US1620509A - Fuel-distributing means for underfeed stokers - Google Patents

Description

March 8 1927.

R. L. lax-:Ens

FUEL DISTRIBUTING MEANS FOR UNDERFEED STOKERS Filed June 3, 1922 QQ/QWaL/WMM'VM Patented Mar. S, 1927.

UNITED ROYCE I.. BEERS, OF DETROIT, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO RILEY STOKER CORPORATION, OF "WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

FUEL-DISTRIBUTING MEANS FOR UNDER/FEED STOKERS.

Application led .Tune 3,

In the operation of underfeed stokers it is general practice to introduce the fuel longitudinally into a retort by means of a reciprocating ram, and in the retort or in connection with the ram to employ supplementary fuel distributing means to assist in moving the fuel longitudinally along the retort after it has started beyond the effective range of direct operation of the ram. Effective distributive action within the retort is highly important, fundamentally effecting, as it does, the depth of fuel and of the fire-bed in different areas of the retort, the permeability of the fuel mass to air for support of combustion, and the resultant combustion-rate and the completeness of fuel consumption. Furthermore, a stoker installation may be called upon to handle fuels of widely varying characteristics as to the conditions which will best attain the desired character of lirebed together with most effective and complete consumption of the combustibles. There are coals which cake very hard and which usually require a deep fuel-bed, while other coals cake but little and may be edectively burned in thinner beds. Some coals coke very quickly and require early agitation in their traverse of the retort to maintain requisite permeability to air; others coke very slowly and are best handled with delayed agitation. For some coals it is desirable to maintain a ratio of depth between the green-fuel receiving end of the retort and its ash-delivery end quite different from the ratio that best will meet the characteristics of other coals; and so, in many stoker installations it is of greatest importance to secure distributive action accordant with peculiar qualities of the coal being burned.

One of the objects of my present invention is to provide in an underfeed stoker fueldistributing means variably operatable to give, most flexibly and over a wide range, those distributive and agitating characteristics which will enable the maintenance and handling of the fuel bed to conform to the conditions requisite for best combustion of widely different fuels, and further objects of my invention are to provide mechanical fuel distributing instrumentalities in simple, inexpensive and effective form widely adaptable to various designs of stokers. Other and further objects of my invention will become apparent from the following descrip- 1922. Serial N0. 565,543.

tion, taken in conjunction with the accompanying drawing, but it will be understood that while, for purposes of disclosure, I have illustrated only a single embodiment of my invention in one well-known type of stoker construction, many variations in specific construction and application of my invention may be made without departure from its spirit and within the scope of the appended claims.

In the drawing, F ig. 1 is a longitudinal vertical section through portions of an un- .derfeed stoker equipped with fuel-distributing means embodying my invention; Fig. 2 is an enlarged sectional view of parts shown in F ig. 1.

The general stoker construction shown comprises a fuel hopper 10 having a bottom opening to a ram-casing 11 in which reciprocates the ram 12, suitably driven by any means not shown, to feed green fuel through an inlet throat 13 into a retort 14, in which the fuel may gradually be coked, and at and above the mouth of which retort the fuel may be burned, accordantly with wellknown practice. 15 indicates the usual marginal tuyres for the retort (fragmentarily shown) receiving air under pressure from the air chamber 16 th'erebelow. The particular retort construction shown provides a closed or non-apertured bottom portion 17 which is horizontal throughout a major portion of its length, and leads to the up-sloping, closed bottom portion 18 at the delivery end of the retort. Preferably the bottom 17 of the retort is somewhat below the bottom 13 of the throat 13, and through the shoulder 19 the fuel distributing means may be led, in the particular construction illustrated. In many instances it is desirable that the fuel distributing means 2O shall be operated harmoniously with the operations of the ram 12, and to this end provision may conveniently be made for operating the distributing means from the ram directly. A ram-finger 21 extending down through slot 22 in the bottom of the ram casing, serves as a convenient means for operating all parts of the fuel distributing structure 20.

In accordance with my invention the fuel distributor 20 comprises a plurality of independently movable fuel-distributing elements of which two only (for simplicity) are shown at 24 and 25, these being arranged for reciprocation in a common line but with relatively variable ranges of throw. I prefer that the two fuel distributors 24 and 25 shall be so shaped as to tend to lift the fuel on which they act in one or both of their courses of reciprocation and that they shall be disposed within the horizontal bottom portion of the retort to travel on a horizontal line. Thus each of the distributors, having its bottom shaped to conform to and rest upon the bottom of the retort, may rise to a peak near the middle of its top, and have its top surface down-sloping both toward the forward or receptive end of the retort and toward the rear or delivery end thereof, the peaks 26 and 26 of the two distributors being shown as approximately the same height, but with the forward face 27 of the forward distributor 2li pitched somewhat more steeply than the corresponding face 27 of the other distributor 25, while face 28 of vdistributor 2a is preferably less abruptly pitched than face 28 of distributor 25. In such matters of advantageous refinement, considerable latitude may be indulged without destroying the eectiveness of operation.

