GB1335731A - Turbulence inducing electrogasdynamic precipitator - Google Patents

Abstract

1335731 Electrostatic precipitators GOURDINE SYSTEMS Inc 7 Jan 1971 904/71 Heading B2J Electro-static precipitation of particles entrained in a gas stream is achieved by charging the particles and rendering the stream turbulent by a corona discharge having a substantial component in opposition to the gas stream and passing the stream over a moving surface to which the charged particles are directed by an electric precipitation field normal to the moving surface. As shown (Figs. 1 and 8) particles 50 in an upwardly moving stream of gas are charged by an ioniser assembly 46 comprising a plurality of discharge electrode wires 302 and a porous attractor electrode screen 300. The opposing directions of movement of the particles and the corona discharge causes turbulence in the gas stream. A converging-diverging nozzle 48 imparts to the particles a velocity sufficient to overcome attractive forces between the particles and the screen 300. The charged particles are ejected into the passages between endless driven belts 20 and a passive electrode 26. The belts 20 comprise a dielectric layer with a metal backing which is earthed and the electrode 26 similarly comprises a dielectric layer on an earthed metal plate. Sets of corona discharge wires 42, 42', 42" are provided for charging the dielectric surfaces of the belts 20 with opposite polarity to the particles 50 whereby fields are set up to direct the particles towards the respective belts and retain the particles securely thereon until removed by brushes 28 which may be made either of metal or a dielectric material. The brushing may be assisted by a corona discharge. The belts 20 may travel in the same direction as, opposite to, or transverse to the gas stream. In modifications, the electrode 26 may be charged oppositely to the belts 20, four endless belts may be arranged in a single housing (Figs. 2 and 3 not shown) and a single endless belt may be wrapped serpentine fashion over a plurality of rollers to form a plurality of precipitation passages (Figs. 5 and 6 not shown) the belt being in this latter case of double sided construction and the brushing for all passages being carried out at a single lateral position. The invention is said to be efficient over a particularly wide range of particle sizes.