US1809595A - Stoker - Google Patents

Description

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Patented June 9, 1931 l terasse UNITED ASrarss rarsnr @Fries CHARLES F. MILLER, F MOOR/ES, PENNSYLVAN 1A, ASSIGNOR T0 WESTINGHOUSE ELEG TRIO & MANUFACTURING COMPANY,

A CORPGBATION OF PENNSYLVANA STOKER Application filed November My invention relates to combustion appay ratus, and more particularly to progressive feed stoker's, and it has for an object to increase the efiiciency of apparatus of this character.

As is well known, the side retort stoker consists of a retort disposed along one wall of the furnace, and .an air-emitting grate extending laterally from the upper edge of the outer wall of the retort. The grate may be either movable or stationary. Fuel is fed longitudinally of the retort and at the same time upwardly and laterally over the side thereof. The il'uel'overflowing from the retort moves onto the laterally-extending grate Where it is burned.`

If the grate be a movable one, such move'- ment willaid, to some extent, in the feeding of the fuel thereon from the retort. Howj ever, in all cases heretofore known to me, the main force effecting the feeding of thc fuel is that of gravity. Consequently, in order that the grate surface may have at all times, the proper amount of fuel, it is necessary to operate with an extremely thick fuel bed over and adjacent to the retort.

An excessively thick fuel bed over the retort will also result in a thick fuel bed at the upper end of the grate surface which is adjacent the retort. The air cannot effectively penetrate the thick fuel bed and therefore the proper combustion condition cannot be maintained at that point. Also, the mass of fuel over and adjacent the retort will matt or fuse together and be very difficult to move. Furthermore, as the lower portion of the overfeed grate is the only point where air can pass freely, air will pass through that portion in excess amounts f and as this excess air has to be heated to stack temperature, Jhe efficiency of the stoker will be lowered to a still greater degree.

More particularly, therefore, it is an ob` i ect of this invention to provide an improved form of stoker having an effective means for positively feeding the coal overflowing from the retort onto a laterally-extending grate surface, thereby making possible thinner fuel bed and more eliicient combustion.

These and other objects are effected by my dump grate 2l.

6, 1929. Serial No. 405,157.,

invention, as will be apparent from tlie`following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. l is a transverse sectional view through a stokerconstructed in accordance n with my invention and taken on the line I-I of Fig. 2;

Fig. 2 is a longitudinal sectional view through the stoker taken on the section lines IIII of Fig. 1;

Fig. 3 is an enlarged fragmentary sectional view taken on the line Ill-H1 of Fig. 2; and, j v

Fig. l is an enlarged fragmentary detail illustrating the adjustment of the driving mechanism and taken on the line IV-IV of Fig. 1.

According to the embodiment of my invention shown on the accompanying drawings, I provide a stoker comprising a retort disposed adjacent one wall of the furnace, an air-emitting grate surface extending lat,- erally from the upper edge of the retort side wall which is remote from the furnace wall, and means for feeding fuel longitudinally of the retort and upwardly and laterally over the side thereof. l also provide a fuel-pushingmeans which is disposed above vthe retort side wall adjacent the furnace wall and operates to feed the fuel overliowing from the retort onto the lateral grate section; thereby making possible the carryingvof a much thinner fuel bed over the retort and over the upper end of the laterally-,extending grate than has heretofore been possible.

Referring now in detail to the construction illustrated,vit will be observed that l have shown on the accompanying drawings a furnace 10 comprising front and rear walls 11 and 12, respectively, and side walls 18 and 14, respectively. A single retort underfeed stoker 15 is disposed within the furnace and divides the same into an air chamber 16 and a combustion chamber 17. Air is supplied to the air chamber by means of an air duct 18.

The stoker comprises a retort 19, a laterally-extending and 1novable`grate'207 and a The retort comprises a bottom. wall 22, and side walls 23 and 24, re-

spectively. The side wall 9.3 is shown as being divided longitudinally into a lower section and an upper section 26 detachably secured by bolts 27 to the section 25. The overfeed grate is so designed as to permit the free passage of air therethrough and comprises parallel grate bars 28, 28, slidably supported at their upper ends by the retort side wall 24 and at their lower ends by an I- beam Q9. The dump grate 21 is supported at its forward end by a shaft 30 and may be operated by suitable mechanism (not shown) connected to the shaft.

Fuel is fed from a suitable hopper 3l and into the ends of the retort by a primary ram 32. A secondary ram 33 is slidably supported by the bottom wall of the retort and is operatively connected to the primary ram by a connecting rod 34. As is well known, the action of the secondary rain is such that the fuel is fed longitudinally of the retort and at the same time upwardly and laterally over the side wall 24 and onto the overfeed grate 20.

As stated, l provide an improved means for aiding in the feeding of the coal onto the overfeed grate section. As shown, l. provide a movable wall which forms an upward extension of `the side wall 23 of the retort and is pivotally supported by the upper section 26 of such side wall. The pivotal connection between the all and the section 26 is provided by a cylindrical enlargement 36 formed integral with the upper surface of the section 26, and fitting within sockets 37 provided by an arcuate portion 3S of the movable wall 35, and cooperating arcuate portions 39 formed on brackets 40, which lat-- ter are detachably secured by bolts 41 to the rear portion of the wall 35.

