GB302725A - Improvements in or relating to the separation of materials of different physical qualities especially of raw mining products - Google Patents

Abstract

302,725. Krupp Grusonwerk Akt.-Ges., F. Dec. 21, 1927, [Convention date]. Thermionic relays.-In a process for separatng materials, particularly raw mining products, the entrance of the material into the field of an induction coil or condenser or both in one of two oscillating circuits, tuned to the same frequency and each acting on an amplifying valve, causes a phase displacement between the anode currents in the oscillating circuits, the current or voltage generated being utilized, either directly or after amplification, to control a separating apparatus. The material is passed through the field of a coil 11 or condenser 12 or both in the circuit 2 which is tuned to the same frequency as the circuit 1 each being connected to a hotcathode valve 3 acting as a high-frequency generator and each anode circuit being provided with resistances 6, 7 respectively. The current produced in the conductor 10 is transmitted through an oscillating circuit 13 and valve 14 to a transformer, the secondary circuit of which contains a glow discharge tube 16, the current through the latter being utilized to control a separating apparatus. In place of the resistances 6, 7 the primary windings of two transformers, the secondary windings of which are in opposition, may be used. With the phase displacement between the two primary currents a resulting E.M.F. is created in the secondary circuit which is transmitted to an amplifier valve in the anode circuit of which is connected the primary winding of the transformer. Specification 284,307, [Class 72 Iron &c.], is referred to.