US1716071A - Distributor for automatic stokers - Google Patents

Description

June 4, 1929.

A. M QARTI- IUR DISTRIBUTOR FOR AUTOMATIC STOKERS Filed Oct. 4, 1923 3 Sheets-Sheet l jzdarzir 1 June 4, 1929. AMa ARTHUR i 1,716,071,

DISTRIBUTOR FOR AUTOMATIC STOKERS Filed o t. 4, 192:5 s Sheets-sheaf. 2

June 4, 1929. A. M ARTHUR DISTRIBUTOR FOR AUTOMATIC STOKERS Filed Oct. 1923 3 Sheets-Sheet ,3

0L 'fgax Patented June 4, 1929.

. unirsosraras ANGUS MACARTHUR, OF CHICAGO, ILLINOIS,

ASSIGNOR TO THE KOPPERS COMPANY,

OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

DISTRIBUTOR FOR AUTOMATIC STOKERS.

Application filed October 4, 1923. Seria1.No. 666,554.

The object of this invention is to provide an efficient distributing means for maintaining lIl boiler furnaces a well distributed fuel bed, without segregation of the fuel into piles of pieces of uniform sizes, throughout the entire area of the grate. The improved distributing means of the invention is characterized by being capable of ready installation in boiler furnaces of standard type, for example, boiler furnaces of the automatic-stoking type which employ a continuousa-nd progressively moving grate; and is further characterized by great simplicity and economy of construction and installation.

In addition to the general objects recited above, the invention has for further objects such other improvements or advantages as may be found to obtain in the structures and devices hereinafter described or claimed.

In the accompanying drawings forming a part of this specification and showing for purposes of exemplification a preferred form and manner in which the invention may be embodied and practiced, but without limiting the claimed invention specifically to such illustrative instance or. instances:

Figure 1 is a front sectional andelevational View, in part diagrammatic, .of an automatic stok'ing furnace of standard type equipped With the improvements ofthe invention;'

Fig. 2 is a side elevation of the front portion of such afurnace; and

Fig. '3 is an elevational sectional view taken longitudinally of the line of feed of the fuel into and through the furnace- The same characters of reference indicate the same parts in each of the several views of the drawings.

In the embodiment illustrated in the drawings, the invention is incorporated in a stand ard type of automatic stoking boiler furnace. For convenience, the persent description will be confined to this illustrated embodiment of the invention; the novel'features and improvements made by the invention are susceptible of other applications, for example, to furnaces of other types; hence, the scope of the invention is not confined to the specific use and embodiment herein described as an illustrated example.

The boiler-furnace illustrated in the drawing is provided with the firebox 11 which ex tends through the front wall 12 of the furnace for receiving a constant supply of fuel. The continuous grate 13 extends from "side to side of and through the fire box and is mounted at its front end beyond the furnace wall 12 on sprocket 14 driven by suitable gearing and power connections 15 for the purpose of advancing the upper reach of the continuous grate constantly into and throughthe fire x.

The fuel is deposited on the grate 13 just in frontof the wall 12zbya gravity feed through a hopper 16 which extends from side to'side of the grate. An adjustablegate 16 mounted in front of the fire box of the firebox opening permits regulation of the depthof the fuel bed on the grate. I i 1 In furnaces .of the type just briefiydescribed, great difficulty has been experienced in maintaining proper distribution of fuel from side to side of the grate because of the wide extent of such structures, and also because of the fact that it is common to employ pulverulent or finely divided fuels. Such fuels have a tendency, especially when moist, to agglomerate and to segre gate in piles of uniform-sized pieces. These conditions of irregularity must be avoided, if that an irregupossible, it being well known lar fuel bed, especially in furnacesof the above described type and when finely divided fuels are employed, is a great detriment to economic distribution of the heating efiect. Attempts have been madc'to avoid such irregularities but experience has proved them unsatisfactory in operation and result. Forexample, it has been proposed to feed the fuel into the feed hopper 16' from a swingingdischarge chute. This arrangement, however, involves an expensive driving equil'amentand does very little towards promoting equality in distribution, because of the practical impossibility of maintaining a contant volume of flow of the fuel through the chute.

The distributing means of the present in'- vention accomplishes the desired result of effecting equality in distribution of the fuel on to the grate and maintains the proper mixture of sizes. of the fuel from side to side of the grate by an extremely simple expedi ent. Extending across and supported by the sides of the upper hopper 17, which may be termed the distributing hopper, is a screw 18 of the ordinary screw-conveyer type. The screw 18 receives the fuel directly from the feed chute 19 and distributes it equally from side to side of the hopper 17 with't-he result that complete equal distribution of-the fuel with mixture of the different sized pieces is effected before it falls into the lower hopper 16 and on to the grate 13. This construction placefrom the center towards the sides, with the result that the amount of distribution necessary is reduced. The distributing screw 18 receives the fuel directly from the centrally mountedstationary feed chute 19 and feeds the fuel toward the opposite sides of the hopper.

