Abstract: A hollow fiber membrane suitable for blood purification is provided, which is durable to .gamma.-ray sterilization and steam sterilization and is not deteriorated by the heat sterilization and which has an excellent capacity for dialysis. The membrane is made of a polyamidimide having a particular structure and has micropores having a mean pore radius of from 10 .ANG. to 200 .ANG..

Abstract: The present invention provides a process for dissolving oxygen comprising forming a liquid membrane of an oxygen-permeable liquid on a support layer made of a hydrophobic porous material, bringing one side of the liquid membrane into contact with an oxygen-containing gas and the other side with an aqueous liquor, and thereby dissolving oxygen in the aqueous liquor; a process for culturing cells in an oxygen-containing aqueous liquor obtained by the oxygen-dissolving process; and apparatus for practicing these processes. According to the present invention, oxygen can be dissolved in an aqueous liquor efficiently and economically, and aerobic cell-culturing can be stably effected even at a high cell concentration.

Abstract: A system for removing acid from a metal-rich acid stream by diffusion dialysis. The acid stream is contacted with a water stream through an ion exchange membrane, in a series, counter-current flow contactor. The contactor is formed of a stack of layers of ion exchange membranes and impervious separators with flow-control apertures. The stack includes switch-back spacers which cause the flow to switch direction.

Abstract: An artificial pancreas system which minimizes the volume of the artificial pancreas by not encapsulating each islet is taught wherein the islets are separated and held within a polymeric matrix which is soluble in an aqueous solution below body temperature but insoluble in aqueous solutions at or above body temperature. The polymer-islet mixture is contained in a pouch having access means such as entry and exit ports. The solubility makes it possible to replace the contents of the pouch by solubilizing the matrix simply by lowering the temperature below the LCST. The pouch is constructed of a biocompatible material permeable to insulin and other substances of similar or lesser molecular weight but is impermeable to cellular and humoral components of the body immune system. The islet-polymer matrix can be functionalized to stimulate insulin secretion from the islets using insulinotropic agents such as sulfonylurea.

Abstract: Polyamide and polypyrrolone membranes for fluid separation having desirable permeabilities, solubilities, diffusivities,, high glass transition temperatures and large fractional free volumes. In particular, the membranes are the polyamide and polypyrrolone forms of hexafluoroisopropylidene-bisphthalic anhydride polymerized with 3,3',4,4' tetraaminodiphenylisopropylidene (6FDA-TADPIP) and polymerized with hexafluorotetraamine (6FDA-6FTA). Fluid separation membranes made from these polymers are described as well as a method of separating fluids using these membranes. Pure gas permeabilities and permeabilities with gas feed mixtures using the fluid separation membranes for feed pressures up to 900 psia indicate desirable permeability and no plasticization effects.

Abstract: A hollow fiber membrane module adapted to be immersed in water to provide filtered water has hollow fibers bundled in a U shape and a securing part that secures the free end portion of the hollow fiber bundle such that the free end portion communicates with a water collecting part provided adjacent to the securing part. A support member is provided inside the U-shaped end portion of the hollow fiber bundle and supports and engages the hollow fibers such that each hollow fiber has a relatively wide U-shaped end portion and the hollow fibers are dispersed over the support member. A spacer is provided near the securing part and retains the hollow fibers such that the hollow fibers extend outward of the axis of the securing part and such that longitudinally extending portions of each hollow fiber are spaced apart from each other. Thus, suspended matter entering the bundle of the hollow fibers can be easily removed by washing and there is no possibility of the hollow fibers adhering together.

Abstract: A process is described for regenerating and recycling a contaminated solution recovered from an aluminum or tin washer process wherein the contaminated solution contains contaminants comprising inorganic soils, organic soils, or both as a result of the use of the solution in the washer process, which comprises(A) regenerating said solution by(A-1) extracting said contaminants from the solution in a manner which does not substantially reduce the amount of any chemicals present in the solutions prior to use; and(A-2) selectively replenishing chemicals as required; and(B) recycling the regenerated solution to the washer process. The process of the present invention significantly reduces the amount of waste water containing chemicals which must be discarded or treated in waste treatment facilities. The process also reduces the amount of process chemicals and water necessary for maintaining the washer processes used for aluminum and tin coil and container washer processes.

Abstract: A composite membrane excelling in organic solvent resistance, heat resistance and organic vapor resistance is disclosed. The composite membrane of the present invention comprises a porous membrane including as a major constituent a polymer having a repeating unit represented by the formula (I)--Ph--S--Ph--SO.sub.2).sub.n (I)(wherein Ph represents phenyl group, n represents a natural number) and an active layer formed on said porous membrane. The composite membrane of the present invention may be used as a composite membrane for pervaporation, gas separation membrane and as a reverse osmosis membrane.

Abstract: This invention relates to cross-flow filtration and more particularly towards disposable, compact cross-flow filters and filtration methods incorporating a novel pressure-balancing arrangement comprising a flexible wall which expands and contracts in response to fluid pulsations. The invention further relates to methods of fluid concentration employing such a device to a fluid concentration system, and to methods of making such a filtration device.

