Abstract: A filtration system suitable for recovering base stock from used lubricating oil and other applications passes feedstock over nano-filtration membranes in a serpentine flow. Pressure boosters installed in the openings separating consecutive stacks serve to restore lost pressure of the feedstock. As pretreatment a “knocking” non-blinding filter separates particulates from a feedstock by a knocking action that dislodges particulate matter which has come to rest on the screen. Further pretreatment includes a vacuum evaporator for flash evaporation of volatile components from a liquid and effecting the extraction of water and glycol from used engine lubricating oil. The liquid is heated or cooled when flowing over some of the surfaces to adjust for heat lost or acquired during exposure of the liquid surface to a gas or vacuum. Liquid moves on the surface of the discs under centrifugal force or a wiper blade guides the liquid as it moves over the support surface.

Abstract: A filtration system suitable for recovering base stock from used lubricating oil and other applications pass feedstock over nano-filtration membranes assembled as a stack of membranes all experiencing parallel flow. On exiting a first stack of membranes the feedstock passes through an opening in a pressure-sustaining separator plate to flow in the reverse direction past a second stack of membranes and subsequently establish a serpentine flow of feedstock through multiple stacks of membranes. The stacks of membranes all share a common pressure containment vessel. Pressure boosters installed in the flow-through openings of separator plates separating consecutive stacks can serve to restore lost pressure of the feedstock and maintain effective permeation of permeate through the membranes. A pressure control valve at the outlet to the permeate-receiving cavities of a stack can be used to adjust the trans-membrane pressure.

Abstract: A filtration system suitable for recovering base stock from used lubricating oil and other applications pass feedstock over nano-filtration membranes assembled as a stack of membranes all experiencing parallel flow. On exiting a first stack of membranes the feedstock passes through an opening in a pressure-sustaining separator plate to flow in the reverse direction past a second stack of membranes and subsequently establish a serpentine flow of feedstock through multiple stacks of membranes. The stacks of membranes all share a common pressure containment vessel. Pressure boosters installed in the flow-through openings of separator plates separating consecutive stacks can serve to restore lost pressure of the feedstock and maintain effective permeation of permeate through the membranes. A pressure control valve at the outlet to the permeate-receiving cavities of a stack can be used to adjust the trans-membrane pressure.

Abstract: The invention disclosed relates to intrinsically bacteriostatic synthetic polymer membranes, and to process for the manufacture thereof. In one embodiment, bacteriostatic metal ions are attached to a surface of a preformed synthetic polymer membrane by static adsorption/adsorption and reduced to the metal in situ. In another embodiment, the instrinsically bacteriostatic membranes are formed by providing a casting solution of a membrane forming synthetic polymer and bacteriostatic metal ions, and casting into a bath containing a reducing agent for the metal ions to form the membrane containing the metal ions incorporated therein.

Abstract: The invention disclosed relates to a process for the extraction of sweet compounds from Stevia rebaudiana Bertoni, by column extraction, followed by purification by filtration. The extraction is at temperatures in the range of 0 to 25.degree. C. Preferably, a pre-treatment step of microfiltration is used to clarify the extract. Purification is by ultrafiltration followed by nanofiltration. The filtration conditions are controlled to optimize the recovery of the sweet compounds.

Abstract: The invention disclosed is a stacked, permeable membrane assembly, comprising two clamping plates with spaced, permeable membrane assemblies between them on a simplified frame. Each membrane assembly includes a membrane support means, conveniently a rigid screen, covered by a pair of membranes. The frame is designed to retain the membrane-covered support in internal grooves. Additional membrane support plates and sealing collars are not required.

Abstract: The invention disclosed is a stacked, permeable membrane assembly, comprising two clamping plates with spaced, permeable membrane assemblies between them on a simplified frame. Each membrane assembly includes a membrane support means, conveniently a rigid screen, covered by a pair of membranes. The frame is designed to retain the membrane-covered support in internal grooves. Additional membrane support plates and sealing collars are not required.

