GB668248A - Improvements in or relating to dielectric heating apparatus - Google Patents

Abstract

668,248. Dielectric heating. WESTING- HOUSE ELECTRIC INTERNATIONAL CO. March 27, 1950 [April 1, 1949; April 1, 1949], No. 7592/50. Class 39(iii) A dielectric heating apparatus, e.g. for grain particles 2, comprises a pair of spaced relatively insulated electrodes 24, 26 between which a H.F. electric field can be established, at least one rotatably mounted work-receiving member 6 located between them and insulated and spaced therefrom, a portion of the member(s) 6 being capacitatively coupled with one of the electrodes and on rotation moving the grain 2 between, and out of contact with, the electrodes. The member 6 is a hollow metal cylinder rotating on a shaft 12, one end being closed by an insulating member 8 having circumferential openings 10, a helical work guide 16 lying within the member 6. The stationary inner and outer electrodes are concentric with the member 6, the outer one 24 being cylindrical, and the inner 26 being cylindrical or partcylindrical and supported by insulating members 28. The member 6 is capacitatively coupled with the outer electrode 24, which is earthed, through the intervening air gap. In a modification, applicable to granular material or liquids, the workreceiving member comprises an annular chamber with its axis vertical, rotatable as before between stationary, concentric, cylindrical electrodes, Fig. 5 (not shown) The electrodes may each have concentric cylinders, or alternatively annular plates, electrically connected to them and interleaving with similar cylinders, or plates, respectively, on the work-receiving member. In a further embodiment, Fig. 10, suitable for sheet material, the workreceiving members are hollow metal rollers 35, 45 which may idle or be driven, one electrode 48, 21 respectively, being contained in each roller. The rollers 35, 45 rotate on fixed shafts 46, 27 respectively, which also support the electrodes, the rollers being insulated from the shafts which may be pressed towards each other, e.g. pneumatically. The work 3 passes between the rollers. The electrodes may be part-cylindrical and the rollers comprise longitudinal alternate conducting and insulating strips, Fig. 14 (not shown). In a further embodiment the rollers are solid, the electrodes being part-cylindrical and lying exterior of the rollers, Fig. 13 (not shown).