| 摘要 |
1,120,059. Reverse osmosis desalination apparatus. GENERAL DYNAMICS CORP. 7 June, 1966 [11 June, 1965], No. 25243/66. Heading B1X. A membrane lay-up for the separation of aqueous solutions by reverse osmosis comprises a system of flaps, each of which is a sandwich of spacer material 30, membrane 34 and backing material 38 with the backing material innermost, there being one continuous sheet of membrane (suitably of cellulose acetate) through all the flaps, the flaps being wound round a central hollow mandrel which is in fluid communication with the backing material but not with the spacer material. Fig. 2 (not shown) illustrates a stage in the production of the layup from feed rolls (49), (50), and (51) of spacer material, membrane, and backing material respectively, the flaps being held in place on jig (52) by pins (46) and (56). When complete, the ends are sealed so that liquid cannot pass directly into the backing material from the spacer material, and then the flaps are wound on to the central mandrel (26), the outer diameter being inside the ring of roller pins (58). Fig. 1 (not shown) shows the unit in place in pressure shell (72). which also comprises cap (74) feed inlet (78), waste outlet (80), and product outlet (94) in communication with apertured mandrel (26) around which the lay-up is wound. The unit is wrapped with tape (70) and liquid is prevented from passing directly from the feed space to the waste outlet by a sealing ring (82). Feed liquid passes under a pressure greater than the osmotic pressure of the solution from the inlet (78) down the spacer material between the membrane folds and solvent diffuses through the membrane to the backing material whence it passes through apertures (40) into the central mandrel which is sealed at the top by plug (48). The backing material may be graphite cloth, glass felt, or sized silicon carbide or sand on plastic felt, but for pressures not exceeding 500 p.s.i. nylon, polyester, rayon, rayon viscose or acrylic fibrous material may be employed; the spacer material is suitably a woven screen grid. The lay-up and apparatus is of particular application in the desalination of brackish or sea water. |
