USRE23319E - Magazine feed stove - Google Patents

Description

Jan. 2, 1951 w SANFORD ETAL Re. 23,319

MAGAZINE FEED STOVE 4 Sheets-Sheet 1 Original Filed Nov. 29, 1941 Jan. 2, 1951 w, SANFORD HAL Re. 23,319

MAGAZINE FEED STOVE Original Filed Nov. 29, 1941 4 Sheets-Sheet 2 Jan. 2, 1951 H. w. SANFORD ET AL MAGAZINE FEED STOVE 4 Sheets-Sheet 25 Original Filed Nov. 29, 1941 WWW Jan. 2, 1951 w, SANFORD ETAL Re. 23,319

MAGAZINE FEED STOVE Original Filed Nov. 29, 1941 4 Sheets-Sheet 4 Reissued Jan. 2, 1951 MAGAZINE FEED STOVE Hugh W. Sanford and William P. Biddle, Jr., Knoxville, Tenn, assignors,by direct and mesne ass gnments, to Sandebond Patents, 1110., Knoxville, Tenn, a corporation of Delaware Original N0. 2,Q03,S29, dated July 9, 1946, Serial No. 42Lfi66, November 29,1941.

Application for reissue June 17, 1947,8eria1 No. 755,106

Matter enclosed in heavy brackets II appears in the "original'patentbut forms no part of this reissue specification; matter printed in italics indicates the "additions made by reissue 40 illaims.

This invention relates to an improvement in magazine feed stoves of the character designed for the burning of coal, particularly soft coal, either in small sizes or in lumps.

Several magazine feed stoves have been proposed heretofore, but difiiculty has been encountered with these designs in more than one respect. In the first place, when soft coal is used, the coal in the magazine hopper, when fresh the is started, is soon penetrated by the heat of the fire, with the result that all the volatile matter in the coal is discharged quite rapidly. With a hundred pound charge of fuel in the magazine, the volatile matter is completely out of the fuel within probably an hour to one and one-half hours from the time the fire starts burning. This rapid discharge of the volatile matter has the result of making the operation of the stove exceedingly smoky during this initial period. Second, it is almost impossible to burn this excess volatile matter at one time efliciently, and a large part of the heat is wasted up the chimney.

In the third place, during the coking of the fuel by discharging the volatile matter in this way, an expansion of the fuel bed takes place to such extent that the mass of coked fuel is bound tightly to the side walls of the magazine, with the result that the mass of unburned coke is held against falling as the fire burns out underneath. This has the effect of leaving this mass of unburned coke considerably above the lower combustion zone, and the fire eats into this mass of suspended fuel from the bottom in such fashionthat it is very difiicult to control the rate of combustion. Experiments with more than one conventional prior design have indicated that the suspended coke will not fall down into the combustion zone until it is about two-thirds consumed, unless it is poked down by an operator, which is not an easy thing to do.

One of the primary objects of this invention is to provide a magazine feed stove, for bituminous coal particularly, that avoids the quick driving off of the volatile matter in a way that is inefficient and also creates an excess of smoke. This invention permits the main body of the fuel in the magazine to remain unvolatilized for a long period of time with a gradual discharge of volatile gases from this mainbody of fuel, whereby the heat value of this vola ile matter can be obtained by the normal processes of combustion, and, finally, it provides means by which the, fuel in the hopper is suiiiciently freed from the side wallsof the magazine to fall down on the fuel bed as fast as the lower parts of the fuel in the licpperrarecon m d.

bustion zone. Thus any volatiles or gases which combustion;

In the preliminary stages wherein heat normally reaches tothe fuel in the magazine to some ezttent', the bituminous coal forms a sticky 'ta-r compound which causes it to adhere to the side walls of the magazine, but this in time'will burn away; and at this latter stage'the sticking of the fuel to the side walls is due principally to the pressure exerted by the expansion 'of the fuel during the'coki ng process.

The objects of this invention are accomplished, according'toone embodiment by admitting primary air to the sides'of the magazine throughout the major portion of the height'thereof to produce heating of the peripheral portion of the column of fuel, liberating the-volatile gases there'- from, 'and'also supporting combustion of the peripheral 'portion of the'fuel, which keeps the column of fuel-burned away from the side walls ascombustion-progresses, thus preventing sticking to the'wal-ls, and causing the fuel to settle down gradually during the combustion process.

Sinceit isd-i-fiicult to" furnish an'ad'equate sup- 'ply'ofprimaryairtoreach all of the volatiles and coke'i n the fuel column, provision is made for admitting a secondary air supply to the comreach this 'po'int i n'the bottom fluein an unburned state, dueto a lack of the necessary oxygen, are thereby supplied with secondary air for" complete consumption thereof, causing complete combustion of Michael.

Both primary and secondary air are preheated when admitted to the stove, thereby aiding-combustion, and both may be controlled so as to regulate the burning: of the volatiles, reducing these as muchfias required. to obtain complete Since free gases are not thereby given off, but are substantially consumed; this resultsin the discharge of. substantially no smoke. Therefore, it. isusubstantially a smokeless stove.

:preferred'embodiment' of: the invention is shown in the accompanying drawings, together with modii'ications"thereof, in. which:

Fig.1; is: a vertical sectional view through the stove;

ing a modified formof magazine; and

Fig. 8 is a horizontal section therethrough.

The invention is shown as applied to a magazine heating stove constructed with a fuel magazine designated generally by the numeral I adapted to receive a quantity of fuel, such as coal, therein necessary to support combustion. The magazine I is formed and enclosed by members 23, hereinafter described. A heating and combustion chamber 2, is disposed beside the fuel magazine, as shown particularly in Figs. 2 and 3.

The fuel magazine I is constructed with a surrounding drum 3, shown as of sheet metal, and having a heating drum 4, attached to opposite sides thereof by seams 5. The heating drum 4 has a partition 6, extending transversely thereof between the heating chamber 2 and the fuel magazine I. A cover I extends over the drums 3 and 4 and forms the top of the stove. The top I has a feed opening therein over the magazine I which is provided with a lid 8 for closing the same.

