Method of dewatering using PTFE membrane
US4780211A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 7, 1986 |
| Grant date | Oct 25, 1988 |
| Priority date | — |
| Expiry date | Nov 7, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/05
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Membranes of highly crystalline PTFE having an average pore size between about 0.01 micron and about 0.5 micron ordinarily reject any passage of water while allowing an organic nonpolar liquid to flow therethrough. By thoroughly wetting an expanded polytetrafluroethylene membrane with isopropyl alcohol, such a membrane will selectively allow the passage of a polar liquid, for example water, therethrough while rejecting other components, including nonpolar organic liquids, such as oil, kerosene or the like, and dissolved components of fairly large molecular size. Such IPA-wetted membranes are used to separate oil-water mixtures by allowing the water to selectively permeate through the membrane. The membrane may include a 5 mil thick backing layer of nonwoven synthetic fibers. The mixture is supplied to the membrane at a pressure not greater than about 90 psig., and often very low pressures of about 5-20 psig. can be used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.