Abstract: Asymmetric hollow fibers having a microporous hollow fiber core comprising a polyolefin, e.g. polypropylene, and an asymmetric coating comprising a fluoropolymer, e.g. SIXEF.TM.-Durene. Optionally, the coating may also comprise glycerine which is applied prior to the fluoropolymer. The fibers are coated by wet-spinning, or alternately by dry jet-wet spinning, through a spinning jet in which a fluoropolymer-containing fluid is applied to the outer surface of the fibers as they pass through the jet. The fibers exit the jet into a water bath. If greater selectivity is needed, the fiber later may be coated with an additional layer of a highly selective material, e.g. polyvinyl alcohol, PVP, and the like.

Abstract: Normally hydrophobic fluoropolymer porous membranes having continuous pores are rendered hydrophilic by coating the pore interior with a mixture of at least one fluoroaliphatic surfactant and at least one hydrophilic but substantially water-insoluble polyurethane.

Abstract: A apparatus for separating water by pervaporation from a liquid mixture comprising isopropanol and water, which comprises (a) heating the liquid mixture, then supplying the heated mixture to a pervaporation membrane module unit using a polyimide-type separating membrane to conduct separation of the liquid mixture, recycling a part or whole of the liquid not permeated through the membrane to a feed liquid mixture, supplying a fresh feed liquid mixture to an optional place in the circulation route, and withdrawing the liquid mixture from an optional place in the circulation route, (b) controlling the amount of the liquid to be recycled among the liquid not permeated through the membrane to a level of at least 10 times by volume the amount of the fresh feed liquid mixture, and (c) controlling the difference between the liquid temperature at the inlet of the membrane module unit and the liquid temperature at the outlet of the membrane module unit to a level of at most 20.degree. C.

Abstract: A single, reverse osmosis membrane system having a double-pass, product-staged design using first and second banks of membranes in series, with excessive pressure supplied by the pump to the feed to the first bank so that the concentrate flow from the first bank will be at sufficient elevated pressure to drive a turbocharger for increasing the low pressure product flow sufficiently to pass through the second bank of membranes, the excess pressure on the first bank being balanced by increased osmotic pressure from feedback of concentrate flow from at least one of the banks to the feed supply. Preferably, part of the concentrate flow from the first bank is dried on a double drum dryer or a single drum flaker for recycle use or disposal. The membranes for the first set are high rejection, high pressure membranes. The membranes for the second set are low rejection, low pressure membranes.

Abstract: An improved shellside feed, countercurrent flow, hollow fiber membrane separation module is provided wherein one or more flow tubes are incorporated into the conventional design. The flow tubes increase the efficiency of the membrane separation module by reducing undesirable flow patterns that are present in the conventional module.

Abstract: A composite membrane which is substantially insoluble (and preferably swells no more than 10%) in acetonitrile, ethanol, hexane, toluene, N-methylpyrrolidone, dimethylsulfoxide, dimethylformamide, dimethylacetamide, and their mixtures with each other and/or with water, comprises a substrate made from copolymers or homopolymers of ethylenically unsaturated nitriles, the substrate having been subjected to the steps of: (1) insolubilizing the polymer by crosslinking; (2) coating with a silicone layer; and (3) crosslinking the silicone layer. Prior to step (2), the substrate is preferably treated with a pore protector in absence of curing agents and catalysts. The pore protector is e.g. a hydroxy-terminated polysiloxane, particularly a silanol-terminated polysiloxane; it prevents the pores from collapsing, when the support is dried during step (3), and prevents passage of the coating material deeply into the pores, thus also preventing an undue reduction of the flux of the finished membrane.

Abstract: The present invention provides a process for the ceramic filtration of contaminants from water-based cleaners by passing a feed solution of water-based cleaner and contaminants through a metal oxide membrane on ceramic support.

Abstract: A method and apparatus are disclosed for preventing bacterial contamination from being introduced into a dental patient's mouth from water flowing through a dental tool water line. A flexible water line typically used for supplying water to a dental syringe, high-speed hand piece, or ultrasonic scaler has been found to support and encourage the growth of a significant biofilm that serves as a source of bacteria. To prevent the bacteria from being introduced into a patient's mouth by water flowing through the line, and thus into the patient's system, an in-line water filter is installed within the water line supplying water to the dental tool, at a point adjacent thereto. Conventional Luer fittings on the in-line water filter facilitate its quick installation and replacement. In addition, a cap protects the sterility of the outlet port of the in-line water filter during the installation process.

Abstract: A filtration apparatus and method utilizes inner and outer walls of porous material which curve around an axis of curvature to define a narrow channel having a spiral shape. The curvature of the spiral and/or the gap width of the channel is selected to create and maintain Dean vortices within the flow of fluid along the channel to maintain good flux of filtrate through the porous walls.

Abstract: The present invention is a fluid separation module having improved permeate flow characteristics and improved space/volume requirements. Such modules comprise a hollow fiber bundle, a first and optional second tubesheet, an optional casing, a feed inlet, a permeate outlet, and a non-permeate outlet. The module is coiled, curved or bent into a useful non-linear shape which reduces the space requirements for the module essentially without diminishing the effectiveness of the fluid separation. The feed fluid is introduced to the module either in a boreside or a shellside manner. Coil, french horn, spiral or U-shaped configuration or combinations thereof are useful.

