US2444985A - Fuel burner - Google Patents

Description

9 Sheds-Sheet 1 July 13, 1948. w. M. FULTON FUEL BURNER Filed April 4, 1944 m M W 5 M a a 7 w H A;v

y 8- w. M. FULTON 2,444,935

FUEL BURNER Filed April 4, 1944 9 Sheets-Sheet 2 w. M. FULTON July 13, 1 948.

FUEL BURNER 9 Sheets-Sheet 3 Q NW 0 h M 0 w l a W M W a Q r xp/H .0 n bun, wfl nn .v v llll l filll mu u u I I 0 1 n .W q m1 R n um N an 7 a N0 8N a mfi m6. km. 8 ha N a 0 am RV N July 13, 1948.

w. M. FULTON FUEL BURNER 9 Sheets-Sheet 4 Filed April 4, 1944 161/ iri/wr/r July 13, 1948.- w. M. FULTON FUEL BURNER 9 Sheets-Sheet 5 Filed April 4, 1944 July 13, 1948.

W. M. FULTON FUEL BURNER 9 Sheets-Sheet 6 Filed April 4, 1944 9 Sheets-Sheet 7 July 13, 1948. w. M. FULTON FUEL BURNER Filed April 4, 1944 w. M. FULTON Jul 13, 1948.

FUEL BURNER 9 Sheets-Sheet 8 Filed April 4, 1944 July 13, 1948.

-w. FULTON FUELBURNER Filed April 4, 1944 9 Sheets-Sheet 9 Patented July 13, 1948 FUEL BURNER Weston M. Fulton, Knoxville, rm. minor to W. J. Savage Company, Inc" Knoxville, Tenn., a corporation of Tennessee Application April 4, 1944, S crial No. 529,503

I 16 Claims.

This invention relates to improvements in fuel burners, and more particularly to the method of and means for the combustion of solid fuels.

The various types of fuel, such as anthracite andbituminous coal and coke, have heretofore required distinctive differences in the construction of the respective burners according to the type of fuel to be consumed therein. Thus a stoker or burner adapted to consume bituminous coal was not suited for burning anthracite coal nor for, coke. Notoniy is there a material differ ence in the classification of the several types of fuel, but stokers fall into several different classes according to what they do: agitating, for heavy coking coals: semi-agitating, for mild coking coals and W1 some clinkering coals; and nonagitating, for clinkering, non-coking andhigh ash coals. Generally, no one stoker proposed heretofore would consume the several types of fuel becauseof the difl'erences of the construction of the respective stokers which make them more nearly adapted for these respective types of uses.

An object of this invention is to provide for the'burning of solid fuels of a wide range of differing-characteristics in a single stoker or burner,.to adapt the one construction to many different types of fuels, according to the desires ,of the user or the availability of the respective fuels.

A further object of the invention is to improve the construction and method of operation of fuel burners, for more efilcient combustion of the fuel, practical operation, and effective heating of the air or space.

These objects may be accomplished by an embodiment of the invention which provides for the feeding of solid fuel (as distin uished from liquid or gaseous fuel) into a combustion chamber, rolling or tumbling said fuel in the'combustion chamber during the burning operation, and so-regulating the rate of fuel feeding with respect to the rate of combustion that the combustion chamber will be at all times only partly filled with the solid fuel. It is preferable to direct air in'toi'and through the body of burning fuel to: support combustion, and progressively to discharge the products of combustion from the whereby substantially complete combustion takes place within the burner. Provision is made preferably for feeding fuel into one end of the burner while the ash and products of combustion are discharged from the opposite end thereof. The burner is provided also with air supply means so arranged as to deliver the air necessary to support combustion, to the desired portion of the burner. The construction also includes means for segregating the solid products of combustion from the gaseous products, and preferably embodies means whereby the device can be quickly and easily adjusted to handle different types of fuel.

Still another object of the invention is to in troduce the fuel to the burner in such manner that the source of fuel supply or body of fuel being supplied is out of the range of radiant heat, which always travels in a straight line. This prevents pre-ignition of the fuel which is being fed into the combustion chamber, a dimculty which would be encountered where the fuel is being fed in a body within the range of radiant heat. This object is accomplished according to an embodiment of this invention by the gra ual feeding of fuel from a bed or body that is located out of the path of radiant heat, such as by providing an oflset in the conveying chute from the bin into the burner.

The invention is illustrated in a preferred embodiment, together with modifications thereof, in the accompanying drawings in which:

Fig. 1 is a vertical sectional view through the feeding end portion of the fuel burner mechanism';

Fig. 2 is a similar view through the combustion end portion thereof shown applied to a chamber,-'t'he' solid portion of said products of furnace;

Fig. 3 is a horizontal sectional view therethrough, with parts in elevation; I

Fig. 4 is a detail cross section therethrough showing a drive connection;

Fig. 5 is a detail longitudinal section through said drive connection;

Fig. 6 is an enlarged vertical section through the burner mechanism, substantally on the line 8-8 of Fig. 2;

Fig. 7 is an enlarged detail cross section through the corrugated wall of the burner;

Fig. 8 is a diagrammatic view illustrating the manner of combustion in the burner;

Fig. 9 is a similar view illustrating a different operating condition therein;

Fig. 10 is an end elevation of a modified form of burner, detached;

Fig. 11 is a side elevation of the modified form of burner of Fig. 10;

Fig. 12 is an end elevation of the burner head of Figs. 1 to 3 detached;

Fig. 13 is a vertical section therethrough on the line 13-" of Fig. 12;

Fig. 14 is a bottom plan view of said head:

Fig. 140 is a detail side elevation. of the burner head mounting;

Fig. 15 is a side elevation of the complete burner unit showing another modification therein;

Fig. 16 is a side elevation of the burner support, detached. for the modified form of burner shown in Fig. 15;

Fig. 17 is a face view of the burner support of Fig. 16 from one side;

Fig. 18 is a similar view from the opposite side thereof;

Fig. 19 is a longitudinal sectional view through another modified form of burner;

Fig. 20 is a cross section through still another modified form of burner; and

Fig. 21 is a detail cross section through still another modified form of burner showing particularly a modified form of air feed in the wall thereof.

The embodiment of the invention shown in Figs. 1 to 14 comprises a rotary burner mounted for turning movement about a horizontal axis, adapted to receive fuel in one end thereof and to discharge products of combustion at the opthereof within the combustion zone, the air being supplied at the fuel inlet end thereof. The heat resulting from the combustion is directed from the burner to any suitable heat utilizing means, such as the hot air furnace illustrated, and shown more particularly in Figs. 2 and 3, and as applied in a slight modification of heated air supply to the furnace, in Fig. 15.

