HUT51938A - Supply unit for electrostatic dust separating filter - Google Patents

Abstract

Electric supply device includes two d.c. voltage sources (1,2) having their opposite polarity terminals (5,6) earthed, and two h.v. switches connected between the other opposite polarity terminals (6,5) of each d.c. voltage source (1,2) and the corona discharge electrode (16) of the filter (17). Also included is a control unit (40) joined by its inputs to the electrical and physical parameters sensors (49-52), and by its outputs to the h.v. switches, which are designed as triode type electron-beam valves (7,8) with hollow anode (11). Also included, additionally, are modulators (18,19) for the sign-changing (a.c.) voltage and equal in number to the number of electron-beam valves (7,8) used, and the input of each of which is connected via its own isolation transformer (38,39) to the control unit (40). - Depending on the current level of the electro-filter (17), on the voltage on the grid electrode (10) of the electron-beam valves (7,8) and the current of the modulators (18,19) output, the valves (7,8) are switched 'on' with a small voltage drop on the anode (11), less than 1kV, and then operate in the resistive mode, when the voltage fall out the anode (11) increases to the breakdown voltage level at the corona electrode (16) of the filter (17).