US27013A - Improvement in the apparatus for superheating steam - Google Patents

Description

VUNITED STATES PATENT OEEIcE.

GEORGE A. STONE, OF ROXBURY, MASSACHUSETTS.

IMPROVEMENT IN THE APPARATUS FOR SUPERHEATING STEAM.

Specification forming part of Letters Patent No. 27,013, dated January 31, 1860.

To @ZZ wiz/0m it may concer/z.-

Bo it known that I, GEORGE A. STONE, of the city of Roxbury, in the county of Norfolk and State of Massachusetts, have invented a new and Improved Apparatus for the Auto matic Regula-tion of the Superheating of Steam; and I do hereby declare that the following specification, taken in connection with the drawings, is a full, clear, and exact description thereof.

In the drawings, Figure l is a section through a superheating apparatus and the automa-tic or self-acting regulator. Fig. 2 is half a section on the line a l) of Fig. l; and Fig. 3 is a plan of half the apparatus, exhibiting, also, the rod. that governs the valve of the steam-j et.

The superheating apparat-us for which my self-acting regulator is designed is one in Which the amount of current of flame or heated gases through the apparatus is determined by a jet of steam. which causes the current, or to a certain extent regulates the velocity thereof, and the apparatus is adjustable, so that the superheated steam maybe kept at nearly a constant temperature after adjustment is made.

The advantages resulting' from the superheating of steam are well known, and so, also, are the disadvantages which follow an improper regulation of the amount of superheating. For instance, When the steam is too much superheated, packing is burned up, the oils or grease in. the engine are converted. into charcoal, and the friction. is much increased, so that it sometimes happens that less power is obtained f rom superheated than from ordinary steam. When the temperature falls too low the economy in fuel is scarcely perceptible, and if the extent to which the superheating is carried fluctuates there is also a fluotuation in the power exerted. by the engine. NOW, my invention is designed to obviatc these difficulties, an d I will proceed. to describe one method of putting it in practice by reference to the dra-Win In them the superheatingchamber is shown at c, a a, and it is to be secured to a boiler, or in some Way connected therewith, so that steam may enter the chamber through a passage, t), and gaseous products of combustion in a heated state or flame may enter the passage c. To the upper part of the chamber is to be attached a pipe-such as (1 -leading either into a chimney or into the open air, and pipes or iues of any proper form and sizesuch as x--one to connect the pipe (Z with the passage c, the construction being such that iiame may pass from c to b Without mingling with steam contained in the chamber a c.. This chamber has also an opening, c, Which connects With the steampipe or cont-rivance for conveying the superheated steam to the place where it is to be used, and from the chamber leads a small pipe, f, which enters the passage d, being at its end inclined, so as to be parallel, or nearly so, with the bore or hollow of the passage, the object being that a jet of steam through the pipe shall cause a current through the passage and through the fines o3 This steamjet pipe may be provided with a cock such as is shown in the drawings, to be opened and shut by hand, and is also to be provided with a valve-seat and valve such as is shown in the drawings, and to this valve is to be attached a metallic rod, y, which extends through the super-heating chamber and through a stuffing-box-such as z--at the rear end thereof, and is then to be secured to some bracket or arm or any proper fixture whose position is not varied or changed by the expansion and contract-ion of the superheating apparatus during the rise and fall of the temperature thereof, which temperature, it is clear, will. vary according to the temperature of the steam contained in the superheating-chambcr. This rod should be secured to a bracket having the above characteristic by set-nuts, such as shown iu the drawings, or in some equivalent manner, so vthat the point of attachment may be varied with respect to the position of; the valve and valve-seat, or, in other Words, so that the actual length of rod between the point of attachment and the valve may be varied. New, if steam be raised in a boiler and admitted into the chamber, and iiame be admitted through the Iiues, the steam in its passage through the chamber will be superheated, and, if the pipe (Z be connected with a chimney or be elongated so as to form a chimney, the amount of current of gas or iiaine will depend upon the draft in the chimney, and this current may be increased by opening the cock, so as to permit a jet of stearnltoescape from the chamber into the chimney; but if the draft should decrease or the temperature of the gas or iiame should fall or the quantity of steam passing through ihe chamber should increase, the temperature of the superheated steam would fall, and the contrary effect would take place if the draft or temperature of flame should happen to increase or if the quantity of steam flowing through the chamber in any fixed period of time were diminished. When an alteration in the temperature of the steam had occurred and been discovered, it might be corrected by opening or shutting the small cock shown in the drawings, so as to increase or diminish the strength ofr jet; but a watchful attendant would be needed for this purpose, and even if attentive he could only guess at the distance through which the faucet-handle should be turned. By the use of the valve and its rod such attention is rendered unnecessary, and they, in connection with the chamber and valve-seat, act as follows: Vhen the chamber expands or contracts, it varies its length, and while varying its length its center-say at the line a h-will remain stationary, or nearly so, while its two ends will move in opposite directions from the center, each to a distance equal to one-half of the whole expansion due to the length of the chamber and the degree of change of temperature. As the chamber varies its length the rod fJ, inclosed within it and kept at the same temperature, will also vary its length, and, as it is fixed at one end to some support distinct from the superheating-chamber its whole variation will be exerted upon the valve, which will move to a distance, due to the expansion of the whole length of the rod, which is at least as long as the chamber. A rise of temperature in the chamber will therefore cause the valveseat which is attached to it to Vmove away from the point of support of the rod; but the valve itself will by the expansion of the `rod move twice as fast as the seat does, or nearly so, and the port or opening in the seat will consequently be closed to a greater or less extent, and the quantity of steam -rushing through the jet will be diminished, and the contrary effects will take place whenever the temperature of the superheating chamber falls. By a proper adjustment of the rod, depending upon the proportions of the apparatus in its various parts and the heat of the gases and the amount of superheating required, the temperature of the superheated steam may be kept nearly constant.

