GB959655A - Improvements in or relating to electro dust separators - Google Patents

Abstract

959,655. Electrostatic separators. A. RAMMELMEYER. March 27, 1963 [April 3, 1962; Jan. 2, 1963 (2)], No. 12144/63. Heading B2J. An electrostatic dust separator comprises a container 8, Figs. 1, 2 and 3, which increases in diameter in the direction of flow and houses perforated collector electrode plates 3 disposed transversely to the flow and discharge electrodes 5 disposed between the plates. Gas containing dust particles, as it is drawn through a radially or tangentially disposed inlet 1 by a fan 16, is caused to turbulate through the perforated plates 3. The discharge electrodes, which are adjustable in the direction of flow and formed of wire elements supported by leads 6 passing through insulators 7, serve to charge the particles and generate an electrostatic field, the lines of force of which lead to the perforated plates. The coarse particles are, however, caused to fall out in the region of the first plate 114 owing to the reduction in velocity created by the widening shape of the container. The finer dust particles which collect on the plates are scraped off by spring-urged brushes or scrapers 20 which direct the dust from the plates to shoots 19, 22 and 23 as the plates are continuously rotated by a shaft 4 driven by bevel gearing 14, 15 and 17, 18 ; instead of the plates bearing on a stepped surface to provide a seal, they may project into a labyrinth sealing arrangement on the sides of the container. The shoots 19 are provided with a double inclined bottom, the upper surface being of porous ceramic material so that compressed air or nitrogen fed into the double bottom can pass through and cause the dust to flow down the incline. Figs. 5 and 8 show an arrangement in which the collector electrode plates 111-114 are stationary and the scrapers and collecting shoots revolved by a hollow shaft 115. Additional discharge electrodes may be provided above the upper plate 111 and below the lower plate 114. Scrapers 128-131 and 136-139 and shoots 132- 135 and 140-143 are supported on sleeves 117- 123 which are spaced-apart by spring means so that the scrapers are resiliently urged against the upper and lower surfaces of the plates. The hollow shaft 115 and a central shaft 149 which carries the fan 148, are driven respectively by bevel gearing 156 and 157, the shaft 149 being driven only when cleaning is to be effected ; the space 181 between the shafts carries compressed air or nitrogen to the double-bottoms of the shoots 132-135, the upper surfaces 172 being porous. The drive of the scrapers is coupled to a switch for inactivating the discharge electrodes during a cleaning operation. Several dust separators, each of a different diameter, can be connected to a central inlet duct via valved branches so that the plant can be adapted to changes of quantity or velocity of flow and permit cleaning of any one separator without interrupting the flow ; for a cleaning operation, the opening or closing of the associated inlet valve is arranged to control the scrapers, fan and voltage supply to the discharge electrodes. The dust separators may be inclined or disposed horizontally as shown in Fig. 11. In this embodiment, when the scrapers, which are carried by a shaft 306, are set in motion to clean stationary plates 302-305, a slide 322 pivoted at 323 and 324 uncovers an aperture in the bottom of the container so that a worm conveyer 320 driven by a motor 321 can discharge the dust at 327, and, if desired, to a trap. In a modification of Fig. 11, shoots are arranged below each side of the plates for directing the dust into traps which, in turn, discharge on to a conveyer. In these horizontal arrangements, the plates may be rotated and the scrapers fixed in a vertical position. Instead of using scrapers or brushes to clean the plates, vacuum, tapping or washing devices can be used.