GB696060A - Method and apparatus for the electrical treatment of liquids - Google Patents

Abstract

696,060. Electrolytic treatment of liquids. FREEBORN, A. G. June 26, 1950 [July 29, 1949], No. 19978/49. Class 41. [Also in Groups VI and VIII] A method of pre-treating a liquid fed through conduiting to a consuming stage, consists in passing an electric current through the liquid across electrodes located in intimate physical relationship with the liquid, and maintaining the potential difference across the electrodes substantially constant irrespective of changes in the specific resistance of the liquid, by connecting the electrodes to a source of low E.M.F., i.e. a small fraction of one volt whilst shunting the source by a resistance which is relatively low when compared with the resistance through the liquid between the electrodes. The method may be applied to the treatment of hard water to prevent scale formation in boilers, pipes, &c., to the treatment of paper pulp liquid to give added strength to the resultant paper, to the treatment of vegetable extracts to improve their flavours 'and keeping qualities, and to stabilize or break down emulsions. As shown in Fig. 1, two hollow metal members 1, 2 each formed with a boss for connection to a pipe line, are provided with flanges 1a, 2a between which is gripped a perforated metal electrode 3. The electrode is insulated from the members 1, 2. The member 1 functioning as an electrode is connected by a terminal 11 to one pole of a source of very low E.M.F., the other pole being connected by a screw 8 to the electrode 3. A resistance 19 which is relatively low, e.g. 1 ohm or less, in relation to the resistance through the liquid between the electrodes 1, 3, is connected across the source of power. In a modification two electrodes similar to the electrode 3 are provided which are insulated from each other and are held spaced apart by means of a flanged metal member interposed between two members 1, 2. The perforated electrodes may be partly coated with an insulating medium such as vitreous enamel. In the construction shown in Fig. 4, the hollow members 1, 2 increase in crosssectional area from the remote ends 16 to the flanged adjacent ends 1a, 2a between which a perforated metal electrode 3 is clamped. Direct current, alternating current, normal or rectified, or pulsating direct current may be used in the method. Specification 487,595 is referred to.