US977078A - Furnace for steam-boilers. - Google Patents

Description

F. DUFFY.

FURNAGB FOR STEAM BOILERS.

APPLICATION FILED MAR. 2, 1910.

Patented Nov. 29, 1910.

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FRANCIS DUFFY, OF CHICAGO, ILLINOIS.

FURNACE FOR STEAM-BOILERS.

Specification of Letters Patent.

Patented Nov. 29, 1910.

Application filed March 2, 1910. Serial No. 546,818.

To all whom t may concern:

Be it known that I, F minors DUFFY, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Furnaces for Steam- Boilers, of which the following is a speciication.

My invention relates to furnaces for steam boilers especially locomotive boilers and the object of the invention is to provide simple and efficient means for pre-heating and oxidizing the air entering into the fire box.

I accomplish my objects by employing a y construction the preferred form of which is shown in the accompanying drawings, in which:

Figure l is a front elevation of a boiler furnace embodying my invention, Fig. 2 is a longitudinal sectional elevation taken on the line 2-2, Fig. l, and Fig. 3 is a detail, drawn to an increased scale showing the most important parts of my invention. The plane of section of Fig. 3 is the same as that of Fig. 2.

Similar letters refer to similar parts throughout the several views.

Referring to the accompanying drawings, the fire box a is provided with grate bars o, and communicates with iire tubes c. Between the front wall a of the fire box and the front wall el of the boiler d is a space e which contains water. As the water in this space is adjacent to the re box it will remain at a temperature approximately the same as the temperature of the water in the other parts of the boiler. There is an opening e in the front of the boiler passing through the walls a and d for the introduction of coal and air into the fire box.

Secured tothe front of the boiler surrounding the opening e is a pre-heating chamber having a front wall f and peripheral walls f. Said chamber has a door frame formed of walls f2 arranged to register with the opening e in the boiler front, these walls in the preferred construction being of cast metal integral -with the por` tions f and f. The frame is provided with a door g of ordinary construction.

rIhe peripheral walls, f of chamber f are apertured to admit of air being drawn into said chamber from all parts of the periphery thereof. Apertures f3 are formed in the walls f2 and permit the air to pass from the chamber f into the .door frame. By preference there is also a space 7L at the rim of the door frame which permits the air to pass directly from the chamber f into the opening e.

At the inner margin of the door frame is formed a duct or passage z' from which a number of small openings lead inwardly to the lire box through the opening e. Said duct is for the purpose of introducing steam which is furnished through a supply pipe j shown in Fig. 1.

In operation the draft through the fire box causes air to be drawn into the chamber f through the apertures in the peripheral walls thereof, this air being finally drawn into the fire box through the apertures f3 and opening e. As the water in the space e keeps the boiler front d at a high temperature, the air thus passing through the chamber f is heated by contact with said boiler front and therefore enters into the opening e at a high temperature thus furnishing oxygen to the gases in the fire box in a heat ed condition. As a result the combustion is rapid and complete and the production of smoke is prevented. The chamber f thus constitutes a pre-heating chamber which enables air to be introduced directly into the fire box without chilling the gases and producing smoke but on the contrary prevents the formation of smoke. The metal adjacent to the duct z' will be kept at a high temperature as a result of exposure to the heat of the iire box and hence said metal will superheat the steam entering the opening e through the apertures Z. This super-heated steam, meeting the preheated air in the opening e" will cause a thorough commingling of heated air and steam prior to entrance into the fire box, with the result that a liberal supply of oxygen will be introduced into the lire box in heated condition, thus efiiciently promoting combustion.

I claim as my invention l. In combination, a steam boiler having a substantially flat front through which there is an opening leading into the fire box, and a shallow dished preheating chamber secured to the boiler front surrounding said opening and communicating therewith and contacting the boiler front at its periphery, the boiler front forming the back of the preheating chamber, and said preheating chamber having inlets for air at its edges whereby the draft Will draw air through said chamber across the boiler front before entering the fire boX.

2. In combination, a steam boiler having a tire-box and an opening in the front leading thereinto, and a iiat preheating chamber secured to the boiler front surrounding said opening and communicating therewith, said preheating chamber having inlets for air at its edges and having a steam duct With apertures arrangedaround kthe margin of said opening for the purpose described.

3. In combination, a ysteam boiler having a fire-box and an opening inthe front leading thereinto, a steam duct arranged around the margin of said opening andhaving apertures leading thereinto, and a flat preheating chamber securedto the front of the boiler, and discharging into the boiler adj acent to the steam duct, substantially as described.

4. In combination, a steam boiler, having a fire-box and an opening in the i'front leading thereinto, and a flat preheating chamber secured to the boiler front surrounding said opening and communicating therewith, said preheating chamber consisting of cast metal and having a duct formed in the metal and arranged to extend around the margin of said opening Where it will be exposed to the heat of the fire in the fire box, there being` small steam outlets leading from said duct into saidopening, substantially as described.

In Witnesswhereof, I have hereunto subscribedv my name in the presence of two Witnesses.

FRANCIS DUFFY. Vitnesses HOWARD M. COX, MARGARET I). Bonn.

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