摘要:
In fabricating membrane elements, and especially spiral wound membrane elements, for the separation of extraction solvents, especially N-methyl-2-pyrrolidone (NMP) from extracted oil fractions (e.g., extract of raffinate), adhesive systems consisting of specific silicone elastomers in combination with specific primers have been identified which are useful in forming the bonds necessary to produce an element, as for example, in forming the edge-seal bonds of the membrane that is used to effect the separation, in bonding the membrane leaves to the metal or plastic components of the element, and in forming a protective outer-wrap for the element.
摘要:
This invention provides spiral-wound hollow fiber membrane fabric-containing cartridges and modules for separations and other phase contact applications, including tube sheets having improved solvent resistance and mechanical durability which are fabricated by extrusion of thermoplastic resins having particular defined characteristics, and methods for making the same.
摘要:
This invention provides spiral-wound hollow fiber membrane fabric-containing cartridges and modules for separations and other phase contact applications, in which the cartridges contain a turbulence-promoting fibrous web which is substantially-co-extensive to the fabric-like array, that induces turbulent fluid flow in the shell side of the hollow fiber membrane bundle; and methods for fabricating such cartridges.
摘要:
This invention provides spiral-wound hollow fiber membrane fabric-containing cartridges and modules for separations and other phase contact applications, in which the cartridges contain baffles that induce radial feed fluid flow in the shell side of the hollow fiber membrane bundle; and methods for fabricating such cartridges.
摘要:
This invention provides spiral-wound hollow fiber membrane fabric-containing cartridges and modules for separations and other phase contact applications, in which the cartridges contain baffles that induce radial feed fluid flow in the shell side of the hollow fiber membrane bundle; and methods for fabricating such cartridges.
摘要:
Asymmetric polyimide reverse osmosis membranes of high flux and selectivity for organic liquid separations are described. These membranes are prepared from undegraded polyimide by dissolving from 14-30 wt. % of the undegraded polymer in a dual solvent system comprising a polymer pro-solvent/anti-solvent wherein the pro-solvent is DMF and the anti-solvent is dioxane, wherein the ratio of anti-solvent/pro-solvent ranges from about 10:1 or more-1:1, preferably about 8:1-1.5:1, most preferably about 7:1-3:1; the polymer-solvent mixture is spread into a thin film of the desired thickness and permitted to evaporate for a time just sufficient to permit formation of an asymmetric dense active layer, i.e., within the range 2-120 seconds, preferably 2-60 seconds, most preferably 2-20 seconds before being immersed in a gelation bath.The membranes may be fabricated in the form of sheets, tubes, hollow fibers, etc.Mixtures of organic liquids, and especially mixtures of dewaxing solvents such as ketones, aromatic hydrocarbons and mixtures thereof, halogenated hydrocarbons such as dichloromethane, dichloroethane and mixtures of such halogenated hydrocarbons with ketones or aromatic hydrocarbons or other polar dewaxing solvents and dewaxed oils, are separated after completion of dewaxing operations, using the asymmetric polyimide reverse osmosis membrane described above.