US2615406A

US2615406A - Traveling grate stoker

Info

Publication number: US2615406A
Application number: US126785A
Authority: US
Inventors: Donald J Mosshart
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1949-11-12
Filing date: 1949-11-12
Publication date: 1952-10-28
Anticipated expiration: 1969-10-28

Description

Oct. 28, 1952 D. J. MossHART TRAVELING CRATE STOKER Filed Nov. l2, 1949 2 SHEETS-SHEET l INVENTR A am a unnnfmwur Nw O wlTNEssEs; p60. @w Cia;

. DONALD J. MOSSHART WTSM ATTORNEY Oct. 28, 1952 D 1 MOSSHART 2,615,406

" TRAVELING GRATE STOKER Filed NOV. l2, 1949 2 SHEETS-SHEET 2 WITNESSES: INVENTOR DONALD `LMossHART nd@ My I L', BY u Hij? A l l mi' -M M i ATTORNEY Patented Oct. 28, 1952 f 1g-.:

, Westinghouse Electric Corporation, EastPittsv K burgh, Pa., a corpination4 of Pennsylvania., v,

This invention relates4 toy stokers, more particularly to 'those of the traveling grate type, and has for' an object to provide improved apparatus of this character.

Another object vof the.: invention is tor provide an improved scraper for removing ash from the discharge end of a traveling lgrate and directing ittoanashpit.- l f Yet another object of the invention is'to provide a traveling grate stokerv having a plenum chamber beneath the entire grate, together with an ash pit external to the plenum chamber.

A further object of the invention is to provide a reciprocating scraper for removing ash and refuse from the discharge end of the traveling grate of a stoker, said scraper being so arranged that it effectively encloses the ash discharge end of the grate and prevents ow of air from the plenum chamber to the ash pit.

These and other objects are effected by my invention as will be apparent from the following description and claim taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a longitudinal sectional view through tail, particularly to Fig. l thereof, the reference character I0 indicates, in its entirety, a traveling grate to which fuel is fed by mechanism of the spreader type, indicated in its entirety by the reference character il. The -fuel feeding mechanism Il comprises a hopper l2 from which fuel discharges by gravity to a ram box i3 in which reciprocate one or more rams I4 which push fuel rearwardly (from left to right as viewed in Fig. 1) over a spill plate IG from gravitational discharge over the rear edge I1 thereof to a rotary impeller I8 disposed therebelow. The blades I9 of the impeller project the fuel rearwardly through the fuel feed opening 2| in the front wall 22 of the furnace 23, and through the atmosphere of the combustion chamber 24 thereof above the fuelsupporting surface 25 of the traveling grate I0, the ne fuel particles burning in suspension .and the heavier particles and pieces falling onto the rear portion of the grate whereon they are gradually advanced by forward travel of the upper run 21 of the grate l0 for discharge as ash and refuse to the ash pit 2S.

The. trave-ling grate Il):` comprises. the-'susual structural frameworkv including longitudinallyextending members 33 and transverse=members34 andv (Fig.Y 1). A lpair ofy transverse spaced lparallel shafts31' and'are journaled in. bearings (not shown) kmountedin the members33. and

carry.- sprockets 39 ron which-'2 aregmounted, the

.grate bars.42 attached vthereto fbyfv links'43- permitting limited pivotal movement of the bars lbetween the two Vpositions shown in Fig. 1 at the top run 21 and the bottom run 44. Each chain 4| is supported between its sprockets 39 by a series of rollers 46 mounted between adjacent pairs of structural members 33. Mechanism (not shown) functions to drive the left-hand sprocket counterclockwise as viewed in Fig. 1 for motivating the grate to effect travel of the upper run 21 from right to left.

A plenum chamber 50 is provided beneath the traveling grate and is defined by front and rear end walls 5| and 52, respectively, and side Walls 53. A sealing structure 54-56 extends forwardly from the upper edge of the plenum chamber rear wall 52 in overlying relation to the rear sprocket 39 and the grate thereon.

At the front or discharge end of the grate there isl a sealing and scraping member 51, here-l inafter referred'to as a scraper. The scraper includes a horizontal ash and refuse-receiving portion 58 adapted to rest upon the upper surfaces of the grate bars 42, and an ash and refusedischarging portion 59 curved or inclined downwardly and away from the receiving portion 58, the two portions preferably being integral (Figs. 1 and 2).

As best shown in Fig. 2, the scraper 51 has a plurality of pairs of lugs 6l, to which links 62 are connected by suitable means, such as the pins "53. The opposite ends of the links 62 are pivotally connected, by pins 64, to bifurcated arms 66 iixedly secured to a transversely-extending rocker shaft 61. It will be apparent from consideration of Fig. l, that oscillation of the rocker shaft 61 will eiect reciprocation of the scraper 51 in directions substantially parallel to y the direction of travel of the grate upper run`21,

and that during its rearward travel it Will move beneath the discharging ash and refuse at the forward or left-hand end of the grate, as viewed in Fig. l. To aid penetration of the receiving portion 58 of the scraper beneath the oppositelymoving bed of ash and refuse, the rearward edge of the scraper is tapered or chamfered. as at 68 (Fig. 1).

The discharging portion 59 of the scraper overy lies a horizontal surface 69 at the upper edge of the plenum chamber end wall 5l and is maintained in sealing relation thereto by one or more plates 1l movable vertically in slots 'l2 provided in the seal assembly 'I3 secured to the lower end of the scraper discharge portion 59 (Fig. 3). Thus, in eiect, the scraper 51 functions as a continuation of the plenum chamber end wall 5l,

to limit upward discharge of air from the plenum chamber to that portion of the grate which sup-` l ports the burning fuel bed.

art that it is not so limited, butl is susceptible of various changes and modications without departing from the spirit thereof.

What I claim is:

In a Stoker, a traveling grate comprising a pair ,of' transverse spaced' parallel shafts, sprockets on said shafts,.endless chains on said sprockets,

transversely-extending grate bars secured to said chains with the upper run thereof providing y'a 'fuel-supporting' grate surface, and structural members supporting'the upper run of said grate bars for maintaining said fuel-supporting surface at; wall structure dening a plenum chamber beneath the entire traveling grate, the wall 4 of said plenum chamber at the discharge end of the traveling grate separating the plenum chamber from an ash pit and terminating at its upper edge in a substantially horizontal surface; and a reciprocal scraper lassociated with the discharge end of the .traveling grate and comprising an ash and refuse-receiving portion resting on the discharge 'end Aof the grate fuelsurface of said plenum chamber end wall upper n l edge and having sliding movement on said sur- While I 'have shown my invention in but oneform, it will be obvious to those skilled in they face during reciprocation of the scraper.

DONALD J. MOSSHART.

REFERENCES CITED The following references are of record in the rile of this patent:

UNITED STATES PATENTS Name s Date-l 2,511,935 Midgette et al June 20, 1950 FOREIGN PATENTS v Number Country Date 13,215 Great Britain Y 1 v 1906 199,295 Germany f June 11, 1908 178,021 Great Britain Apr. 13, 1922