Supporting the drum 3 that encloses the fuel a magazine I, and the heating drum 4, is a base 3, within which is mounted a base casting III which extends transversely beneath the fuel magazine and the heating chamber, and is supported on the periphery of the base 9 intermediate the latter and the drums 3 and 4, as shown in Fig. 1.

Mounted within the base casting I beneath the fuel magazine I, is a rotary ash grate ll, beneath which is supported a draw-center ash dump I2 within an ash pit I3. The rotary ash grate II and ash dump I2 are of conventional shaking down the ashes into the ash pit I3, while the ash dump I2 is adapted to be withdrawn for dumping the entire contents of the fuel magazine. The ash pit I3 has a door I4 in air-tight sealing relation therewith at the periphery of the base 3 adapted for opening movement for access to the ash pit I3.

The base casting Ill has a transverse supporting bar I5 extending thereover in bridging relation, one side of which is in sealing relation with the lower edge of the partition Ii. Theopposite edge of the bar I5 is in sealing relation with the lower edge of the drum 3 forming an air space I6 therebetween which partially surrounds the fuel magazine I, as shown in Figs. 2 and 3, and within which air space the primary air may be preheated. Air is admitted to the air space I6 through openings I! in one side of the drum 4, which openings are controlled by a slide damper I8 (Fig. 3).

The upper end of the air space I6 is in open communication with a distributing duct [9 that surrounds a dome 20. The dome 20 extends downwardly from the fuel opening in the top 1 into the upper end of the drum 3, and has a laterally extending flange 2| thereon, extending outwardly 'to the drum 3 and secured thereto for supporting the dome 20.

The flange 2| on the bottom edge of the dome 20, is provided with a plurality of notches 22 in the periphery thereof at spaced intervals around the drum 3, each of which notches has a channel member 23 extending downwardly theretrough. A series of channel members 23 is thus provided surrounding and enclosing the fuel magazine I and forming the surrounding Wall thereof, as

' shown in Fig. 2. Each of these channel members is constructed preferably of a channel bar, and is slidably received in the notch 22 for expansive action under heat, or for ready removal and replacement when desired. The channel shape of each bar 23 forms a passageway therethrough,

construction, designed for turning movement in which is adapted to have communication with the fuel magazine through orifices 24 formed at intervals in the inner wall of said channel and through orifices 25 in one of the lateral flanges thereof. The orifices 2d and 25 are arranged at intervals along the length of each channel 23, as shown in Fig. 1, to admit air from the passageway through the channel into the fuel magazine I at the periphery of the latter.

The channel cars 23 are spaced relatively close together, as shown in Fig. 2, so that lumps of coal will not get into the {space} elongated opening therebetween and thereby the orifices 25 will be effective to supply air to the periphery of the column of fuel, even if the orifices 24 should be closed by the lodging of fuel therein. However, ribs 26 extend lengthwise on each channel bar 23 on opposite sides of the row of orifices 24 therein to keep the coal from lodging in the orifices, plugging them up, or from lying flat thereagainst. Any fine coal that should pass through the air orifices 24 will fall downward through the channel bars 23 into the ash pit at the bottom, thus keeping these air passageways clear.

The lower ends of the channel bars 23 are supported on the upper edge of a fire-brick ring 21, which is seated in turn upon the base casting if or carried thereby. The fire-brick 21 has a series of grooves 23?. extending lengthwise thereof, forming air passageways in alignment and open communication with the passageways through the channel bars 23. The lower ends of the grooves or passageways 2% are turned inward to the inner surface of the fire-brick 21, forming air jets 29 around the periphery of the column of fuel in the fuel magazine I.

The fuel magazine is adapted to contain a column of fuel therein, rising from the ash grate I I, with the primary burning zone located at the lower portion of said column of fuel. Extending laterall ther from in the base casting ID is a bottom fine 35 entirely above the ash grate II, the outer end of which flue 3.! is in open communication with the heating and combustion chamber 2. Said heating and combustion chamber 2 has transversely overlapped baffles 3| therein, as shown in Fig. l, with a flue outlet 32 at one side of the upper end thereof.

Provision is made for admitting secondary air to the burning zone at the bottom flue 30 for complete combustion of any volatiles, gas or fuel, at this point, aiding particularly in the combustion of the volatile matter that remains in the fuel when the latter has reached the combustion zone and there discharges the volatile gases. For this purpose, a preheating chamber 33 is provided between the partition 6 and an auxiliary partition 34, as shown in Figs. 1 and 2. The preheating chamber 33 has air inlets 35 at one end thereof controlled by a register 38 of the slide valve type (Fig. 2).

The auxiliary partition 34 is provided with a ledge 37 at the lower edge thereof for supporting a fire-brick bafile 38 thereon, which fire-brick 38 has a-shoulder 39 along one edge thereof in position to seat upon the ledge 31. of the fire-brick 38 has a plurality of ribs 40 seated upon a shoulder formed by the [connecting] supporting bar I5. This holds the fire-brick baflie 38 with the side wall thereof spaced from the adjacent edge of the transverse supporting bar I5, with secondary air outlet openings 4| therebetween for admitting secondary air from within the preheating chamber 33 into the top of The opposite side 7 and in such fashion as to burn the part of the column of fuel immediately at the surrounding wall which would otherwise stick to the wall and prevent the automatic lowering of the column as combustion takes place.

The entire column of fuel does not burn because the primary air is drawn down about the periphery thereof without substantial penetration, not being passed directly through the center of the column, and no primary air being drawn in from the bottom up into and through the column of fuel. Thus the fuel column will burn only at the points where primary air is admitted to substantial extent, namely, at the bottom of the column and immediately surrounding the periphery thereof, and the primary air will pass out through the flue 36 at the bottom, drawing off the liberated combustible gases from the fuel. Suficient secondary air is admitted at the point of opening 4! to support combustion in said flue and in the combustion chamber 2, for complete consumption of these gases before they are discharged from the stove. This results in a completely smokeless stove since substantially no combustible particles are discharged through the fiue thereof.

