| 摘要 |
<p>A combination heating and thermal insulating unit for heating a particular region of a furnace or the like, in accordance with the present invention comprises a block (12) of thermal and electrical insulating inorganic fibers material which is provided with elongated slots (28) which extend into the block (12) forming opposed walls (30, 32) on opposite sides of the axis of the slot (28), a heating element (38) in the form of an elongated serpentine wire (40) with opposed bends (42, 44) on opposite sides of the axis of the wire (40) is disposed in the slot (28) with the bends (42) on one side engaging one wall (30) of the slot (28) and the bends (44) on the other side engaging the other wall (32) of the slot (28). The heating element (38) is mounted near the surface (16) of the thermal insulating block (12) without the use of mounting brackets and provides for the advantage that more of the heat produced by the heating element (38) is transferred to the work load by radiation and convection whereby the temperature difference between the hottest portion of the heating element (38) and the coolest portion of the heating element is substantially lower than in a prior constructions of heating units of this type. </p> |
