US1895947A - Heat radiator - Google Patents

Description

M. UNGER HEAT RADIATOR Filed Nov;

Inventor: Magnus Un ger,

His Attorney.

, I?! z I /Illllllllllrll Patented Jan. 31, 1933 UNITED STATES.

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PATENT OFFICE PITTS IIELD, IASSACHUSETTS, ASSIGNOB TO GENERAL ELECTRIC COKPAKY, A CORPORATION OF NEW YORK rma'r nama'roa Application filed November 11 193 'Seflal 110. 574,388.

My invention relates to heat radiators and more'particularly to the type of heat radiator having top and bottom headers connected by tubes. In the-production of radiators of this type, it'has been customary to make the headers of sheet metal with flanged openings into. which the ends of the tubes are welded. The general object of the invention-is to'prov'idexan improved radiator of this type. a I

The objects and advantages of the invention will be apparent from the-following description taken in connection with the accompanying drawing in' which Fig. 1 is a side'view of a radiator constructedin accordance with the invention and connected to the casing of a transformer for cooling a body of liquid in which the transformer is immersed, and Fig. 2 is an enlarged sectional view on the line 2-2 of Fig. 1 of one side of the radiator with the central parts of the tubes broken away.

Like reference characters indicate similar parts in both figures of the drawing.

The radiator shown in the drawing has a top header 10 and bottom header 11 connected by metal tubes 12. The headerslO and 11 are formed of sheet metal with openings having flanged edges 13 into which the ends of the tubes are inserted and welded.

,In Fig. 1, the headers are shown connected is immersed in an insulating liquid 16. As

the liquid about the transformer is heated, it rises by convection, flows into the top header 10, down through the tubes 12 where it is cooled, and finally returns through the bottom header 11 to the transformer casing ready to absorb more heat from the transformer. t

The purpose of the radiator is to transfer heat from the liquid inside the tubes to the air surrounding the tubes and in the spaces between them. In order to do this most efiiciently, the walls of the tubes should be as, thin as possible and still have the necessary mechanical strength and the air around and between the tubes should be free to rise by convection along the surfaces of the tubes with the least possible obstruction. If simple,

straight tubes with very thin walls are used, however, it is 'not easy to weld the ends of the tubes into the headers without burning through the thin tube walls. If more than one row of'tubes is used as indicated in the drawing, the air that flows up between the tubes cannot flow through the .radiator headers but must flow in-between the lower ends of the tubes and out between the up er ends of the tubes. If simple straight tuhes are spaced far enough apart so that they do not interfere with this flow of air between them, the radiator is unduly bulky and if the tubes are spaced closely together to make the radiator compact the air cannot flow freely into and out of the spaces between the tubes. The invention avoids all these difficulties by using jointless thin walled tubes 12 with their ends 17 swaged to reduce their diameters. The swaging process not only reduces the diameters of the ends of the tubes but increases the thickness of the walls of the tube ends so that they may be welded easily into the headers without danger of burning through the tubes. The swaging process also increases the spacing between the ends of the tubes so that the intermediate portions of the tubes may be spaced'very closely together and still the air can flow readily 'in and out between their ends. The increased spacing of the ends of the tubes due to the swagin of the tube ends also makes the welded oints between the tubes and headers more readil accessible for the repair of any leakswhich may develop in these joints.

The invention has been explained by describing and illustrating a particular radiator constructed in accordance with the inven-tion, but it will be ap arent that changes may be .made without departing from the spirit of the invention or the scope of the Y said headers, the tubes having ends of greater wall thickness than the intermediate portions of the tubes, and said tube ends extending into said flanges and bein welded thereto. a

2. A heat radiator inclu ing top and bottom headershaving openings surrounded by" 5 external flanges and trreta l tubes connecting said headers thetubs having ends of smaller diameter and greater wall thickness than the intermediate portions of the tubes, and 7 said tube ends extending into said flanges and 10 being welded thereto. I

' In witness whereof, I have hereunto set my hand.

-MAGNU S UNGER.

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