In admitting the primary air at this low point in the stove, while the ash pit is sealed at [4 as described above, there is substantially no tendency for any of the gases of combustion to escape when the main top 8 is substantially removed because there is no upward draft through the mass of fuel in the magazine. Furthermore, there is substantially no escape of gases of coinbustion when the ash pit door I4 is opened because of the manner in which the air is drawn in at the side and the low point of admission.

The air chambers It and 33 allow the pre-heating of the primary and secondary air supplies before the air is admitted to the stove, and these air chambers serve also to insulate the combustion and heating chamber 2 from the fuel magazine. The relatively narrow passageway through which the secondary air is admitted to the flue 33 at 3| provides a very simple and effective manner of admitting secondary air behind the baffle formed by the fire brick 38 which will cause the secondary air to mingle with the gases of combustion so as to complete the combustion of such gases and thus avoid smoking by the stove. The downward projection of the fire brick baflle or arch 38 into the flue 30 also tends to prevent the fuel from working its way into the combustion chamber 2, and increases the velocity of the gases passing through the fine by reducing the cross sectional area of the latter, whereby no flyash lodges on the arch in a way that would be detrimental through accumulative effect.

Two different designs are described herein where the magazine has rigid side walls ,one being illustrated in Figs. 1 to 5, and the other in Fig. 6. In actual practice with this invention, using ordinary nut and slack bituminous coal, it has been found that in the design shown in Figs. 4

and 5 of the drawings, we can fill up the magazine with bituminous coal, after having started a fresh fire, and we will have smoke for about fifteen to twenty minutes, but the percentage of smoke is very small, and it will pass the tests of the usual smoke ordinances in cities that are trying to eliminate smoke from the air. Furthermore, this original firing, since it takes place usually only once or twice during the winter months, is relatively inconsequential. We have proved that when the fire is burning continuously twenty to twenty-five per cent of the volatile matter is discharged from the fuel, even when the combustion rate is high, during the first hour. The rest of the volatile in the unburned fuel substantially remains until the fuel has reached the fire zone, where the volatile matter remaining is consumed along with the solid fuel. With this invention it has been proven that the central volume of the fuel in the magazine remains relatively cool and below the temperature that would cause the volatile to be discharged.

Therefore, this invention provides a magazine stove that is substantially smokeless with ordinary grades of bituminous coal of the size of nut and slack, ordinary stoker sizes, or larger; that is exceedingly efficient; in which the volatile matter is burned mostly along with the solid fuel itself; and a design in which the combustion rate of the fuel can be controlled readily. It has been found that the stove will idle and keep the fire alive for as long as seventy-two hours with one hundred pounds of nut and slack coal originally put into the magazine, and that at any time during this period the fire can be made to supply its maximum heat very shortly after damper regulation giving the required amount of primary air for full combustion.

If desired, a hot water heater may be utilized in connection with this stove, by providing a water back around the air passageways, or in place of the fire-brick H, in a manner that will be obvious.

Provision may be made in the stove for relieving the side pressure on the magazine walls mechanically, so as to let the coke bed settle down as fuel is consumed in the combustion zone, as shown in Figs. '7 and 8. In this form, the magazine drum 5| is constructed with a combustion zone 52 in the lower portion thereof, having the usual grate at the bottom, and surrounded by a fire-brick ring 53 at the lower end of the fuel magazine. A filling opening is formed within a dome 54, having a removable cover 55.

The side walls of the magazine are formed of a plurality of metal plates 55, preferably of cast iron, which extend downward in truncated conical form, within the drum 5|. The upper ends of the plates 56 are formed with hooks 57 which engage over a surrounding ring 58 carried by brackets attached to the dome 54, thus pivotally supporting the plates thereon in downwardly inclined directions, with the lower ends of the plates 56 bearing upon the upper edge of the fire-brick ring 53. The angle of the plates 55 to the vertical axis should be such that the plates will hold the side pressure of fresh fuel supply, but will swing outward in a laterally expanding action when the heat of combustion in the stove causes a swelling action of the coal.

The plates 56 are provided with ribs 59 extending vertically along edges thereof, and these edges are arranged in overlapping relation, as shown in Fig. 8. The edge of one plate 56 is beveled at 6%], forming a feathered edge thereon, in position to overlap an angular corner 6| on the adjacent section, which arrangement effectively ch arging the efrom a tion with the openings and orifices for suppl ing air to said openings and orifices, said orifices being of appreciably smaller air capacity than the air space or air spaces in communication therewith, means for directing the products of combustion laterally from said zone of primary combustion. and means for admitting secondary air to said last-mentioned means to support secondary combustion therein.

6. A magazine-feed stove comprising a fuel magazine structure adapted to contain a column of fuel therein with an incandescent layer at the bottom thereof, a grate structure for supporting the column of fuel in the magazine with the incandescent layer directly above the grate, a bottom flux extending laterally from the fuel magazine and having an intake end connected with the magazine entirely above the grate in position for di charge of the gaseous products of combustion through the flue above the grate, means for admitting primary air to the peripherv of the fuel magazine [through] and haoinq constricted orifices through which said air is admitted directly above the intake end of the flue in close proximity therewith, means for supplying air to the periphery of the fuel magazine along the height of the column of fuel therein and including openings disposed substantially throughout the periphery of the fuel magazine, means externall of the fuel magazine for supplying air directly to the orifices and openings without passage through said magazine, and means for supplying secondarv air to the bottom fine to support s condary combustion of the products of combustion passing therethrough.

