US1731448A - Boiler construction - Google Patents

Description

Patented a. 15, 1929 PATENT OFFICE ARTHUR V. ADAMSON, OF HEMPSTEAD, NEW YORK, ASSIGNOR TO COMBUSTION ENGI- NEERING CORPORATION, A CORPORATION OF NEW YORK BOILER CONSTRUCTION Application filed January 20, 1925. Serial No. 3,561.

This invention relates to boiler constructions and is especially useful 1n connection with water screens for furnaces burning finely divided fuel, as, for example, pulverized coal.

The objects and advantages of the invention will be best understood from the following description thereof, reference being had to the accompanying drawings, wherein Fig. 1 is a vertical section thru a furnace and boiler embodying my improvements;

Fig. 2 is a section taken on the line 22 of Fig. 1, and

Fig. 3 illustrates a modification of the vention.

I have illustrated my improvements in association with a. furnace and boiler arrangement such as is generally illustrated in the Kreisinger Patent No. 1,463.283 issued July 31, 1923, and my invention will be described in association with a water screen such as disclosed in such patent.

Referring now to the drawings, the reference character A denotes the combustion chamber, having an outlet 7 over which extend the boiler tubes 8 of any conventional design of boiler. The powdered coal is admitted into the upper part of the combustion space in a downward direction by means of a plurality of burners B, thru and around the nozzles of which, a portion of the air required for combustion is admitted, the balance of the air required for combustion being admitted thru openings 9 in the front wall of the combustion chamber.

In the lower portion of the combustion chamber is the water screen C composed of a plurality of suitably spaced tubes 10 which connect into the header 11 at one end and Into the header 12 at the other end, these headers in turn being connected by downcomers 13 and upcomers 14 into the circulation of the boiler. The tubes 10 are spaced sufficiently far apart to permit the refuse particles gravitating out of the flame stream to pass freely to the ash space beneath the screen. The screen b Y reason of its high rate of absorption per orms a very large portion of the work of evaporation. The fuel and flame stream takes the U shaped course indicated in the drawing, the level of the bend in the flame being determined very largely by the rate at which the furnace and boiler are being operated. If the boiler is forced to very high rates, the flame may come well down toward and possibly impinge upon the tubes of the water screen.

There is a tendency for the tubes of the water screen to sag, producing steam pockets resulting in blistering of the tubes which, of course, is to be avoided. I propose to preventthis sagging and minimize the tendency to blister. I accomplish this by equipping the tubes with fins 15, which are preferably in the form of metallic strips welded to the lower sides of the tubes. These fins impart stiffness to the tubes and prevent sagging. They also serve to conduct heat into the tubes and, therefore, add to the efliciency of the screen.

In the construction of Fig. 3 I have shown fins on opposite sides of the tubes, that is to say both above and below. Where such a construction is employed, the width of the fins is such thatthey will conduct sufiicient heat into the tubes to prevent burning off of the free edge portions of the fins.

While I have described my invention as applied to water screens, there may well be other applications coming within the sphere of this invention.

I claim:

1. In boiler and furnace construction, a water-screen, exposed to the heat of the furnace, including substantially horizontally positioned isolated water tubes of relatively small diameter with respect to their length and the spacing between them, said tubes being supported at their ends, and vertically disposed metallic reinforcing fins on said tubes extending longitudinally thereof.

2. In boiler and furnace construction, a water-screen, exposed to the heat of the furnace, including substantially horizontally positioned isolated water tubes of relatively small diameter with respect to their length and the spacing between them, said tubes being supported at their ends, and vertically disposed metallic reinforcing fins on said tubes extending longitudinally thereof on the under side.

3. In boiler and furnace construction, a plurality of substantially horizontally disposed water tubes supported at their ends and connected into the circulation of the boiler, exposed to the heat of the furnace and substantially spaced apart to provide for passage of products of combustion between them, and vertically disposed metallic reinforcing fins on said tubes extending longitudinally thereof.

4. In boiler and furnace construction. a plurality of substantially horizontally disposed water tubes supported at their ends and connected into the circulation of the boiler, exposed to the heat of the furnace and substantially spaced apart to provide for passage of products of combustion between them, and vertically disposed metallic reinforcing fins on said tubes extending longitudinally thereof on the side remote from the source of heat of the furnace.

In testimony whereof, I have hereunto signed my na e ARTHUR V. ADAMSON.

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