The burner is designated generally by the numeral i. This burner is tubular or cylindrical in shape, and may be made of cast iron or of other suitable material. Although the burner is shown in Fig. 6 to be cylindrical, it is evident that it may be constructed of other tubular shapes, such as polygonal, square, pentagonal, hexagonal, octagonal, or of other suitable shape.

The peripheral wall of the burner I is formed substantially of corrugated shape, as shown more in detail in Figs. 6 and "l, with longitudinal air passages 2 through the wall, each of which is connected with the interior of the burner by a longitudinal slot 3 forming a tuyere in the wall, the slots 3 extending to the inner surface Ia of the solid wall portion 3b (Fig. 7). corrugations 4 between adjacent air passages I extend lengthwise of the burner at the periphery thereof, but these corrugations are closed against communication with the inside of the burner by the solid portion 312 of the wall thereof, as shown in Figs. 6 and 7. The air passages 2, slots 3 and corrugations 4 extend from the inlet end of the burnersubstantially to the discharge end thereof.

Adjacent the discharge end of the burner, on the inner side thereof, is an annular closure at the ends of the air passages 2, which air passtages are closed except for a small orifice 6 therein (Fig. 'i) for the purpose of admitting a limited amount of air into the space I in the discharge and of the burner immediately adjacent the inturned end portion 8 thereof. This inturned portion 8 forms a discharge opening l at the end of the burner smaller than the inlet end of the burner, shown in Fig. 3.

The discharge end of the burner at its periphery is formed with a spherical section II having its center on the center axis of the burner I, as

.indlcated by the dot and dash radius lines in Fig. 2. This spherical portion II is mounted in a similarly shaped seat Ii in a surrounding ring II. The ring I! has a peripheral portion also of spherical shape as shown at II, seated within a surrounding support I and confined thereagainst by a series of clamps ll held in place by screws II. The spherical seat II is generated on a radius from a center located on the axis of roin a universal connection in the ring if. The

' burner is also capable of rotation therein while maintaining a reasonably gas-tight Joint between the burner and the ring. When the clamps I! are loosened upon loosening of the screws ll, it is possible to adjust the ring it, which is otherwise held stationary, to'vary the position of the device'relative to the support l4.

At the inlet end of the burner l is mounted a head I], which is recessed on its inner side with a peripheral flange ll surrounding the burner, and is adapted to bear in slidable relation against the end of the burner substantially in a closed air-tight fit. The head I1 is adapted to supply air to the burner, as well as to admit the fuel thereto.

The head I1 is supported on longitudinally adjustable arms, designated generally at 18, see Fig. 12. Each of the arms I! is shown as formed of a screw 20 telescoping into a sleeve 2i, and

having the interconnection thereof controlled by a nut 22 threaded on the screw 2' and bearing against the end of the sleeve 2!, so that upon turning of the nut 22 in either direction, the in.- terfitting ofthe parts 20, II is adjusted, thereby lengthening or shortening the supporting arm It. Each arm II is pivotally supported at its lower end at 23 by brackets 2C. The upper end of each arm I! is pivotally connected with the head II by means of a trunnion 25' extending laterall from the head and secured thereto. 4

By means of the adjustable arms ii, the head I] may be readily adjusted to different elevated positions. The arms it are inclined at an acute angle to the horizontal toward the head l1, so that the weight of saidhead produces a component of force always pressing it against the end of the burner I.

The arms is supported upon the brackets N. are mounted on a base 28 which extends generally horizontally beneath the burner, as shown in Figs. 1 and 2, and forms a platform upon which the major portion of the stoker structure is mounted, as hereinafter described. At its outer end, the base 28 is supported upon adjusting screws 21 (Figs. 1 and 3) bearing upon the floor or other foundation. and which screws are shown as threaded through the base to be adjusted relative thereto and thereby raise or lower said outer end of the base relative to the floor of the furnace room, designated F in the drawings. The inner end of the base II is connected by screws 2! to the lower extension member 20 formed on the ring I! and extending outwardly therefrom.

A jacket ll, preferably of sheet metal, extends around the burner over the base 28, as shown in 6, beingsupported at the top by screw connections II from a flange portion on the ring l2. The Jacket ill extends across the top and down opposite sides of the burner I, being secured at 32 to the base I. The jacket 30 has an end section 33 .closing the outer end thereof and secured to the body portion of said jacket at 3|, extending downwardly to the base 28 to which it is secured at 35.

The head I1 is shown more in detail in F185. 12 to 14. This burner head is provided with ribs or fins 38 disposed vertically on its-outer surface and integral therewith for purpose of heat radiation.

The head II has an arcuate slot 31 extending about a portion of the lower periphery thereof, as shown in Figs. 12 and 13, coextensive in length with an air chamber a. The outer side of the air chamber 38 is provided with an air inlet ll. The slot 11 and airchamber 3' are adapted to supply air to the passages 2 of the burner, but the arcuate extension of this slot is such that it will supply air throughout onlya portion of the fuel bed, the fuel bed normally extending upwardly to a point higher than the upper end of the slot 3'l.

The arrangement is such that air can pass freely from the slot 31 into all of the air. passages 2 which are included within the angle subtended by the arcuate slot 31, so that those air passages, being filled with air, discharge it through the slots 3 thereof into and through the bed of fuel. A small portion of air is discharged also through the orifices 6 at the closed ends of the passages 2 to complete the combustion of any portion of fuel which may pass into the space I at the discharge end of the burner. The air thus being discharged through the orifices 6 also carries with it any particles of ash that may fall into the air passages through the slots 3, thus preventing the air passages from becoming clogged by an accumulation of ash therein.

The slot 31 not only registers with the air passages 2 to supply air thereto as described, but it registers also with the corrugations l which are included within the arc of the slot. This air thus supplied to the corrugations performs the function of aiding in the cooling of the outer surface of the burner i, thereby quickening the circulation of air through the heating system as hereinafter described, through connections with the space in the jacket 30. The air thus supplied to the periphery of the burner through the slotj'l has a cooling effect during the time that the burner is in operation and the maximum amount of heat is being generated within the burner, because it is only during the operation of the burner that air is thus supplied, as hereinafter explained; hence the additional cooling effect is desirable during this period of time.

. 6 I have found that this may be prevented by main taining the temperature of the insidesurface of the burner substantially below the temperature of fusion of the fuel, which is accomplished by the supply of air thereto.