7. A magazine-feed stove comprising a fuel magazine structure a apted to contain a column of fuel therein, said magazine structure having a surrounding wall adapted to enclose the fuel column, a bottom f el-supporting structure at the lower end of said wall adapted to confine a combustion zone therein adjacent the bottom end of the magazine structure. said wall having vertical air passages therein with slots connected therewith and extending upwardly in the fuel magazine substantiall throughout a major portion of the height of said magazine, said air passages being closed externally and extending downwardlv directly to the combustion zone and having air inlets into the magazine at the combustion zone of appreciably smaller ca acity than said air passages. and means for supplying air into the upper ends of said passages independently and externally of the fuel magazine without passing through said magazine for flow through said passages directl to the inlets at the combustion zone and for flow through said slots for admitting air therefrom into the periphery of the fuel magazine.

8. A stove comprising a magazine structure having a grate for sup orting a column of fuel therein. conduit means for su plying primary air to said fuel column, including means spaced above the fuel column supporting grate for supplying air to one end thereof, and said conduit means having constricted orifices capable of disportion of the total primary air of the stove when the draft through said conduit means is fully o en, and a flue having unrestricted communication with the magazine structure for directing products of combustion therefrom, said constricted orifices being arranged for introducing the constricted supply of primary air to the vertical outside wall of the fuel column adjacent to the unrestricted flue leading therefrom, the means for supplying t e primary air to the fuel column including the orifices being substantially entirely above the fuel column supporting grate, whereby when the draft is reduced appreciably from the full draft of normal combustion the said primary air supply introduced through the orifices to the periphery of the fuel column will enter the magazine structure and produce combustion of the periphery of the fuel column with sufficient temperature to consume the gaseous products of combustion producing a smokeless operation at such a reduced rate of combustion.

9. A stove comprising a fuel magazine structure having a fire zone at the lower end thereof, a bottom structure for supporting the fuel in the magazine structure, conduit means having damper control means therefor and constructed for supplying downwardly moving primary air substantially to the entire perimeter of the fuel column in the magazine structure, a flue connected with the magazine structure adjacent the bottom structure for drawing the gaseous products of combustion laterally from a substantially uninterrupted portion of the perimeter of the fuel column, said flue having the intake thereof extending circumferentially of the fuel column less than one-half of the total perimeter thereof, said conduit means having one or more constricted ports in the magazine structure above the lower end thereof for directing the flow of primary air against the perimeter of the fuel column and having one or more additional ports thereto in position to be adjacent the fire pone, said {port or] ports being [so located and] extended substantially along the height of the magazine structure and spaced about the perimeter thereof and so constricted that upon full opening of the damper means for maximum capacity a major portion of the primary air is directed to the perimeter of the fuel column above the fire zone' and when the stove is being operated at a low heating capacity the major part of the primary air passes through the conduit means to the constricted port or ports at the bottom of the magazine structure and directly above the entrance to said flue, whereby the perimeter of the burning fuel column adjacent thereto is supplied with sufficient primary air to promote full consumption of the fuel at this point.

10. A down-draft magazine-feed heating stove comprising a fuel magazine structure for containing a column of fuel therein, said structure having an opening at the top thereof for supplying fresh fuel by gravity to the magazine structure, a closure for said opening and constructed for sealing said opening against the entrance of air therethrough when the closure is in place over the opening, a bottom structure including a grate for supporting the fuel in the magazine structure and including de-ashing means for separating ashes from the column of fuel, and an ash pit below said fuel supporting means, means for gaining access into the ash pit to remove the ashes therefrom and including an opening and a cover therefor constructed for sealing the opening substantially against the entrance of air thereto when the cover is in place, said closure and cover being constructed to prevent the admission of air to the ins magazine and ash pit during operation except when fuel is being supplied to the magazine or ashes are being taken out, means for introducing primary air into the magazine structure at points wholly above the see-i9 13 level of thebottern structure, and a-flue cit-t dliig laterally from the fiiel magazine incommunication therewith above thegrate" fr conireying the gaseous products of combustion laterally away from the burning fuel; the air sup-- ply andair introducing means being constructed for introducing at least a major portion of the primary air to the perimeter of the fuel column at pointssubstanti-ally above the level of the horizontal plane ofthe top of the fine adjacent the fuel column, means for introducing secondary air into said flue; and separatemeans for controlling the primary and secondary airintroduced by the respective means.

11; A magazine-feed stove com-prisinga fuel magazine structure adapted to contain a column of fuel therein with'an incandescei'it layer at the bottom thereof; abottom. fuel-supporting structure for supporting the fuel in the magazine structure with the incandescent layer di- A rectly above said bottom structure; a flue for conv'eying off the gaseous products of combustion and having anintake" end connectedwiththe magazine structure wholly at a point above the bottom structure in position for the discharge of gaseous products of combustion entirely above the bottom structure, mean-s closely spaced; for admitting air to substantially the ontine'p e'ripherg (if the fuel column substantially throughout me height thereof, and means for supplying primary air to the magazine structure and opening into the magazine structure directly above and in close proximity withthe intake" end of the flue, said air supplying means having an intake end substantially [at the same level as the incandescent layer of fueljlat the bottom of the magazine structure, whereby said air supply means will be at the s'anie level as the incan descent layer of fuel daring combustion in the s'totc.

