US638934A - Stove or furnace. - Google Patents

Description

Patented Dec. l2, I899." s. A. McKENZIE & c. w. nous.

STOVE 0R FURNACE.

(Application filed Feb. 20, 1899.)

(No Model.)

' 5 moan Mom 1 A. M. K @513 Mahler/14mg W. HM L.

PATENT rrr GEORGE A. MCKENZIE AND CHARLES WM. I-IOUGI-I, OF VEST BAY CITY,

MICHIGAN.

STOVE OR FURNACE.

SPECIFICATION forming part of Letters Patent N0. 638,934, dated December 12, 1899.

Application filed February 20, 1899. Serial No. 706,175. (No model.)

To all whom, it may concern:

Be it known that we, GEORGE A. lVICKENZIE and CHARLES WM. HoUeH, citizens of the United States, residing at West Bay City, in the county of Bay and State of M ichigan,have invented certain new and useful Improvements in Stoves or Furnaces; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to stoves, and more particularly to stoves using the cheaper grades of coal, such as bituminous slack, for fuel.

The improvement consists in certain arrangements of the parts of the fire-box, distribution of the air-supply to the fire, and means for inducing currents of heated air through the stove and room, all as more fully set forth hereinafter.

The objects of the invention are, first, to produce a soft-coal-burning stove, to which the coal is supplied from above and burned on a grate below, the draft being downward through the fire-bed and grate and around the base of the stove; second, to produce a fire-bed in the shape of an annular ring of burning coal, to which air may be supplied from within the ring or without, or both; third, to produce a stove for burning soft coal having means for regulating the height at which the coal is coked, thus increasing or decreasing the depth of the fire-bed, and, fourth, to provide means for producing a circulation of air through the center of the stove and through the room. The means by which we accomplish these results is plainly shown in the accompanying drawings, throughout the several views of which similar figures of reference designate similar parts and devices.

Figure 1 is a central vertical section of a stove embodying our improvements, the section being taken parallel to the front of the stove. Fig. 2 is a partial horizontal section of the stove, taken on the line m a: of Fig. 1. Fig. 3 is a central vertical section of the stove, the section being taken parallel to the sides of the stove. Fig. 4 is a cross-sectional detail of an inner fire-pot ring.

As is clearly shown in the drawings, the

stove consists of a rectangular base surmounted by a cylindrical shell containing the fire-box and magazine.

The fire-box 1 consists of a cylindrical shell of cast-iron or other suitable material placed above the grate 2, as is usual in stoves of this class, and supported by lugs 1 on the outer shell of the stove. Around the fire-box are openings l for the intake of air. These openings are preferably provided by casting the fire-box in two parts, the upper part 1 resting upon the lower and separated from it by projections, the spaces between which form the openings 1", as shown in Figs. 1 and 3.

The coal is supplied to the fire-box through a funnel-shaped chute 3, supported around its circumference by the fire-box and having a central opening of smaller diameter than the fire-box.

Extending vertically through the grate and fire-box and concentric with the latter is a hollow cylindrical tube or pipe 4, which forms an essential feature of our invention. This pipe 4 is preferably built up of a number of annular rings of cast-iron, each ring having its upper surface beveled downwardly and outwardly, as at m, Fig. 4, and its lower surface parallel with the upper surface. the upper beveled surface of each ring are a number of projections or distance-pieces n. It is apparent that-when the several rings are built up they form a tube or pipe 4, having at various heights downwardly-directed openings or twyers connecting the interior of the tube with the fire-box. A vertical pipe 5 is attached at its lower end by screwthreads or otherwise to the top ring 4 of the tube 4 and extends through the magazine to the air. A protecting-covering of fire-brick 5 may be applied to the pipe 5. A smaller pipe 6 extends through the tube 4 and communicates with the pipe 5 by screwing into the lower end of the ring 4, which thus forms a reducer for the pipes 5 and 6, as shown in Fig. 1. A tapered annular space 7 is left between the pipe 6 and the tube 4, through which air may flow to the fire-box. Air is supplied to the space 7 and thence to the firebox by a pipe 8, which communicates with the air through a chamber 8.

Goal is introduced into the magazine through a door 9, the operation of which will be more fully described hereinafter. The ashes drop through the grate Z and a suitable chute 10 into the ash-box l1.

The lower end of the pipe 6 communicates with an opening 6 cored in the bottom section of the tube 4, which in turn opens to the air near the floor through a pipe 6".

The operation of the stove is as follows: Coal introduced into the magazine through the door 9 feeds through the chute 3 to the fire-box l, where it is coked by the combined heat of the fire beneath and the admixture of air through the openings 1 and the draftdoors 12, which are mounted in the outer shell 13, surrounding the fire-box, as shown in Figs. 1 and 2. The combined air and volatile gases given off by the coal in coking pass downwardly through the fire bed and grate 2 and into the space 14:, which surrounds the ash-pan 11. Thence they pass back through the passage 14 to the chimney. Meanwhile air is admitted to the chamber 8 through a draft-door 8 in the side of the stove, passes through the pipe 8 into the space 7, and thence is drawn through the twyers into the coalbed surrounding the tube 4. It is thus seen that an annular ring of coke is formed in the fire-box and is subjected to the combined drafts from the openings 1 around the outside aud the twyers of tube 4 around the inside. The effect of these combined drafts is to entirely consume the combustible matter of the coal and to. produce a smokeless fire with even the cheapest grades of slack coal.

