Method for making tubular polymeric membranes for reverse osmosis
Abstract
Abstract Tubular polymeric membranes for reverse osmosis are produced by placing a casting bob in the one of a casting tube, pouring casting solution on the casting bob, attaching a leading bob on the casting bob to form a casting solution cavity over the casting bob, causing relative movement between the casting tube on one hand and the leading bob and casting bob on the other hand so that the position of the leading bob and casting bob in the casting tube is changed to adjacent the other end thereof and a tubular polymeric membrane is cast inside the casting tube, whilst the leading bob centers the casting bob in the casting tube, circulating a gelation medium inside the cast polymeric membrane, and then removing the cast polymeric membrane from the casting tube. Preferably fresh air is circulated along the inside surface of the tubular polymeric membrane as it is being cast. A cylindrical casing may be placed in sealing engagement on the casting bob and center the casting bob, and the casting solution poured in the casing, so that with the leading bob secured to the cylindrical casing, the cylindrical casing may be moved by a winch relative to the casting bob to release the casting solution as the casting bob is drawn along the casting tube.
Inventors
- 👤 William Thayer
- 👤 Lucien Pageau
- 👤 Srinivasa Sourirajan
Bibliographic Details
Claims Analysis
Total Claims: 5References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |