US2398009A - Multiple retort stoker - Google Patents

Description

. April 9, 1946- G. P. JACKSON 2,398,009

MULTIPLE RETORT STOKER Filed Dec. 18, 1943 3 Sheets-Sheet l INVENTOR. GeorGe P. J ackson April 9, 1946 G. P. JACKSON I MULTIPLE RETORT STOKER Filed Dec. 18, 1943 3 Sheets-Sheet 2 INVENTOR. G-QoY -JP l ac WSoM April 1946- G. P. JACKSON 2,398,009

MULTIPLE RETORT STOKER Filed Dec. 18, 1945 3 Sheets-Sheet 3 INVENTOR. C7 caree J acksoh fl RNE Y Patented Apr. 9, 1946 MULTIPLE RETORT STOKER George P. Jackson, Flushing, N. Y., assignor to Combustion Engineering Company, Inc; New

York, N. '1.

Application December 18, 1943., Serial No. 514,800

6 Claims.

This invention relates to stokers and particularly to improvements in multiple retort underfeed stokers.

Conventional multiple retort strikers comprise a number of retorts and tu'yeres extending longitudinally of the furnace and arranged in alternation across the width of the furnace. Each retort is provided at its front'end with a ram which reciprocates through a ram box extending from below a fuel hopper into the retort and delivers the fuel dropping into' the ram box from the hopper by pushing it into the retort. The fuel is then moved along each retort toward the rear of the furnace by means of pushers which are arranged for reciprocation in the bottom of the retort. air for combustion into the burning mass of fuel being moved along the retort. At the rear ends of the retorts there are overfeed sections that receive the burning fuel from the retorts and The tuyeres adjacent each retort deliver tuyeres for completing the burning of the fuel before it is delivered to the ash receiving means. Heretofore the practice in multiple retort stoker construction has been to have an individual ram for each retort. One of the limitations in burn-' ing the fuel has been due to the Width of the retorts which was established by the width of the ram that feeds it. The Width of the ram was made ample to prevent the packing of the fuel in the ram boxand because ram boxes are costly to make it was considered desirable to use as few of them as possible which led to increasing their width and that of the retorts to an undesirable degree. I

In operation it has been found that the fuel bed forms in ridges longitudinally of the furnace because most of the burning of the fuel occurs above the tuyere surfaces and to a limited extent above the retorts. through the tuyres does not completely penetrate the wide fuel bed over the retorts. To partly compensate for this unequal distribution of the air through the fuel bed the stoker must be operated with a thicker fuel bed than would be the case where air admission were more uniform. Furthermore, as the fuel .is carried along through the furnace by the action of the pushers, the action of the pushers has been found to be effective in distributing and moving the fuel above the retorts but not so eifective in moving the fuel along the top of the adjacent tuyere rows. Due'to the present widths of the tuyeres the longitudinal movement along the middle of the tuyeres is found to be sluggish and if the fuel ash becomes soft at a comparatively low temperature and has clinkering tendencies,the fuel does not move down the middle of the stoker tuyeres but adheres thereto partially shutting on the air and further aggravating the difficulties in operating the stoker.

This is because the air admitted An object of this invention is to provide an improved multiple retort :stoker to overcome the above diiiiculties.

In the accompanying drawings:

Figure 1 is a sectional elevation taken longitudinally through a stoker embodying the invention;v

Figure 2 is a sectional plan view on line 22 of Figure 1; I

Figure 3 is a section on line 3-3 of Figure 1;

Figure 4 is a section on line 4-4 of Figure 2; and

Figure 5 is a view similar to .Figure 2 showing another embodiment of the invention.

The operating parts of the stoker shown in Fig. 1 are in general the same as those disclosed in the patent to Zinkernagel et al., 2,164,100, issued June 27, 1939. The 'stoker drive includes a drive shaft l0 operating through reduction gearing, designated as a whole by the numeral H in Figure 1, to drive a crank shaft 12 having cranks 13 for reciprocating the rams M in ram boxes 15 through connecting rods '16.. Other connecting rods 11 act through bell-cranks l8 and the adjustiabl'e stepped cams 20 to actuate the push rod assembly 21 to reciprocate the fuel pushers 22 in the retorts 25.

As appears in Fig. 2, the retorts 25 and tuyeres 26 extend longitudinally of the stoker and are arranged in alternation. Retorts 25 are grouped preferably two to a ram box I5; thus one ram 14 as it reoiprocates delivers fuel from the hopper through one ram box l5 to the forward ends of two adjacent retorts Hi. The pushers 22 at the bottom of the retorts advance the fuel tothe rear of the stoker. Alternating with the retorts 25 are the tuyeres so that there is a tuyere 26 between the two retorts 25 fed by one ram. M and also a tuyere 26A between each such pair of retorts and the adjacent pair of retorts, the tuyeres 25A thus being opposite the spacers 28 intervening between two rams I4 and associated boxes. The forward ends 21 of the tuyeres 25 facing the rams M are spaced rearwardly from the rams and shaped wedgelike to divide the fuel flowing from the ram box I 5 into two separate streams, one for each of two adjacent retorts 25. Ram boxes iii are spaced apart transversely of the stoker and one tuyere 26A is in longitudinal alignment with the space intermediate the ram boxes. Since this intervening space 28 may be wider than the aligned tuyere 26A the latter may be flared at its front end so as to meet flushly with the sides of the adjacent ram boxes l5 and form a smooth side wall for the flow of the fuel therealone.

