US174552A - Improvement in water-tube steam-boilers - Google Patents

Description

M; mmm W. J. MUNCASTER.

WATER-TUBE STEAM-Boum. v N0,174,55z; Patented March 7,1876.

N.PETERS. PHOTU-LXTHDGRAPHER. WASHINGTON. D C.

grates, to the front tube-sheet.

UNITED STATES PATENT. Qrron.

A M EnwIN Maxam AND'WALTER J. Mono/ASTER, or OUMBERLAND, MD.

IMPROVEMENT IN WATER-TUBE s'TEAMfBoILERs;

Specitication forming part of Letters Patent No. 174,552, dated March 7, 1876; application filed January 20, 1876.

To all whomit may concern:

Be it known that we, MERWIN MGKAIG and WALTER J. MUNCASTER, oit' Cumberland,

in the county of Allegheny and State of Maryland, have invented certain new and valuable Improvements in Steam Boilers, intended more particularly for canal-boats and steamtugs, but applicable to land or any purpose or place where economy of fuel and space is desired, of which the following` is a specitication Figure l is a longitudinal section, and Fig. 2 is a transverse section, ot' my boiler. Fig. 3 is a transverse section of the tubes, showing' the bridge-wall blocks.

This invention relates to a boiler of the water-tube type, and it consists, first, of watertubes inelining downward from their front ends, at an angle of about twenty degrees, to a point j ust in rear of the bridge-wall,whence to the rear ends they are horizontal or nearly so, whereby, at their forward and hottest ends, steam and hot water have a free escape upward 5 and the tubes are, at all points, sub,- stantially transverse or at right angles to the draft or current of hot products of combustion, and are all equally exposed to the heat thereof; second, in a bridge-wall, constructedof blocks slipped onto the pipes, and overlapping each other, whereby the pipes are not crmped in their expansion and contraction; third, in external form, a box, A, with semi-cylindrical top, provided with a steam-dome, a.

The interior chamber, composing the furnace and tube-box B, corresponds somewhat to the outside shell in shape, with a tlat elliptical top, reaching within tive inches or six inches ofthe water-line, and the vertical Walls slightly inclined to provide a gradual increase of water-space.' The front and back heads b ot this chamber are drilled to receive and support the tubes c, which stretch across through the interior in vertically-staggered rows, which staggering makes the tube-surface more effective. The axes of these tubes are horizontal or slightly inclined from back tube-sheet to a point in line lwith bridge-wall D, then deect upward at an angle of about twenty degrees, passing through the b1 idge -wall, over the The object of this is to 'cause rapid circulation, induced by the tubes being inclined. The bend caused thereby provides for expansion and contraction, which in all s traighttubes cause an enormous strain on the tube-sheets. The plates of outside shell are also provided with circular openingsE, corresponding with the center line of tubes, for the purpose of cleaning and replacing, and are closed with suitable plates and nuts, or the holes tapped and bungs screwed in. The lower portion of the front is pierced with an opening of proper size for furnace-door F. At the rear of the furnacechamber, and above the tubes, there is an opening, G, of proper size, for the purpose of being able to examine and clean the upper space above the tubes;l also, to replace a crown-bolt without removing thetubes. This opening communicates with the smoke-stack H, and is closed by a suitable damper, I, which will be found advantageous in starting the fire, because opening this damper will allow the products of combustion to pass directly into the stack, which may be formed on the back of the boiler; when the tire is well started, this damper is closed, causing the products of combustion to pass downward through the tubes to the base of the stack. At the back end of the furnace-chamber, and under the tubes, is placed a mud-drum, J, attached to the leg of the boiler, in which the feed-Water is received. When in position, this boiler rests upon a casting, K, forming the ash-pit and smoke-due, which also furnishes/ the support for the grate-bars and bridge-wall D an opening, L, is formed in the side of same for cleaning. The extension of the bridge-wall upward among the tubes is formed of blocks d slipped on each tube, and projecting far enough to lap the block on the next tube below, but not to come in contact with the tube, which allows each tube to expand.

and contract independent of the others. Below the tubes the bridge-wall D is formed, preferably ofire-brick, supported by a plate of iron at the back.

From the above description, it will be per ceived that the tubes rest in, and are wholly supported by, their coupling to the tube-sheets b and b, and that their change of direction at or near the bridge-wall` places theiru midway portions at a distance from a right line, joining their ends; therefore, any expansion-orf contraction lengthwise will be `partly or wholly: counterbalanced by an increased or diminished deflection of said tubes, and thus the tubesheet connections will be subjected "to less strain than would be the case if said tubes werestraight.v This'e'ectis facilitated bythe structure of the bridge-wall, which permits the utmost freedom of motion there.

Having described'our invention, what We claim as new is- 1. The water-tubes C C, connected at their rear ends to the rear tnbe-sheet b'," and 'pass'ing thence forward, horizontally or nearly so,to a point just in rear of the bridge-Wall', then, bending upward at an angle of twenty degrees or' thereabouts,` they pass through thebridgei wall and over the grate to the front tubes'heet b', therebybeing `at allf points transverse or at?l as' set forth.

right angles tothe draft, and with a free nii ward discharge atthe hot end, substantially 2. A bridge-wan formed of blocks d a, slipped onto, and combined with, the Water-tubes, s0

as to lap one another and `permit freedom of -motion-in-s`aid tubes in 1 expanding and .'contracting, as set forth.

3. In combination, the within -described V'tubes'c, bridge-wall d, furnace-chamber B,

surrounded by an outside shell, with steamdome and flue H, and directdamper G, ar-

* ranged? sbstantiallyas' described.

MERWIN MKAIG. W. J. MUNCASTER.

Witnesses 4WM. L. ,MoRGAN, H. IW-ALLGERD.

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