The corrugated outer surface of the burner provides a large surface area exposed to the cooling medium of the air, and at the same time, the deep corrugations permit the air to penetrate to a point not far removed from the interior of the burner where a rapid exchange of heat takes place from the hot inner surface by conduction to the cooled outer surface. It is evident, of course, that the air which cools the burner passes into the heating system and is thus utilized to aid in heating the building, so that the cooling effect is accomplished only as a part of the heat exchange desired. The air is supplied to the air chamber a fro a blower 40 (Figs. 1 and 3), having an outlet nozzle ll extending through the adjacent wall of the Jacket portion 33 into a flexible Sylphon metal bellows 42. The opening around the blower nozzle II and the adjacent end of the bellows 42 is sealed off as indicated at 43. The opposite end of the bellows I2 is sealed to the air inlet 39 (Figs. 3 and 13). Thus, the air from the blower ID will be supplied to the air chamber 38 during the operation of the blower which will function simultaneously with the rotation of the burner I, as hereinafter described,

The burner head I! also has an upwardly inclined'fuel inlet N in the upper portion thereof, as shdwn in Figs. 12 and 13. The fuel inlet '44 is inclined upwardly at such an angle that the fuel will slide down its interior wall freely by gravity and drop onto the interior surface of the burner I or the partial fuel bed therein at a point slightly spaced from the inner surface of the burner head 11.

The fuel inlet 44 is adapted to be supplied with 7 fuel from a coal hopper designated generally at 45. The hopper 45 is supported in an elevated position upon a saddle 46 carried by legs 41 which extend upwardly from the base 26 to which the legs are rigidly secured at 48..

The bottom portion of the hopper may be substantially trough-shaped, as designated at 49, and having disposed therein or resting thereon a coal conveyor screw 50 journaled at one end portion thereof in a bearing 5|. This conveyor screw 50 has its cylindrical portion generally of conical shape and may be termed a conical screw," being smaller at its discharge end. The discharge end of the screw 50 extends to an extension 51 on one side of the hopper 45, which extension in turn has a down-spout 53 that extends therefrom and is telescoped into the upper end of the fuel inlet 44. The down-spout 53 extends also The cooling effect of this air supply around the burner is particularly desired in connection with the type of fuel known as clinkering coal. Ex-

.perience has demonstrated that whenever these through a part of the. Jacket portion 33, and has a sealed connection. therewith as well as with the fuel inlet N by means of a flexible metal Sylphon bellows 54 which is secured in sealed relation with a flange 55 on the fuel inlet and with the upper wall of the Jacket portion 33. The down-spout 58 is shown as having a surrounding flange SGseated upon said upper wall of the jacket portion 33, these parts being sealed in secure relationship as indicated generally at 51.

In the top of the hopper extension M is an access opening it normally closed by a-iid Bl pivotally supported at 60 on an arm 61 which in turn is pivoted at one end at 62 to the extension 52. The oppo ite. end of the arm II is adapted spout II, as when fire is to be started in the burner.

Another conveyor screw II is mounted below the screw 00, in the hopper extension 02, in position to receive the fuel from the screw and to convey it to the down-spout I3, thence to the fuel inlet 40. This arrangement provides for the feeding of only small quantities of fuel from the body of fuel in the hopper 0i. and through a zigzag path, whereby the body of fuel in the hopper is out of the range of radiant heat in the burner. Thus radiant heat from the burner is not directed to the body of fuel in the hopper,

,and the feed by the screws 00 and 65 is sufliciently slow and gradual that there is no body of fuel in the range of radiant heat from the burner. The fuel inlet 44 is not maintained full or substantially full, and as the fuel is fed therethrough by gravity, it drops directly into the lower part of the burner I or upon the fuel bed therein, immediately after being discharged into the downspout by the conveyor 65.

The hopper may be filled with coal or other fuel. This hopper is provided with a lid 00 hinged at one side, at 01. At the opposite side of the hopper, a fastening latch 00 is connected with the lid 00 and has an operating handle 00.

The conveyor screw 05 is fixed to a shaft 10 journaled in bearings in the bottom of the hopper 0B and saddle 06. The outer end of the shaft It carries. a pinion Ii meshing with a gear I! fixed on the shaft 13 of the conveyor screw 00. Thus, the screw 65 will be driven considerably faster than the screw 50, so as to prevent an accumulation of fuel at the discharge end of the feed screw for a sufficient length of time to become ignited by the radiant heat emitted from the incandescent fuel in the burner I thereby preventing burn back into the fuel hopper.

This is accomplished without the use of a baiile damper which would be objectionable in the construction.

The conveyor screws are operated by means of a ratchet wheel I0 actuated by a pawl carried by a lever '55, shown as forked and straddling the ratchet wheel, being pivotally mounted on the shaft If. The lever I0 is connected through a link It with a crank 11 which is mounted on a shaft 18 (see Figs. 1 and 3). The shaft II extends transversely through a gear box IS in which it is journaled. A worm gear 00 is fixed on the shaft 10 and meshes with a worm I! mounted on a drive shaft 82 that extends transversely relative to the shaft II to a point externally of the gear box I9. The gear box or housing I0 is fixed rigidly to the base 25.

Referring to Fig. 3, a step-cone pulley 03 is mounted on the shaft 82 for free rotation thereon, and said pulley 03 carries on its outer (face rigid therewith one part 04 of a crown clutch, the other part 05 of which is slidably keyed to the shaft 82 so that the part 05 can slide freely lengthwise of the shaft but is held to rotate with the shaft.

The pulley I3 is connected through a belt 08 with a step-cone pulley 01 mounted on one end 8 of an armature shaft 00 of an electric motor 00 fixed on the base 20. The opposite end of the armature shaft 00. carries the rotor of the blower 40 that is mounted on the base 20 beside the motor 09. When the parts 04-00 of the crown clutch are inter-engaged, as shown in Fig. 3. the operation of the motor 00 will rotate the shaft .02 and the .parts connected therewith. This operation of the motor may be controlled by thermostatic or other means, aswillbe evident and usually employed in stokers.

Also mounted on the shaft 10 is a beveled pinion 00 in mesh with bevel gears II on opposite sides thereof fixed to shafts 02 and 02' that ex-.

tend into the jacket 00 through packing glands designated generally at 00. The shafts 02, 02 have one end of each iournaled in a bearing in the gear housing 10, with the opposite end Journaled in a bearing mounted upon the base 20 at each side of the burner I. The shafts 02, 02', (Figs. 3 and 6) embrace opposite sides of the burner substantially on the-axis thereof in normal position, the trunnions 25 being disposed below the center axis of the burner head I! (Fig. 12) sufficiently to prevent interference with the shafts 02, 02'.