Figs. 3 and :4 show the tuyeres 2% superimposed on wind boxes 28 which support them. Fig. I3 shows :a cross-section through the front tapered end 21 of a 'tuyere "26 which divides the flow of fuel from the ram box l5 to the two adjacent retorts.

In Figure 5 showing a modification of the in vention several rams 34 are arranged side by side transversely of'the stoker in a'single ram box 35, there being no partitions between rams,

34. Consequently the fuel is delivered substantially uniformly across the width of the stoken, I

The rams 34 deliver the coal from the hopper to the retorts 25 but do not all'move forwardly at the same time. The ram movements preferably In operation, the improved stoker overcomes the difficulties outlined at the beginning of this specification because both the tuyeres and retorts have been reduced in width compared to conventional arrangements while the advantages of the wide rams andframboxes as to cost and non-packing of fuel have been retained. Preferably the tuyeres and retorts are made of about the same widthand due to their being much nar- V rower than heretofore, the distribution across the stoker of air through the fuel bed is-more uniform. The narrower width of the fuel bed above the retort bottom permits a better penetration of theair therethrough. The narrower width of the fuel bed above a tuyere assures a more uniform movement along the stoker of the fuel covering the entire width of the tuyere even when a clinkering coal is used because it is drawn along by the'sides of the body of moving coal in the retorts. Consequently the air stoppage over a tuyere by the fuel clinkering to the middle of its top surface is avoided. The improved stoker therefore provides a more uniform burning of the fuel throughout the entire fuel bed.

What I claim is: a

1. In an underfeed stoker having a plurality of spaced pairs of retorts with tuyeres intervenretorts for moving the fuel toward the rear thereof; and means for delivering air through the tuyeres into the fuel above the adjacent retorts and tuyeres.

' 3; In an underfeed tuyres arranged in alternation transversely thereof; a fuel hopper; a ram box extending the. full width of the stoker communicating with the ends of all the retorts; a plurality of adjacent contacting reciprocating rams in said ram box each delivering fuel from the hopper through said ram box to at least two retorts; means at the tuyre ends facing the rams spaced therefrom and shaped to divide the fuel therefrom into the adjacent retorts; means for reciprocating the rams; means in the retorts for moving the fuel toward the rear thereof; and means for deliver-'- ing air through the tuyres into the fuel above th adjacentretorts and tuyres.

4. In an underfeedstoker. havinga multiplicity of retorts and tuyeres of relatively narrow width and of substantial length arranged in alternation transversely of the stoker; a fuel hopper and a conduit extending therefrom to the front ends of at least two adjacent retorts; feeding means for delivering fuel from the hopper through the conduit to said retort ends; means in each of the retorts foradvancing fuel longitudinally along the retorts and the adjacent tuyeres; means positioned between said two retorts and facing said feeding means in spaced relation to the latter and shaped to divide the fuel flow from said feeding means. into the adjacent retorts; means for operating said feeding means, means for operating said fuel advancing means; and means for delivering air through the tuyres into the fuel above the adjacent retorts and tuyres.

5. In an underfeed stoker having a multiplicity of retorts and tuyres of relatively narrow width 40 and of substantial length arranged in alternaversely of the stoker of relatively narrow Width and of substantial length; a fuel hopper and ram boxes spaced transversely of the stoker extending from said fuel hopper to the front ends of both retorts of each pair; a reciprocating ram in each box for delivering fuel from the hopper through the ram box to said'retorts'; means at the end of each tuyere facing said rams shaped to divide the fuel flow delivered thereby into the adjacent retorts; means for reciprocating the rams; reciprocating pushers in the retorts for moving the fuel toward the rear thereof; means for reciprocating said pushers; other tuyres disposed in the spaces between adjacent'pairs of retorts and aligned with the spaces between ram boxes; and means for delivering air through all of the tuyres into the fuel above the adjacent retorts and tuyeres.

2. In an underfeed stoker having retorts and tuyeres arranged in alternation transversely thereof; a fuel hopper; a ram box extending the full width of thestoker communicating withit'he front ends of all the retorts; a plurality of reciprocating rams for delivering fuel from vthe hopper j acent retorts and tuyres.

tion transversely of the stoker; a fuel hopper and a ram box extending therefrom to the front ends ofat least two adjacent retorts; a reciprocating ram 'for delivering fuel from the hopper through the ram box to saidretort ends; reciprocating pushers in each of the retorts for advancing fuel longitudinally along the retorts and the adjacent tuyeres; means positioned between said two'retorts and facing said ram in spaced relation to the latter and shaped to divide the fuel flow from said ram into the adjacent retorts; means for reciproc'ating'said ram; means for reciprocating said pushers; and means for delivering air through the tuyeres into the fuel above the adjacent retorts and tuyres.

6. In an underfeed stoker having a multiplicity of retorts and tuyeres of relatively narrow width and of substantial length arranged in alternate parallel rows transversely of the stoker; a fuel hopper and a ram box extending therefrom to the front ends of each of two adjacent retorts; a reciprocating ram for delivering fuel from the hopper through each ram box to said retort ends; reciprocating pushers in each of the retorts for advancing fuel longitudinally along the retorts and. the adjacent tuyeres toward the rear thereof; means positioned between each said two retorts and-facing said rams in spaced relation to the latter and'shaped to divide the fuel flow from said rams into each of the adjacent two retorts; means for reciproca'tingsaid rams; means for reciprocating said pushers; and means for delivering air through the tuyres into the fuel above the ad- GEORGE P. JACKSON.

stoker having retorts and

Images