US2179420A - Electrically heated radiator - Google Patents

Description

Nov.. 7, 1939.

J MULLER 2,179,420

ELECTRICALLY HEATED RADIATOR Filed Oct. 12, 1958 fiweizial Patented Nov. 7, 1939 \PATENT OFFICE ELECTRICALLY HEATED RADIATOR Johann Miiller, Arbon, Switzerland, assignor to Aktiengesellschaft Hermann Forster, Arbon,

Switzerland Application October 12, 1938, Serial No. 234,683 In Switzerland April 2, 1987 1 Claim. (on. 219 -ss) This invention relates to electrically heated radiators for room heating purposes of the type having a plurality of spaced radiating elements which are in communication at their lower ends 5 only with a common header containing the electric heating element, and which are formed by separate tube coils each constituting an endless circulating system for the heat accumulating and transfer medium. v

In known radiators of this type, a number of hollow cast radiating elements have been connected to each other by nipples whereby two connections were provided between each two adjacentelements. It is not possible to have such radiators work under pressure since leaks are liable to occur at the joints through which the heating medium would escape, and cast radiating elements are moreover not reliable for operation under pressure. Further, with this manner of connecting the elements to each other,

no regular circulating motion is obtained within the elements, the heating medium in proximity to the heater being heated too much, while the upper portion of the elements became barely warm, and thus no favorable utilisation of heat was obtained.

The object of the present invention is to provide a radiator of the type above mentioned in which the tube coils forming the radiating ele- 3 ments are connected to the header in such manner as to permit operation of the radiator under pressure and to create an intensive and forced circulation of heating medium without any possibility of leaks occurring at the joints between the coils and the header.

According to the invention the tubular coils are formed eccentrically relative to the header which extends substantially at right angles to the planes of the tube coils, and one of the branches of each coil rises directly from the header in vertical direction, while the other branch is connected to the header by a laterally extending portion. In this manner the air can freely circulate all around the tube coils which thus provide a large heat exchange area and which are accessible from all sides for cleaning purposes. Since the air not only makes contact with the exterior surfaces of the radiator elements, but can also flow through the interior 50 of the relatively large coils or loops of the elements, an excellent and eflicient transfer of heat between the radiator and the air is obtained. The header is preferably of rectangular or square cross section and the ends of the coils are weld- 55 ed or soldered into the wall of the header. This latter can contain a copper tube in the interior of which the electric heater is mounted.

A preferred embodiment of the invention is illustrated in the accompanying drawing, in which 5 Figure 1 is a partial side view of a radiator according to the invention.

Figure 2 is a vertical section through a radiator element on the line 11-11 of Fig. l.

The represented radiator comprises a plu- 1 rality of regularly spaced separate pipe elements forming circulation tubes l, in each of which there is formed a closed circulation path for heating medium. All the circulation tubes l are connected at their lower portion to a header 2 15 of square cross section which is laterally or eccentrically disposed relative to the tube coils l. A vertically rising branch la of the coil 9 is connected to the upper face of the header 2, while the branch l1 through which the heating 20 medium, preferably oil, returns, is connected to a lateral face of the header by means of a laterally extending tube portion l. The ends of both branches la and Ir are welded or soldered into openings of the header, so that no joints are 25 present in the finished radiator and accordingly no leaks can be formed. Owing to the provision of the vertically rising branch la and the laterally extending portion of the return branch l r, the header 2 is laterally offset relative to the median axis of the coils l, and an intensive circulation of oil is obtained whereby a correspondingly high heat transfer action is realized. The tube coils l are almost completely filled with oil, only so much of free space being left as is necessary to permit the expansion of oil due to temperature rise. Thus, during operation of the radiator an internal overpressure of 1 to 3 atmospheres is formed within the radiator elements. The electric heating element 4 is disposed within a copper tube 3 inserted into the header 2, and is electrically connected to a socket 5 adapted to receive the plug of a cable connecting the heating element to any source of electric current. In this manner the heating resistance element cannot make contact with the oil. The radiator is provided with feet 6 by means of which it is placed on the floor of a room.

Various changes and modifications may be made in the practice of my invention without departing from the principle or spirit thereof, by adding customary practice and established knowledge of the art to the present disclosure 55 a point of the header above the heating tube and by a branch extending laterally from a point of the header below the junction point of the vertical branch with the header, then upwardly, and then laterally reversely to join said first-mentioned branch integrally, the junctions of the branches of said radiating tubes being welded to said header, said radiator thus being entirely closed and adapted to operate under pressure, and the arrangement of the branches of the elements causing a circulation induced by heat expansion of the fluid.

JOHANN MfiLLER,

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