duct, the other, end of said section l2 being closed but operatively connected to a driving gear containing box. structure l3. In the sections II and I2 is a means for conveying fuel through the tube to the retort and as herein shown, said means constitutes ascrew l4 which is driven by means shortly to be described. l5, as a whole, indicates a hopper for solid fuel. This hopper is offset laterally with respect to the tube section l2 and its bottom l6 may form an integral part of that tube section. As herein shown, the hopper bottom I6 is rectangular and communicates with one side of the tube section l2 which mayhave a top opening I! therein at this point. A removable cover plate l8 (see Fig. l) is. provided for said opening, whereby access may be had to the feed tube or duct for the re.- moval of such obstructions as may here occur.

The outer end of the feed screw It extends to or toward the drive box l3 and is there operatively connected to a shaft on which is mounted a ratchet wheel l9. At proper intervals this ratchet wheel is. rotated step by step, whereby the feed screw is actuated to convey the solid fuel fed .thereinto from the hopper, to the retort. For actuating said'wheel l9, the following-mechanism is provided. On one end of the box I3 is Q mounted amotor 20 operatively connected to one 5 end of a horizontal shaft 2| located :in the top portion of the box and at a right angle to the axis of the 'screw- 1!. This shaft is 'journalled in suitable bearings 'provided therefor in the feed box and on said shaft is secured a worm 22. Said worm meshes witha worm gear 23 on a horizontal shaft 24 arranged transversely of and journalled in opposite walls of the box l3. The shaft 24 is provided with an eccentric 25 upon which" one end of a pair of connecting rods 26 is operatively engaged. The other ends of said rodsare connected to assoclatedarms 21 pivoted coa xiallywith respect to the axis of the ratchet'wheel l9. On each arm iscarried a pawl 28 for engage- 5o ment with the teeth of said ratchet wheel. Thus, in the rotation of the worm gear 23, the arms 21 are rocked back and forth to turn the ratchet wheel l9 and the feed screw l4 step by step.

A holding pawl 29 is provided in the box I; to

hold the ratchet wheel against retrograde movement.

The other end of the shaft 2| projects through the associated wall of the box l3 and a fan or impeller of a blower 30 is fixed thereto. The discharge end of the blower is connected to an air duct 3| associated with the retort I0 whereby air to support combustion is delivered to the wind box Ma and thence through tuyeres 31b to the fuel bed in said retort.

In the bottom I6 of the hopper is located a circular feeding disk or plate 32 of such a diameter as to be out of all engagement with the feed screw l4. 'Ihis'disk is provided with a central hub 33 fixed to the top end of an upright shaft 34 journalled in and extending downwardly through the bottom wall of the hopper, as shown in Fig. 3; The disk, as shown in Fig. 2 is provided with a plurality of radial ribs 35 which taper in height from the hub toward the periphery of the feeding disk. This feeding disk is driven concurrently with, but independent of, the feed screw and operates to move suflicient solid fuel toward the outlet of the hopper bottom into the conveyor tube, and at the same time cause a circular movement of the fuel in the bottom of thehopper to prevent its arching and packing. 4

As shown in Figs. 2 and 3, the feeding disk is driven from the box l3 as follows." Below and at one side of the plane of the shaft 24, is located another horizontal shaft 36. One end of this shaft is journalled in one side wall of the feed box and on said end, within the box, is secured a sprocket wheel 31. A chain 38 is trained about said sprocket and over a companion sprocket 39 on the shaft 24. The other end of the shaft 36 extends under the bottom of the hopper, radially of the shaft 34 therein and is Journalled in a bracket 40 depending from said hopper bottom. Coacting bevel gearsJl-fl are secured to said shaft ends as best shown in Fig. 3.

It is apparent that with the structure described, both the feed screw l4 and the feed disk 32 in the hopper bottom are driven from the feed box at the proper speed ratio. As the disk 32 is in no manner directly engaged with the helical rib or flight of the feed screw, a better feeding of solid fuel is possible because of a more unobstructed outlet from the hopper into the conveyor tube. Also, wear on the feed screw and feed disk is reduced. By such a driving arrangement it is possible to move the feed disk at such speed that the feed screw' conduit can be maintained substantially full of fuel at all times that there is fuel in the hopper.

In Fig. 5, I have showna modified form of the invention wherein the feeding disk in the fuel hopper is driven independently of not only the feeding disk, instead of being radial with respect.

to the axis of the feeding disk, may be tangential to the hub, as shown. This arrangement provides a better feeding action of the fuel from the hopper out through the outlet of the hopper bottom into the conveyor tuba-as a more direct "push is given to the fuel in its movement from the hopper bottom into the conveyor tube. When an independent motor is employed for driving the hopper feed, the motor may be controlled in any desired manner, to be energized and deenergiz'ed with the motor which, of course, would then only drive the feed screw and the blower.

As the feeding disk is driven independently of and is in no manner engaged with the feed screw; the wear on the disk and feed screw 'respectively is reduced to a minimum. Also, because of the omission of the interengagement of the teeth of the feed disk with the threads of the feed screw, the coal may flow or move with greater freedom into the feed screw conduit.

While in describing the invention, I have referred in detail to the form, arrangementand construction of the parts thereof, the same is .to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention: a

1. In a fuel feeding mechanism, a fuel duct, a fuel hopper arranged to one side of said duct and having a bottom with an outlet opening laterally into the duct, means in the duct for moving fuel therethrough, and a rotative feeding disk in the bottom of said hopper having a plurality of fuel feeding ribs engaged with the fuel in said bottom of the hopper for feeding fuel through the outlet into the duct, said ribs being arranged other than radial to the axis of the-disk.

'2. In a fuel feeding mechanism, a fuel duct, a fuel hopper arranged to one side of the duct and having a bottom with an outlet opening laterally,

ROBERT E. BRESSLER.

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