US1886577A - Coalburning apparatus - Google Patents

Description

Nov. .8, 1932. A. USDAHL' 1,886,577

COAL BURNING APPARATUS I Original Filed Feb. 10, 1925 3 Sheets-Sheet 1 INVENTOR Adolph Ousdahl Nov. 8, 1 932. A SDAHL 1,886,577

GOAL BURNING APPARATUS Original Filed Feb. 10, 1925 s Shets-Sheet 2 l m I r 0/ I INVENTOR I Adolph Ousdahl Nov. 8, 1932. QUSDAHL 1,886,577

COAL BURNING APPARATUS Original Filed Feb. 10, 1925 3 Sheets-Sheet 5 50 2 1o 79 o 0 IO INVENTOR Adolpg Ouadahl z v 5- 6 mzr A ORNEYs Patented Nov. 8, 1932 UNITED STATES PATENT OFFICE? ADOLPH OUSDAHL, OF SEATTLE, WASHINGTON, ASSIGNOR TO AUTOMATIC CO AL BURNER 00., A CORPORATION OF WASHINGTON COAL BURNING APPARATUS Application filed February 10, 1925, Serial No. 8,295. Renewed December 1, 1980.

My invention relates to apparatus intended for use in furnaces for heating homes, apartment houses and the like. This application a,

is particularly directed to the burner or furnace end of the apparatus, including the means for delivering fresh coal to the fire, the delivery of air to the fire,the handling of the fuel mass while burning, and the removal of ashes. A companion application Serial No. 8,294, filed coincidentally herewith relates more particularly to a control and drive mechanism for apparatus of the type here concerned.

The primary object of this invention is the provision of apparatus of the character described which will accommodate a'large or a small amount of fuel, as may be determined by the character of fire desired, and which will insure proper combustion of the fuel whatever the character of the fire. Thus, when a hot, forced fire is desired, my device will properly handle a sufficient quantityof I fuel, and will supply air in amounts and in a manner to insure proper and complete combustion of the fuel, and when a slow,- holding 7 them at a rate materially lower than the normal, that the fire will die down and perhaps be extinguished. These defects appear to be due chiefly to improper supply of air and improper admixture thereof with the fuel. It is, therefore, an object of utmost importance to provide a stoker of this type in which the supply of air for combustion will be in such amounts, and its application to the fire will be at such points and in such manner, as to insure, at widely varying rates of feed of the fuel, proper combustion of the fuel and proper regulation of the fire.

A further object lies in the provision of means for en'iploying the coal itself or the mass of burning fuel to maintain clean and free the grate apertures.

A further object is the provision of automatic means for collecting and removing the ashes.

A further object is the provision of means whereby accumulations of dust, a'shes, bits of coal and the like may be readily removed and combinations thereof which are shown in the accompanying drawings, described in the specification and particularly defined by the claims terminating the same.

In the accompanyin drawings I have shown myinvention in orms which are now preferred by me, the modifications being chiefly to adapt the device to different types of fuel.

Figure 1 is aside elevation with parts broken away, and Figure 2 is an end elevation showing the general arrangement of the apparatus.-

Figure 3 is a vertical section along the axis of the feed screw, taken through the burner and associated parts.

Figure 4' is a section through one side of the apparatus, on the line 4.f1 of Figure 3.

Figure 5 is a similar section taken at the opposite side of the apparatus, and showing a slight modification.

Figure'G is a sect-ion, substantially on the line 6-6 of Fi re 3.

Figure 7 is a detail elevation, with parts shown in section, of the ash sweeper ori scraper.

Figure 8 is a detail section on line 8 -8 of Figure .5. v

Figure 9 is a perspective view of a detail.

It will be understood that my present invention may be employed with any type of fuel feeding mechanism, and the form shown' in Figures 1 and 2, which is at present preferred by me, and whlch forms the sub ectto hereinabove, may be replaced by any suitable mechanism. In this preferred form' the coal drops from hopper 9 into a coal conduit 4 80 within which a feed screw 8 advances it to the fire-pot, contained within a casing 2, and air is supplied to the pot from a fan 90, the latter being connected to the pot through i a conduit 81. This latter air conduit is shown as surrounding the coal conduit 80.

The feed screw 8 and the fan 90 are shown as driven from a motor 91, operating through suitable gearing contained in a gear box indicated at 92, to drive a sprocket wheel 93, and thus in turn to drive a shaft 94 through a chain 98. The shaft 94 is connected to the feed screw 8 through some such intermittent drive means as the clutch mechanism illustrated diagrammatically at 95, the control means for this intermittent action being illustrated more or less diagrammatically at 96. A chain 97 is shown as connecting the shaft 94 with a shaft 71 to which is secured a screw 7 the latter being intended to remove ashes from beneath the burner and todeliver them to a suitable point, as, for example, to an elevating arrangement 72 by means of which the ashes may be delivered to a can '73 or othersuitable receptacle. Inasmuch as these constructions form part of and are more fully described in my companion application, further description here is deemed unnecessary.

The present invention is concerned with the means for handling and burning the fuel after it has been delivered by the feed screw 8 into the fire pot, and the means for removing ashes from the burner itself. The burner, as has been stated, is enclosed within a casing 2, which casing is .formed with an open top and preferably with one end, that opposite the end at which the feed screw en- 'ters, being also open. Within this casing is formed a cup 3, the cup being fixed within the casing and spaced from its walls and the fuel conduit 80 connecting to one side thereof (Fig. 3), the feed screw 8 extending thereinto to deliver coal to the bottom of the cup and to advance it upward therethrough by pressure of coal from beneath. Above the cup is positioned the annular burner or grate l the walls of which are substantially vertical,'but fiaredoutwardly at the top, this burner covering the open top of the casing 2 and extending over the upper edge thereof, but leaving free a central aperture for the discharge of coal. In effect this burner. forms a continuation of the cup 3, and these two elements together form the burner pot. The space between the burner pot and the walls of the casing 2 form an air chamber 20 through which the air for combustion of the coal, received from conduit 81, is fed to the burner. I

The burner or grate 1 is rotatable relative to the casing 2 and cup 3. It is shown as vice is rendered easy.

.ceived lugs 41 upstanding from the ring 4.

The bottom surface 13 of the burner is horizontal and is preferably finished to fit upon a similarly horizontal and finished upper surface 31 of the cup 3. These two surfaces, fitting together, form a joint which will .prevent passage of any but the finest partlcles of coal and of any appreciable amount of air. To enable proper seating of these two surfaces, leveling means may be employed between the ring 4 and grate 1, such as the leveling screws 14. Centering and clamping screws 19 may be. employed to retain the grate in proper position upon the ring 4, and the ring may be retained in proper position by screws 49, which are only accessible after removal of the grate.

' Rotation of the ring 4 and consequently of the annular gratel is secured in any suitable manner, and conveniently through the conveyor or feed screw 8 at the burner end of the apparatus. For this purpose I have shown a shaft 38 journaled in a side of the cup 3 and having operative engagement with the endof the feed screw 8, as indicated at 39. Preferably this arrangement is in the form of axially interlocking fingers, as shown in Figure 3, whereby the feed screw may be withdrawn axially from engagement with the shaft 38. Upon this shaft, in the chamber 20, is secured a bevel pinion 37 meshing with a bevel gear 43 upon a vertical shaft 40. This vertical shaft is supported within the chamber 20 in some suitable manner, as in bearings 24 in-a cover plate 23 which closes the open end of the casing 2. By thus supporting it assembly or disassembly of the de- At the upper end of the shaft 40 is secured a spur pinion 44, meshing with a ring gear 45 secured to the ring 4. By such means the ring 4 and annular grate 1 are rotated as the fuel is fed into the fire,

ly to the chamber 20 to deliver air thereinto' from the fan 90. Air is thus supplied through the apertures 12 directly to the fire in the burner, and by locating these apertures towards the edge of the burner it is insured that air will be supplied in such man ner as to insure complete combustion of the previously ignited coal. Ordinarily when the employment of the helical ribs in consuch apertures are employed in a burner or grate they will in a short time become clogged with ashes, with bits of coal and with clinkers. By rotation of the burner 1 the burner is moved past the burning mass and a scouring'action ensues, by means of which these apertures 12 are maintained free. This is especially true when means are provided for insuring to a large extent that the mass in the burner will not rotate also, and is assisted b means which feed the material upward t ough the.burnerpot, and for moving it thus transversely of the apertures 12. This latter means comprises a rib 15 extending helically about the' interior of the burner 1 and inclined with respect to the direction of rotation so that it will advance the coal therein upward toward the curledover edge 10. The means, for insuring that the coal will not rotate with the burner, may be any found suitable, but for this purpose I have found one 'or more pillars 5 or 5' positioned in the burner-pot but eccentrically of the axis of rotation of the burner, to be suitable for the purpose. wo such pillars are employed in the embodiment shown.

