Improvements in or relating to the separation of one or more constituents from a liquid or gaseous material

摘要

An apparatus for treating a gas or a liquid with a solid comprises a rotatable annular drum divided into a plurality of cells by radial partitions, each cell being provided with radial supply and discharge duct, closable ducts being also provided to convey liquid or gas from each cell to an adjacent cell in a generally circumferential manner. As shown in Fig. 1 the annular drum is divided into 18 cells each having ducts communicating (as shown with respect to cell 16) with a head 25 (Fig. 2) which rotates with the drum and co-operates with a fixed head 26. Pairs of adjacent cells are linked by flexible tubes 32 shown between cells 6 and 7, and 7 and 8. These tubes are closed in certain positions by the pinching action of rollers 33. Alternatively valves operated by compressed air or magnetically and programmed by the control heads 25 and 26 may be provided between the cells. Inlet ducts are provided with screens such as 35 to prevent solids passing into the pipes. The ducts such as 28, 29 in head 25 co-operate in certain positions with ducts 27a, 27b which are located so that a sequence of events can be performed such as that illustrated in Fig. 3 which relates to the recovery of a metal salt from a waste galvanizing liquor by means of a cation exchanger and in which the position shown is the same as in Figs. 1 and 2. In the illustrated process, the drum is periodically rotated clockwise a distance equivalent to the movement of one cell into the position previously occupied by an adjacent cell: thus when cell 18 becomes saturated it is moved into the position formerly occupied by cell 17 where the residual liquid is withdrawn (and returned to cell 1), the flexible tube between cells 1 and 18 being pinched by a roller 33 to prevent the withdrawal of liquid from cell 1. Meanwhile cell 1 which was partly saturated in the position shown is moved into the position formerly occupied by cell 18. The cation exchanger is thereafter successively washed, washing water withdrawn, dried with hot air, regenerated with an acid in a series of positions corresponding to those of cells 13-9, regenerating liquid (containing the concentrated metal salt) is withdrawn, the exchanger washed, washing water withdrawn, and the exchanger evacuated, dried and reused for adsorption of the metallic ions in positions corresponding to those of cells 4-1 and 18. A similar process is described in relation to the removal of solvent vapours from air, in which a given cell is successively charged in the position of cells 4-1 and 18, solvents removed with steam in the position of cells 17-12, dried with hot air, electric heating or steam pipes in the position of cells 11 and 10, and cooled. Rotation of the drum may be controlled by the varying physical properties of the fluid supplied and discharged e.g. thermal conductivity or light absorption (for gases) or electrical conductivity or electrode potential (for liquids). The use of the apparatus in fractional separation of two or more components in a carrier liquid or gas by means of adsorbents or ion exchangers is also referred to: different fractions may be caused to collect in separate cells and be eluted separately. For a mixture comprising a carrier gas and at least two further components to be separated, a solid impregnated with a liquid may be used as an adsorbent and the adsorbed gases may be recovered by flushing with a solvent for this liquid and separately recoving the components.