US2033062A - Stoker - Google Patents

Description

March 3, 1936. H. P. ANDERsoN STOKER FiledNov. 4, 1935 e INVENTOR. lfawafa/naefffan ATTORNEY.

v35 gravity breaks the column.

Patented Mar. 3, 1936 STOKER Howard P. Anderson, Erie, Pa., assignor to The Standard Stoker Company, Incorporated, a corporation of Delaware Application November 4, 1933, Serial No. 696,622

6 Claims.

This invention relates to mechanical stokers for boilers of locomotives and the like. It appertains particularly to that type of stoker in which the coal is conveyed to the base of, and is then pushed upwardly in columnar formation in,

a comparatively long upstanding inclined conduit having a laterally opening mouth portion with a distributor head positioned therein or adjacent the mouth portion forward of the fuel column. The mouth portion permits the advancing column o-f coal to rise to a sufficient height above the distributor head so that the action of gravity will break the columnar formation of the coal and place the lower and forward edge of the sloping fuel face forward of the distributor head, whereby the jets issuing from the head will act upon the fuel, thus assisting the action of gravity in breaking its columnar formation, creating a more or less fixed angle of repose of the fuel dependent upon the kind and condition of the fuel being used, which jets project the coal over a distributor plate and scatter it over the rebox.

Ordinarily, in stokers of this type, the coal moves continuously through the conduit to the fuel projecting jets at a rate equal to the rate of combustion. This is desirable to procure the maximum eciency and eliminate the smoke nuisance. There are times, however, when fine or slack coal of a low carbon content is used and when such coal is quite moist or very wet that it forms a compact sticky fuel column which rises above the distributor head and above the usual angle of repose before the action of The result is that the coal breaks or drops intermittently onto the distributor plate in front of the distributor head in large gobs. This intermittent feed of heavy gobs of coal is objectionable because uniform distribution of the heavy gobs over the fire is difficult to obtain and control and the intermittent feed causes smoke and incomplete combustion.

The object of this invention is to obviate this objectionable intermittent feed of heavy gobs of gltudinal sectional View showing the rear portion of a locomotive rebcx with the invention applied thereto;

Figure 2 is a fragmentary end View of the invention taken on the line 2--2 of Figure 1;

Figure 3 is a fragmentary plan View of the upstanding conduit of the invention with some portions broken away;

Figure 4 is a side elevational view of the upper end portion ofthe stoker conduit of the invention; and

Figure 5 is a view similar to Figure 1, illustrating a modification of the invention.

On the drawing the invention is illustrated, and it will be described, as applied to a locomotive rebox but it is capable of use with other furnaces o-r reboxes of similar construction.

Referring to Figure l, the rebox is represented at l0, its backhead at II and the firing opening therein at I 2. Coal is conveyed from the locomotive tender (not shown) or other source of supply by the screw conveyor I3 within the housing I4 to the base of the upstanding inclined riser or discharge conduit I5 mounted in'any suitable manner on the backhead II in communication with the firing opening I2. For- Y ward of the spherical joint structure I6 the conduit I5 is substantially rectangular in transverse cross sectional shape.

After the coal leaves the end of the screw I3 it is forced upwardly in the conduit I5 the shape of which forms the coal into a column of substantially rectangular shape in cross section. As the column of coal advances it moves upwardly into the forwardly opening mouth portion II of the conduit where there is disposed in the lower portion thereof the distributor head or nozzle I8 positioned forward of the fuel column and the distributor plate I9 extending forward from the head into the firing opening. Jet openings as at 2i! in the front face of the head above the plate communicate with pressure iiuid chambers 2| supplied with pressure uid such as steam by the pipes 22 for discharging fuel projecting blasts across the distributor plate.

'I'he rear wall of the conduit I5 including its separate hood or cover portion 23 extends upward above the distributor head and plate in a substantially continuous line with its lower portion, a distance sulcient to permit the angularly advancing column of coal under ordinary conditions to rise to a height above the distributing plate so that the action of gravity may break the columnar formation of the coal and place the lower and forward edge of the sloping fuel face forward of the distributor head. The jets discharging from the openings 20 then act to project the coal forwardly across the distributor plate into the flrebox and thus assist the action of gravity under ordinary conditions to maintain a more or less fixed angle of repose of the fuel in the mouth portion of the conduit.

As heretofore explained there are times representative of unusual conditions when the column of coal rises above the distributor head and intermittently breaks over the ledge formed by the head in heavy gobs instead of breaking away continuously as the coal rises. Thus far the construction and operation described is well known.

The present invention resides chiey in the provision of fuel splitting means in the conduit I5 now to be explained. This means consists preferably of a plurality of spaced wedges 24 disposed in alignment transversely of the conduit l5 on the rear wall thereof and being equally spaced from one side wall to the other. Each wedge is constructed in approximately the form of a tetrahedron and disposed on the rear wall in the path of the advancing column of coal and arranged with two triangular sides thereof extending angularly toward one another from the rear wall to form an inclined splitting edge having a point directed downwardly in the conduit at the rear wall. Ille number of wedges 2e and their spacing depends upon the size and shape of the conduits and the characteristics of the coal used. They must not be spaced so close or made so large as to obstruct seriously the movement of the fuel column.