12. A" dowri draft magazine-feed stove comprising a magazine structure for containing a column of fuel therein, a bottom fuel sup'porting structure for supporting the fuel iri'the magazine structure, a combustion chamber beside the i magazine structure and spaced laterally therefroin, means for insulating the combustioh Chainber from the magazine structure, a bottom flue for conveying the gaseous products of combustion laterally frond the ma azine structure enmay above the bottom fuel-supporting structure to the combustion chamber, and means for supplying to the magazine structure all of the primary air at the'p'eriph'eral portion of the magazine structure at points [above the bottom ruelsupporting structure, said air'supplymeahs being constructed with means for admitting air at a combustion zone adjacent the bottom of the fuel magazine and arranged for passage of air eaternally of the fuel magazine to said air admitting means, whereby the temperature of the fuel] abooetlie bottom fuel supp'orfing' structure, said air supply means being constructed with means for supplying air at a combustion zone adjacent the bottom of the fuel magazine and means arranged for passage" of air externally of the fuel magazine in heat exchange relation therewith to the respective air supplying means, whereby the temperature of the fuel in the upper part of the magazine structure is maintained by said air sufficiently low to prevent the fuel frb'm' eX- panding and adhering to the sidewalls' of the magazine structure. 7

13. A down-draft magazine-feed heatihg'is'tove comprising a fuel magazine for containinga colextending between the um ofbituminouscoal therein, a de-ashing bot-- tom structure for supporting the coal in the magazine structure, an ash pit below said doashing structure for receiving the ashes therethrough, said ash pit having an access opening thereto; a cover'for closin'gfsaid opening against the admission of air therethrough, and means for supplying primary air downwardly in the fuel magazine throughout a substantial portion of the height thereof andhavi-n'g an opening. into the magazine'directly above the bottom structure and including a conduit extending thereto, means forming an exit hue and open to the magazine structure at a side thereof entirely above the deashing bottom in such position that none. of the gaseous products of combustion pass through the d'e-ashing structure in moving to the exit fine, said air supply conduit having an air inlet located adjacentto a horizontal plane through the top of the bottom structure [in such position that there will be no tendency for back draft upwardly through the fuel zone of gaseous products of combustion from the magazine when the ash pit closure is opened].

14; In a magazine heating stove, the combination of-a fuel magazine adapted to contain a column of fuel therein, a combustion chamber spaced laterally from the fuel magazine, a bottom flue extending between the lower end portions of the fuel magazine and the combustion chamber and in open communication therewith for directing cornbiistible gases from said magazine to said chamber, an air chamber having means for admitting air thereto on a horizontal level at the lowerportion of the fuel magazine and above the bottom flue, means for circulating primary air from said air chamber downwardly externally of thefuel rnagazine about the periphery thereof and admitting said primary air to the'magaz'ine at a plurality of points along the height thereof and substantially entirely above the lower end of the fuel column and adjacent the first-mentioned air admitting means to support combustion in said magazine and around the walls thereof.

15. In a magazine heating stove, the combina tion' of a fuel magazine adapted to contain a column of fuel therein, a combustion chamber spaced laterally from the fuel magazine, a flue lower end portions of the fuel magazine and the combustion chamber and in open communication therewith for directing combustiblegases from said magazine to said chamber, means for admitting the primary air to the fuel magazine about the periphery tl'iereof and at a plurality of points'along the height thereof substantially entirely above the lower end of the fuel column to support combustion in said magazine and around the walls thereof, said air admitting means being constructed of constricted orice's and having downwardly extending passageways communicating with the orifices at a series of vertically spaced points about the maga- Zinc.

16. In a magazine heating'stove, the combination of a fuel magazine adapted to contain a column of fuel therein, a combustion chamber ced laterally from the fuel magazine, a flue home between the lower end portions of the fuel magazine and the combustion chamber and in open'comm'unication therewith for directing gases from said magazine to leans for admitting primary air to the he aboht'tli periphery thereof and ality of points along the height thereof .15 to support combustion in said magazine. and around the walls thereof, said air admitting means being constructed of constricted orifices and having downwardly extending passageways communicating with the orifices at a series of vertically spaced points about the magazine with the lowermost orifices spaced above the flue, and

means for admitting primary air into the upper ends of said passageways for downward circulation therethrough to the orifices.

17. In a magazine heating stove, the combination of a fuel magazine adapted to contain a column of fuel therein, a combustion chamber spaced laterally from the fuel magazine, a flue extending between the lower end portions of the fuel magazine and the combustion chamber and in open communication therewith for directing combustible gases from said magazine to said combustion chamber, an air chamber interposed between the fuel magazine and the combustion chamber and extendin substantially from side to side thereof insulating said magazine and combustion chamber from each other, means for admitting cold air into said air chamber at a point adjacent the bottom of the fuel magazine, and

means for circulating air from the top of said air chamber above the magazine downwardly externally of the air chamber about the periphery of the magazine to a point adjacent the bottom thereof.

18. In a magazine heating stove, the combination of an upright fuel magazine adapted to contain a column of fuel therein, a grate at the bottom of the fuel magazine substantially within the confines of the wall thereof for supporting said column of fuel, an upright combustion chamber disposed beside the fuel magazine and spaced bodily therefrom, a flue extending laterally between the lower ends of the fuel magazine and combustion chamber and in open communication therewith only above the grate arranged for passage of gaseous products of combustion to the flue entirely above the grate without passing downward through the grate, means for admiting the primary air to the fuel magazine at a point wholly above said fine to support combustion in the bottom of said magazine and at higher points at the periphery of the fuel magazine below the top thereof for discharging combustible gases through said flue and to cause settling down of bituminous coal in the fuel magazine Without adhering to the surrounding wall of the magazine, and :means for admitting secondary air into the top of said flue for combustion of said gases.

19. In a magazine heating stove, the combination of an upright fuel magazine adapted to contain a column of fuel therein, an upright cornbustion chamber disposed beside the fuel magazine and spaced bodily therefrom, a flue extending laterally between the lower ends of the fuel magazine and combustion chamber and in open communication therewith, means for admitting the primary air to the fuel magazine at a point wholly above said flue to support combustion in the bottom of said magazine and for discharging combustible gases through said flue, a baffle extending transversely of said flue and projecting downwardly [below] from the top thereof, and means for admitting secondary air into the top of said flue beside said baffle and between said battle and the fuel magazine for causing intermixing of said air with the combustible gases.

20. A magazine-feed stove comprising a magazine structure for containing a column of fuel,

said magazine structure including a plurality of upright channel members arranged at closely spaced intervals about the periphery of the fuel magazine [with] and thereby forming elongated openings between the channel members [forming] constituting air passageways in open communication with the interior of the magazine structure, said channel members having means of communication from the [air passageways therein] interiors thereof into the openings, and means for supplying air into said channel members.

