FR1455660A - Improvements to electrolysis cells - Google Patents

Abstract

1,128, 804. Electrolytic production of chlorine and hypochlorite. E. H. B. NYSTROEM. Nov. 5, 1965 [Dec.3, 1964; Dec.4, 1964], Nos.49300/64 and 49364/64. Heading C7B. Chlorine is produced by electrolysis of an aqueous chloride solution at a pressure not exceeding about 200 mm. Hg. Typically sodium or potassium chloride solution is continuously introduced into the cell and chlorine is continuously removed. Chlorine so removed or an aqueous solution of active chlorine (hypochlorite) produced by such electrolysis is added to water to be chlorinated at a rate depending on a determined property of water which has been previously chlorinated, the amount of chlorine or active chlorine solution being controlled by varying the electrolysis current. Typically in this case the electrolysis is carried out at a pressure of 1 to 10 mm. Hg. obtained by use of a jet pump employing as the jet a stream of the water to be chlorinated, the pump also removing electrolysis products from the cell. The electrolysis cell may be a tubular cathode surrounding an anode or may be of a rectangular vertical stack construction held together by I-bolts, the stack consisting in order upwardly of a plastic plate, an apertured packing piece, a graphite anode, a further apertured packing piece, a plastic frame, another apertured packing piece and a further plastic plate, the cathode of perforated iron (or an iron-containing compound) being disposed close to the anode in a holder depending from the second plastic plate. The cell temperature may be held below a value at which side-reactions occur by allowing boiling, this occurring at a temperature dependent on the pressure, and cooling tubes may also be provided.