Most effective results are obtained by placing the wedges 29 on the rear wall of the conduit l5 as shown below the normal or ordinary angle of repose of the fuel indicated at A by the dot and dash line. In this location, the wedges have a splitting action on the fuel column in advance of the action of gravity and in advance of the action of the pressure fluid jets from the head I8. The wedges exert a lateral and forward force upon the upwardly moving fuel column causing the fuel column, particularly when of sticky agglomerate formation, to split and crack longitudinally and consequently, breaking into a loose formation readily responsive to the action of gravity and the assisting action of the distributing jets whereby a more or less fixed angle of repose of the fuel in the mouth portion is created as with ordinary operating conditions and resulting in a continuous feeding of coal.

If found desirable to supplement the splitting action of the wedges 24, pressure jets may be discharged forwardly between adjacent wedges across the fuel column as at 25. The jet openings 25 are located intermediate the upper and lower ends of the wedges or if preferred they may be disposed above the wedges as at 26 in Figure 5. These jets are intended only to assist in moving the advancing fuel into the Zone of action of the distributing jets of the head I8.

Preferably, the wedges 24 and the supplemental jets 25 or 26 are formed on and in a separable section 21 of the rear wall of the conduit l5, which section 21 constitutes the lower or rearward part of the conduit cover or hood portion 23 made up of the three sections or parts 21, 28

and 29. The sections 2 and 28 are secured to the main portion of the conduit I5 by tap bolts 30 and the section 29 is in the form of a lid hinged as at 3l to the section 28 and arranged torbe locked to the section 2l as by hinge bolts ing a point directed downwardly in the Y at the aforesaid wall thereof. 1

A cored hole 33 extending from one side to the other of the cover section 21 is threaded at one end to receive a supply line as at 34 for supplying pressure fluid to the cored hole 33 and thence to the communicating jet openings 25.

It will be seen the cover sections 2 and 28 constitute extensions of the rear and side walls of the lower portion of the conduit and that the lid section 29 is positioned intermediate the sides of the section 28. The adjacent upstanding edges 10 of the sections 2T and 28 are flanged and bolted together at 35. This hood or cover construction is rigid and durable yet comparatively inexpensive to manufacture and maintain.

By raising the lid section 29, access may be 15 had to the interior of the conduit or fuel may be delivered manually to the distributing jet. Constructing the wedges 24 and the supplemental jet openings in a small separable portion of the conduit cover permits repairs or replacements to be 20 made with a minimum of time and expense.

Various other embodiments of the fuel splitting means of this invention may be constructed within the scope of the appended claims.

I claim:

l. In a stoker, in combination, an upstanding conduit having an intake opening at its lower end and a discharge mouth at its upper end, said conduit including a front wall and rear and sidewalls extending above the front wall, a distrib- .30 utor head positioned adjacent said disch-arge Vmouth at the upper end of the front wall, means for advancing fuel in columnar formation upwardly in said conduit rearward of said head and then forwardly over said head to points in 35 front thereof, and fuel splitting means on the rear wall of the conduit above the level of the distributor head and rearward of but adjacent the angle of repose of thefuel column formed with the co-action of said head acting on the 540 fuel column prior to the action of the distributor head, said splitting means including a plurality of wedge shaped members spaced transversely across said rear wall.

2. In a stoker, in combination, an upstandingflifg, conduit having an intake opening at its lower end and a discharge mouth at its upper end, said conduit including a front wall and rear and sidewalls extending above the front wall, a distributor head positioned adjacent said discharge 'V50 mouth at the upper end of the front wall, means for advancing fuel in columnar formation upwardly in said conduit rearward of said head land then forwardly over said head to pointsu in front thereof, and fuel splitting means on"-55 the rear wall of the conduit above the level of .the distributor head and rearward of but adwhich each of the wedge shaped members is constructed in approximately the form of a tetrahedron disposed on the rear wall of the conduit'l() and arranged with two triangular sides thereof extending angularly toward one another from said wall to form an inclined splitting edge havconduitv 4. A structure as set forth in claim 2, in which each of the wedge shaped members is constructed in approximately the form of a tetrahedron disposed on the rear wall of the conduit and arranged with two triangular sides thereof extending angularly toward one another from said wall to form an inclined splitting edge having a point directed downwardly in the conduit at the aforesaid wall thereof.

5. 1n a stoker, in combination, an upstanding conduit having an intake opening at its lower end and a discharge mouth at its upper end, said conduit including a front wall and rear and sidewalls extending above the front wall, a distributor head positioned adjacent said discharge mouth at the upper end of the front wall, means for advancing fuel in columnar formation upwardly in said conduit rearward of said head and then forwardly over said head to points in front thereof, and fuel splitting means on the rear wall of the conduit above the level of the distributor head and rearward of but adjacent the angle of repose of the fuel column formed with the co-action of said head acting on the fuel column prior to the action of the distributor head, said splitting means including a pluof said rear wall carrying the wedge shaped members being constructed as a detachable section of the wall.

6. In a stoker, in combination, an upstanding conduit having an intake opening at its lower end and a discharge mouth at its upper end, said conduit including a front wall and rear and sidewalls extending above the front wall, a distributor head positioned adjacent said discharge mouth at the upper end of the front wall, means for advancing fuel in columnar formation upwardly in said conduit rearward of said head and then forwardly over said head to points in front thereof, and fuel splitting means on the rear wall of the conduit above the level of the distributor head and rearward of but adjacent the angle of repose of the fuel column formed with the co-action of said head acting on the fuel column prior to the action of the distributor head, said splitting means consisting of a plurality of wedge shaped members spaced transversely across said rear wall, and a plurality of forwardly directed pressure fluid jets acting on the fuel rising between the wedge shaped members, and that portion of said rear wall carrying the splitting means being constructed as a detachable section of the wall.

HOWARD P. ANDERSON.

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