| 摘要 |
<p>931,298. Induction heating. BLAW-KNOX CO. July 6, 1960 [July 17, 1959], No. 23634/60. Class 39 (3). An induction heater for a plastic extruder includes a metal barrel 7, a group of laminated metal flux guides 8, Fig. 3, being mounted on the outer barrel wall, and an electric induction heating coil 26 being located between the guides and the barrel. Located between the barrel and the heating coils 26 is a cooling chamber formed by a non-magnetic steel sleeve 15 inwardly turned at its ends and supplied by cooling fluid through pipes 29, 33. Adjacent the sleeve is mounted a mass 16 of thermal insulating material held in place by heatresistant tape 17 so as to leave an air gap 20 between itself and the heating coils. The lugs 8a, Fig. 5, of the flux guides are cut to the curvature of the barrel walls and are riveted on to flanged semi-circular clamping units 23 held together by screws 25. A symmetrical disposition of the guides may be ensured if the guides are fitted into the channels of channelled spacers 27, Fig. 3, located between coils 26 and the guides. Temperature control is attained by means of a thermocouple located within the annular space 28 between the coils 26. The coils are of copper-wire with a square crosssection. The insulating layer 16 and the air gap 20 serve to prevent overheating of the outside casing of the apparatus.</p> |