When the inner tube 4 is omitted and the outer draft-openings 1 alone are used, it is found in practice that the coal nearest the openings burns first, and an easy passage for the air being then established near the firebox shell the coal in the center is not readily consumed and an inverted cone of unconsumed coal remains embedded in the ashes after the fire has burned out, whereas upon inserting the tube 4 into the fire-box and by it supplying air to the inside of the fire-bed combustion is greatly facilitated, and on allowing the fire to burn out no unconsumed coal remains in the fire-box.

In practice we prefer to provide doors or openings below the chute 3, as 12, Fig. 1, through which the coke may be broken by a poker, if desired. Similar doors 12 are provided above the level of the grate for poking the ashes and removing any clinkers that may accumulate in the magazine.-

By passing the pipe 6 through the tube 45 and connecting 6 to the pipe 5 we are enabled to produce a current of air from near the floor through the heated parts of the stove and into the room above the stove, thus increasing the circ ulation of heated air throughout the room and efficiently warming it.

The door 9, through which coal is introduced into the magazine, is preferably made to conform in shape to. the shell of the stove when closed, and being hinged at its lower end by bolts 9, attached to the stove, it rests on the chute 9 when open, as is plainly shown in Fig. 1. Two sides or wings 9 project inwardly from the door 9 and, with the door, form a chute through which the coal passes.

A lug 9 projecting upwardly from the edge of one of the wings is arranged to engage the under surface of a trap-door 15 in the magazine-top 16 and to raise this door as the door 9 opens. The trap door 15 is preferably hinged to the stove at 15, as shown in Fig. 1.

Above the magazine-top 16 is a second cover 17,'and the space between the two communicates with the chimney-pipe through a pipe 18. Gas that may have accumulated in the top of the magazine will pass through the trap-door opening and into the chimney as soon as the trap-door is raised by the lug 9 when the door 9 is opened. By this means we prevent gas escaping into the room when coal is put into the stove. In practice we prefer to surmount the chute 9 with a bellmouth 19 and a cover 19.

Although the normal draft of the fire is downward through the fire-box around the base and into the stovepipe, it is sometimes desirable in starting the fire to use direct draft. We accomplish this object by providing a pipe 20, Fig. 3, connecting the space around the magazine-openings 1 with the stovepipe and placing a damper 20, as shown, so as to allow the gases to pass directly from the fire-box into the stovepipe when the damper is horizontal or to cause them to circulate around the base when the damper is vertical.

In order to prevent overheating the floor by the hot gases circulating through the base of the stove, we provide below the stove-bottom a second bottom 21 for containing nonconducting material or for allowing the free circulation of air between the two bottoms, if desired.

Although we have shown and described our improvement as applied to a vertical heating-stove, we wish it understood that the im-' proved magazine construction is equally ap-' plicable to cooking-stoves and to furnaces. In applying to a range or furnace the Ventilating-pipes 6 and 5 may be omitted, as the office of these pipes is mainly to increase the circulation of heated air in the roomin which the fire is placed.

What we claim as our invention, and desire to secure by Letters Patent, is as follows:

1. In a stove, a fire-box consisting of a grate in combination with a fire-box shell having downwardly and inwardly directed openings around its periphery, the inner ends of said openings being flush with the inner surface of the fire-box shell; a tube within the firebox, said tube having downwardly and outwardly directed openings around its periphcry; a pipe for admitting air to the tube and having a draft-door for regulating the airsupply; a second pipe extending vertically through the tube, the coal-magazine and the fire-box, and open to the air at both ends, said pipe having means for regulating the passage of air therethrough, substantially as described.

2. In a downdraft magazine stove or furnace the combination with an outer fire-box shell having air-passages around its circumference adapted to discharge air into the firebox from the space surrounding the fire-box; of a tube extendingly upwardly within the fire-box and having series of air passages around its circumference adapted to discharge air outwardly; a pipe connecting the tube with the outer air and having means for regu lating the air-supply to the interior of the tube; said fire-box shell and tube comprising means whereby air is drawn by the natural draft of the fire into the fire-box and delivered against the annular fire-bed both from within and from without, substantially as described and for the purposes set forth.

3. The combination in a downdraft-stove, of an outer fire-box shell built up of superimposed cylinders having air passages between the cylinders, an inner fire-box tube built up of superimposed rings having airpassages between the rings, a pipe for admitting air to the tube, a second pipe extending centrally through the tube and fire-box and open to the air at both ends, substantially as and for the purpose described.

4. A downdraft magazine stove or furnace comprising an outer fire -box shell having openings through its circumference for entrance of air from without; of an upwardly-ex tending tube within the fire-box having airpassages adapted to discharge air outwardly; a pipe leading from the bottom of said tube to the outer air and having a damper for regu lating the flow of air therethrough; said firebox and tube having substantially vertical walls without lateral projections, thus pre venting fuel from clinging to the Walls, all arranged substantially as described and for the purposes set forth.

In testimony whereof we affix our signa= tures in presence of two witnesses.

GEORGE A. MCKENZIE. CHARLES WM. HOUGI-I.

Witnesses:

DAVID Ln FAvoUR, J OHN J. RownLL.

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