US1946482A - Feeding device for stokers - Google Patents

Description

Feb. 13, 1934. w n BURTON 1,946,482

FEEDING DEVICE FOR STOKERS Filed Nov. 5. 1931 :fillllllllllllllll! QIrz/U 677157- wan" new 17. ,Bzufiom Patented Feb. 13, 1934 1,948,582 I rename DEVICE roa sroxans Warren Bean Burton,

tion of Illinois Goshen,--Ind., assignor to Combustioneer, Inc G oshen, 11111., a corpora-' Application November 5, 1931. Serial No. 573,088 3 Claims. (01. 259-44) The present invention relates to feeding devices for stokers and particularly for stokers-in which fuel is automatically supplied from the bottom portion of a hopper.

Coarse, dry fuel moves readily downward ina hopper to the discharge opening thereof. However, flnely comminuted fuel, particularly when wet, tends to pack and bank and will arch over the feeding mechanism. Partial agitation will not bring down the fuel but will only cut a swath in the mass without dislodging the rest. Obviously, failure of the fuel to feed uniformly is highly objectionable.

Various important objects of the invention, therefore, reside in the provision of an improved agitator for fuel feeding hoppers which is capable of reaching practically every particle of the mass of fuel so as to thoroughly dislodge any fuel tending to pack, which will be effective regardless of the position it may occupy when the hopper is filled, and which does not require an excessive amount of power.

Another object of the invention is to provide an agitator of this character having improved means for driving said agitator, the moving parts of the agitator and driving mechanism being so arranged that the action thereof cannot be impaired or clogged by the fuel.

Other objects of the invention are to provide 3 a new and improved agitator which will tend, upon movement through its orbit, to dig into the body of the fuel in the hopper whereby to operate efficiently as long as any particle of fuel remains in the hopper.

Figure 1 is a plan section of a feeding device embodying the invention and is taken along the lines 1-1 of Fig. 2.

Fig. 2 is a longitudinal vertical section through the device taken along the line 2-2 of Fig. 1. Fig. 3 is a transverse, fragmentary, vertical section through the agitating mechanism on the line 3-3 of Fig. 2 and showing the details of construction on an enlarged scale.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawing and will herein describe in detail the preferred embodiment, but

it is to be understood that I do not thereby in tend to limit the invention to the specific form disclosed, butintend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawing, the invention is adapted for various types of the wall 16 into a gear box housing 24 within A general aim of the invention is to provide an agitator mechanism which is simple and inex- Y The present fo Zmediate the walls 1}; v through a suitably formed aperture in the flat stokers embodying feed hoppers and for purposes of illustration is described in connection with a vertical hopper 10 having a conveyer screw 11 extending laterally through the bottom for discharging the fuel from one side thereof. Preferably, the hopper 10 is' rectangular in cross section and embodies a base 12 having inclined opposed side walls 13 and 14 defining a V-shaped trough 15 in which the feed screw 11 is disposed. End walls 16 and 17 complete the base structure. Walls 18, forming the upper portion of the hopper 10, are supported by the several walls of the base 12 and the walls 18, immediately above the base, are arranged to flare outwardly for a considerable distance above the base. At a suitable point, indicated 19 (Fig. 2) thewalls taper inwardly to define a somewhat restricted open top face 20 which may be closed by any suitable type of cover (not shown). The conveyer screw 11, which. comprises a helical plate 21 carried by an axial shaft- 22, extends from the trough 15 through the wall 17 into a discharge duct 23 which leads to the fire box of the stoker (not shown). The opposite end of the shaft 22 extends through which a well-known type of change speed gear mechanism (not shown) drivingly connects the shaft 22 with a sourceof power such as an electric motor 25.

-The. presentdevelopment embodies a driven shaft 26 whichoperates an ash 'conveyer screw (not shown) for removing ashes from the retort. This shaft, in the present instance, is driven from the shaft 22 through a chain and sprocket connection (not shown) but located within the housing 2'7. This shaft 26 is horizontally spaced from the shaft 22 and extends beneath the base -12 of the hopper, as may be clearly seen in Fig.

2. The agitator mechanism is supported by the base 12 and it is preferred that the base be enlarged at one side, as indicated at 28, to provide a flat horizontal portion 29 overlying the shaft 26.

of agitator embodies an elongated shaft 30 whl h extends vertically through the hopper at 'one side of the feed screw 11 interm and 1'7. The shaft passes portion 29 of the base at one side of the shaft 26 and is rotatably journalled in upper and lower bearings 31 and 32 respectively formed in a brack- 1] et 33 which is secured to the flat portion 29. The

upper bearing 31 preferably is elongated and extends upwardly through the aperture in the flat portion 29 into the hopper where the bearing is internally screw-threaded to engage screw 1 threads formed on the lower end of ashaft-encompassing sleeve 34. The sleeve 34 extends nearly to the top of the shaft 30 (see Fig. 2) and is, in turn, encompassed by an outer sleeve 85 which is secured to the upper end of the shaft 30 1 within the'end of the sleeve 35 and a pin 3'1 extending through the parts drivingly secures theshaft, plug and sleeve together. If desired, an

axially disposed lubricating aperture may be pro vided in the plug 36, which aperture is normally closed by a suitable screw 38. H