The wall may be in one tends for the whole length of the retort. Preferably, however, it is divided transversely into a plurality of sections 42 to facilitate repair. It will be observed that a space is provided between the ends of the wall 35 and the furnace walls 11 and 12, respectively. The reason for this is to permit the wall 35 to expand due to heat. The spaces between the ends of the wall and the furnace walls 11 and 1Ql are sealed by plates disposed behind the ends of the wall 35 and held against the furnace walls by counterweighted follower mechanisms 44. (See Figs. 2 and A follower 4.5 engages the end of each sealing plate 43. The follower is keyed to a shaft 46 carried by the wall 35 and a guide plate 47,

piece which eirwhich latter is also secured to the wall A counter- Wei hted lever arm 48 is also keyed to the sha t and serves to urge the follower against the sealing plate. i

The wall 35 lits within a recess 49 formed Within the. furnace wall 13. rllhe lower portion of the recess is in open communication with the air chamber or wind box 16, and the upper portion of the recess communicates with the combustion chamber through openings 50 formed in plates 51. The plates 51 rest loesely on the flanged upper portion of the wall 35 and are held in position by spaced flanges 52 projecting downwardly from a supporting plate 53 for the furnace wall 13.

It will thus be seen that I have provided means for supplying air for combustion over the retort. lf desired, the number of openings 50 may be increased or reduced, or the opening may be done away with, depending, of course, upon the combustion condition required and the character of the coal used.

Means is provided for reciprocating the laterally-extending grate 20 and for oscillating the wall 35 about its pivotal support, so that the fuel overflowing from the retort 19 will be positively and effectively fed on the grate 20. As shown, an oscillating power shaft 54 is disposed transversely beneath the grate 2O and is provided with one or more upwardly-extending operating arms 55 which are connected to the grate 2O by means of a cylinder and socket connection 56. The shaft 54 is adapted to be oscillated by any suitable means disposed eXteriorly of the stoker (not shown).

The shaft 54 is also provided with one or more downwardly-extending lever arms 57, each of which is pivotally connected at its lower ond by a lost motion connection 53 Vto an end of a link 59. The opposite end of each link 59 is pivotally connected to the lower en l cf an arm 60. Vlllie arms 60 are each rigidly secured at their upper ends to one of the brackets 40.

The lost motion connections 58 may be adjusted to vary the degree of motion imparted to the wall 35 from the shaft 54. Referring to Figs. 1 and 4, it will be observed that the lower portion of each of the arms 57 is bifurcated to receive the end of the link 59. The end of the link 59 is provided with a longitudinally-eXtending slot 61 and a plurality of spaced openings 62. The bifurcated end of the lever arm is secured to the end of the link by a pin 63 extending through aligned openings in the arm andthe slot 61 in the link. A block 64 lits over the link 59 and may be secured thereto by a pin 65 litting within aligned openings in the block and any one of the openings in the link. lt will thus be seen that the motion of the lever arm toward 'the left of the drawings is transmitted through the block 64 to the link 61. As the position of the block 64 may be varied with respect to the arm 57, more or less lost motion may be had, thereby varying the degree of motion imparted to the movable wall 35.

The operation of the stoker will be apparent from the above description. The coal is 130 fed longitudinally of the retort and at the same time upwardly toward the top thereof, by the rams. The fuel overflowing from the retort is positively pushed onto the grate by the movable wall. By reason of this construction, a relatively thin fuel bed can'be carried over the retort and the upper end of the grate, thereby permitting the air to pass freely through theupper portion of the fuel bed and combine eliiciently with the volatiles and solid carbons to produce combustion.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, Without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In Stoker apparatus, the combination with a. fuel trough having bottom' and side walls; of a plate-like member disposed above one of the side walls, means for supporting the plate-like member adjacent its lower edge for movement about an axis extending' substantially parallel to the walls of the trough; and means for moving the plate-like member about its axis of movement.

2. In stoker apparatus, the combination of a retort; means for feeding fuel longitudinally of the retort and upwardly toward the top thereof; a grate disposed along one side of the retort for receiving and supporting the fuel during combustion; and means disposed along the opposite side oftheretort forpushingonto the grate the fuel overflowing from the retort, said last-mentioned means comprising a platelike member pivoted to move about an axis extending substantially parallel to the retort.

In a furnace including a wall, the combination of a retort disposed along the furnace wall; means for feeding fuel longitudinally of the retort and upwardly toward the top thereof; a grate extending laterally from the side of the retort remote from the wall; and fuel pushing means disposed along the furnace wall for pushing onto the grate the fuel overflowing from the retort, said pushing means including a plate-like member pivotally supported at one end thereof, and means for moving said plate about its pivotal suport. p 4. In combustion apparatus, thev combination of a furnace including a side wall; a retort having spaced parallel side walls and one of the side walls being disposed along the furnace side wall; means for feeding fuel to said retort and upward toward the top thereof; a grate surface disposed laterally from the side wall of the retort remote from the furnace side wall; a sectional wall forming an upward extension of the retort side wall lying adjacent the furnace Wall and pivscribed my name this lst day of November, 1929.

CHARLES F. MILLER.

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