US2237938A - Stoker - Google Patents

Description

F. A. METC HFEL.

STOKEH Filed Sept. 15, 1957 3 Sheets-Sheet l 5 E H N m E 0 VC T w P. A. KETQHPEL 2.237.938

STOKER Filed Sept. 1.5, 1937 3 Sheets-Sheet 2 {TE .42 .f L? 41 l INVENTOR.

10 62 4 61 PH!!!- A. K: TCHPEL BY v ATTORNEYS AWN 8, 1941., P A KETCHPEL 2,237.,93fi

STOKER Filed Sept. 15, 1937 3 Sheets-Shaet 3 llllllllllllllllllllllllllli mm:-

INVENTOR, P/wl. A K: TOHPEL BY .35 .3 5 aZ/mm/ 36 I I ATTORNEYS Patented Apr. 8, 1941 STOKER Paul A. Ketchpel, Bergenfield, N. J., assignor to The Standard Stoker Company, Incorporated, a. corporation of Delaware Application September 15, 1937, Serial No. 163,929

4 Claims.

The present invention relates to stokers employing a fiuid stream forpropelling fuel through a conduit and into the furnace for distribution over the grates thereof.

One object of this invention resides in the provision of a novel stoker of the type specified and wherein the fluid stream utilized to propel fuel through the conduit and into the furnace is heated prior to its admission over the firebed.

Another object of this invention is to provide means for propelling fuel through the conduit by an air stream having a relatively short passage from its point of generation to the point of discharge into the stoker conduit.

A further object of this invention resides in the provision of improved means for operating the fan utilized to generate the air stream in the stoker conduit, and whereby a very compact relation is attained between the stoker conduit, the fan and drive unit for said fan.

A still further object of this invention resides in providing new and improved means for heating the air which is utilized to propel fuel through the conduit and into the furnace.

Other objects, together with their advantages, will become apparent as the following description of the invention is read in connection with the accompanying drawings, in which:

Figure 1 is a central vertical longitudinal section through the rearward portion of a locomo- 1 tive and adjacent portion of its tender, showing the invention in side elevation as applied thereto, portions of which are in section;

Figure 2 is an elevation of the structure shown in Figure 1 as viewed along the line 2-2 of Figure 1;

Figure 3 is a plan view taken on the line 33 of Figure 1 with portions of the locomotive in firebox o-r furnace II having grates I2, and a backwall I3. The backwall I3 is provided with an opening I4 above the grates I2 and cab deck I5. Rearward of the locomotive L is a tender T having a frame I6 and a deck l1.

Fuel stored on the tender is conveyed and distributed over the firebed by means of a stoker S which includes a tubular conduit I8 leading forwardly from the tender T to a fuel discharge or delivery conduit I9 mounted on the locomotive L; The conduit [8 comprises a pair of telescoped sections 20, 2|, the latter having a spherical shell 22 fitted within the spherical seat 23 formed at the lower end of the discharge conduit I3, forming a universal connection 24 between the conduits I3 and I9. A conveyor screw 25 is disposed within the conduit I8 and urges fuel forwardly into the lower portion of the discharge or delivery conduit IS, the latter being provided with a ledge 26 extending forwardly and upwardlyfrom the spherical seat 23 to form a lip 21 over which fuel urged by the conveyor screw 25 falls downwardly toward a chamber 28 disposed subjacent the ledge 26.

The fuel delivered into the conduit I9 is propelled therethrough and distributed over the firebed by a swiftly moving stream of air. Forgencrating the air stream through the conduit I9, a fan 29 is provided and it is disposed within a housing 33 formed at one side of the discharge conduit I9. The fan 29, which is driven through a shaft 80 disposed forward of the lip 21 and below the bottom wall 3| of the conduit I9, is provided with an axial air intake opening 32 formed in the cover 33 of the housing 30, and a radial outlet 34 arranged toicommunicate through a duct 35 with the chamber 28. It will be observed that the outlet 34 is atone side of the conduit I9, but that the duct 35 curves inwardly toward the chamber 28 whereby the swiftly moving stream of air will be discharged axially into the conduit I9 through an aperture 36 formed between the ledge 26 and the lower end of the bottom wall 3I. Foreign matter in the fuel too heavy to be propelled by the air stream will lodge in the chamber 28 fro-m which it may be removed through openings 9 upon detachment of the covers 8.