The means for operating the independently reciprocable distributors or pusher-blocks extend to the exterior of the furnace, preferably, for relatively variable, and preferably independently adjustable, operation from, preferably, a common operating member such as the ram-linger 2l. The operating connections may include stems for the respective distributors concentrically and coaxially arranged one withinA another, the stem for a distributor block closer to the delivery end of the retort extending, at its outer end, beyond the extremity of the tubular stem for a block nearer the receiving end of the retort. Thus, as shown, block 25 may have an operating stem 30 of rod form threaded therein, this rod passing through an aperture in block 24 and through the tubular stem 31 for the latter block, both of these stem structures extending out through the front of the furnace with the outer extremity of rod 3() projecting from tube 31. The outer extremity of each stem, as shown, has lost-motion connection with the pusher finger 21, and each of these connections is preferably made individually adjustable as to throw, so that the range of travel of each pusher may be predetermined and their relative ranges widely varied. Thus, rod 30 has thereon an extension 33 resting on roller 34 of the ram finger, said extension provided with a xed stop 35 and an adjustable stop 36 for variable lost-motion connection with said finger, while tube 31 has clamped thereon a similar extension piece 37 arranged above the extension 33, and carrying the fixed and adjustable stops 38 and 39 for c0- action with said finger 2l.

It will be seen that in operation the person in charge of the Stoker may have most complete control over the distributive action. Adjustment can be made to vary the throw of either distributor from the outside of the stoker and while it is in operation. distributor block is so shaped as to push the fuel bed along and also to lift the fuel, for agitating effect. If a short stroke is taken with front block 24, and a longer stroke for block 25, the fuel bed is maintained of considerable depth at the front end as compared with a thinner fuel bed at the rear end of the retort. If approxin'iately the same length of stroke be taken as to both blocks, approximately the same depth of fuel bed will be carried from front to rear of the retort. Substantially any desired ratio of range of movement as between the two blocks may be had, consistently with either a long stroke or a short stroke setting for one of the blocks, and by thus varying stroke length of both blocks, both agitating effect and rapidity of fuel displacement may be largely varied, with accordant control over the depth of the fuel bed and character of the combustion.

It will be understood that while I have specifically described a particular and advantageous construction, of simple form, in

connection with a single form and arrange- .1'

ment of Stoker retort, I do not desire to be understood as limiting my invention, in its broader aspects, to the details illustratively given, although some of these details are specifically claimed hereinafter for their particular advantage.

I claim:

l. In an underfeed stoker, a fuel distributor comprising a plurality of independently movable elements arranged directly in tandem for reciprocation in a common line, respective operating stems for said elements tightly attached thereto and extending parallel with the line of reciprocation, and means for operating all of said stems together in the same directions of reciprocation, said means having provision to vary the relative throw of said stems.

2. In an underfeed Stoker, the combination of a retort, fuel distributing means within said retort comprising a plurality of independently movable elements arranged directly in tandem and reciprocable longitudinally of the retort in a common line, ldngidudinally extending stems respectively tightly connected to said elements, and

Each

lll() means for operating said stems to reciprocate said elements having provision for the adjustment of the throw of cach said stem independently of the other and arranged to operate all of said stems together in each direction of reciprocation.

3. In an underfeed stoker, a fuel distributor comprising a plurality of independently movable elements arranged directly in tandem for reciprocation in a common line, respective operating stems tightly attached to said respective elements within thestoker and extending to the outside of said stoker, and means for operating said stems together in each direction of reciprocation and having provision outside of the stoker to vary the relative throw of said stems.

4:. In an underfeed stoker, the combination of a retort the bottom whereof provides a longitudinally extensive portion lying in a straight line, means for supplying fuel to said retort, and fuel distributing means comprising a plurality of independently movable distributing blocks arranged directly in tandem within said retort for reciprocation along the bottom thereof in a common line, respective longitudinally reciprocable stems extending longitudinally of said retort and tightly connected with said respective elements, and extending to the outside of said stoker, and means actuated by said fuel supply means for operating said stems together in each direction of reciprocation and having provision outside of said stoker for independently varying the throw of each said stem.

5. In an underfeed stoker, a retort having a solid bottom portion and an opening at its end above said bottom portion, a fuel distributor comprising a plurality of distributor blocks arranged in tandem for reciprocation along said bottom, coaxial actuating stems for said blocks arranged one within another and extending through said end opening, and means outside of said retort for moving said actuating stems independently.

6. In an underfeed stoker, a retort having a solid bottom portion and an opening at its end above said bottom portion, a fuel distributor comprising a plurality of distributor blocks arranged in tandem for reciprocation along said bottom, coaxial actuating stems for said blocks arranged one within another and extending through said end opening, and means outside of said retort for reciprocating said stems together in like directions of reciprocation and having provision for adjustment of the relative ranges of throw of said stems.

7. In an underfeed stoker, a retort having a solid bottom portion and an opening at its end above said bottom portion, a fuel distributor comprising a plurality of distributor blocks arranged in tandem for reciprocation along said bottom, coaxial actu ating stems for said blocks arranged one within another and extending through said end opening, and means outside of said re tort for reciprocating said stems together in like directions of reciprocation and having provision for independent adjustment of the range of throw of each of said stems.

8. In an underfeed stoker, the combination with a retort having a horizontal, closed bottom portion and an opening above said bottom at one end of the retort, a feed-ram for said retort; a plurality of distributing blocks reciprocable within said retort along the bottom thereof and arranged in tandem; operating stems for the respective blocks coaxially arranged one within the other, and separately-adjustable, independent lost-motion connections between said respective stems and the ram.

9. In an underfeed stoker, the combination of a retort having a closed bottom and an opening at one end, and fuel distributing means comprising a plurality of independently reciprocable blocks within said retort arranged in tandem, operating stems for said respective blocks coaxially arranged one within the other and extending through said end opening of the retort, and means for reciprocating said stems together in like directions of reciprocation and having provision outside of the stoker for adjustment of their relative ranges of throw.

ROYCE L. BEERS.

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