GB813070A - An electrode for use in electrostatic separation - Google Patents

Abstract

813,070. Electrostatic separation. QUAKER OATS CO. Nov. 30, 1956 [Dec. 2, 1955], No. 36670/56. Class 117 [Also in Groups XXXV, XXXVI and XL(a)] Electrostatic separation apparatus includes an electrode with means for limiting the energy of a spark which may occur when the air gap or the insulation value of the air gap through which the material being treated passes is substantially reduced. As shown, an electrode 10 comprises a tube 20 containing a bus-bar 21 and provided with a series of needle-like emission elements 25. A liquid having substantial electrical resistance is contained within the tube and preferably consists of one or more of the solutes diphenyl, diphenyl amine, thiodiphenylamine, pyridine, benzophenone, or diphenylmethane, in a solvent comprising a mixture of chlorinated phenyls and polyphenyls in polyhalogen substitution products of benzine. Connection to the positive pole of a high voltage source 16 is by means of a plug 35 engaging a member 31 having a rod 32 contacting the busbar 21. Fig. 4 shows the electrode 10 used with a grounded drum 12 on to which material to be separated is supplied from a hopper 15; a divider 14 assists in the separation of the material. In the event of the air gap F being reduced by tramp metal or its insulation being lessened by high moisture content material passing through it, the energy level of any spark which may be produced is restricted by the degree of electric isolation provided by the liquid between one emission element and another. The proportions of the solutes and solvent for the liquid are chosen to provide the required current flow from the bus-bar to the elements 25. In a modification, Fig. 5 (not shown), the bus-bar is a cylindrical member with which the plug connector directly engages.