| 摘要 |
<p>Annular resistance heater comprises: an upper ring (1) and a lower ring (2), which are connected to the lower ring adjacent to an annular gap (3) by an electrically conductive loop (4) such that the flow direction of electric current is directed through the rings, in the opposite direction of the rings; connecting elements which hold the upper and the lower rings together at a distance, where the distance is 2-150 mm; and power supply lines (11) for conducting electrical current through the upper and lower ring.</p> |