My burner is intended to burn either coking or non-coking coal, but the inherent characteristics of such coals require variation in the manner of handling them, and in the manner of supplying air to the burning mass. In Figures 3 and I have shown a pillar 5 which is of a type intended for use wlth coking coal, and in Figure 5 I have shown a pillar 5' intended more particularly for noncoking coals. The chief difference lies in the fact that the pillar-5 is arranged in such a manner that upon rotation it will breakup masses of coal in the burner-pot, whereas the pillar 5' serves principally to supply additional air to the center of the burning mass inside of the burner. In either type the primary function is to revent, to a large extent, the rotation with the burner of the burning mass therein. Both types of pillars are perforated preferabl for admission of air, the air being supplied to a chamber 50 within the pillar through a hollow shaft 51, this extending vertically through a bore 35 in the cup 3;

If desired, and as'shown in Figures 3 and 4, the pillars may be so mounted upon the upper end of the shaft 51 that upon rotation of the shaft the pillars will rotate, and to assist in breaking up the masses ofcoal which tend to form when coking coal is burned, the pillars 5 are inclined relative to its axis and may be provided with a helical rib 55. By making the inclination of the pillars 5 substantially at the same angle as the angle of the adjacent side wall of the burner 1, and by junction with the rib- 15 on the inside of the grate, the action of the rib 15 is augmented by the action of the ribs 55, the pillars thus serving the dual purpose of breaking up the mass and of raising the particles, thus further preventing clogging of the holes, both in itself and the apertures 12in the burner. Rotation of the shafts-51 is secured by any suitable means where rotation is desired. As shown herein a sprocket 52 is secured to the lower end of each such shaft, and a chain 45 passes about each of the sprockets 52 and about a drive sprocket 46 upon the shaft 40, whereby upon rotation of the shaft 40 the shafts 51 are rotated. This drive connection may be omitted if desired, and as shown in Figure 5, wherein the hollow shaft 5lserves merely as a positioning means and as a conduit for air from the chamber 20 through the apertures at the top of the pillar 5 and thus into the burner-pot.

It is inevitable that particles of ashes, soot, coal, and clinkers will from time to time pass through the apertures 12 or 54 and will drop into the air chamber 20 within the casing 2. Means must be provided for removing these particles and to this end I have shown the bottom of the casing as having a series of apertures 26, these being normally closed by a shaker plate 6 which has apertures 62 adapted upon movement from the normal position of the plate 6 to register with the apertures 26 in the bottom of the casing 2. The shaker plate is movable in the bottom as, for example, being pivotedat 61 in the center of the bottom and is suitably controlled preferably from a distant point. This may be accomplished through a rod 60 secured to a link 63 secured to the shaker plate 6 at 65. By moving the rod 60' backwards and forwards the shaker plate is actuated. Stops, such as the shoulders 64 on the shaker plate and a pin 66 in the bottom of the casing, serve to indicate when the holes 62 and 26 are in and out of registry.

The coal as it burns forms ashes which by the addition offresh coal from the bottom of the burner-pot, are pushed outward over the edge 10 of the burner whence they pass in substantially equal quantities at a plurality of 'points around the vertical center line of the burner, or, more specifically, whence they pass substantially uniformly around the circumference and vertical center line of the burner. I provide a ring 79 having a peripheral flange 70 upstanding therefrom to receive these ashes. The ring is positioned below the edge 10 of the grate and all ashes forced over this edge fall upon the ash-receiving ring 79. Inasmuch as the burner rotates, it is possible by providing one or more sweepers or scrapers as 17, pivoted at 18 upon the grate, to cause this scraper 17 to move over the ring 79, that is to say, in an annular path to which the ashes from the burner find their way and to sweep the ashes in front of it. Then by providing a localized opening or hole in the bottom of the ring 79 communicating with a spout 7 4 (Figures 1 and 2) the ashes may be swept around to the spout 74 and dropped therethrough into position to be carried away by the screw 7 as has been previously described.

