GB1350600A - Electro-hydraulic crushing apparatus - Google Patents

Abstract

1350600 Electrohydraulic crushers UNITED KINGDOM ATOMIC ENERGY AUTHORITY 8 Dec 1971 [30 Dec 1970] 61884/70 Heading B2A [Also in Division H1] The width of the spark gap of an electrohydrohydraulic crusher is adjusted in response to a quantity which varies with the applied voltage, so that breakdown occurs within a given voltage range. A circuit is arranged so that a substantial number of breakdowns outside the given voltage range needs to take place before the gap is adjusted. The apparatus comprises a vessel 1 of e.g. monocast nylon having electrodes 3/1 and 3/2, Fig. 5. Both electrodes may be movable but as shown 3/2 is fixed and 3/1 is secured to a worm wheel 22 running in a threaded insulating sleeve 23 whose upper end is secured to a bevel gear 24. The worm 22 is prevented from rotating with the sleeve by engagement of an insulating strip 35 with a slotted member 36 secured to the crusher enclosure 34. Rotation of the gear 24 by a motor 21 thus moves the electrode in or out of the vessel 1. E.H.T. is applied to the electrode 3/1, via a bar 32 secured to a housing 29 which contacts the electrode via a split metal bush in which the electrode is a sliding fit. The motor 21 is reversible and controlled by one or other of relays 19, 20, Fig. 4, in response to a waveform voltage developed across a resister R 1 Fig. 1. The signal is filtered, converted to a square wave, differentiated and processed in circuitry Fig. 4, so that after a preset number of pulses a signal energises one or other of the relays 19, 20. The signal used to control the gap may alternatively be the interval between the triggering of the thyratron V Fig. 1, and the occurrence of the breakdown detected, e.g. by piezo- or photo-electric means.