The shafts, 92, 92' carry pinions 05 fixed thereon at opposite sides of the burner I In mesh with a ring gear 96 surrounding the burner I. The ring gear 96 carrieslugs 91. extending outward from its'inner rim and spaced from each other to fit upon pads 98 spaced around the burner I and securely fastened thereto by machine screws 00.

justing mechanism is shown as comprising two companion flanges I00, IOI, fixed respectively to the driving and driven end sections of the shaft. The flanges I00, IOI are connected to-' gether by screws I02 fixed to the flange Ill and extending through slots I00 in the flange "I. The slots I03 are formed on arcs of a circle described about the center axis of the flanges and slidably receive therein the head portions of the screws. The flange IOI also carries spaced lugs I04 projecting from its outer edge and receiving therebetween a lug I05 projecting outwardly and forwardly from the adjacent portion of the flange I00. Adjusting screws I06 are threaded through the lugs I04 into engagement with opposite sides of the lug I05. Thus upon loosening of the screws I02 suificient for freedom of movement in the slots I03, the flanges I00, IOI, can be adjusted relative to each other upon tightening of one of the screws I08, and loosening the other. This makes it possible to rotate the pinion II on the shaft 92' slightly while the pinion on the shaft v92 at the opposite side of the burner remains stationary. In this way, the burner I can be raised or lowered slightly and thereby adjusted for wear. After an adjustment is made, the screws I02 are again tightened to maintain the relative positions of the sections of the shaft 92'. a

As stated above, the coal feeding mechanism is so adjusted with respect to the rate of combustion in the burner I that a fire bed of suitable thickness will be maintained, as illustrated in Figs. 1, 2 and 6, but the fuel bed will be disposed in the lower section of the burner with the major portion thereof on the side of the center of the burner in the direction of rotation. Although the burner may be rotated in either direction, it is shown, for purpose of illustration, as rotated in a clockwise direction as indicated by the arrows in Figs. 6 and 8. The fuel is carried around by the rotation of the burner I until-the surface of the fuel attains its angle of repose, substantially as indicated diagrammatically in Fig. 8. As here illustrated, the surface of the fuel bed is designated generally at B, and a lump of coal,

for instance, is designated at L. As the burner I is rotated, the fuel particle or lump L will be carried around the circumference of the burner in the fuel bed until it reaches its angle of repose substantially at the point L3 in Fig. 8, when it will roll down the surface of the fuel bed B until it reaches the bottom thereof. Then it will be carried around again through the bed of burning fuel until it reaches the top of the fuel bed or is completely consumed. This produces substantially an underfeed effect, as hereinafter described.

The invention is shown as applied to a hot air furnace, generally of a conventional type as illustrated in Figs. 2 and 3. This consists of the usual cast iron heater 6 surrounded by the sheet metal jacket I Ii provided with one or more hot air outlets H2, and cold or return air ina passage I25 therein opening into the interior of the heater I I5. As shown in Fig. 3, the burner is preferably installed so that its center axis will beoil'set from the enter of the circular chamber The conventional furnace floor F upon which the furnace rests is provided with a circular opening I25 underneath the chamber I22 and the passageway I25. At the bottom of the opening I25 and in open communication therewith is a conveyor trough I21 carrying a conveyor screw lets Ill, the latter leading to the bottom of the' jacket I while the hot air is discharged from the top thereof. A fire door Ill opens into the side of the furnace. A smoke pipe II5 extends outward from the top of the heater III) for carrying off the gaseous products of combustion as usual. The usual grates normally provided in the bottom of the heater III may be removed or omitted.

The furnace sets upon the usual base I I5, which normally forms the ash pit of the furnace and having an opening H1 at one side thereof. Above and around the opining II1, I preferably construct walls III, II! to enclose a gas chamher I25 immediately adjacent the opening 5 at the discharge end of the burner. The gas chamber I25 is closed on all sides by the walls III and H9, except at the opening 5 and at the bottom. These walls are preferably formed of refractory material, such as flre brick. The purpose of the chamber I 25 is to direct the hot gaseous products from the burner I into the opening H1, and also to provide a hot surface at the face of the wall Iii against which the gaseous products from the burner will impinge upon emerging from the open end 9 thereof.

It is well-known to combustion engineers that an appreciable length of time is required for complete combustion to take place of the hot gases given off from burning fuel. For this reason, it is desirable to maintain these gases at a relatively high temperature for a suflicient length of time before they are brought into contact with the relatively cooler surfaceof the heater Ill. The

general direction of thesegases is indicated by the arrows in Fig. 2.

The inside of the base H5 is lined with a refractory wall I2I, as shown in Fig. 3, forming an interior circular chamber I22. Inside of the chamber I22, and concentric therewith, is a member composed of heat refractory material including an annular flange portion I23 supported on the top of the wall I2I and carrying a downwardly extending cyclonic portion I24, providing is shown as located in a pit I3I in the floor F which pit may be provided with a removable lid or closure I32, to permit removal of the receptacle when desired. An openingv I33 (Fig. 2) is provided at the bottom of the chamber I25 through which ashes are dropped therefrom onto the con veyor screw I28. i

.Fine particles of waste material from the burning fuel in the burner 6, generally termed fly ash" are carried along in the stream of hot gases from the burner in the general direction indicated by the arrows in Fig. 2. Upon reaching the chamher I 22, these hot gases, with fly ash in suspension, are caused to travel at a relatively high velocity around the chamber I22 in a descendin spiral course until they reach the bottom opening into the passage I25. Then they proceed in an ascending spiral course to the upper discharge end of said passage I25 and spread out tangentially from the center of gyration, impinging upon the inner surface of the heater H0. The gyrotory action thus produced by the chambers I22, I25, causes the solid particles of fly ash to be driven by centrifugal force against the outer surface of the inner walls of the chambers I22, I25, where they drop by gravity through the circular opening I25, the surface of which may be inclined toward the conveyor trough I21, into said trough, so that the solid matter thus descends by gravity to the conveyor screw for discharge. I

As shown in Fig. l, the outer end of the shaft of the screw I28 is journaled in a bearing I35 connected with a housing I35 that extends upwardly from the trough I21. "The housing I35 projects upwardly through the floor F on which it is mounted at I35, and is connected rigidly with the outer end of the trough I21. The housing L35 has an access opening in one side thereof, normally closed by a cover plate I31.