It is believed the operation of the device will be clear from the above description. Fuel from the hopper 9 is fed through the conduit 80 by the screw 8 directly into the bottom of the cup 3 forming part of the burner-pot. Itisraised primarilythroughthe action of the screw 8 into the upper part of the burner-pot, where it finally becomes heated and ignites. The rotation of the burner 1 serves to main? tain its air supplying apertures 12 open, and

in effect maintains the fire fresh and bright through relative movement of the burner and fire such as occurs when the ordinary furnace grate is shaken. The effect is the same as would be secured by continuous gentle shaking of such a grate. It serves also to raise the burning mass through the action of the helical rib 15. The pillars 5 or 5 supply additional air to the interior of the mass and prevent rotation of the mass of coal. In addition, for coking coal the pillar 5 serves to break up the mass and to raise it. The coal will become consumed in its upward passage through. the

annular burner l and the ashes will pass outward over the edge thereof, being forced out by the supplying of more coal from below and by the feeding action of the rib 15. The ashes are received in the ring 79 and are scraped therefrom by the scraper 17 to be delivered to the chute 7 4 and finally to be removed to the receptacle 73. i

One advantage of this type of burner is that when it is desired to burn more coal, that is, to force the furnace, it is possible to do so merely by increasing the speed of. the feed .screw and consequently'of the burner 1. Bo-

tation of the burner serves always to maintain its apertures clear and free of obstructions, and to maintain the fire bright. Though the diameter of the burner may be small, this insures supplying suflicient air to the coal to fully consume it, between quite low and quite high feeding, rates. Speeding up the feed screw in the arrangement shown, speeds up the fan 90 also and supplies additional air both through the apertures 12 and throughthe pillars 5 and 5'. The air is thoroughly mixed with the coal in such way that the coal is properly and thoroughly consumed. At the same time when it is desired to maintain a low fire this may be done by slowing down the rate of feed and the air supply. The feature of flexibility is one which is lacking in the. stokers of which I am aware and is due chiefly to the rotary character of the burner and the manner in which the same maintains itself free of obstructions, to permit the addition of the requisite amount of air to the fire, and the manner in which ashes are constantly removed from the incandescent particles. The device-is also extremely simple to as semble or disassemble and has no parts which need to wear or give out, except as the pillars 5 or 5' may burn out, and these are so arran ed that they may be readily removed or repl aced.

What I claim as my invention is 1. In coal burning apparatus, a cup, means for feeding fuel upward therethrough, an annular burner forming an upward extension of said cup, means for rotating said burner relative to said cup, said burner having apertures thereabout for the admission of air, and

having a helical rib extending about its inner wall to a point above the lower limit of said apertures.

2. In coal burning apparatus, a fixed cup, means for feeding fuel upward therethrough, an annular burner forming an upward extension of said cup, means for rotating said burner relative to said cup, and means fixedly located relative to said cup, and positioned within said burner and eccentric to its axis of rotation, and extending upward within the zone where coking begins, to intercept and break up masses tending to rotate with said burner.

3. In coal burning apparatus, a two part burner pot, thelower portion thereof comprising a cup adapted to receive fuel, and the upper portion comprising a rotative burner,

means for feeding fuel upward through said burner-pot, and'pillars supported in and extending upward from said cup into the burner, eccentrically of the axis of rotation thereof, to intercept coals tending to rotate therewith.

' 4. In coal burning apparatus, a two part burner pot, the lower portion thereof comprising a cup adapted to receive fuel, the upper portion comprisinga rotative burner, means for feeding fuel upward through said burner pot, and means fixedl Qlocated relative to said cup and positione in said-burner pot eccentrically of the axis of rotation of the burner to intercept coals tending to rotate therewith.

5. In coal burning apparatus, a two part burner pot, the lower portion thereof comprising a cup adapted to receive fuel, the upper portion comprising a rotative burner, means for feeding fuel. upward through said burner pot, and a helical rib upon the inner surface of said burner inclined in a direction.

prising a cup adapted to receive fuel, and the upper portion comprising a rotative burner forming an upward continuation of said cup, means for feeding fuel upward substantially in astraight line through said burner pot, an ash-receiving ring positioned beneath the outer edge of said burner, and an ash scraper carried by said grate and movable therewith over said ring.