If greater range of motion of the valve with reference to its seat should be required, a lever or series of levers may be interposed between the valve and the rod, .so that the motion of the former shall be greater than that of the free end of the latter; or these levers may be so arranged that the seat and valve shall move in opposite directions at the same time as the temperature varies, and in place of an arrangement of rod such as shown' a compound rod like a gridiron pendulum might be employed, the metal rods composing it being so proportioned and attached to each other that the valve should stand still at all temperatures, while the seat moved under it. Any arrangement of rods acted upon by the heat within the chamber that will cause the valveand seat to slide past each other as the temperature changes will answer the purpose, and in place of the valve shown a simple cock or other kinds or forms of valve than that shown in the draw- 1 ings may be used, so long as such valves control a steam-j et and have their position relatively to their seats regulated by an arrange ment of rods substantially such as represented. The jet itself, moreover, need not, of necessity, proceed from the superheatingchamber, but may be connected with and receive steam from the boiler which supplies the superheating-chamber with steam, so long as the valve in the jet-pipe is governed by rods or their equivalent expanded or contracted by the heat in the superheating-chamber.

The uses of the chamber and fines may also be reversed-that is to say, the steam may be made to pass through the Iiues and the gases through the chamber, in which case the rod must be located within one of the iiues, so as to be exposed to the heat of the steam, and the jet-pipe must be connected to a flue and the pipe d or its equivalent to the chamber.

Having thus described my apparatus, l claim as of my own invention- The combination, substantially in the manner and for the purposes speciiied, of these four things, namely: first, a superheatingchamber provided with flues or their equivalent for the passage of heated gases or flame, and with passages for the entrance and escape of steam; second, a steam -jet pipe leading into a passage or pipe connecting with the iiues and receiving steam from the chamber or boiler and discharging it so as to make or increase a draft through the fines; third; a valve in the jet-pipe, and, fourth, a rod or itsequivalent exposed to the heat of the superheating-chamber and acting upon the valve, substantially in the manner specified, the whole combination being substantially such as is described, and acting to supply or furnish superheated steam at a nearly A constant temperature.

In testimony whereof l have hereunto subscribed my name, in the city of Boston, on this 10th day of October, A. D. 1859.

GEORGE A. STONE.

In presence of- BENJ. F. COOKE, JNO. L. HUNTER.

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