Abstract: The present invention relates to apparatus for facilitating distribution of bicarbonate concentration for use in hemodialysis. More particularly, the present invention relates to a centralized bicarbonate concentrate circulatory system for automatically controlled distribution and recirculation of bicarbonate concentrate to service a plurality of remote hemodialysis stations while achieving necessary control of various bicarbonate concentration characteristics, including concentrations, acidity and temperature, as well as the degree of contaminants.

Abstract: A fluid filter has a bundle of hollow fibres (40) within a casing. At one end of the casing (40) there is a header (41) which has a feed passageway (55) therethrough and in communication with the interior of the casing (40) and the exterior of the fibres. The header (41) also has a filtrate passageway (64) therethrough and in communication with the open ends of the fibres.

Abstract: Charge containing dewaxed oil and dewaxing solvent (typically methyl ethyl ketone and toluene) is treated to separate dewaxing solvent by use of a separating elastomer membrane barrier of a polysiloxane which has been cross-linked as with toluene diisocyanate, adipoyl dichloride, a dialkoxy silane, or a diacetoxy silane.

Abstract: Filtering apparatus provided for separating contaminants from a fluid flow includes a hollow housing having an inlet and an outlet therein adapted to permit the flow of fluid therethrough, and a hollow, generally concave shaped, porous, self-supporting filtering membrane having an opening into the interior thereof at its base end. The filter membrane is secured in the housing intermediate the inlet and outlet, so that the fluid flow enters the interior portion of the filtering membrane through the opening at its base end and exits therefrom through the porous filtering membrane to the outlet.

Abstract: A method for recovering crystals from a slurry by supplying the slurry to a rotary sucking filter while rotating a cylindrical filter medium thereof to effect a sequence of operations of sucking filtration, washing and further sucking filtration, which method comprises conducting a sucking filtration while pressurizing the slurry side so as to maintain such a temperature and pressure that the filtrate of the rotary sucking filter will not reach a condition of supersaturation, whereby stuffing of the filter medium due to deposition of crystals from the mother liquor with increase in the slurry viscosity is prevented and the recovery of the crystals are realized efficiently over a long period of time. This method is suitable for recovering crude and purified crystals of terephthalic acid and can be applied also for the recovery of general crystilline products, such as hydroquinone, resorcin and so on from slurries of them.

Abstract: To eliminate welds when forming connections from coupling joints of membrane filter structures having two external housing plates between which a membrane filter assembly (3, 4) is positioned, one (2) of the housing plates (1, 2) is formed with a bored or milled, essentially circular recess at each one of the locations where fluid connection couplings (6-9) are to be placed, the fluid connection couplings being formed by a plug element which is clamped in sealing engagement against a sealing bottom wall surface (13) of the respective recess. To provide absolute tightness, even of molecular substances such as bacteria, tissue elements, yeasts and the like, a sealing ring, preferably an O ring (15) is placed in a groove (14) formed in the sealing wall surface (13).

Abstract: A portable ultrafiltration device is disclosed comprising a prefilter, pump, membrane filter cartridges, temperature sensors, pressure sensors, process interdiction and control means placed to detect temperature and pressure variations of a feed mixture being processed by the device, and means cooperating with said temperature and pressure means to interdict the operation of the device to prevent damage to the components. Provision is also made for an improved feed mixture pick-up tube comprising a sliding gate means for interdicting liquid pick-up from an oil/water feed mixture.

Abstract: A filter component for aiding in the removal of particulate matter from a circulating lubrication fluid. Several embodiments utilize magnetic attraction of particulate matter to remove the matter from the fluid. Removal of extremely small matter aids in the prevention of clogging of straining type filtering elements and further cleans the fluid. The magnetically attractive element will trap and remove particles which are of a size too small to be inhibited be straining type filter elements. The component can be implemented in a number of ways, alone, or in conjunction with a straining type filter element, such that the component attracts the particles away from the element and out of the fluid flow stream.

Abstract: A process and apparatus is provided in which aqueous based wastes are processed to remove solids, decant phase separated product, optimize chemically for solvent specific extraction, remove toxic metals and organics via solvent extraction and remove residual metals and organics via flocculation/filtration and adsorption with activated carbon. The system employs chemical optimization of the aqueous waste stream by the addition of reagents to optimize subsequent treatment and the addition of chelating agents which inhibit the precipitation of heavy metals so that they are maintained in the waste stream as an organometallic complex which can be extracted via carbon dioxide extraction and concentrated for recovery, recycling or final disposal.