21. A magazine-feed stove comprising a magazine structure for containing a column of fuel, said magazine structure including a plurality of upright channel members arranged at intervals about the periphery of the fuel magazine with said channel members spaced apart to provide spaces therebetween with slots opening from said spaces into the periphery of the fuel magazine and said slots being elongated in an upward direction throughout a substantial portion of the height of said magazine, the sides of the channel members at opposite sides of the spaces converging toward said slots inwardly relative to the having means of communication from the air passageway extending therethrough into the fuel magazine, said channel members being spaced apart with the spaces therebetween open into the fuel magazine and having means of communication through the side walls thereof from the air passageways into said spaces.

23. A magazine feed stove comprising a fuel magazine for containing a column of fuel therein and having a surrounding wall structure, said wall structure including a surrounding enclosure, a plurality of channel members spaced at intervals about the enclosure, each of said channel members having an inner wall facing the interior of the magazine with side flanges directed toward the enclosure and forming an air passageway therethrough extending lengthwise of the fuel magazine, a fire-brick extending about the lower portion of the fuel magazine and having passageways therethrough in alignment with the channel passageways in open communication therewith and extending to points within the fuel magazine for supplying air to the column of fuel therein.

24. A magazine feed stove comprising a fuel magazine for containing a column of fuel therein and having a surrounding wall structure, said wall structure including a surrounding drum, a plurality of channel members spaced at intervals about the drum, each of said channel members having an inner wall facing the interior of the magazine with side flanges directed toward the drum and forming an air passageway therethrough extending lengthwise of the fuel magazine, a fire-brick lining extending about the fuel magazine and supporting the channel members thereon, said fire-brick lining having grooves therein in alignment with the passageways in the channel members in open communication therewith, and extending to the inner surface of said lining for supplying air to the column of fuel in the magazine, and means slidably receiving and mounting the channel members in upright positions within the drum.

25. A magazine feed stove comprising a fuel magazine for containing a column of fuel therein and having a surrounding enclosure, a heating structure disposed beside the fuel magazine and connected with the first-mentioned enclosure, a partition extending transversely of the heating structure forming a preheating chamber between said partition and the magazine enclosure having means for admitting air thereto, said fuel magazine having a plurality of air inlets about the periphery thereof, means forming one or more passageways extending downwardly to said air inlets from the upper end portion of said magazine enclosure and being in open communication with the preheating chamber.

26. A magazine feed stove comprising a fuel magazine for containing a column of fuel therein and having a surrounding wall structure, a heating structure connected with the wall structure and extending laterally therefrom enclosing a heating chamber, a partition extending transversely of the heating structure spaced from the wall structure forming a preheating chamber therebetween having an air inlet, means connected with said preheating chamber for supplying air therefrom through the wall structure to the inner periphery of the fuel magazine for supporting combustion therein, a flue connecting the lower end portions of the fuel magazine and the heating chamber, and means for admitting secondary air to said flue intermediate the fuel magazine and the heating chamber.

27. A magazine feed stove comprising a fuel magazine for containing a column of fuel therein, a heating structure disposed beside the fuel magazine, means forming a flue connecting the lower end portion of the fuel magazine with the heating structure, and secondary air supply means intermediate the heating chamber and the fuel ma azine, said air supply means including wall structures enclosing an air preheating chamher, one of said wall structures having a ledge connected therewith and the opposite wall structure having a shoulder connected therewith, a fire-brick having one side seated on said ledge and having one or more ribs extending laterally from the opposite side thereof and seated on the shoulder for supporting the fire-brick therebetween, saidv shoulder having the inner edge thereof spaced from the adjacent side of the firebrick forming on opening therebetween from the preheating chamber into the flue.

28. A magazine heating stove comprising means forming a combustion space, a fuel magazine thereabove adapted to contain bituminous coal and arranged for discharging the same by gravity into the combustion space automatically as fuel is consumed therein, and means for introducing primary air above the combustion space for downward movement thereto in part through the fuel supply in the magazine, whereby the down draft carries the volatile matter produced in the lower portion of the fuel supply into the combus tion space without heating all of the fuel in the magazine sufiiciently to volatilize it completely until it has reached a location adjacent the combustion space, said fuel magazine having side walls thereof constructed for lateral expansion automatically under internal pressure to reduce the pressure of the coal against said side walls when the coal is swelled by the heat of combus- 18 tion in the stove, whereby the coal will settle by gravity into the combustion space as coal is consumed therein.

29. A magazine feed stove comprising a fuel magazine structure adapted to contain a column of fuel therein with a zone of primary combustion at the bottom thereof, a bottom structure for supporting the column of fuel in the magazine, a bottom flue extending laterally from the fuel magazine and having an intake end connected with the magazine at the zone of primary combustion for discharge of the products of combustion through the bottom flue, means above said bottom support for admitting the primary air into the fuel magazine adfacent the zone of primary combustion and substantially entirely above the bottom support for the fuel column, means closely spaced for supplying air to the periphery of the fuel magazine substantially throughout the height thereof at a point spaced above said primary air admitting means, and means for supplying secondary air to the bottom flue to support secondary combustion of the products of combustion passing thcrethrough.

30. A magazine feed stove comprising a fuel magazine structure adapted to contain a col-- umn of fuel therein with an incandescent layer at the bottom thereof, a bottom fuel-supporting structure for supporting the fuel in the magazine structure with the incandescent layer directly above said bottom structure, a flue for conveying off the gaseous products of combustion and having an intake end connected with the magazine structure wholly at a point above the bottom structure in position for the discharge of gaseous products ofcombustion entirely above the bottom structure, and means above the bottom support for supplying the primary air to the magazine structure, said means including means for supplying a relatively small percentage of primary air under maximum draft condition to the magazine structure at a point adfacenta horizontal plane through the magazine structure in close proximity to the intake end of the flue, and additional means closely spaced for admitting air to the periphery of the fuel column substantially throughout the height thereof said air supplying means having an intake end substantially at the bottom of the magazine structure and extending from said intake end in heat exchange relation with the magazine to preheat the air before supplying said air to the first-mentioned point of admission of primary air to the magazine structure.

