| 摘要 |
<p>An electric heater including a heating element (2) in a refractory material and incorporating at least one electric heating resistor (7), characterised in that the heating element (2) defines a heating enclosure (3) closed at the top and bottom portions thereof and enclosing said resistor(s) (7); and the heating element (2) comprises apertures (12, 12A), in its peripheral wall (4), for transversally ventilating the heating enclosure (3).</p> |
