GB838730A - Improvements in or relating to process and apparatus for the elimination of foreign particles from gases - Google Patents

Abstract

838,730. Electrostatic precipitation. VICARD, P. G. Aug. 28, 1957 [Nov. 2, 1956 ; Feb. 1, 1957], No. 27090/57. Class 39(1). [Also in Group XII] In a method of removing foreign particles suspended in a gas the gas to be treated is sprayed with a liquid, e.g. water, at 3 to saturate the gas with the vapour of the liquid and at 4 with a mist of the liquid to supersaturate the gas before entering the throat 5 of a Venturi-tube where condensation of the liquid on the foreign particles occurs, the gas then being submitted to an ionizing electric field before the liquid condensed on the foreign particles has evaporated and ionized foreign particles being separated from the gas. In the apparatus shown in Fig. 1, the ionization of the wetted foreign particles is effected in an insulated chamber 7 which is joined to the outlet of the Venturi-tube and in which there is created an intense electric field between one or more wires or high voltage electrodes 8 and earthed surfaces 9. The ionized wetted foreign particles collect on the earthed surfaces 9 and run off through an outlet 10. The ionizing electrode may also be formed of a plurality of wires disposed normally to the gas stream. In the apparatus of Fig. 2, the electrode or electrode system 8 is extended into and through the throat of the Venturi-tube, earthed surfaces 11 and 12 being arranged as shown. The surface 11 may be perforated and precipitating surfaces 13 are provided in the insulated chamber 7. Removal of the ionized wetted foreign particles may be effected by an electrostatic precipitator, a centrifugal separator, a filter or a scrubber. In a modification a Venturitube having a succession of convergent-divergent sections is employed.