31. A down-draft magazine-feed heating stove c'omprising a fuel magazine structure for con taining a column of fuel therein, said structure having an opening at the top thereof for supplying fresh fuel by gravity to the magazine structure, a closure for said opening and constructed for sealing said opening" against the entrance of air therethrough when the closure is in place over the opening, a bottom structure including a grate for supporting the fuel in the magazine structure and including de-ashing means for separating ashes from the column of fuel, and an ash pit below said fuel supporting means, means for gaining access into the ash pit to remove the ashes therefrom and including an opening and a cover therefor constructed for sealing the opening substantially against the entrance of air t e when the cover is in place, said closure and cover being constructed to prevent the admission of air to the fuel magazine and ash pit during operation except when fuel is being supp to the magazine or ashes are being taken out, means for introducing primary air into the magazine structurelat points wholly above the level of the bottom structure, and a flue extending laterally from the fuel magazine in communication therewith above the grate for conveying the gaseous prodacts of combustion laterally away from the burning fuel, the means for introducing the primary air to the magazine being disposed wholly above the top of said flue, the air supply and air introducing means being constructed for introducing a portion of the primary airto a side of the fuel column opposite from the entrance of the flue, and means for introducing secondary air into said flue.

32. In a heating stove for burning solid fuel, a magazine structure adapted to contain a column of fuel therein and having a bottom structure at the lower end of the magazine structure for supporting the column of fuel thereon for combustion of the fuel thereabove, means forming an ash-pit beneath the magazine bottom structure and constructed substantially to close the magazine against the entrance of primary air through the ash-pit into the magazine structure, means forming a discharge flue for the gaseous products of combustion from the lower portion of the magazine structure to one side thereof, means for supplying the primary air to the fuel magazine wholly above said flue and having one or more ports into the magazine substantially opposite from the flue and above the top of the flue constructed for admitting a substantial portion of the primary air under maximum operating conditions, and the hot gases of combustion pass transversely across and above the bottom structure and through the fuel supported thereon to the discharge flue.

33. In a heating stove for burning solid fuel, a magazine structure adapted to contain a column of fuel therein and having a grate at the lower end of the magazine structure for supporting the column of fuel therein, means forming an ash-pit beneath the grate and constructed substantially to close the grate against the entrance of primary air through the ash-pit and the grate into the magazine structure, said grate being located adjacent the bottom of the stove for combustion of the fuel in a combustion zone thereabove, means forming a discharge flue for the gaseous products of combustion from the lower portion of the fuel magazine and extending laterally from a side of the fuel magazine, and means for supplying the primary air to the fuel magazine wholly above said flue at the combustion zone and having ports leading intothe combustion zone which are spaced an appreciable distance above the uppermost level of the grate and above the top of the flue whereby the hot gases do not tend to pass downward through said grate, and wherein all of the primary air follows the path of least resistance to reach the flue by either passing through the fuel in the combustion zone or passing around the perimeter of the fuel in the combustion zone and wherein, when the stove is running at a fair heating capacity, a substantial part of the primary air that is introduced to the combustion zone above the grate passes transversely across through the fuel towards and into the oppositely disposed flue for taking away the gaseous products of combustion.

34. In a, heating stove for burning solid fuel, a magazine structure adapted to contain a column of fuel therein and having a grate at the lower end of the magazine structure for supporting the column of fuel therein, means forming an ash-pit beneath the grate and constructed substantially to close the grate against the entrance of primary air through the ash-pit and the grate into the magazine structure, said grate being located adiacent the bottom of the stove for combustion of the fuel in a combustion zone thereabove, means for supplying primary air to the fuel magazine and having one or more ports into the magazine spaced an appreciable distance above the uppermost level of the grate, whereby the hot gases of combustion do not tend to pass downward through said grate and substantially all of the air passes transversely across above the grate either through the fuel supported thereon or around the perimeter of the fuel thereon in the combustion zone, means forming a discharge flue for the gaseous products of combustion from the lower portion of the fuel magazine at the side thereof substantially opposite at least some of said ports, the means for introducing the primary air to the magazine being disposed wholly above the top of said flue, said flue having an entrance to the magazine structure of appreciable area such that the burning fuel and ashes in the combustion zone tend to spread out sidewise into the flue in the direction of flow therethrough, and the lower portion of the flue being substantially imperforate and extending upwardly and forwardly away from the plane of the top surface of the grate.

35. In a heating stove for burning solid fuel, a magazine structure adapted to contain a column of fuel therein and having a grate at the lower end of the ma azine structure for supporting the column of fuel therein, means forming an ash-pit beneath the grate and constructed substantially to close the grate against the entrance of primary air through the ash-pit and the grate into the magazine structure, said grate being located adfacent the bottom of the stove for combustion of the fuel a combustion zone thereabove, means for supplying primary air to the fuel magazine and having one or more ports into the magazine spaced an appreciable distance above the uppermost level of the grate, whereby the hot gases of combustion do not tend to pass downward through said grate and substantially all of the air passes transversely across and above the grate either through the fuel supported thereon or around the perimeter of the fuel in the combustion zone, means forming a discharge flue for the gaseous products of combustion from the lower portion of the fuel magazine at the side thereof substantially opposite at least some of said ports, the means for introducing the primary air to the magazine being disposed wholly above the top of said flue, said flue having a lower wall laterally of the grate substantially imperforate whereby there is no tendency for the hot gases to pass downward through said grate and pass across underneath the grate and up into the flue, and to confine the gaseous products of combustion to discharge above the grate through the flue.

