US469749A - Furnace for burning granular fuel - Google Patents

Description

2 Sheets-'Sheet 1.,

(No Model.)

` ,0.3. P'ENFIELD. PURNAGE POR BURNING GRANULAR FUEL.

No. 469,749. Pmtente'dMar. 1, 1892..

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(No'ModeL) 2 Sheets-Sheet 2.

C. R. PE-NFIBLD. y PURNAGE FOR BURNING GRANULAR FUEL.

No. 469,749. y Patented Mar. l, 1892.l

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UNITED STATES PATENT 'rrrca.

FURNACE FOR BURNING GRANULAR FUEL.v

SPECIFICATION forming part Of Letters Patent N0. 469,749, (lated March 1, 1892. Application liled May 28, 1891. Serial No. 394,489. (No model.)

T0 all whom it may concern:

Be it known that I, CHARLES R. PENFIELD, of Duluth, in the county of St. Louis and State of Minnesota, have invented a certain new and useful Improvement in Furnaces for Burning Granular Fuel; and do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the drawings accompanying this specilication. d

My improvement relates to means for introducing a blast of air into the furnace of a steam-boiler and equally distributing the same for burning sawdust, tan-bark, coaldust, and other granular' fuels in an effective manner. v

rlhe invention consists in the construction and arrangement of the lire-bed, as hereinafter more fully described and definitely claimed.

In the drawings, Figure l is a verticalcrosssection in line oo of Fig. 2, showing three boilers set side by side and exhibiting my improvement. Fig. 2 is a longitudinal vertical section in line 'y y of Fig. l. Fig. 3 is an enlarged sectional view across the air-trunk and lengthwise of one of the distributing-tubes of the air-feeding apparatus. Fig. t is a perspective view of the same.

A A A indicate three steam-boilers set side' by side and inclosed in suitable brick-work. A greater or less number may be used. B is the furnace or fire-place of the same.

My improvement is as follows: C is abridgewall located in the furnace-space transversely of the boilers, the same rising to a suitable height, but leaving sufficient space above the wall and under the lboilers for the passage of the draft to the rear of the boilers, as shown.

D is an air-trunk located in the nre-space, either at the front or back of the furnace, also extending transversely of the boilers and parallel with the bridge-wall and connected at one end with a blower or other device by which air is blownthrough the trunk. The trunk is of the sinuous or undulating form shown, being concave under each boiler and convex between them, thereby forming hollows under the boilers, into which the fuel collects and by which a better combustion is maintained, and ridges between the boilers for dividing and spreading the fuel.

E E E are distributing air-pipes attached to the air-trunk and extending crosswise at right angles thereto, reaching nearly to or passing through the bridge-wall, as may be desired. Following the curves of the air-trunk, these air-pipes form hollow beds under the boiler, on which the fuel falls to be burned, and elevations between the boilers to spread the fuel. The top of the air-trunk and also the pipes have small holes a a a, through which the air is forced in jets up through the body of fuel that falls on the pipes. The air, being forced in numerous jets, is equally distributed through the whole furnace-space. The airtrunk is preferably made square and the lateral pipes round in cross-section. The masonry is filled around the bottom and between the pipes, leaving only that part exposed in which the holes are located, and as cold air is being constantly forced through they do not easily burn out. The ends of the lateral pipes have small oppenings h b, through which jets of air areblown, the effect of which is to blowout any ashes or other material that may get into the pipes, thus keeping them clear.

G is a trough located above the boilers and transversely of the same and provided with spouts c c c, which extend down at the sides of the boilers and open into the furnace-space above the air-pipes. These spouts may be provided with suitable cut-off valves to regulate the iow of the fuel through the same. At one end is a hopper d, into which the fuel is fed to be carried to the spouts. H is a conveyer consisting of an endless band or apron resting in the trough and provided with lags, which catch the fuel and carry it. forward to the spouts. The apron passes around suitable pulleys, to one of which motion is given to operate the apron. By this means the fuel is fed evenly to the spouts and dropped down between the boilers and upon the air-pipes below. The fire-bed being undulating, the fuel forms in approximate shape, va portion sliding down the sides of the ridges and filling the hollows to an even depth over all the pipes. Thus the fuel is spread of substantially the same thickness throughout the bed, which would not be the case if the bed were fiat, the fuel collecting in that case in piles, leaving much of the fire-bed uncovered.

It is found in practice that green or wet IOO sawdust directly from the log can-bereadily burned, requiring no special attention, except to regulate the supply.

Having described my invention, I do not claim the fuel-feeding'apparatus, as the same is old; but what I claim as new, and desire to secure by Letters Patent, is- A l." The combination, with a steam -boiler furnace, of the air-trunk D, arranged in sinuous or undulating form, as described, adapted to receive grate-bars, as E, and provided at its top with aseries of holes opening upward for the purpose of supplying jets of air to the fuel, as herein shown and described.

2. The combination, with a steamboiler `and described.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

CHARLES R. PENFIELD.

Witnesses:

AGNES M. STEBBINs, GEO. W. HAwKINs.

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