An intermittent drive is provided for the distributing screw 18. Secured to the constantly rotating shaft 20 of the drive mechanism is a slotted arm 21, in the slot of which projects a stud 22 carried by the lower end of a connecting rod 23. The connecting rod 23 is pivoted at its upper end to an arm 2-l, which arm is in turn pivoted on the axis of rotation of the screw 18. The arm 24 is provided with a pawl 25 which operates a ratchet 26 secured to one end of the screw. Vith this construction each downward thrust of the connecting rod 23 causes the pawl 25 to effect a one-step movement of the ratchet 26 and screw 18. During the reverse movement of the connecting rod 23 the pawl 25 travels idly over the ratchet teeth.

The invention as hereinabove set forth 1 may be variously embodied within the scope of the claims hereinafter made.

I claim:

1. The combination with a continuously movable endless chain grate of a reservoir hopper extending across the'entire width of saidgrate and mounted directly over said grate so that saidgrate supports a vertically descending column of fuel in said hopper as said grate takes up aportion of the fuel while moving across the lower portion of said hopper; a spreader hopper above said reservoir hopper and co-extensive in length therewith and communicating throughout its full length, at its lower portion, with said reservoir hopper at theupper part thereof; a distributing screw arranged in said spreader hopper and provided with both right and left-hand threads respectively extending in opposite directions'from a longitudinal central point in said spreader hopper to spread fuel in opposite directions in said spreader hopper from said central point and to discharge fuel from itself throughout its length a fuel delivery chute communicating with said spreader hopper at said central point for feeding fuel to said distributing screw; and driving mechanism for effecting a stepby-step movement of the distributing screw.

2. The combination with a stoker grate of a reservoir hopper extending transversely of the direction of feed by said stoker grate andmounted directly over said grate so that said grate supports a reserve column of fuel in said hopper as it takes up a portion of the fuel therein while feeding transversely across the lower portion of said reservoir hopper; a fuel spreader hopper mounted above said reservoir hopper and'extending lengthwise thereof and communicating throughoutv its full length with said reservoir hopper at the upper part thereof, and arranged to receive fuel from a source of supply; and a powerdriven spreader comprising two sections arranged to move fuel from said source of supply in opposite directions in said spreader hopper and to discharge fuel from themselves to said reservoir hopper throughout their length, whereby the delivery of fuel to the upper portion of said reservoir hopper is constantly uniform throughout the length thereof and the depth of reserve fuel in said reservoir hopper is maintained constant throughout its entire length.

r 3. The combination with a stoker grate of a reservoir hopper extending transversely of the direction of feed by said stoker grate and mounted directly over said grate so that said grate supports areserve column of fuel in said hopper as it takes up a portion of the fuel therein while feeding transversely across the lower portion of said reservoir hopper; a fuel spreader hopper mounted above said reservoir hopper and extending lengthwise thereof and communicating throughout its full length with said reservoir hopper at the upper part thereof and arranged to receive fuel from a source of supply; and a driven spreader unit arranged to'move fuel from said source longitudinally in said spreader hopper and to discharge fuel from itself throughout its length to said reservoir hopper; whereby the delivery of fuel to upper portion of said reservoir hopper is constantly uniform throughout the length thereof and the depth of the reserve fuel in said reservoir hopper is maintained constant throughout its entire length.

4. The combination with a stoker grate of a reservoir hopper extending transversely of the direction of feed by said stoker grate and mounted directly over said grate so that said grate supports a reserve column of fuel in said hopper as it takes up a portion of the fuel therein while feeding transversely across the lower portion of said reservoir hopper; a fuel spreader hopper mounted'above said reservoir hopper and extending'lengthwise thereof and communicating throughout its full length with said reservoir hopper at the upper part thereof and underlying an overhanging fuel delivery chute for said reservoir hopper; and a screw in said spreader hopper for moving fuel from said chute longitudinally along said spreader hopper and adapted Cir for discharge of fuel from itself throughout its length downwardly through said spreader hopper to said reservoir hopper; whereby the delivery of fuel from the chute to the upper portion of said reservoir hopper is constantly uniform throughout the length thereof and the depth of the reserve fuel in said reservoir hopper is maintained constant throughoutits entire length.

5. The combination with a stoker grate of a reservoir hopper extending transversely of the direction of feed by said stoker grate and mounted directly over said grate so that said grate supports a reserve column of fuel in said hopper as it takes up a portion of the fuel therein while feeding transversely across the lower portion of said reservoir hopper; a fuel spreader hopper mounted above said reservoir hopper and extending lengthwise thereof and communicating throughout its full length with said reservoir hopper at the spreaderhopper on opposite sides of said means I for delivering a constant flow of fuel, arranged to spread fuel in opposite directions away from said means and to discharge fuel from themselves throughout their. length downwardly through said spreader hopper to said reservoir hopper; whereby the delivery of fuel from said means to the upper part of said reservoir hopper is constantly uniform throughout the length thereof and the depth of the reserve fuel in said reservoir hopper is maintained constant throughout its entire length.

In testimony whereof I have hereunto set my hand.

ANGUS MAOARTHUR.

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