GB814044A - Flashover elimination in electrostatic precipitators - Google Patents

Abstract

814,044. Control systems for electrostatic precipitators. APRA PRECIPITATOR CORPORATION. March 5, 1957 [April 30, 1956], No. 7231/57. Class 38 (4). Flashovers in an electrostatic precipitator apparatus are minimized by an arrangement whereby the high voltage supply to the precipitator electrodes is periodically removed. The high voltage electrodes of an electrostatic precipitator 12 are supplied from a power supply 40 by way of thermionic valves 36 each having a control electrode 38 fed with a normal negative bias voltage from a supply line 42 and a superimposed pulse supplied from an impulse producing element such that when the electrode 38 receives an impulse the valve 36 is extinguished and the supply to the electrode removed. During the time that the supply is removed the normal ionisation may be sustained by the charge existing in the electrostatic capacity of the electrodes and the supply cables. The impulse producing element may be a saturable transformer 44 fed from a 60-cycle per second supply which produces a series of pulses having a duration of about one millisecond and an amplitude of a few hundred volts, the pulses occurring 60 times per second. Alternatively the impulse producing element may be an electronic device.