8.- Coal burning apparatus as in claim 7, said ash scraper comprising a shoe adapted to ride over said ring, and pivotally supported thereabove from the rotative member.

9. The combination with a burner of means for feeding fuel thereto and therethrough,

a ring positioned about and beneath the edge of said burner, and an ash-scraper carried by the burner and bearing upon said ring.

10. In coal burning apparatus, in combination, a casing open at its top, a ring rotative at the upper edge of said casing, means ac-' cessible from within the ring to maintain it in place upon the casing, a rotative burner mounted upon said ring to rotate therewith, means accessible from without the burner for securing it upon said ring, means for feeding fuel upward through said burner,

and means for rotating said ring and burner.

11. In a coal-burning apparatus, a twopart burner pot, the lower portion comprising a cup adapted to receive fuel, and the upper 'portlon comprising a rotative burner forming an upward continuation of said cup, means for feeding fuel upward through said burner pot, a pillar fixedly located relative to said cup and positioned within said burner eccentric to the axis of rotation of said ro ttative burner, means for rotating said burner, and helical ribs on the interior of said burner positioned and co-operating with the pillar to lift fuel particles engaged thereby as it rotates.

In coal .burning apparatus, in combination, a casing interiorly divided into two coaxial chambers each open at its top, a burner member supported upon the top of said casing, and extending. thereinto to close the top of the outer chamber, the lower portion of the 1nner chamber comprising a fixed cup spaced from the outer wall of the outer chamber, and the burner member being fitted upon the upper edge of said cup and forming an upward extension thereof, said cup and burner member constituting a burner pot a ring rotative upon said casing and engaging with said burner member for rotation thereof, means for feeding fuel upwards through said burnerpot, and means for ro tating said ring and burner member.

13. Acoal burning apparatus as in claim 12, the bottom of the casing being formed and adapted to be opened to release ashes falling thereupon, and to be closed to confine air in the outer chamber.

14. In coal burning apparatus, in combination, a caslng open at its top, a ring rotative at the upper edge of said casing, a cup within said casing below its top, a burner member,

supported on said ring, and'havin a horizontal lower edge fitting closely 't e upper means for leveling said burner member upon the ring. a

15; In coal burning apparatus, in combination, a casing open at its top, a non-rotative cup within said casing below its top and spaced from its side walls, an annular apertured burner, member supported androtatable upon the upper edge of the casing, and fitting thereinto to close the top of the easing, between its wall and said cup, the adjacent edges of the burner member and cup fitting closely together, a coal conduit extending into said casin and discharging into said cup, an air conduit connected to said casing and discharging into the chamber therein defined by the cup, the burner member, and the casing walls, means for advancing fuel through said coal conduit into the on means for rotating said burner member to eep the apertures in the latter free of obstructlons, and apertured pillars supported in said cup and extending upwardly through the burner member to prevent bodily rotation of the fuel mass therein contained the apertures in said pillars and in the burner member being in free communication with the air, chamber within said casing.

16. A coal burning apparatus as in claim 15, including a rotative ring interposed between said burner member and the upper edge;

of the casing, said ring resting upon and being rotative about the casing burner member being secure to said ring.-

17. In' coal burning apparatus including an annular rotary burner member and a stationary member therebelow, together constituting a burner pot, a. casing surroundmg said members and forming therewith a closed air chamber surrounding the burner pot, a

hollow upright shaft supported in the stationary member and extending from said air edge, and said chamber to the rotary burner member, and an I apertured pillar having an interior, chamber in communication with the bore in said shaft, and supported on said hollow shaft to extend into said rotary burner member, to discharge air from said air chamber thereinto through its apertures.

