US30258A - smith and j - Google Patents

Description

E. W. SMITH &,J. H. MARS. STEAM BOILER.

IND. 30,258. Patented OottZ, 1860.

'HHHIHIIHIIII UNITED STATES PANT FTQE.

E. W. SMITH AND J. H. MARS, OF NEW YORK, N. Y.

STEAM-BOIL ER.

Specification of Letters Patent No. 30,258, dated October 2, 1860.

To all whom it may concern:

Be it known that we, ERASTUS W. SMITH, of New York city, resident engineer to the New York and Havre United States Mail Steam Ship Company and JOHN H. MARS, of New York city, chief engineer of the steamship Amgo, belonging to said company, have invented a certain new and Improved Steam-Boiler; and we do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawing, which represents a longitudinal section through all the parts of our boiler.

The nature of our invention consists in a certain combination and arrangement'of a mixing or combustion chamber with two tiers of furnaces and a direct and returning series of fiues or of fiues and tubes whereby the current of gases from the upper furnace is drawn down and mixed in the middle and lower portion of the chamber and the mixture and combustion is allowed to proceed in large flues at the base of the boiler and the heat is extracted in a series of smaller lines or tubes which series makes a partial return of the draft and discharges into an uptake immediately behind the upper furnace.

Two tiers of furnaces have often been employed with difierent arrangements of the fiues and chambers, and single return ascending flues have been employed in boilers with single tiers of furnaces and have in such boilers been arranged with the uptake directly behind the furnaces but these features have not so far as we can learn been employed in connection or combination, each with the other. In our invention they are thus combined and are furthermore so arranged relatively to each other and to a combustion chamber which connects them that our boiler possesses advantages not before attained in any equivalent manner.

In managing boilers with two tiers of furnaces it is common to supply fresh fuel to the two series alternately so that while the average of the gases discharged is in about its proper proportion one series of furnaces is liable to discharge volatile matter in an uncombined or unburned condition while the other is discharging an excess of free oxygen or unchanged atmospheric air and it is desirable intimately to mix the gases discharged from the one series with the gases discharged from the other series while their temperature is very high.

Our invention induces a degree of admixture of the gases from the two series before entering the fines and a continuation of the admixture and combustion within the flues which has not before been attained in any boiler with a double tier of furnaces.

In our invention the gases from the upper tier of furnaces are bent downward in a suitable combustion chamber and mingle with the current of gases ejected over the bridge from the lower tier of furnaces and the combustion chamber or space in which they may thus mingle is extended downward to the base of the lower fiues, which latter are of large diameter and receiving the agitated gases allow combustion to proceed while they are traversing a considerable distance therein.

The gases from two tiers of furnaces have before been allowed to meet previous to entering the fines but an equivalent extension of the combustion chamber is for obvious reasons not practicable when the gases are presented to each other at the bridge of the upper tier of furnaces, neither is it practicable to allow the gases to enter and burn in large flues at such a level because fiues at such level are liable to be uncovered by the water and must be small and exposed to less heat in order to sustain themselves under such conditions. They are furthermore immersed in water which at best is highly charged with particles of steam and is therefore less efficient in absorbing the heat from the metal. Our invention also allows the furnaces to occupy the whole depth of the boiler from the base to near the surface of the water and pro vides in connection with this a larger area for the draft than any arrangement previously known in boilers with two tiers of furnaces. This large area for the draft in each series allows of the employment of very small flues or tubes in the returning series and thus admits of ultimately extracting the heat very perfectly from the gases without sensibly retarding the draft. The use of tubes in lieu of liues in any of the returning series is not practicable in any boilers with two tiers of furnaces before known because the space afiorded for such return series in former boilers of this type was too small to admit of such minute subdivision of the current.

The small area in all former boilers was due to the necessity either for a double return as in the drop fiue style and consequently for dividing the flue areas into three divisions or the necessity in single return boilers of this character for traversing the space between the upper furnaces and the surface of the water, thereby necessarily curtailing both the height of the furnaces and the area of the returning series.

Two of our improved boilers in the proportions represented in the drawing on a scale of three eighths of an inch equal one foot are in use on the U. S. mail steamship Fulton. As thus proportioned they have a good draft, are easily accessible at every part for repairs, are believed to have an active circulation in the water, promise to be very durable and their'efiiciency and economy as compared with the two tiered furnace boilers in the sister ship the Arago which are considered excellent, substantiate all that we have claimed for them.

To enable other skilled in the art to make and use our invention we will proceed to describe its construction by the aid of the drawing.

A is the shell of a boiler in any ordinary form. The water surface therein is denoted by a a.

B is the lower tier of furnaces.

C is the upper tier.

D is a connection or combustion chamber connecting C and D and extending below the back end of B in the manner represented.

E is a series of flues the lower of which are of so large size as to carry the principal portion of the draft and allow the freshly mixed gases to burn therein forming in some degree a continuation of the combustion chamber. These fiues being below the points at which the gases pass over the bridge walls of either furnace compel a cross current and an intimate admixture of the two currents in the middle and lower portion of the combustion chamber.

F is a back connection.

G is a series of tubes or small fines and H is a chamber located as represented into which the gaseous products of combustion .after their entrance therein and to maintain a sufliciently high temperature to ignite at every point at which a suitable measure of air meets a suitable measure of combustible gas, until nearly the whole extent of the flue is traversed. This is equal in effect or nearly equal to an extension of the combustion chamber along the bottom of the boiler. The high temperature of the metal thereof is rapidly absorbed by the dense water with which these fiues are from their position certain to be always covered.

e do not claim the employment of two series of furnaces, nor the employment of a combustion chamber and fines arranged as described except when the same are used in connection with two series of furnaces and arranged relatively thereto substantially as herein represented, but

Having now fully described our boiler what we claim as new therein and desire to secure by Letters Patent is- The arrangement of the combustion chamber D relatively to the two tiers of furnaces and to the fines or their equivalents whereby the gases from the upper tier of furnaces are drawn downward and mingled with those from the lower tier in the middle and lower portion of the combustion chamber and the agitation and combustion is allowed to proceed in the large fiues along the bottom of the boiler and the heat is extracted in a series of smaller fiues or tubes which makes a partial return of the draft and terminates in an uptake or equivalent connection H immediately behind the upper furnaces substantially as herein set forth.

In testimony whereof we have hereunto set our names in the presence of two subscribing witnesses.

ERASTUS W. SMITH. JOHN H. MARS. Witnesses:

THOMAS D. STETSON, A. SNYDER.

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