摘要 |
<p>This invention relates to an insert intended for electrical furnaces and of the type that comprises, on one hand, an insulating shell (1) having an outside (4) and an inside (3) having a rotationally symmetrical, e.g., cylindrical shape, and on the other hand a heater element (2) that is arranged inside the shell and extends a plurality of turns in a continuous loop having an overall shape corresponding to the rotationally symmetrical shape of the shell. According to the invention, the wire loop comprises a plurality of spaced- apart bends (7), which divide the same into a plurality of individual sections of limited length to which occurring thermal expansion is isolated locally. In a preferred embodiment, the bends (7) are U-shaped to impart the wire loop meander shape. In an additional aspect, the invention also relates to a heater element as such.</p> |