36'. In a stove for burning solid fuel, a magazine structure adapted to contain the fuel, a grate substantially at the bottom of the magazine structure, means forming an ash receiving space below the grate inside the stove and for closing said space substantially against the entrance of outside air through the space to the grate, means forming a smoke discharge opening for the stove, a flue connected with said opening and extending thereto from the bottom portion of the fuel magazine, said grate being adapted to support the fuel in the magazine with a fuel burning zone adfacent the grate, the flue being connected with the magazine structure and extending laterally from a side of the magazine structure the grate and above the grate, means for supplying primary air to the magazine structure substantially at the top of the burning zone of the fuel in'position for passage of the air around and directly through the burning fuel and into the flue without passage of said primary air downward through the grate, and additional means for supplying air to the major portion of the periphery of the fuel magazine for a substantial distance above the grate to support combustion at the periphery and prevent sticking of the fuel to the magazine.

37. In a stove for burning solid fuel, a magazine structure adapted to contain the fuel, a grate substantially at the bottom of the magazine structure, means forming an ash receiving space below the grate inside the stove and for closing said space substantially against the entrance of outside air through the space to the grate, means forming a smoke discharge opening for the stove, a flue connected with said opening and extending thereto from the bottom portion of the fuel magazine, said grate being adapted to support the fuel in the magazine with a fuel burning zone adjacent the grate, the flue being connected with the magazine structure at a point adjacent the grate and above the grate, means for supplying primary air to the magazine structure substantially at the top of the burning zone of the fuel in position for passage of the air around and directly through the burning fuel and into the flue without passage of said primary air downward through the grate, said flue adjacent the grate having substantially an imperforate lower portion tending to prevent the passage of air through the grate and beneath the latter into the flue at a point spaced laterally of the grate in such fashion that under normal working conditions there will be a greater resistance to the travel of the draft down through and back up through the openings in the grate than there will be for the movement in the draft through the burning fuel in a line leading directly from the air admitting means to the flue and whereby the volume of the cross draft through the fuel is not appreciaby reduced by being diverted through the grate, and additional means for supplying air to the major portion of the periphery of the fuel magazine for a substantial distance above the grate to support combustion at the periphery and prevent sticking of the fuel to the magazine.

38. In a stove for burning solid fuel, a magazine structure adapted to contain the fuel, a grate substantially at the bottom of the magazine structure. means forming an ash receiving space below the grate inside the stove and for closing said space substantially against the entrance of outside air through the space to the grate, means forming a smoke discharge opening for the stove, a flue connected with said opening and extending thereto from the bottom portion of the fuel magazine, said grate being adapted to support the fuel in the magazine with a fuel burning zone adjacent the grate, the flue being connected with the magazine structure at a point adjacent the grate and above the grate, means for supplying primary air to the magazine structure wholly above the top of the flue and substantially at the top of the burning zone of the fuel in position for passage of the air around and directly through the burning fuel and into the flue without passage of said primary air downward through the grate, said' flue having a bottom portion sloping upwardly the direction away from the grate.

39. In a stove for burning solid fuel, a magazine structure adapted to contain the fuel, a grate substantially at the bottom of the magazine structure, means forming an ash receiving space below the grate inside the stove and for closing said space substantially against the entrance of outside air through the space to the grate, means forming a smoke discharge opening for the stove, a flue connected with said opening and eptending thereto from the bottom portion of the fuel magazine, said grate being adapted to support the fuel in the magazine with a fuel burning zone adjacent th grate, the flue being connected with the magazine structure at a point adjacent the grate and above the grate, means for supplying primary air to the magazine structure substantially at the top of the burning zone of the fuel in position for passage of the air around and directly through the burning fuel and into the flue without passage of said primary air downward through. the grate, and means for admitting additional primary air to the burning zone within the bottom portion of the magazine structure and intersecting the first mentioned primary air within the burning zone, the means for introducing the p imary air to the magazine being disposed wholly above the top of said flue.

40. in a stove for burning solid fuel, a magazine structure adapted to contain the fuel, a grate substantially at the bottom of the magazine structure, means forming an ash receiving space below the grate inside the stove and for closing said space substantially against the entrance of outside air through the space to the grate, means forming a smoke discharge opening for the stove, a flue connected with said opening extending thereto from the bottom portion of the fuel magazine, said grate being adapted to support the fuel in the magazine with a fuel burning zone adjacent the grate, the flue being connected with the magazine structure at a point adjacent the grate and above the grate, means for supplying primary air to the magazine structure substantially at the top of the burning zone of the fuel in position for passage of the air around and directly through the burning fuel and into the flue without passage of said primary air downward through the grate, means for admitting additional primary air to the burning zone within the bottom portion of the magazine structure and intersecting the first mentioned primary air within the burning zone, the means for introducing the primary air to the magazine being disposed wholly above the top of said flue, and means for introducing secondary air into the gaseous products of combustion created within the burning zone by the respective sources of primary air, whereby smoke within the products of combustion will be substantially eliminated.

HUGH W. SANFORD. WILLIAM P. BIDDLE, JR.

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

UNITED STATES PATENTS Number (Other references on following page) Number 23 UNITED STATES PATENTS- Name Date Bussey et a1. May 2, 1871 La. Rue Oct. 15, 1872 Hess Jan. 25, 1887 Rube Aug. 12, 1890 Hinstin Nov. 13, 1894 Knauss Jan. 14, 1896 Lynott June 2, 1896 Borma-n Nov. 30, 1897 Pampus Dec. 28, 1897 Litchfield May 31, 1898 Washburn Oct. 2, 1900 Heuer Oct. 21, 1902 Reck Dec. 1, 1908 Number Number Name Date Howell July 15, 1924 Wier Nov. 17, 1925 Fellows et a1 Sept. 15, 1942 F'leer Jan. 14, 1947 FOREIGN PATENTS Country Date Great Britain July 29, 1887 Austria 1 May 11, 1908 Germany June 3, 1893 Germany Mar. 7, 1901 Germany June 26, 1902 Germany Sept. 30, 1933

Images