Abstract: A liquid filter includes an annular filter cartridge and a combination anti-drain back and relief valve assembly. The combination valve includes a valve seat from which axially extending arms extend and a spring retainer and spring which holds a gasket against the valve seat. The gasket includes an anti-drainback portion which projects from the valve seat and a relief valve portion which is supported on the valve seat. Upon assembly the combination valve and filter element in the housing, the filter assembly is supported by the spring retainer and is forced into sealing engagement with the gasket, holding the latter against the valve seat in a gasket engaging area between the relief valve portion and the anti-drainback portion. This assembly process also removes the coil spring load from the barbs on the valve seat arms.

Abstract: A filtration medium especially useful in cross-flow type filtration systems comprising a length of porous strong substrate, preferably woven, and a thin porous membrane, such membrane being bonded to the strands of the substrate by islands of resin uniformly spaced apart and disposed generally between the substrate and the membrane. The islands of resin enhance the integrity of the composite during its use in a filtration system. A method and apparatus for the manufacture of the filtration medium is disclosed.

Abstract: This invention relates to a method for ultrafiltering heavy hydrocarbons containing detrimental qualities of metals and CCR, said method comprising feeding the heavy hydrocarbons to a first ultrafiltration stage wherein the feed is contacted with an ultrafiltration membrane thereby producing a first permeate and a first retentate and feeding the first permeate to a second ultrafiltration stage wherein the first permeate is contacted with an ultrafiltration membrane which is the same as the ultrafiltration membrane in the first ultrafiltration stage to recover a second permeate of significantly reduced metals and CCR content and a second retentate. The second permeate can be sent to subsequent ultrafiltration stages utilizing the same membrane with permeate from each such stage being used as feed to the next subsequent downstream stage.

Abstract: A method for inhibiting calcium sulfate scale formation and deposition and/or dispersing iron from a feedstream passing through a reverse osmosis system which comprises the steps of: controlling the pH of the feedstream within the range between about 6.0 to about 7.0; controlling the temperature of the feedstream within the range between about 50.degree. to about 80.degree. F.; and adding a scale inhibitor and/or iron disperant to the feedstream in an amount between about 0.002 ppm per ppm hardness (as CaCO.sub.3) of the feedstream to about 0.005 ppm per ppm hardness (as CaCO.sub.3) of the feedstream, the scale inhibitor comprising a water-soluble organic phosphonate and an N-substituted acrylamide polymer containing an amide structure as follows: ##STR1## where R.sub.2 is hydrogen or methyl, R.sub.

Abstract: A rotary filtration system comprising a device having a fluid filtration gap between a filter and a rotating member (e.g., a disc), a filter pack for use in the rotary filtration device, and a cartridge formed by structurally connecting (and optionally fluidly connecting) two or more of the filter packs is disclosed. In the filter pack, the filter lies adjacent a permeate collection member, which also desirably can support the filter. The permeate collection member has one or more passageways for collecting the permeate that flows through the filter and is connected to a permeate collection header in the device. The filter pack and device are designed so that the filter pack may be easily inserted into and removed from the device, preferably by moving the filter pack in a direction generally perpendicular to the longitudinal axis of the shaft that rotates the rotating member. Desirably the rotating member and/or filter has one or more spiral grooves in fluid communication with fluid in the gap.

Abstract: A process is set forth for the separation of one or more, more permeable components from one or more, less permeable components in a feed stream. The process suggests two membrane separation stages in series wherein the feed is introduced into the high pressure side of the first stage, the non-permeate stream from the first stage is introduced into the high pressure side of the second stage and wherein the permeate stream from the second stage is compressed and recycled to the low pressure side of the first stage.

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. In one embodiment, the extractor includes a fraction collector for extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions. To automatically perform extraction, valves for the fluids are automatically opened and closed in synchronism with the insertion and removal of the cartridges. These valves force a hard valve element into a softer valve seat with a valve stem that does not rotate significantly under the control of a rotary motor.

Abstract: A method of treating an aqueous charge liquid, such as oilfield produced waters, containing boron and solubilized hydrocarbon compounds to reduce boron concentration, which comprises water softening to remove substantially all divalent cations, raising the pH of the liquid above about 9.5, and driving the liquid through a reverse osmosis membrane.

Abstract: A frameless array unconfined in a modular shell, proves to be a surprisingly effective membrane device for withdrawing permeate from a substrate, the flux through the membranes reaching an essentially constant relatively high value because of the critical deployment of fibers of the array as a skein, arching in a buoyantly swayable generally parabolic configuration within the substrate, above at least one of the array's headers in which the terminal end portions of the fibers are potted. The length of each fiber must be greater than the direct center-to-center distance between the array's pair of headers. For use in a large reservoir, an assembly of the array and a gas distributor means has fibers preferably >0.5 meter long, which together provide a surface area >10 m.sup.2. The terminal end portions of fibers in each header are substantially free from fiber-to-fiber contact.

Abstract: This invention relates to an improved thermite coated molten metal filter. According to the invention, a molten metal filter is coated with an aqueous thermite coating slurry containing oleic acid, water-miscible surfactants, water-soluble binders, and water-soluble dispersants.

Abstract: Photographic emulsions, particularly those produced by a silver halide reaction, are concentrated and, optionally, washed in a 2-stage ultrafiltration system. The system includes a spiral wound ultrafiltration module and a plate and frame ultrafiltration module. Serial use of these two ultrafiltration systems permits the viscosity of the resulting emulsion to be increased, at commercial scale production levels, to a level suitable for curtain coating photographic substrates.