GB1086819A - Improvements in electrostatic precipitators - Google Patents

Abstract

1,086,819. Electrostatic precipitators; air filters. GENERAL ELECTRIC CO. Oct. 22, 1965 [Nov. 4, 1964], No. 44804/65. Headings BIT and B2J. An electrostatic precipitator for removing dust particles from a gas stream comprises a casing in which is provided, between the gas inlet and outlet, a filter unit, Fig. 2, comprising a grounded apertured plate 31 adjacent the gas inlet and a charging grid 32 located on the downstream side of the plate 31 and connected to a high voltage d.c. supply, the grid 32 including electrodes 37 having spikes 46 the tips of which are disposed in the apertures 35 of the plate 31, Fig. 3, (not shown), whereby an electrostatic field is established between the edge of each aperture and the corresponding electrode spike tip so as to charge the dust particles to cause them to precipitate on or move towards grounded parts of the filter unit thereby to move through porous gas-filtering media 49 and/or 52 in the unit. The plate 31 is provided on its inside surface with parallel vanes 36, Fig. 4 (not shown). The electrodes 37 are supported in parallel fashion in a frame which terminates in a bus bar 38 provided with a pair of terminals 39 and which are insulated by insulators 43 from channel members 44 which support the entire filter unit. To create an equal stress field between each electrode spike tip and the aperture edge, the tip has a square cross-section. A grid 33 provided on the downstream side of the charging grid 32 comprises parallel vanes 51. The members 31, 32, 33 are made of conductive sheet metal such as steel or aluminium. The porous filtering media between the grid 32 and the plate 31 and the grid 33 is of dielectric material such as fibreglass. When the filtering unit is assembled the members 31 and 33 are fastened together by latches 54 engaging lock pins 56. The spikes 37 then extending through the porous media and between the vanes 36 while the vanes 51 extend between the electrodes 37. In a modification the filtering media 49 may be omitted. In another modification, the media 52 and the grid 33 may be omitted. The precipitator may be used in the return air duct of a warm air furnace of an air conditioning system, Fig. 1 (not shown) or may be attached to a room air conditioner, an air circulating fanunit or a portable air circulating unit.