US270915A - Steam-boiler - Google Patents

Description

(No Model.)

N. P. STEVENS.

STEAM BOILER. No, 270,915. Patented Jan.23,1883.-

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UNITE STATES PATENT QFFICE.

NATHAN P. STEVENS, OF CONCORD, NEW HAMPSHIRE.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 270,915, dated January 23, 1883.

Application filed May23,1882. (No model.)

To all whom it may concern:

Be it known that I, NATHAN P. STEVENS, of Concord, in the county of Merrimack, of the State of New Hampshire, have invented a new and useful Improvementin Steam-Boilers; and

I do hereby declare the same to be described in the following specification, and represented in the accompanying drawing, which is a longitudinal-section of a boiler of my improved kind, the nature of my invention being defined in the claim hereinafter presented.

I would remark that although I have represented in the drawing a boiler for a locomotive steam-engine, a boiler for a stationary engine may be constructed with my improvement.

In such drawing, A represents the water and steam chamber of a locomotive steam-engine boiler, such being surmounted at its middle with a steam-receiving drum, B. .The firechamber shown at (l is at the middle of such water and steam chamber A, and extends out of and below such, and where extending below it is surrounded by an extension, D, of the boiler. The grate of such fire chamber is shown at a. There should be over such grate a suitable opening for the admission of fuel to the chamber, which opening should be provided with a door or doors. From the firechamber, at its upper part, there are extended in opposite directions two stacks of fire-tubes, I), each of which opens at the outer end of its tubes into one oftwo smoke boxes or chambers, D, arranged as shown, each of them being provided with a chimney, E. In advance of one of the said smoke-chambers is a supplementary chamber, F,into which the exhaust-steam from the cylinder or cylinders of the engine is to be led by a suitable conduit or conduits. From the said supplementary chamber blast-pipes G H are led into the lower parts of the two chimneys,each ofsuchblast-pipes,atits mouth, being provided with a valve or damper, e, for regulating the flow of steam into such pipe. The supplementary chamber 'E being common to both stacks, there is an equal flow through the blast-pipes G H, which produces an equal draft and keeps both portions of the boiler at an even temperature. From the dome one or more pipes, j, lead steam to the valve-chests of the cylinders.

From the above it will be seen that the smoke and gases generated in the fire-place will pass out of such in opposite directions through the two stacks of flue-tubes, and from them will flow into the two smoke boxes or chambers and escape by their chimneys, in which case each stack of pipes may be very short in comparison to what would be required were there to be to the boiler but one stack, one smoke box or chamber, and one chimney, as locomotive-engine boilers are usually constructed. Byhaving the pipes so diminished in length they are much easier cleaned of deposits, and, besides, advantages are otherwise gained by them.

The supplementary chamber is to effect a uniform or approximately uniform blast of 'steam in each of the chimneys, and not an intermittent one,as would follow without such a chamber; The waste steam entering the supplementary chamber can expand therein, and will be driven therefrom into the chimney in uniform or approximately uniform currents, whereby the draft of the furnace will be rendered substantially uniform, with little, if any, danger of the coalsor fuel being sucked into the tube-stacks.

With the dampers or valves to the two blastpipes the blast of either can be regulated in quantity, as occasion may require/to effect uniformity of draft through the two stacks of fluetubes.

In my improved boiler I have but one fire place or chamber tothe two stacks of fluetubes leading in opposite directions. out of it, and through the water-chamber to the smokechambers, such being decidedly advantageous over separate fire-chambers to the two stacks, for with the single fire place, the exhaust-steam chamberF, and its blast-pipes and their valves, the smoke and heat can be directed through eitherof'the stacks, or caused to flow equally or unequally through both, as occasion may require. Furthermore, it will be seen that the said fire-place is wholly within the water-space of the boiler, so that the crown-sheet or top of.

the fire-place is covered by the water when in the boiler. It will also be seen that the fireplace is not extended underneath either of the stacks of flue-tubes, but is directly between them and projects below them, all of which is avery advantageous construction of the boiler, provided with the steam-exhaust chamber, the two smoke-boxes, and their chimneys, as explained.

1 am aware that double boilers are old, and that it has been proposed to exhaust through their smoke-chambers into one or two chimneys. I am also aware that a boiler has been devised having an outside jacket, thus forming a double boiler for the purpose of utilizing the heat of exhaust-steam to add to the temperature of the water in the boiler. In this latter construction the steam passes between the jacket and boiler, through the lower tubes of the latter, into a chamber provided with an adjustable valve which only lets the steam out under certain conditions, and after it has lost nearly all of its valuable heat. My invention is different from these constructions. In my device the steam passes directly from the cylinder into the supplemental chamber F, which thus forms a reservoir for the exhaust-steam. From this chamber the steam -is conducted directly into the chimneys by the pipes G and H in an active condition and calculated to materially assist the draft. In this way the steam is utilized in an efficient manner, and as the chamber F is common to both chimneys the same draft'is maintained on both sides of the fire, equalizing the temperature. I Having described my invention, what I claim The double boiler A, having the fire-tubes b b, and chimneys E E, in combination with the supplementalchamber F, common to both chimneys, and the pipes G H, leading from this chamber to the chimneys, and provided with the valves 0, as set forth.

NATHAN P. STEVENS.

Witnesses:

M. P. FOSTER, A; B. GRoss.

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