US2464681A - High-temperature fan - Google Patents

Description

March 15,1949. N. J. G'RovER 2,464,681

HIGH TEMPERATURE FAN Filed Feb. 19, 1946 INVENTM A/orwaq. Grover Patented Mar. 15, 1949 2,464,681 HIGH-TEMPERATURE FAN Norman J. Grover, Westwood,` Mass., assignor, by mesne assignments, to Westinghouse Electric Corporation, a corporation of Pennsylvania Application February 19, 1946, Serial No. 648,756

2 Claims.

This invention relates to the cooling of the hubs of fans used for moving high temperature gases.

Fans are used for moving gases having temperatures as high as 1600 F. The temperature of the gas in one installation may cy-cle between 800 F. and 1600 F. The blades of the fans are under mechanical stress as Well as being exposed to the high temperatures, and unless the hubs to which they are secured, are adequately cooled, the metal in the blades becomes brittle, and the blades and their joints to the hubs, crack and fail.

When the hubs of such fans are inadequately cooled, the hubs expand away from the shafts and take permanent sets leaving air gaps between the hubs and shafts. The characteristic of metal which resists su-ch a permanent set is called creep strengt The creep strength of steel decreases very rapidly when heated to temperatures above 900 F.

Attempts have been made to cool the hubs of fans used for high temperature duties, by .circulating water through the hollow shafts upon which the hubs were supported, but such cooling was not effective so that when the fans were first used with high temperature gases, the hubs expanded away from the shafts taking permanent sets leaving air gaps between the hubs and shafts, which air gaps lessened the heat transfer from the hubs to the shafts with the result that as the fans continued to be used with the high temperature gases, the conditions became progressively worse. The lives of such fans were relatively short for the blades soon failed.

This invention provides for circulating cooling water through the hub of a fan whereby the hub is cooled directly by the water instead of being cooled through the intermediary of a shaft as has been the practice in the past. Utilizing this invention, the hub of a fan handling gases the temperature of which cycled between 800 F. and 1600 F., was cooled to a temperature which varied between 600 F. and 700 F.

An object of the invention is to prevent the overheating of the hubs of fans handling high temperature gases.

Another object of the invention is to cool the hub of a fan handling high temperature gases, by circulating a cooling liquid directly in conta-ct with the inner surface of the hub.

The invention will now be described with reference to the drawing, of which:

Fig. 1 is a side elevation, in section, of a centrifugal fan embodying this invention, and

Fig. 2 is a sectional view along the lines 2-2 of Fig. 1.

The fan illustrated is of the general type disclosed in detail in the U. S. Patent No. Re. 20,409, and has the casing 6 to which is supported the bearing 'l through which the shaft 8 extends. The inner end of the shaft has the iiange 9 formed thereon and which is attached by the bolts I0 to a similar flange I I on the outer end of the hub I2. The fan blades I3 have their root edges joined to the hub as by welding, or they may be cast integral therewith.

The shaft 8 has a central longitudinal opening I4, and the hub l2 has a similar opening I5 aligned therewith. The water supply tube IB extends through the shaft opening I4 and into the hub opening I5 and terminates therein adjacent the inner end of the tub. The openings I4 and I5 have the same diameter, and the tube I6 has a substantially smaller outer diameter whereby water discharged from the tube can circulate around its exterior surface in the openings I4 and I5.

The tube I6 extends through the packing box I9 into the shaft. The water supplied through the tube I6, after circulating through the hub and the shaft, is discharged through the pipe 20.

In operation, the water supplied through the tube I6, passes out its inner end into the opening I5 in the hub I2 and contacts the inner sur face of the hub around the opening I5. After traversing the inner surface of the hub it passes out the shaft opening I4 and the pipe 20 to waste or for recooling.

The cooling water is seen to contact the inner surface of the hub thereby directly cooling same.

The bearing 'l as located would be water cooled but since forming no part of this invention, its cooling details have not been illustrated.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated, since modifications thereof may be suggested by those skilled in the art without departure from the essence of the invention.

What is claimed is:

1. A fan comprising a shaft having a central, longitudinal opening therein, a hub having a central, longitudinal opening therein, means for attaching one end of said hub to one end of said shaft whereby said openings extend in axial alignment, said openings having substantially the same diameter, and a liquid supply tube extending through said opening in said shaft and into said opening in said hub, said tube having a sub- 3 stantially smaller diameter than that of said openings whereby liquid supplied through said -tube into said hub is returned around said tube in contact with the inner surface of said hub, said shaft having means for exhausting the liquid returned around said-tube.

2. A fan comprising a shaft having a central, longitudinal opening therein and having a ange formed on one end thereof, a hub having a eentral, longitudinal opening therein and having a ange formed on one end thereof, means for attaching said flanges together whereby said openings extend in axial alignment, said openings having substantially the same diameter, and a liquid supply tube extending through said opening in said shaft and into said opening in said hub, said tube having a substantially smaller diameter of said openings whereby liquid supplied through said tube into said hub is returned around said tube in contact with the inner surface of said hub, said shaft having means for exhausting the liquid returned around said tube.

NORMAN J. GROVER.

REFERENCES CITED The following references` are of record in the file of this patent:

UNITED STATES PATENTS

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