On the side of the conduit I9 opposite the fan 29 is a turbine 31, the wheel 38 of which is secured in known manner to the fan shaft 89. The turbine wheel 38 is enclosed within a casing 39 formed at one side of the conduit I9 and includes a cover 40 which carries the steam intake and exhaust pipes 4|, 42 for supplying steam to the turbine 31 and for exhausting it therefrom, respectively. The turbine operates at a speed sufficiently high which will enable the air stream generated by the fan 29 to lift the larger fuel particles or lumps for propulsion into the firebox ll. Preferably, the fuel fed by the conveyor screw 25 to the conduit I9 is first reduced, by well-known means, to a size which can be efiiciently propelled and distributed by an air stream.

Air is supplied to the axial intake opening 32 of the fan 29 by means of a curved tubular elbow 43, one end of which is secured to the fan housing cover 33 and the opposite end of which is attached to the expansion plate 44, the latter forming a support for the rearward end of the boiler firebox II and also defines the rearward extent of a chamber 45 with which the tubular elbow 43 communicates. The back sheet 46 of the ash pan 4! defines the forward extent of the chamber 45 which is closed on its bottom by a plate 48 and a door 49 arranged to be opened or closed manually through linkage 50. The ash pan sheet 46 is perforated at for withdrawal of air from the ash pan 4'! into the fan intake elbow 43. Preferably, the chamber 45 is provided with a bafile 52 which causes air entrained from the ash pan 41 to pass through spaces between the pipes 53 which contain steam or other heating medium. In this manner, the air entering the fan 29 is relatively warm whereby it will have no detrimental effect upon firebox conditions when admitted therein-to by the fan. In fact, the warm air entering the firebox will promote combustion by thoroughly mixing with unburned particles of fuel and in this manner supply .the oxygen necessary for their complete combustion. The air which enters the ash pan 4! along the sides 54 of the firebox H may also be heated by providing heating pipes 55, as shown in Figure 8. Any ash particles which may be entrained through the perforations 5| into the chamber 45 will settle in the trough 56 formed by the converging plate 48 and door 49. training the air around the baflle 52, its course, and that of any fuel or ash particles carried thereby, is changed considerably so that the solid particles will drop for accumulation in the trough 56. At intervals, the door 49 may be opened to allow the accumulated ash particles to escape from the trough 56.

At its forward end, the discharge conduit i6 is secured by bolts 51a to a frame 58 which embraces the firing opening Hi and is secured to the firebox backwall by bolts 51 and also carries a door 59 to close that portion of the firing opening above the terminal end 66 of the stoker conduit. The lower end of the conduit I9 is provided with a flanged foot member 6! which rests upon a guideway 62 formed with the l0co motive frame It). The terminal end 66 of the conduit [9 includes a hood portion 63 which is detachably secured to the conduit l9 and the frame 58 by bolts 64 and 65, respectively. Upon opening of the firedoor 59 and removal of bolts 64, 65, the hood portion 63 may be removed to afford free and easy access into the firebox.

Upon being propelled through the conduit 29 by the air stream, the fuel is caused to be defiected evenly to all parts of the firebed by means of distributor D. In effect, the distributor D stops the forward advance of certain portions of the fuel stream and causes such portions to be deflected to predetermined areas of the firebed. This distributor D consists of a lower deflector member 66 and an upper deflector 6?, the latter including a pair of independently operable sections 67a and 61b. The lower deflector 66 is secured by bolts 68 to the stoker conduit By en- 1 l9 and fits between the wall-like extensions 68, HI formed with the firedoor frame 58, which extensions are disposed Within the firing opening :4. A V-shaped block II is formed on the upper surface of the lower deflector 66 and serves to spread laterally portions of the lower stratum of fuel as it is propelled through the conduit I9.