Abstract: A rotary separator is described, of the type which includes membrane packs lying in a rapidly rotating chamber, which provides ready access to the chamber to change or inspect membrane packs, as well as ready access to at least one dynamic seal. The rotary frame includes upper and lower parts (40, 42) forming a chamber (22) between them and held together by bolts. The lower part (42) is rotatably supported by a pair of bearings (60, 62), but the upper part (40) is not directly supported by bearings. A pair of concentric conduits (20, 30) extend through the lower part, but not the upper part (40). The conduits include an inner conduit in the form of a pipe whose top (86) lies slightly within the chamber and which is sealed thereat by a dynamic seal 80. The top part (40) can be readily removed to provide access to the membrane packs (44) and to the inner conduit seal (80).

Abstract: A diffusion cell to facilitate the automated removal of test aliquots of liquid from a receptor chamber of the diffusion cell so as to determine percutanous absorption through a membrane of a donor fluid from a donor chamber into the receptor chamber of the diffusion cell. There is utilized a sampling port through which the test aliquot is to be removed, the removal being achieved by means of a sample tube which is to be movable into and out of the receptor chamber. Within the receptor chamber is located a stirring device in the form of a helical coil which is to be rotated to achieve stirring and homogeneous mixing of the liquid within the receptor chamber. A refilling tube connects also with the receptor chamber to add liquid into the receptor chamber as the test aliquot has been removed. A leveling tube within the sampling port is to restore the initial preset receptor liquid volume between sampling intervals.

Abstract: Mixtures of salts of organic carboxylic acids and organic compounds of non-salt character, dissolved in a C.sub.1 -C.sub.4 alkanol, can be concentrated or separated with a semipermeable membrane made from a copolyamide or copolyimide-amide which contains(a) a first aromatic diamine radical and (b) a second aromatic diamine radical which carries--SO.sub.3 M groups, where M is H.sym., a monovalent to polyvalent metal cation or an ammonium cation. Provided the first diamine radical contains C.sub.1 -C.sub.4 alkyl groups in the o-positions to the amino groups, the copolymers are radiation-sensitive and can be used for producing protective layers or relief images, development being carried out in an aqueous alkaline medium.

Abstract: A filter useful for separating contaminants from fluids includes a fused single crystal acicular ceramic support having a discriminating layer thereon, such as a sintered, porous alpha-alumina membrane, on at least part of the support. The support is preferably composed of a non-stoichiometric acicular mullite of about 76 percent by weight Al.sub.2 O.sub.3 and about 24 percent by weight SiO.sub.2. The support can be any one of a variety of shapes, but is conveniently elongated in form and preferably includes a plurality of parallel channels through it. The support may be in either a dead-end or cross-flow configuration. In the dead-end configuration, half of the channel holes at each end are plugged in a checkerboard arrangement with the holes open at one end and plugged at the other end. In the cross-flow configuration, all channels are connected by a series of shallow slits cut in the filter, and no end plugs are used.

Abstract: An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. Because of the low pressure difference, the extraction cartridge need not have the strength to withstand significant pressure and can be made out of molded plastic for disposable use as well as stainless steel and/or machined plastic for reusability. The extraction cartridge can be removed and opened for sample access without the use of tools. The outside of the cartridge can be purged after it is installed in a heated high pressure vessel to remove contamination from its exterior. In one embodiment, the extractor includes a fraction collector for extractments, an automatic sample changer and an automatic carteidge transfer mechanism which provide completely automated extractions.

Abstract: An integrated sample extraction and separation system includes a number of substantially identical supercritical fluid extraction modules and sample separation modules connected in common to a source of supercritical fluid and modifier and to instruments for sample analysis. Each of the supercritical fluid extraction columns is provided with separate pressure and temperature controls. Preferably, each sample separation module provides the choice of sample separation by dissolving the extracted sample in solvent, by adsorption, or by size exclusion chromatography. Either the supercritical fluid or various solvents may be used as the mobile phase in the sample separation step.

Abstract: Operative fluids containing lower glycol are contacted with semi-permeable membranes under reverse osmosis conditions to permeate lower glycol to provide a reclaimed lower glycol product. Exemplary operative fluids include antifreeze solutions, heat transfer fluids, deicers, quenchants, hydraulic fluids, lubricants, solvents and absorbents.

Abstract: A method of creating a silica ceramic membrane is disclosed. The method begins with the hydrolyzing of a silicon alkoxide with ammonia until the sol is formed. The sol is dialyzed to approximately pH 8 and then acidified to approximately pH 3. The sol is then formed into a membrane by controlled evaporation followed by sintering.

Abstract: An improved faucet having a quick disconnect adapter, fitting for connecting a sink faucet, to a water purifier which has a body (22) defining three passageways for receiving and retaining three jointly sheathed resilient tubes. Each passageway has a separate function, i.e., supplying water to the purifier receiving and dumping overflow and metering waste flow. The tubes are held in place on a side connector (28) with a tube retainer (72). A quick-disconnect assembly attaches the fitting to the faucet adapter and includes a sleeve (50) with inwardly facing jaws (56) and a retracting collar (66) with a compression spring (68) permitting manual release or attachment by withdrawal of the jaws. A two-position valve (82) provides volume control for the waste flow and allows periodical flushing of deposits from the purifier.

Abstract: A cross-flow structure useful for filtering a fluid, for exchanging one or more constituents between two fluids, or for exchanging heat between two fluids, includes a body having porous partition walls defining at least one open channel extending entirely through it, and a portion of collecting fluid exiting the body through the porous partition walls, rather than through the open channel(s). The body is composed of a fused, interlocked, single crystal acicular ceramic material, preferably a non-stoichiometric acicular mullite of about 76 percent by weight Al.sub.2 O.sub.3 and about 24 percent by weight SiO.sub.2. The portion for collecting fluid exiting from the porous walls is preferably an impermeable coating, such as a glaze, substantially covering the exterior of the body, except for the areas where fluid enters the open channel(s) and exits the porous walls.