Abstract: A biocompatible dialysis membrane for hemodialysis in the form of flat sheets, tubular sheets or hollow filaments is disclosed. The dialysis membrane comprises a mixed polysaccharide ester of acetic acid, and/or propionic acid and/or butyric acid and has a structure represented by the formula ##STR1## wherein Cell denotes the skeleton of the polysaccharide molecule without hydroxyl groups; a, b, p, and s are numbers wherein s is a maximum degreee of substitution and the following equations are satisfied: ##EQU1## with the provision that, if a=0, then p and b must be greater than 0 and, if p or b=0, then a must be greater than 0.

Abstract: A selectively water-permeable hydrolyzed membrane characterized in that it is mainly made of a material which can generate a carboxyl group by hydrolysis and that a part of the material is hydrolyzed to have carboxyl groups, which may be further coated with a hydrophilic polymer. The above membrane is useful as a selectively water-permeable membrane and is applicable not only to pervaporation and vapor permeation, but also to reverse osmosis, dehumidification of air and so on.

Abstract: Improved polymeric membranes and their method of manufacture are disclosed. The improved membranes are produced by increasing the draw ratio employed during the manufacture of the membrane. The membranes show at least substantially constant or increased selectivity and mechanical properties as the draw ratio is increased.

Abstract: A method for designing and making composite membranes having a microporous support membrane coated with a permselective layer. The method involves calculating the minimum thickness of the permselective layer such that the selectivity of the composite membrane is close to the intrinsic selectivity of the perselective layer. The invention also provides high performance membranes with optimized properties.

Abstract: The present invention is directed to an improved reverse osmosis membrane that shows surprisingly improved solute rejection and permeation properties. The membrane includes a separating layer of a polyamideurethane formed in situ by reaction of a haloformyloxy-substituted acyl haldide with a diamine-treated substrate.

Abstract: A polyethylene imine membrane which has been cross-linked by heat treating at 100.degree. C.-200.degree. C. for 3-20 minutes may be used to dewater isopropanol or methyl ethyl ketone/toluene mixtures.

Abstract: There is provided a method for treating zinc-containing sulfate solutions which comprises an acid removal for the recovery of a substantially pure sulfuric acid solution and a solution low in acid and containing the zinc and metal impurities from the sulfate solution. The acid removal is carried out by a membrane process that consists of dialysis, electrodialysis or dialysis integrated with electrodialysis. The dialyzate or diluate is subjected to a dual-circuit, side-by-side, simultaneous solvent extraction of zinc and sulfuric acid. In one circuit sulfuric acid is extracted from the dialyzate or diluate and the raffinate from the zinc extraction with an amine-containing extractant. Acid is stripped from the loaded organic with water or an alkaline substance, and is recovered as sulfuric acid or as a sulfate, preferably as ammonium sulfate.

Abstract: In the method of making a filtration unit, envelope-shaped membrane units (62) are placed in a stack, a curable liquid binder (101) is introduced between the membrane units from at least one surface of the filtration unit to a predetermined depth (a), and upon curing of the binder a layer of the binder together with the marginal portions of the edges of the membrane units embedded therein is removed, such as by surface cutting or machining, up to a depth (b) smaller than the depth (a).

Abstract: The present invention is directed to methods for using an improved reverse osmosis membrane that shows surprisingly improved solute rejection and permeation properties. The membrane includes a separating layer of a polyamideurea formed in situ by reaction of isocyanate-substituted acyl chloride and a diamine-treated microporous substrate.

Abstract: A hydrophilic polytetramethylene adipamide microporous membrane has a narrow pore-size distribution. The membrane is formed by a rapid quench process in a quench bath having solubility parameter above and 21 Hildebrands.

Abstract: The press comprises a pair of moving endless filter bands having two parallel lengths sandwiching material to be dehydrated and clamped between two presser plates each of which acts against a corresponding one of the lengths of band via a respective moving endless belt. Each presser plate is associated with at least one endless bearing chain carrying a series of wheels which are free to rotate and which are interposed between the presser plates and the associated endless belt.