Abstract: A stacked permeable membrane envelope assembly comprises two clamping plates with spaced, permeable membrane envelope assemblies clamped between them on frames. Each membrane envelope comprises two membrane covered, perforated plates clamped together to provide inner permeate chambers and outer feed fluid passages. Fluid distributing and permeable membrane sealing collars are provided comprising two annular plates with a radially scalloped, stiff-spring-like, channel separator ring located between them. The annular plates seal the membranes against the dished plates around feed fluid passages through the envelope assemblies while the radial scallops form passages for fluid to flow between adjacent membrane envelopes.

Abstract: This invention relates to aromatic polysulfone compounds and their manufacture. More particularly, this invention relates to functional group containing aromatic polysulfones, and their manufacture by metalation with organo-lithium compounds, of halogenated (e.g. brominated or chloromethylated) aromatic polysulfone compounds. The degree of halogenation of the starting material determines the sites that may be metalated, and the degree of metalation determines how many of these sites will be metalated. At least one of the metalated sites may be treated with an electrophile so that the lithium at that site is replaced by a residuum of the electrophile.

Abstract: Halogenation of Udel (trademark) and Radel (trademark) polysulfone occurs adily by electrophilic substitution. The reactive substitution position is situated ortho- to the aryl ether linkage in the Bisphenol-A portion of the repeat units. Halogenated polysulfones are obtained by reaction of the polymer with elemental halogen. Thus, a solution of Udel polysulfone in chloroform, treated with excess bromine at room temperature, gives dibrominated polysulfone III in high yield. The degree of substitution after 18-24 hours is typically 1.80 to 2.05 by bromine analysis. Similar results are obtained by reaction of the polymer with elemental chlorine. Lower degrees of substitution are obtained with shorter reaction times or using lesser amounts of halogen.

Abstract: A method of casting porous membranes of polymeric material is provided wherein the membrane has at least one of the following: a more homogeneous active skin layer for separation purposes with a lower molecular weight cut off, a more homogeneous active skin layer with a sharper molecular weight cut off curve, a relatively thinner active skin layer with a relatively greater flux for a given separation of a substance from a solution thereof, and relatively fewer imperfections through the active skin layer.

Abstract: A process is provided for producing aromatic polysulfones which contain repeating units of the formula: ##STR1## wherein each R is ortho to the sulfone, at least one R per polymer chain is an aliphatic or aromatic substituent, a heteroatom or heteroatom-containing group or a metal or metal-containing group, with any remainder thereof being hydrogen, R.sub.1 and R.sub.2 each represents alkyl or aryl, each R.sub.s is hydrogen, and n is zero or one. The process comprises:(a) metalating (e.g. lithiating) a polysulfone, preferably dissolved in a solvent, containing repeating units of the formula: ##STR2## wherein R.sub.1, R.sub.2, R.sub.s and n are as defined above, so as to form a metalated (e.g. lithiated) polymer containing repeating units of the formula: ##STR3## wherein R.sub.1, R.sub.2, R.sub.s and n are as defined above, at least one M per polymer chain is metal l(e.g. lithium), with any remainder thereof being hydrogen; and(b) Quenching the metalated (e.g.

Abstract: A method for the molecular filtration of predominantly aliphatic hydrocarbon liquids (e.g. spent diesel lubrication oil, crude oil or pipeline blend crude oils and heavy oils, and bitumen), wherein, at a viscosity less than 600 centipoise, the predominantly aliphatic hydrocarbon liquid is passed through a membrane, having at least a swelled outer layer on the high pressure side comprising a microporous, membrane of an aliphatic hydrocarbon liquid swellable, polysulfone compound, at a pressure differential in the range 1 to 100 atmospheres oil. The microporous membrane having been swelled in the aliphatic hydrocarbon liquid from having a molecular weight cut off less of than 20,000 when measured in an aqueous medium to, after adsorption of hydrocarbon liquid and having been swelled thereby, a molecular weight cut off less than 4,000 when measured in hydrocarbon liquid, so that oil depleted in the substance to be filtered therefrom permeates the membrane.