The screw I25 is driven by a sprocket chain I35 extending over a sprocket wheel on the shaft of the screw and over a sprocket wheel on a stub shaft I35 journaled in the upper end portion of the housing I35. The stub shaft I35 is connected with a flexible shaft I55 formed of sections telescopically connected for longitudinal sliding movement. The opposite end of the shaft I45 is connected through a universal joint I with the shaft 13 of the screw 55. Thus, upon rotation of the shaft 13, the shaft I55 will be turned to operate the sprocket chain I35, and thereby, the screw I25. Nevertheless, the shaft I55 and its universal connections will accommodate themselves to adjustments that may be made in the position of the base 25 and the parts supported thereon. Y

'and thumb screw II.

ll Operation The hopper Il may be filled with fuel and then closed tight by the lid II which is secured by the latch II. When the burner mechanism is then ready .to be used, combustion may be started without the feeding of fuel from the hopper. The lid II should be raised and kindling introduced through the opening II. down-spout II and fuel inlet I. Then pieces of llghtedpaper may be dropped down by gravity in the same manner into registry with said slot, the air being discharged from the air passages 2 through the slots I into the burner to support combustion of the kindling therein. The burner remains stationary during this time when the kindling is burning therein.

Coal or other fuel 'may be introduced by hand through the opening II and allowed to fall by gravity on top of the burning kindling.

As soon as a substantial fire has been started in this manner, the crown clutch member I5 may be moved inward into engagement with the blown through. the slots 3 by the force of the blower II, which air passes into and through the bed of burning fuel from the air passages covered by the fire .bed. The fresh fuel being fed automatically into the burner from the fuel hopper II, drops onto the lower edge portion of the fire bed substantially in the vertical pulley clutch member II which will immediately cause rotation of the shaft I2, and through the gearing II-II, will rotate the shaft II. The shaft II will rotate the beveled pinion II to drive the gears II, shafts II, If, and turn the gear II to rotate the'burner I. At the sametime,

the shaft I8 rotates the crank arm I1, and the latter operates through the link II and lever IS with the pawl connected therewith. to'impart rotation to the ratchet wheel II. The ratchet wheel 14 is flxed on the shaft 13, whereby its rotation perates the screw II, and, through the gears II, I2, and the shaft II, it operates the screw II. These conveyor screws then function to feed fuel from the hopper-II into the downspout but at such speed that the fuel falls immediately by gravity into the burner .l. Additional fuel may be added by hand, if desired, through the opening II until the fuel bed has attained-the desired proportions, substantially as indicated in Figs. 6 and 8, or at least sufllclent to provide the desired amount of heat. The opening UI- should then be closed by the lid 5! which is clamped in place Combustion is then allowed to proceed autorn'atically according to the demands for heat. Fuel is fed into the burner I by the operation of the conveyor screws II, II, and air is supplied by the blower II to support rapid combustion.

'It will be noted that the fuel fed from the hopper I! by the screw II is discharged by gravity onto the screw I5, and the latter, being driven at a higher speed than the screw II.

discharges it quickly into the down-spout II through which it falls directly by gravity onto the burning fuel in the burner I. This prevents the range of radiant heat emitted from the 'burner I through the fuel intake passage.

As combustion proceeds, the rotation of the by the yoke II,

longitudinal plane through the axis of the l'mrner. This fuel or lumps of coal will be carried around through or beneath the burning fuel, and the rotation of the burner I also causes the fuel to feed or flow gradually from the inlet end of the burner I toward the outlet opening I. .The rates of fuel feeding, fued combustion and fuel travel in the burner are all socoordinated that the fuel will be substantially completely consumed by the time that it reaches the outlet opening I, and all that then remains will be the non-combustible part of the fuel in the form of ashes and/or clinkers, if a clinkering fuel is being used. These ashes fall by gravity through the opening I onto the conveyor screw III;

The incandescent gaseous. products of' combustion form a cyclonic spiral inside the burner I which escape through the discharge opening I as indicated by the arrows in Fig. 2. These heat products are deflected through the chamber III by the walls I II, III, into and through the opening I", thence through the cyclonic passageways I 22, III, into the heater III, to the walls of which they impart their heat. It will be evident that the heat from the walls-of'the heater III will be conducted therethrough to the air surrounding the heater within the jacket III. The heat from-this jacket is conducted through the pipes III to the desired portion of the building. a

. Fly ash from the burning fuel is carried to some extent, depending upon the nature of the fuel, in suspension in the current of hot gases .emerging from the burner I. This ily ash is separated from the gases by the cyclonic effect obtained at III-III described aboveLand falls by gravity through the opening m in the furnace floor 1'' onto the conveyor screw III. The walls ofthe opening or surrounding said opening, preferably slope toward the screw. forming a surface that will direct all solid particles thereto. An appreciable length of time is required ordinarily for complete combustion to take place where solid fuel is being burned. For this reason, a prolonged fire-travel, combined with agitation of the hot gases, are desired between the point where combustion begins and the point where the hot gases impinge against a relatively cool surface. It is also necessary that the'gases, while thus travelling and being agitated, shall be maintained at a relatively high temperature.

usually not below 1200 F., and as much higher as practicable. This is accomplished effectively by the present invention. The bame wall III, being made of heat refractory material of low conductivity remains constantly heated to a high temperature at the surface facing the burner.

thus keeping the entire interior of the chamber III substantially at white heat, thereby P eventmaintained at a high temperature, are

and thereby through this chamber I20.

Likewise, the'walls Iii, cyclonic ash separator, are composed ofv similar heat refractory material, and in like manner, afford no opportunity for the gases to become cool: At the same time, these gases, while being agitated in passing through the opening ill and are given still greater agitation in passing through the chambers m; m, thus insuring the separation of the ash and solid particles therefrom, preventing smoke from being discharged from the furnace.

I Referring to Fig. 1, the rotation ofthe shaft "to drive the screws 50, W, alsoimparts rotation to the shaft, Ill, driving the sprocket chain L38, turning the screw I26. This causes the screw to collect all of the ashes and other solid substances dropped into the trough I271, and to convey, these products lengthwise through the trough to the delivery opening us, where they fall by gravity into the receptacle m, located in the pit 833. 'This receptacle may be removed perlodically upon removal'of the lid I32, or to perunit eln'ptying of the receptacle at desired intervals.