The sections 67a, 67b of the upper deflector 6'! are carried by the hood portion 63 whereby they may be removed from their position in the ring opening l4 upon detachment of the hood portion 63 from the stoker conduit I 9. On its central forward portion, the hood portion 63 is provided with a lug '12 in which is journalled a pin 13 which also has secured thereto the deflector section 67b. The outer end of the pin 13 is journalled in the hood portion 63 and carries a handle M whereby the deflector section 61b may be raised or lowered about the axis of pin T3. The deflector section 67a is provided with a pin 15 and is also supported on its inner end upon the pin '13. A handle 16 afiords manual angular adjustment of the deflector section 61a about the axis of the pins 73, 75, independent of the adjustment of deflector section 612). Each handle M, E6, is provided with a latch Tl arranged to engage any one of a number of holes 78 formed in the hood portion 63 adjacent a respective handle whereby each deflector section 610:, Gib may be securely locked in its adjusted position. Each deflector section 67a, 6'ib is provided on its underside with an outwardly curved rib 8!, 82, respectively, for deflecting laterally portions of the upper stratum of fuel propelled through the conduit l9.

From the foregoing, it will be apparent that a novel stoker has been provided which employs a heated air stream for propelling fuel through the stoker and over the firebed; the construction being such that distribution of projected coal may be controlled at one side of the firebed independently of the opposite side. Furthermore, a novel arrangement has been attained between the fan, its driving turbine and the stoker discharge conduit; the arrangement being cf a compact design so as to occupy very little space and at the same time, the fan discharges an air stream into the discharge conduit by a duct having a very direct communication between the discharge conduit and the outlet of the fan. In this manner, the stated objects of this invention have been fully attained.

I claim:

1. In a furnace having a grate and an ash compartment therebeneath, a stoker for supplying fuel over said grate comprising a discharge conduit leading from a source of fuel and cornmunicating with said furnace, means for generating an air stream in said conduit for propelling fuel toward the furnace, means providing a passage for supplying air from said ash compartment to said first named means, and a heating device in said passage intermediate said ash compartment and said first named means for heating the air passing from said ash compartment to said first named means.

2. In a furnace having a grate, and an ash compartment therebeneath arranged to receive air, a stoker for supplying fuel over the grate comprising a discharge conduit leading from a source of fuel and communicating with said furnace, means for generating an air stream in said conduit for propelling fuel toward the furnace, a chamber adjacent said ash compartment and in communication therewith, a conduit establishing communication between said chamber and said first named means, said first named means arranged to entrain air from said ash compartment to said chamber and from said chamber to said last named conduit, means in said chamber for separating ash particles from the entrained air stream, and a heating device in said chamber for warming the air passing therethrough into said second named conduit.

3. In combination, a firebox having a grate and an ash compartment therebeneath, means for preheating the air for combustion in the firebox including walls forming a chamber adjacent said ash compartment, one of said Walls having apertures for admission of hot air from the ash compartment to said chamber and the opposite wall being provided with an outlet, a plate within said chamber separating said air admission apertures from said outlet and forming a bailie, said baflie forming with said chamber walls a circuitous passage within said chamber, heating elements disposed in said circuitous passage, and means communicating with said outlet for withdrawing air from said ash compartment through said chamber and outlet and arranged to introduce it into said firebox.

4. In combination, a firebox having a grate and an ash compartment therebeneath, means for preheating the air for combustion in the firebox including walls forming a chamber adjacent said ash compartment, said walls including a perforated wall common to said chamber and ash compartment providing communication therebetween, and a wall opposite said perforated wall having an outlet, a plate within said chamber separating said perforated wall from said outlet and forming a baffle, said baffie forming with said chamber walls a circuitous passage within said chamber, heating elements disposed in said circuitous passage between said baflie and said second named wall, and means communicating with said chamber for Withdrawing air from said ash compartment through said perforated wall, chamber and outlet and arranged to introduce it into said firebox.

PAUL A. KETCHPEL.

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