GB624092A - Method of and apparatus for heating dielectric materials electronically - Google Patents

Abstract

624,092. Dielectric heating. RADIO CORPORATION OF AMERICA. July 12, 1946, No. 20940. Convention date, Aug. 30, 1945. [Class 39(iii)] Articles are passed along a pre-set path through an electric field whose heating effectiveness is varied at a relatively low rate between the inlet to the path and an intermediate point, and at a relatively higher rate from this point to the outlet from the path by connecting a variable inductor in parallel therewith. In an embodiment wet rayon cakes 21, Figs. 1 and 2, are advanced through electrode screens 3, 17 by a belt 23 driven by a motor 31. A fixed inductor 19, and a variable inductor formed by conductive portions 39 of copper tubing, and a bridge 41, controlled by a rod 43, are connected across and intermediate the ends of electrodes 3, 17. A capacitor, formed by screens 55 and 5 and varied to tune the circuit to resonance by raising or lowering the framework 53 by a crank 57, is connected across the outlet end of the electrodes as shown in Fig. 5. The power supply is connected by a concentric transmission line 61 to the grounded screen 3 via a strap 63 and to the variable inductor via a strap 65. E2 and E1, Fig. 6, represent the voltage distribution along the electrodes with and without the variable inductor.