I It will be understood that this means for disposing of ashes is described merely for purpose of illustration, and as one example thereof that may be used. If desired, the pit 63! in the floor of the furnace room may be eliminated where m and m of the.

being conditions permit, and the conveyor screw I29 with its trough Ml may be extended to any, convenient point outside the furnace room. to permit the ashes to be discharged onto an outside ash dump. The ash conveyor screw may be eliminated entirely by the location of the pit directly beneath the openings I28 and I33, either with or without a receptacle therein, into which the ashes may drop directly through these openings. These and other forms of ash removing means may be utilized,-as desired or found suitable, according to the conditions in which the burner mechanism may be used.

As explained above, 'a portion of the air discharged from the air chamber 38 by the blower it, enters the corrugations 4, as these are moved past the slot 31, through the length of this slot. The air thus supplied to the corrugations 4 aids in cooling the burner, and also furnishes an additional supply of hot air for heating the building. This air is supplied through a pipe I45 (Fig. 6) extending from the top of the jacket to a suitable point-of connection with the heating chamber Iii of the furnace, preferably near the top thereof. An air supply pipe 6 may be provided, if desired, extending from the lower portion of the heating chamber ill to the bottom of the air jacket 30, as shown in Fig. 6, thus recirculating air therefrom into heat exchange relation with the periphery .of the burner I, as will be evident from Fig. 6.

Referring to Fig. 3, the air admitted to the blower 4! may be fresh air derived from theatmosphere either takenv directly from the basement or other point of location of the. stoker mechanism in the building, or supplied to the- 14 tion. Since many stokers are applied to heating systems that have been in use for a considerable length of time, these must be capable of meeting the conditions then existing, for anything like universal use. a

It will be noted further that both fuel and air are supplied through flexible connections at ll, ll (Fig. 1), which permit the burner head I! to adjust itself continuously for wear at the contact of its inner face with the rotating inlet end surface of the burner I. since the burner head II is I supported on the adjustable arms ll. The angle of support of these arms ll, combined with the weight of the burner head ll, produces a component of force which constantly presses this cally the movement of fuel within the burner l during its rotation, indicating particularly the movement of a single lump or coal in successive steps during such continuous movement. This lump drops from the fuel inlet 44 substantially at the point Ll, rolling to the lower edge. of the fuel bed B, as shown at L2. Assuming that the burner is rotating in the direction indicated by the arrow, this particle of fuel will be carried around in the path indicated at the bottom oi the fuel bed of burning fuel, substantially to the point L3 .at the upper end of the fuel bed. During the entire time that this particle is travelling from the point L2 to the point L3, it is underneath the bed of burning fuel, and consequently, all of the volatile constituents of this particle that are distilled off during its travel through the fuel bed tuyeres into and through the bed of fuel along with these volatile constituents, the latter will become burned before they emerge from the surface of the fuel bed.

As the. fuel particles reach the point L3 substantially at the angle of repose of the burning fuel, they roll quickly by gravity down the inclined fuel surface B back to the point L! at the lower edge of the fuel bed, where they again enter the "underfeed cycle Just described and pass again through the fuel bed for complete consumption of all combustible portions thereof. These lumps or particles of fuel will be gradually consumed in passing through or beneath the fuel bed as indicated by the progressively decreasing sizes of the circles in Fig. 8. Furthermore, as

each particle is moved through this cycle, it also moves away from the intake end of the burner toward the discharge end, so that its path is substantially helical with the center of the helix extending lengthwise of the burner and passing through the center of the fuel bed.

When non-agitating fuels are being burned, I the burner l is rotated at such a slow speed that centrifugal force has no appreciable effect upon the fuel. However, when semi-agitating or'agitating fuel is being burned, the speed of rotation of the burnermay be increased to a point where centrifugal force is quite appreciable. In this event, the fuel will be held against the wall of the burner throughout a greater portion of its travel,-

and the angle of repose, affected by centrifugal force, will be shifted to a steeper slope, as indicated by the line Bl. Particles of fuel will then be carried upto a higher point on the circumference of the burner i at the upper end of the line Bl before these particles roll down the surface Bl back to the starting point L3, as indicated in Fig. 8.

Some fuels, such as slack coal, nut-and-slack, and many ofthe steam coals," contain a high percentage of very fine particles. Such fuels can be burned advantageously in this burner. Fig. 9 shows how this may be accomplished merely by speeding up the rotation of the burner to where the fuel is retained against the inner wall of the burner by the action of centrifugal force, until it gets'to a point near the vertical longitudinal plane through the center of the burner, whereupon the force of gravity overcomes the action of centrifugal force and the fuel falls in a cataract, as indicated at L5, back to the bottom part of the burner when its combustion process is repeated by the recirculation of the fuel particles through the bed of burning fuel. Each time that the fuel particles fall from the top to the bottom of the banner, if more than once, the larger particles will break into smaller particles and the abrasive actionof these particles produces more "flnes which are burned in suspension as the process continues.

When using non-agitating fuels which may not permit a sufficiently rapid rotation of the burner to obtain the burning efl'ect indicated in Fig. 9, the burner may be modified as indicated in Fig. to handle these fuels. As here shown, a suitable-numberof the outer corrugations l are prolonged angularly into the interior of the where they form vanes I54 extending lengthwise of the burner and projecting therein tangent to a circle described about the center of the burner.

These vanes form shelves as the burner is rotated in the direction indicated by the arrow and carry the fuel upward therein for downward discharge in streams over the edges of the 'vanes, as indicated in Fig. 20, producing a burning eilect similar to that described inconnection with Fig. 9. It will be noted that these deep corrugations or vanes 154 permit the free circulation of cooling air down into their deep folds and thus forestall the ill effects of over-heating.

It will be evident that this burner construction may be used with all of the different types of coals or fuel with equal efliciency. Consequently it"has a wide range of application and can be manufactured and sold more economically than would otherwise be practicable, thus reducing the cost of production and of selling. This is made possible by reason of the easy. quick adjustments of which the burner construction is capable.

, The adaptability of this burner to different types of fuel depends upon: (1) the speed at which the burner is rotated; (2) the speed at which the burning fuel passes throughthe burner from inlet to outlet; and (3) the speed or rate (measured inpounds per hour) at which the fuel is fed into the burner.

I have provided an adjustment for the speed of rotation by means of the step-cone pulleys I2, 81, These may have any desired number of steps or other provisions may be made for varying the of the invention shown, the speed of rotation of the burner i' can be changed quickly and easily by shifting the belt 86 from one set of steps to another.

