US2026805A - Stoker - Google Patents

Description

Jan. 7, 1936. 7 L: R, T W 2,026,805

STOKER Filed Sept. 12, 1951 2 Sheets-Sheet l Luz c7 8 Stowe, f/vl/f/vrola 75 (961% M v ATTORNEYS Jan. 7, 1936. L R TOWE 2,026,805

STOKER Filed Sept. 12, 193l 2 Sheets-Sheet 2 INVENTOR. L 0 a? 711 52 0 we A TTORNEYS.

Patented Jan. 7, 1936 PATENT OFFICE STOKER Loyd R. Stowe, Shaker Heights, Ohio Application September 12,1931, Serial No. 562,436

2 Claims.

The present invention has for its object the provision of certain advantageous improvements in the construction of a mechanically operated furnace, or as more commonly termed, stoker.

Briefly outlined, the novel improvements embodying the principle of my invention reside in the provision of a plurality of multipart grate bars, all lying in the same plane, said bars being alternately fixed and reciprocable. My construction also contemplates the provision of air passages of progressively varying areas throughout the length of the fuel bed. Furthermore, such a multipart construction of the grate bars prevents warpage or misalignment. Another advantage of this assembly of small parts is that the cost of replacement and maintenance is greatly reduced inasmuch as in case of burning out or damaging a portion of a grate bar, it is necessary to remove and replace only the injured or affected part without discarding the remaining undamaged portion of the grate bar assembly as would be the case in a one-piece or unit construction. I

A further advantage is that by virtue of the fact that the grate surface as composed of the stationary and reciprocable grate bar elements,

which are disposed in a single plane, there is presented a uniform and unbroken plane surface for the perfect forwarding of the fuel from the feeding end to the discharge end. Furthermore, inasmuch as it is found practical to construct the reciprocating bars of greater width,

any disturbing action of the fuel bed which is necessarily incident to a narrow bar construction is eliminated.

Objects and advantages additional to those above enumerated shall become apparent as the description proceeds. To the accomplishment of the foregoing and related ends, said invention then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various 'mechanical forms in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is a side elevation illustrative of a stoker construction embodying the principle of my invention; Fig. 2 is an enlarged plan view of a portion of the grate surface; and Fig. 3 is an enlarged sectional view takensubstantially upon the line 3-3 of Fig. 2.

Referring more particularly to the drawings, in Fig. 1 I have shown a combustion chamber having the front wall I, the back or bridge wall -2, and the ash pit 3. The stoker frame 4.0ccupies the space below the combustion chamber, 5 and is suitably supported at both ends by the vertical beams 5 and 6. The stoker frame carries upon its upper portion the grate bar elements, indicated generally by the numeral I, upon which the fuel bed is intended to be posi- 10 tioned. The fuel is fed to the upper end of the grate surface I by means of the reciprocable action of the pusher plate 8, which is actuated by a motor'lll connected to a worm reduction unit II, which in turn is connected to the large gear l2 mounted upon the shaft l3. The shaft l3 extends across the front of the stoker and on its opposite end carries the crank arm M connected to the slotted lever arm I5 which in turn actuates a plurality of pinions l6 which engage 20 with the gear racks H on the under side of the pusher plate 8. The lever arm l5 has a longitudinal slot l8 in which the end of the pitman arm l9 may be adjustably positioned by suitable means, with the result that the degree of recip- 25 rocable travel of the pusher plate 8 can be adjusted or varied.

The pusher plate has on its under side a plurality of downwardly extending lugs 20 to which are bolted or otherwise secured the sections 2| 30 of the reciprocating grate bars. As shown in Fig. 2,. two of the sections 2| are bolted together laterally in order to compose a grate bar element. Stationary grate bars composed of the sections 22 are then alternately placed between the re- 35 ciprocable grate bars, the latter being spaced apart to permit this arrangement. The sections 2| and 22 of each bar are positioned in such a longitudinal contact that the entire grate bar element is essentially rigid and non-flexible This latter structural expedient may be accomplished by means of squaring the contacting ends of the sections as shown in Fig. 1, or by any other equivalent design, such as interfitting notches on the ends of the sections.

These grate bar elements are supported by means of several transverse channel bars 23 carried by the stoker frame 4. In order to provide a means for guiding the travel of the reciprocating grate bars, the guides 24, which are mounted against the cross channel bars 23, are held in aligned position by means of a rod 26 extending the length of the stoker frame. In order to properly longitudinally space the guides 24, there may be placed between the guidesand 56 the adjacent channel bars a plurality of pipe sec tions 21. As best shown in Fig. 3, the guides 24 have the upwardly projecting lugs 28 and 29 in order to prevent lateral displacement of the reciprocating sections 2!.

Adjacent sections 2| have the complementary lateral bosses 30 and 3! which are adapted to bear against each other along a line 32. Suitable bolts 33 and nuts 34 may be provided in order to laterally secure the sections 2! together. The upper flanges 35 of the sections 2| are made progressively wider from the lower end of the stoker to the upper end with the result that there will occur a series of tapered air passages longitudinally extending up the face of the grate surface. One advantage of such a construction is that the air admitted to the fuel bed may be appropriately varied for successive stages of combustion down the stoker. Another advantage of providing reduced air passages at the upper end of the stoker is that the amount of sifting before the fuel bed has had an opportunity to thoroughly coke, is reduced. Directing attention to Fig. 1, the stationary grate bars are secured at the lowerend of the stoker by means of downwardly extending lugs 36 on the last sections. A hook bolt 31 connects the lugs 36 to the bracket 38 on the transverse channel beam 39. It will thus be seen that the stationary grate bar elements are free to expand upward and lengthwise of the stoker frame; and that the reciprocating grate bar elements 2| being secured to the pusher plate 8 are free to expand lengthwise and downward of the stoker frame.

The retarding or dump plate 40 may be pivotally secured at the point 4| on the lower end of the stoker frame. The angular inclination of the dump plate 40 may be appropriately varied in any suitable manner, as for example, by means of the set screw 42. along the ash pit 3 in order to facilitate remova of ashes therefrom.

The retarding or dump plate 40 serves the function of regulating the rate of movement and the depth of the fuel bed on the grate bars, which will be proportionate to the resisting or retarding action of the plate 40. Furthermore different A door 43 may be positioned types of fuel will require different degrees of retardation, which varies inversely as the ash content of the particular fuel. The variation in angular inclination of the plate 40 serves as a convenient means for adjustment to accommodate various types and grades of fuel.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a stoker, the combination of an inclined 1 spect to each other, a plurality of stationary L..-

grate bars similarly composed of sectional elements, said stationary bars being alternately disposed with respect to said movable bars, and means for slidably sup-porting said movable bars comprising members secured to said frame and positioned transversely with respect to said movable bars, and guide members mounted against said transverse members and bearing against said movable bars.

2; In a stoker, the combination of an inclined y frame, a plurality of movable grate bars mounted upon said frame, said grate bars being composed of small sectional elements rigidly secured together both laterally and longitudinally with re spect to each other, a plurality of stationary grate bars similarly composed of sectional elements, said stationary bars being alternately disposed with respect to said movable bars, the upper surfaces of all of said grate bars being disposed in a common plane, and means for slidably 4 supporting said movable bars comprising members secured to said frame and positioned transversely with respect to said movable bars, and guide members mounted against said transverse members and bearing against said movable bars. 4

LOYD R. STOWE.

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