The agitator shaft 30 is driven in the following manner. The shaft 30 intermediate the bearings 31 and 32 has a worm wheel 39 aflixed thereto as by means of a pin 40*. This wheel'is located in the horizontal plane of the shaft 26, which shaft carries a worm 40 arranged to mesh with the worm wheel 39. It'will thus be evident that the drive for the agitator shaft 30 is outside the'hopper where it cannot be afiected by fuel dust or the like. Moreover, the arrangement of the shaft 30, the intermediate sleeve 34, *andthe outer sleeve 35 positively prevents fine fuel or dust from entering between the relatively rotating members and also protects the bearing 31 from such foreign matter. This construction, therefore, eliminates undue wear of the moving parts as well as interruption of the operation thereof due to clogging by thepacking of finefuel between the relatively moving parts.

Within the hopper, and spaced a short distance from the bottom thereof, the outer sleeve 35 has a collar 41 rigidly secured thereto as by welding. One side of the collar 41 carries a lateral exten-- sion 42 (Fig. 3) which is vertically recessed as at 43 (Figs. 1 and 3) to receive an eye 44 formed at one end of an agitator rod 45. 1 The rod is pivotally mounted on the collar 41 in any suitable manner as by a stub shaft 46 traversing the recess and to which the eye is secured by a pin 4'7. Thus, as the outer sleeve 35 is driven by the agitator shaft 30, the agitator rod 45 may describe a substantially circulatory path throughout the interior of the hopper. The movement of the agitator rod is eccentric with respect to the axis of the agitator shaft 30 due to the fact that the connection of the rod withithe sleeve 35 is offset laterally of the sleeve by the collar 41.

Means is provided for urging theagitator rod.

35 outwardly toward the walls of the hopper. One preferred form of such means; comprises a helically coiled spring 48 mounted in a tubular housing 49 located above the collar 41. The

\ tubular housing 49 is rigidly secured, as by welding, to the outer sleeve 35 and has a lower open end through which the spherically headed end of a connecting'link 50 may extend into engagement with the spring 48. The other end of the link 50 is enlarged and has a horizontal bore 51 (Fig. 3).

zontal apertures therein arranged to be brought into registration with the bore 51 in the link- 50 to receive a bolt 53 which serves as a connecting shaft for the parts. 7

Preferably, the-bolt has an enlarged portion providing an intermediate shoulder 54 which is arranged to abut against one side of the clip 52,

An inverted U-shaped clip 52, arranged to straddle the agitator rod 45, has alined hori'-' arms. Adjustment of the connection between the link 50 along the length of the agitator rod 45 may, therefore, be easily accomplished by loosening the nut 53, moving the assembly into proper position with respect to the agitator arm, and then tightening the nut to secure the parts together. The tension of the spring 48 is adjustable in any convenient manner, as by providing a plug 56 (Fig..2) in the upper end of the tubular housing 49, which plug carries an adjusting screw 57 having a head 58 within the housing and bearing against the upper end of the spring.

In operation, upon filling the hopper 10 with fuel, such as finely comminuted coal, and driving the-screw conveyer 11, the agitator rod 45 will be driven through the driving connections within the housing 27, shaft 26, worm and worm wheel 39, 40, shaft 30 and sleeve 35. The eccentric location of the arm with respect to the axis of its driving means causes the rod 45 to describe fuel is fed from the hopper, the spring 48 exerts a force tending to move the rod 45 out wardly toward the wall of the hopper, thereby causing the arm to move through paths of increasing scope as the fuel is fed. Although the hopper is of irregular shape, the tension of the spring 48 is sufficient to cause the rod to reach into practically all parts of the hopper including the corners. Consequently, fuel cannot arch in the upper portion of the hopper but is supplied, as required, to the conveyer 11.

- I claim as my invention:

1. In a stoker, the combination of a hopper having means for conveying fuel therefrom, a vertical shaft projecting into said hopper through the bottom thereof, means for driving said shaft, a collar located in the lower portion of said hopper and drivingly connected with said shaft, an agitating arm extending sidewardly and upwardly from said collar, a lateral projection on said collar having a recess therein to receive one end of said arm, means for pivotally connecting said arm and said collar and projection together, and resilient means for urging said arm downwardly and outwardly towards the walls of said hopper.

2.;In a stoker, the combination of a hopper, a shaft extending vertically toward the bottom thereof, a sleeve encompassing said shaft and connected therewith, a collar on said sleeve disposed in the lower portion of said hopper, an

,wardly and outwardly, said point of connection being eccentric with respect to the axis of rota- ,tion of the shaft, and spring means interposed between said sleeve and said arm for urging said arm downwardly and outwardly toward the wall of the hopper.

- thereof, a sleeve encompassing said shaft and connected therewith, an arm pivotally connected with said sleeve in the lower portion of said hopper for movement on a horizontal axis, a tubular housing rigid with said sleeve, a helical spring within said housing, and a connecting link interposed between one end of said spring and said arm for urging said arm toward the walls of said hopper.

o j WARREN DEAN BURTON.

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