, I [have provided an adjustment for the speed at which the burning fuel passes through the burner by means of the adjusting screws 21 which support the outer end of the base 26, comburner bined with the adjustable head l2. It will be evident that if the base 28 is lowered to the lower dotted-line position in Figs. 1 and 2, the-burner I, which is supported on the base 26, will be tilted so that its intake end is lower than its outlet end. This will retard the travelof fuel through theburner. Likewise. if the base 26 is elevated to its upper dotted line position, fuel travel through the burner will be facilitated and increased. At all intermediate positions between those shown in dotted lines, the effect on fuel travel will be governed by the inclination of the burner away from the horizontal. In order to make this adjustment in elevation, it is merely necessary to loosen the screws it which thereby loosen the clamps I! (see Figs. 2 and 6). This leaves the ring I 2 free to move in its ball-joint connection at It with the supporting member N and clamps l5. Then upon turning the screws 21, the base 26 will be'raised or lowered until the desired degree of angularity is obtained. Then the screws I should be tightened again, and these will ihOld tion in the support ll.

During the adjustment described above, the flexible Joint connections Iii-Ill that drive the ash screw, will adjust themselves automatically since universal connections are provided with .the shaft I" while said shaft is made up of telescopic sections that are relatively slidable.

Provision is made for controlling the rateat which the fuel is fed into the burner by an adjustment of the point of connection with the lever H of the link ll. Through such an adjustable connection, .thelever H may be caused to oscillate through arcs of varying length, with the result that the feed screws 50, C5 are driven at a greater or fewer number of revolutions per hour, thereby delivering more or less fuel to the burner, according to the adjustment.

I have found that the speed of burner rotation, the angle of burner inclination and the rate of fuel feed, can all be determined by laboratory tests for the various types of fuel. Thus all adjustments can be made easily by the mechanic who installs the burner so'that it willhandle satisfactorily the particular fuel which the owner desires to use. No further adjustment will be necessary until the owner wishes to change to a different type of fuel, in which event, the adjustment can be made easily and readily. A further adjustment may b provided, if desired, to control the amount of air supplied to the burner by the blower 40, in any suitable or well-known manner. It is customary to provide the blower of a stoker with electrically controlled shutters for this purpose, connected with the control of the drive from the motor to the shaft 82. In the form motor so as to be opened or closed according to the operation of the motor.

It will be understood that the method described for installing the burner is intended only for purpose of illustration. The physical condl tions of each individual heating plant must be taken into consideration when the installation is made, Some heating plants may make it desirable to use a different type of installation.

Figs. 15 to 18 show a method of installation which may be desirable where practicable. This is shown applied to a furnace 260 surrounded by a heater Jacket 26L This heater jacket is provided with an opening 262 in a side thereof, and an air jacket 263, usually of sheet metal, and corresponding with the jacket 3., is inserted and sealed to the edges of the opening 282. Thus the air from the heating system in the-.furnace the ring I! rigidly locked in pdsl- 17 jacket 26l is free to circulate throughthe jacket 263 around the outside of the burner, designated resisting material is placed directly against the fire bowl of the furnace 260, and serves as a bafile wall, corresponding with the wall 8 in Fig. 2. Cooperating with the slab 264 are companion walls 265, 266 and 261 which enclose a chamber 268 through which the hot gases from I the burner lb are conducted to the interior .of

the furnace 260. This arrangement makes it possible to locate the burner in close relationship to the furnace 260, so that the burner constitutes a part or an extension of the furnace. Furthermore, they act together to heat the air as it circulates through the heating system around the burner and furnace.

Many hot air heating systems are provided with a power driven fan installed in the air circulating line so that the flow of hot air to the various parts of the building is quickened by forced blast. This would cause the circulation of air around the burner lb to be sufficiently vigorous to make it unnecessary to reinforce it with additional air from the blower that supplies air to the tuyres I of the burner.

In this event, the outside corrugations may be blanked off at the intake end of the burner, substantially as shown in Figs. 10 and 11, so that these corrugations would not extend to the end nor be supplied with air from the air chamber 38 (Figs. 12 to 14). The burner lb is provided with the usual air passages 2b extending therethrough, similar to those shown in Fig. 7, as described above, bud; outwardly of the air passages 2b, the burner lb is provided with a rib 269 which closes the ends of the peripheral corrugations at the intake end of the burner, so that air from the air chamber (38 in Fig. 13) does not enter the ends of these corrugations. Otherwise the corrugations in the periphery of the burner lb are identical with those described above and designated 4 in Fig. '7.

This type of installation cannot b re-adjusted after the burner has been installed, as is true of the installation described above, because the jacket 263 which encloses the burner is rigidly attached to the heater jacket 26l', so that the burner cannot be raised and lowered. However,

the inclination of the burner will be adjusted by the mechanic who installs it and it is not often necessary to re-adjust it thereafter. The other advantages of this installation may make it desirable for use in some instances, even though not thus adjustable.

In Fig. 19 is shown another feature of the burner, in which the slots from the air passages converge from the inlet toward the outlet end of the burner, as shown at 3b. The progressively narrow or converging slots thus provided gradually decreases the space for air discharge from the inlet to the outlet end of the burner, thereby decreasing the amount of air that is discharged at the outlet end and assuring the major portion of the air discharge at the inlet end. This prevents the air from passing through the air passages to the discharge end of the burner before being released into the burner and assures a more even distribution of air throughout the combustion area of the burner.

A further modification is shown in Fig. 21, wherein the air passages 20 are provided with discharge slots to, which slots hovever are arranged for discharge approximately tangentially of the burner about the circumference thereof, instead of radially as shown in Fig. 7. This circumferential discharge of the air from the air passages tends to keep the fly ash from entering the air passages of the burner.

I claim:

1. In a heater, an elongated'tubular burner having a fuel inlet at one end thereof, means journaling one end of said burner for turning movement and including a universal joint supporting the'burner for tilting movement, means journaling the opposite end portion of the burner, meansmounting said last-mentioned journaling means for vertical adjustment and including a base, and means for adjusting said base vertically to different angular positions.

2. In a heater, an elongated cylindrical burner having a fuel inlet at one end thereof, means journaling one end of said burner for turning movement and including a universal joint supporting the burner for tilting movement, means journaling the opposite end portion of the burner, means mounting said last-mentioned journaling means for vertical adjustment and including a base, means for adjusting said base viertically to different angular positions, and

means mounted on said base and having driving connection with the burner for rotating said burner in different adjusted positions thereof.

