Improvements in or relating to the melting of solidified materials by high frequency electric heating

摘要

833,714. Dielectric heating. VICARS Ltd., T. & T., and NAYLOR, J. F. June 25, 1958 [March 28, 1957], No. 10115/57. Class 39(3) In a method of melting solidified material one or more blocks of the material are melted under the influence of a high frequency electric field while supported on a metallic grid constituting the lower of a pair of electrodes utilized in establishing said field. As shown, melting apparatus comprises an upper electrode 36, which may be of grid or plate form and which is suspended by insulators 37 from an aluminium screen 38 supported by ropes 39 from pulleys 40, and a lower electrode 10 which supports the material to be melted and which is of grid form constituted by spaced bars or tubes 11 supported at their ends by frame members 12 of a supporting table through which molten material may flow by gravity into an inclined tray 15 and thence to a duct 33 leading to a storage tank (not shown). The electrode 10, its insulators 17 and 31, and the tray 15 together with a lower door member 23 and an upper door member 32 form part of a unitary structure mounted upon a parallel linkage system 18, 19, 22 pivotal about horizontal axes 20 and 21 to be movable from an operable position within a housing to the loading position shown in chain dotted lines in Fig. 2. Leads 48 and 53 connect the electrodes 10 and 36 respectively to a H.F. generator 45, the former connection (Fig. 3, not shown) being broken when the electrode 10 is in the loading position. The pulleys 40 supporting the upper electrode 36 are rotatable by belts 42, 43 from a motor 44 energized by means embodied in the generator 45 to enable the electrode as a whole automatically to descend with a hunting motion to maintain a substantially constant generator output as melting progresses. One end of the upper electrode may be adjusted relatively to the other to compensate for inequalities in the electric field.