| 摘要 |
Electrical heating elements which consist of a tubular heater and a profiled outer casing of aluminium, enclosing said tubular heater, can be produced in a simple manner and in a multiplicity of designs by using standard components. If such heating elements are to be suitable, however, for high operational temperatures, an outer casing of steel or steel alloys is necessary. Steel profiles, however, cannot be produced or can be produced only with great difficulty in the known design having a continuous hole. It was therefore the object of the present invention to provide the outer casing with a form which makes possible a simple construction of steel without the necessity of having to do without the advantages of the design using standard components. This object is solved according to the present invention in that the outer casing consists of two profiled casing parts (4, 10) which in cross-section are congruent, are formed from steel and which have in each case two opposite recesses (5 and 6, respectively) of semicircular cross-section which, when the profiled casing parts are placed against one another, receive and enclose the tubular heater (1) and which are provided with two frames (grooves, notches) (7) enclosing a recess (6) and two further recesses (8) which are arranged at the side of the second recess (5), correspond to the shape of the frame (7) and serve to receive said frames. <IMAGE>
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