3. In a heater, a cylindrical. burner for solid fuel, means mounting said burner for rotation about an approximately horizontal axis, said burner having a fuel supply inlet at one end thereof and an ash .and gas discharge outlet at the opposite end thereof, means for adjusting the burner to diflerent'angular positions, power means for rotating the burner and including means for changing the speed of rotation thereof relative to the power means, and means for sup- ,plying fuel to said fuel inlet, said power means I ports into the burner, said discharge air ports decreasing in size toward the discharge end, and means for supplying air to said air passages to support combustion in the burner.

5. A rotary burner adapted for the burning of solid fuel including a tubular structure having a gas discharge outlet at one end thereof, said structure having air passages therethrough extending lengthwise of the burner, each of said air passages having a slot in the inner side thereof for admitting air into the burner to support combustion therein, each slot having the sides thereof converging toward the discharge end of a the burner.

6. A rotary burner adapted for the burning of solid fuel including a cylindrical structure having air passages therethrough extending lengthwise of the burner, each of said air passages having a slot in the inner side thereof for admitting air into the burner to support combustion therein, said slots opening in a tangential direction opposite from the direction of rotation about the circumference of the burner for circumferential discharge of the air therein.

7. A rotary burner adapted for the burning of solid fuel including a cylindrical structure having air passages therethrough extending lengthwise of the burner, each of said air passages having a slot in the inner side thereof for admitting air into the burner to support combustion therein, and means for causing a decrease in the amount of air discharged through said slots from the inlet toward the outlet end of the burner.

B. A rotary burner for solid fuel comprising a cylindrical wall structure of elongated form, said wall structure having air passageways therethrough with openings into the burner and having a corrugated external surface with passages separating said air passageways and open externally of the burner for circulation of a fluid through said passages about the periphery of the burner to absorb heat from said burner.

9. In a heater, a rotary burner of tubular form having a fuel inlet at one end thereof and a fuel discharge attheopposite end thereof, means mounting said burner for rotary movement about an approximately horizontal axis, and a refractory wall directly in front of the ischarge end of the burner spaced therefrom and extending over the area of said discharge end to form a gas discharge chamber at said discharge end and to reflect heat from the open end of the burner into said chamber.

10.- The combination with a furnace having a base, means forming a chamber within the base,

a wall extending downwardly from the furnace 7 into said chamber and having means of communication therewith, refractory wall structure disposed beside the furnace and enclosing a chamber in communication through the base with the first-mentioned chamber, a rotary burner extending laterally from said refractory wall structure and having a discharge end in open communication with the second-mentioned chamber, and means mounting said burner on the refractory wall structure.

11. In a heater, the combination of an elongated tubular burner adapted to receive fuel at one end thereof and to discharge products of combustion from the opposite end thereof, means journaling said burner at the last-mentioned end portion including a support having a universal connection with the burner and a head at the fuel inlet end of the burner journaling the burner thereon for turning movement, and means supporting the head and constructed to apply pressure to the universal connection with the firstmentioned support so as to maintain said burner in supported position thereby.

12. In a heater, the combination of an elongated tubular burner having a surrounding wall with air passages leading therefrom and having openings to the interior of the burner substantially throughout the length of the burner, said burner being adapted to receive fuel in one end portion thereof and to discharge products of combustion from the opposite end portion thereof, a support at the last-mentioned end of the burner having a, concave seat therein-mounting the burner for universal movement, a head engaging the burner at the fuel inlet end and journaling the burner for turning movement, said head having means connected therewith for admitting air to the air passages, and means mounting the head and acting thereon for applying end pressure to the burner against the concave seat.

13. In a heater, the combination of an elongated tubular burner having a surrounding wall with air passages leading therefrom and having openings to the interior of the burner substanthe burner for universal movement, a head engaging the burner at the fuel inlet end and Journaling the burner for turning movement, said head havingmeans connected therewith for admitting air to the air passages, means mounting the head and acting thereon for applying end pressure to the burner against the concave seat, a ring gear surrounding the burner and secured thereto, shafts on opposite sides of the burner and having gears thereon meshing with the ring gear, and power means for driving said shafts.

14. In a beaten-the combination of a tubular burner for solid fuel, means mounting said burner for rotation about an approximate horizontal axis, said burner having a fuel supply inlet at one end portion thereof and an outlet for products of combustion at the opposite end portion thereof, power means for rotating the burner and including meansfor changing the speed of ro'-. tation thereof, and means actuated by the power means in timed relation with the burner rotating means for supplying fuel to said fuel inlet at such a rate Related to the speed of rotation that combustion will be substantially complete before the fuel reaches the outlet end of the burner. 1

15. In the process of burning solid fuel in a cylindrical structure supporting a fuel bed hav:

ing respectively opposite leading and followingedges, the steps comprising rotating the fuel bed about an approximately horizontal axis in the direction of the leading edge thereof, while combustion proceeds, thereby rolling and tumbling the fuel particles over each other, and at such speed that the major portion of the fuel bed is maintained at one side of the vertical .plane through said axis, supplying fuel particles to said cylindrical structure externally of said fuel bed and dropping the fuel particles onto the fuel bed at the following edge portion thereof whereby the fuel particles move through the under side of the fuel bed approximately throughout the width thereof during rotation of the fuel bed, supplying air at the periphery of the fuel bed underneath the fuel bed and at points along the axis of rotation, and passing said air through the fuel bed to the surface thereof.

16. In a heater, an elongated cylindrical'burner, means mounting said burner for rotary move-, ment about an approximately horizontal axis, said burner being constructed to support a fuel bed therein with respectively leading and following edges corresponding with the direction of rotation of the burner, means for supplying fuel to said burner at one end thereof and at a point to cause the fuel to drop by gravity onto the upper surface of the fuel bed adjacent the follow ing edge thereof, whereby the fuel is moved through the under surface of the fuel bed ape proximately throughout the width thereof during rotation of the fuel bed, means for supplying air to the under side of the fuel bed at points along the axis of rotation thereof for movement of said air through the fuel bed to the surface thereof,

and means for withdrawing products of combustion at the opposite end 01 the burner from the fuel supply.

. WESTON M. FULTON.

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

UNITED STATES PATENTS Number Name Date 560,599 Bonneville Sept. 29, 1396 661,700 Lewis Nov. 13, 1900 993,604 Kieier May 30, 1911 1,079,151 Smailwood Nov. 18, 1913 1,278,334

Grieve Sept. 10, 1918 Number Number

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