GB1506492A - Apparatus for liquid extraction - Google Patents

Abstract

1506492 Liquid/liquid extraction PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 19 March 1975 [22 March 1974] 11417/75 Heading BIF Apparatus for extracting substances from a first liquid comprises supply means for separately supplying the contaminated first liquid and an immiscible second extraction liquid, a mixing piece for allowing one liquid to split of portions of the other liquid and having inputs connected to the supply means. an extraction tube 1, Fig. 4 made of a material having a higher adhesion for the one liquid 3; than the other and connected to the outlet of the mixing piece, the internal size of the tube 1 being such that only the one liquid, 3, wets the tube wall and the other liquid forms oblong drops 4, in the tube, which are completely surrounded by the one liquid and which have a cross section which is substantially equal to the local cross section of the tube, so that as the liquids flow through with an average velocity V the drops 4 which are trapped in the tube roll through the tube, whilst in the longitudinal axis of the drop a flow occurs, as shown by the long arrows, which is greater than V and extraction takes place at the contact surface of the two liquids, which surface changes constantly owing to the flow, and a separating vessel for receiving and separating the two liquids from the tube. The tube may be of P.T.F.E. and up to 4 mm in diameter. The mixing piece may be as shown in Fig. 7. The liquids may be fed to the mixing piece by pumps, or by gravity from tanks at different heights, one tank possibly acting as the separator e.g. as shown in Figs. 8b and c where in Fig. 8b, separated heavy liquid recycling down pipe 36 to pass up extraction tube 1 with light liquid from tank 9, and in Fig. 8c light liquid recycling up tube 36 passes down extraction tube 1 with heavy liquid from tank 9. The purification of water with carbon tetrafluoride is described.