Abstract: Novel substituted aromatic polysulfones are disclosed which contain repeating units of the formula: ##STR1## wherein each R represents hydrogen or a substituent, such as an aliphatic or aromatic substituent, a heteroatom or heteroatom-containing group or a metal-containing group, at least one of the groups R being other than hydrogen in some repeating units of the polymer chain, R.sub.1 and R.sub.2 each represents alkyl or aryl, each R.sub.s is the same or different and represents hydrogen or one or more noninterfering substituents, and n is zero or one. The substituted polysulfones (I) are useful materials which exhibit improved or modified physical, mechanical and chemical properties, such as glass transition temperature, hydrophilicity, lipophilicity, solubility, processability or resistance to chemicals. Also disclosed are processes for the preparation of the novel compounds (I) involving lithiated intermediates.

Abstract: An aromatic ionomeric copolymer having arylether and arylsulfone linkages has been prepared by condensation of both:(a) The alkali metal bisphenate salts of 9,9-bis(4-hydroxyphenyl-fluoren-4-carboxylic acid, optionally with up to 99 mol percent of another dihydric phenol based on the combined bisphenates in the mixture;and(b) dihalodiphenylsulfones where the halogen is selected from chlorine or fluorine.The copolymers are useful inter alia as ion exchange materials and permselective membranes.A process of preparing and purifying the carboxylic acid containing bisphenol monomer is described.

Abstract: A gelation shrinkable, polymer casting solution, that has been cast on the internal surface of a tubular support is gelled using pressure gelation by supporting the tubular support with one end higher than the other and pumping gelation liquid upwardly along the tube at a velocity in the range of the order of 10 to 100 cm/second and at a pressure of at least 10 kPa gauge at all points of contact between the gelation liquid and polymer casting solution. This achieves asymmetricity of the pore structure and ensures that the cast polymer solution is continuously in contact with the tubular support as a gelled membrane. If the tubular support is a porous, tubular support, then preferably the pressure gelation is continued until gelation liquid has passed through the cast polymer solution and the porous support removing solvent and any additives from the cast polymer solution.

Abstract: An ultrafiltration and reverse osmosis module comprising a tubular casing having a plurality of tubular membrane assemblies spaced therein by spacing plates, in stepped end portions of the casing bore, and held therein by sealing plates clamped to flanges on the ends of the casing. The tubular membrane assemblies are sealed around bores in the spacing plates and boxes in the sealing plates by "O"-rings and are held against collapse by sleeves in the ends of the tubular membrane assemblies.

Abstract: Polysulfone cast films, including polyethersulfone cast films, are partially gelled with mineral acid prior to or during the conventional water gelation to control the porosity of and improve the productivity of reverse osmosis and ultrafiltration membranes thus produced. The partial gelation may be carried out prior to the water gelation by contacting the cast film with the mineral acid in a gaseous or aqueous form and the gaseous form may be diluted with air. The partial gelation may, in different embodiments, be carried out simultaneously with the conventional gelation by dissolving the mineral acid in the gelation liquid.

Abstract: A novel dual or more interconnected pumping mechanisms pump is provided herein. It comprises a first pumping mechanism within a casing. A first pumping mechanism is provided within the casing, the first pumping mechanism having an operating shaft within the casing, the operating shaft being operated by a motor. The first pumping mechanism has pumping structure so constructed and arranged as exclusively to provide a high pressure, low volume aqueous liquid flow, the first pumping mechanism having axial output. A second pumping mechanism is also provided within the casing, and is in direct liquid flow connection with the first pumping mechanism, the second pumping mechanism also having an operating shaft within the casing, the operating shaft being operated by the same motor. The second pumping mechanism has pumping structure so constructed and arranged as exclusively to provide a low pressure, high volume aqueous liquid flow.

Abstract: An improvement in the method of casting a reverse osmosis or ultrafiltration polymeric membrane on a wall of porous support having a first, high pressure side under service conditions, and a second, low pressure side under service conditions, wherein the first side is coated wih a cellulose ester casting solution to at least partially impregnate the support, solvent carrier of the casting solution is partially evaporated to leave a residue, and then residues adjacent the first and second sides are gelled with a gelation liquid comprising a monohydric alcohol. The improvement comprises gelling the residue adjacent the first side with a gelation liquid which is separate from that used to gel the residue adjacent the second side, and the monohydric alcohol mole fractions of the separate gelation liquid, and their temperatures during gelation, are chosen so that relatively larger pores are formed towards the second side of the porous support.