18. In coal burning apparatus, in combination, a casing open at its top and at an end, a cup within said casing below its top and spaced from its walls, an annular apertured burner member supported for rotation from the upper edge of said casing, and fitting within said casing, said burner member forming an extension of said cup, and constituting therewith aclosure for the top of said casing, to define a chamber within said casing, a coal conduit discharging into said cup, a feed screw rotatable in said conduit, a shaft extending through and journaled in a wall of said cup, said shaft and feed screw being opera'tively connected, a cover plate for closing the open end of said casing, a vertical shaft journaled on the inside of said cover plate,

and drive connections within said chamber between said two shafts and between the ver tical shaft and said burner member, to rotate the latter.

19. Goal burning apparatus as in claim 18, characterized by the interposition of a ring having gear teeth thereon between the burner member and the upper edgeof the casing,

said ring resting upon the casing and supof, and means provided with a localized opening to receive the ashes transported by the sweeper hereinafter mentioned, of a sweeper revolvable, around a vertical line extending through said center opening in the burner, in an annular path to which the ashes passing from the periphery of the burner find their way, and means for revolving said sweeper in said path.

21. In a coal burning apparatus, the combination with a substantially annular burner,

means for feeding the coal thereto comprising means for forcing the coal upwardly through the center opening in the burner, the solid material'thence passing outwardly and the ashes discharging from the burner substantially uniformly throughout substantially the entire periphery thereof, and means provided with a localized opening to receive the ashes transported by the sweeper hereinafter mentioned, of a sweeper revolvable, around a ver tical line passing through said center opening of the burner, in an annular path to which the ashes so discharging from the burner find their way, and means for revolving said sweeper in said path.

22. In coal burning apparatus, the combination of a substantiallv circular burner, a stationary casing surrounding the vertical center line of said burner and cooperating with said burner to form an air chamber from whence combustion air passes to the fuel on the burner, means for feeding coal to the center of the burner, whence the solid material passes outwardly and the ashes are discharged from the burner substantially throughout the entire periphery thereof, a rotatable ring mounted on said stationary casing for rotation around said vertical center line, means for rotating said ring, and an ash sweeper carried by said ring for revolution in a path to which the ashes from the burner find their way, and means providedwith a localized opening to receive the ashes transported by said sweeper.

23. The subject matter of claim 22, characterized by the fact that said burner includes a rotatable part, and said rotatable part is mounted on and driven by the said rotatable ring.

24:. In a coal burning apparatus, a stationary upwardly open casing member, a stationary upwardly open cup therein, spaced from a surrounding wall of said casing member to provide a space for the passage of combustion air to the burner hereinafter mentioned, a burner having a center opening to receive coal passing upwardly from said cup and extendingfrom above the edge of said cup across said space between said cup and said wall of the casing member, means for forcibly feeding fuel both into a side of said cup and thence upwardly to said burner, the solid material thence passing outwardly and the ashes discharging from the burner sub stantially throughout the entire periphery thereof, a ring rotatably mounted on said casing member for rotation around a vertical line passing through said center opening of the burner, means for rotating said ring, and an ash sweeper mounted on said ring for revolution thereby in a path to which ashes from the outer edge of said burner find their way, and means provided with an opening for ashes transported by said sweeper.

25. In an automatic coal burning apparatus, the combination of a center-underfed annul'ar burner, a solid-material conveyor below the burner serving the same, the solid material passing upwardly through said burner and outwardly and the ashes discharging from the burner substantially throughout the entire periphery thereof, means for driving said conveyor, a ring rotatable around a vertical line extending through the center opening of said burner, a connection, at the burner end of the apparatus, between said conveyor and-said ring for driving the latter, and an ash sweeper carried by said ring for revolution in a path to which said ashes from the burner find their way, and means provided with a localized opening to receive ashes transported by said sweeper.

26. In coal burning apparatus, in combination, apparatus at which the coal is burned oibly feeding coal upwardly through and over said grate, means for rotating said rotatable member, an ash sweeper, carried by said rotatable member, in the path of the ashes falling from said grate, and means provided with a localized opening to receive the ashes transported by said sweeper characterized by the fact that the burned ashes "are free to pass to the periphery of said grate,

under the thrust of fresh coal fed by said coal conveyor, substantially uniformly throughout substantially the whole of said periphery, and are free to fall'th'erefrom, throughout substantially the whole of the periphery of the grate as and when they are thrust to the grate periphery by the thrust of the fresh coal.

Signed at Seattle, King County, Washington, this 4th day of February, 1925.

ADOLPH OUSDAHL.

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