GB885503A - Apparatus for contacting a liquid with a liquid or a particulate solid - Google Patents

Abstract

885,503. Extracts making. AVIATION, MINISTER OF. Jan. 10, 1958 [Oct. 10, 1956], No. 30852/56. Class 81 (1). [Also in Groups I and II] Apparatus for contacting two immiscible or partly immiscible components of different densities (both may be liquids or one a liquid and the other a particulate solid) in an extraction process comprises a long rectangular vessel subdivided by vertical crosswalls into a single series of alternate mixing vessels M1 to M5 and countercurrent flow displacement vessels C1 to C4, each displacement vessel between a pair of mixing vessels being connected at its bottom end to the bottom of one mixing vessel whilst its upper end is connected to the upper end of the other mixing vessel of the pair and mixing devices in the form of rotary impellers R1 to R5 in the mixing vessels. The end vessels M1 to M5 are respectively connected to the top of a separation vessel SH for the denser component and to the bottom of a separation vessel SL for the lighter component. The lighter component is supplied continuously to the vessel M1 whilst the denser component is supplied continuously to the vessel M5. When the apparatus is full of liquid and equilibrium conditions have been set-up, the components in the mixing vessels are thoroughly mixed throughout the height of the latter and the mixture is swept at the top and bottom into the adjacent displacement vessels or, in the case of the end vessels M1 and M5, also into the separator vessels SH and SL. The impellers do not produce any significant overall upward or downward flow. In each vessel C1 to C4 the lighter component will rise whilst the denser component will gravitate without separation of the components into two separate layers. The lighter component will pass through the series of mixing vessels and displacement vessels as indicated by the dotted arrows and is drawn-off from the separator SL at LL. Similarly the denser component will pass through the series in the opposite direction as indicated by the full-line arrows and is drawn-off from the separator SH at LH. The vessels C1 to C4 also serve as extraction units in the process. In modifications described with reference to Figs. 2 and 3 (not shown), the mixing vessels and displacement vessels consist of individual cylindrical or rectangular vessels linked by short straight pipes of rectangular or circular cross-sections, or the displacement vessels may each be in the form of a single S-shaped pipe connecting the bottom of one mixing vessel with the top of a succeeding mixing vessel.