| 摘要 |
1325672 Coating tubes UNITED KINGDOM ATOMIC ENERGY AUTHORITY 8 July 1970 [16 July 1969] 35786/69 Heading F2P [Also in Divisions B1 and B2] A reverse osmosis membrane assembly is made by helically winding on a mandrel one or more porous fibrous tapes to produce a single or multiply tube, and continuously casting as a liquid doped a semi-permeable membrane on to the inside or outside of the tube formed on the mandrel. In the embodiment shown, a tube formed by wrapping an inner tape 30 and an outer adhesive-coated tape 31 which has passed over heater 29 around a mandrel and sealing the overlapping sections 35 by heat and pressure applied by shoe 36 is moved leftwards (as shown) while membrane dope 34 is supplied to the inner surface of the formed tube through opposed passage 27 (28). The dope may comprise formamide/acetone/cellulose acetate. The tape(s) may be of paper or synthetic woven or non-woven fibre material, for example of polyester. The mandrel assembly (Fig. 1, not shown) comprises tubular section 16 containing hollow concentric tubes 17, 18 for passage of cooling fluid and hollow centre passage 20 communicating with passages 13 and 17, 28 for passage of casting dope. The mandrel is rotated by belt 40. |
