Abstract: A fluid filter assembly and method of making is disclosed for filtering a fluid. The fluid filter assembly comprises a first filter component including a filter media comprising a matrix of metallic fibers. A second filter component includes a filter support. A sinter bond bonds the matrix of metallic fibers of the filter media to the second filter component.

Abstract: An apparatus and process for making a capacitor comprising the steps of covering a first capacitor plate element with a dielectric material. The process includes encasing the first capacitor plate element and the dielectric material with a second capacitor element. The second capacitor plate element is drawn for reducing the outer diameter thereof and for forming a capacitor element. A multiplicity of the capacitor elements are encased within a second capacitor plate connector. The second capacitor plate connector is drawn for reducing the outer diameter of the metallic tube and for electrically interconnecting the multiplicity of the second capacitor plate elements with the second capacitor plate connector to form a second capacitor plate. The multiplicity of the first capacitor elements are interconnected with a first capacitor plate connector to form a first capacitor plate.

Abstract: A method and apparatus for determining the fouling effect of a feedstream on a filter having known characteristics disclosed. The method comprises passing the feedstream through a filter (5) having known characteristics; determining the change in resistance to flow of the feedstream across the filter, either continuously or over a number of time intervals and from this data, calculating a feed fouling index (FFI) representative of the fouling characteristics of the feedstream with respect to the filter. A method and apparatus for monitoring the operation of a filtration system is also disclosed the method comprising sampling system parameter values at selected locations within the filtration system at a predetermined sampling rate; generating a parameter profile characteristic from the sampled parameter values at predetermined intervals of time; and analysing the parameter profile characteristic to determine correct operation of the filtration system.

Abstract: The present invention relates to the field of synthetic polymeric microfiltration membrane materials that are fabricated to separate liquids from solids contained therein. One aspect of the invention relates to a highly asymmetric, hydrophilic microfiltration membrane with high surface porosity. The membrane is rendered hydrophilic through co-casting the sulfone polymer with a hydrophilic polymer, such as polyvinylpyrrolidone. The membranes of the invention are highly useful in testing devices for the quick detection of properties or components contained in liquid samples, such as diagnostic applications, as well as for other filtration applications that demand relatively large pore sizes, thick membranes, high asymmetry, and/or high lateral wicking speeds.

Abstract: The present invention relates to cationically charge-modified membranes and methods of preparing such membranes. In one major aspect of the invention, the membranes are hydrophobic membranes that are treated with one or more polymeric wetting agents to render the membranes substantially hydrophilic, followed by treatment with one or more charge-modifying agents, the agents causing the membranes to possess a fixed formal positive charge. In another major aspect of the invention, a cationic membrane is formed from casting in a film a mixed polymer solution comprising a sulfone polymer and a copolymer of vinylpyrrolidone and a cationic imidazolinium compound, and quenching the film in an aqueous bath to produce a coagulated membrane. The membrane can be further cationically charge-modified with one or more charge-modifying agents.

Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.

Abstract: The present invention relates to highly asymmetric polymer membranes for ultrafiltration (UF), and to a simplified method of their manufacture. Disclosed herein are UF membranes with a high degree of asymmetry between the size of pores at the skin face of the membrane and the size of pores at the opposite face of the membrane. Asymmetry ratios of these membranes range from about 20 to about 1000. The porous support layer between the skin face and the opposite face is reticular and is substantially free of macrovoids. These membranes thus have higher flow rates than prior UF membranes. The membranes are cast from polymer dope mixes that are either homogeneous solutions or stable colloidal dispersions.

Abstract: A method for determining the concentration of a reduced or oxidized form of a redox species in an electrochemical cell (FIG. 10) of the kind comprising a working electrode (2) and a counter electrode (16) spaced from the working electrode such that reaction products from the counter electrode arrive at the working electrode, the method comprising the steps (FIG. 5) of applying (21) an electric potential between the electrodes, such that the electro-oxidation of the redox species is diffusion controlled, determining the current as a function of time, estimating the magnitude of the steady state current (23), reversing the potential, again determining current as a function of time and estimating the reverse potential steady state (25).

Abstract: The present invention relates to highly asymmetric polymer membranes for ultrafiltration (UF), and to a simplified method of their manufacture. Disclosed herein are UF membranes with a high degree of asymmetry between the size of pores at the skin face of the membrane and the size of pores at the opposite face of the membrane. Asymmetry ratios of these membranes range from about 20 to about 1000. The porous support layer between the skin face and the opposite face is reticular and is substantially free of macrovoids. These membranes thus have higher flow rates than prior UF membranes. The membranes are cast from polymer dope mixes that are either homogeneous solutions or stable colloidal dispersions.

Abstract: A failed hollow fiber is located in a membrane filtration module by supplying a gas under pressure to the space between fibers and shell, wetting the ends of fibers, and monitoring the ends of the fibers for bubble formation.

Abstract: Apparatus and methods are disclosed whereby elongate preformed thermoplastic elements are friction-welded coaxially in an end-to-end manner so that the core elements are joined integrally to one another. Most preferably, the elongate elements are perforated tubular elements formed of a thermoplastic material which are employed as core elements in the production of cylindrical melt-blown filter cartridges. As such, the integrally joined core elements can be rotated and traversed as a unit relative to a melt-blowing die during the continuous production of indefinite length cylindrical melt-blown filter cartridges.

Abstract: The present invention relates to the field synthetic polymeric microfiltration membrane materials that are fabricated to separate liquids from solids contained therein. One aspect of the invention relates to a sulfone polymer membrane with high surface porosity (high pore density) and distinctive asymmetry that can separate solids (i.e., blood cells) from a liquid (i.e., plasma) without the need for centrifugation. The membrane is further rendered hydrophilic through co-casting the sulfone polymer (which is a hydrophobic polymer) with a hydrophilic polymer, such as polyvinylpyrrolidone. Because of these properties and the fact that it requires only a small amount of the solid containing liquid (i.e., whole blood) to be applied to the larger pore surface, the membranes of the invention are highly useful in testing devices for the quick detection of properties or components contained in liquid samples, such as diagnostic applications (i.e., the detection of physiological conditions (i.e.

Abstract: A back-flushable filter cartridge includes a cylindrical exterior fluid-permeable filter media cage, a cylindrical interior fluid-permeable core element coaxially disposed within the filter media cage so as to establish therebetween an interior space, and longitudinally pleated filter media surrounding the core element and disposed in the interior space such that individual pleats thereof extend substantially radially outwardly from the core element. An annular space is established between outer longitudinal folds of the pleated filter media and the filter media cage. The pleated filter media is radially expandable into the established annular space to allow individual adjacent pleats of the pleated filter media to circumferentially separate from one another in response to fluid flowing in a radial direction from the core element toward the filter media cage.

Abstract: A process for making fine metallic fibers comprising coating a plurality of metallic wires with a coating material. The plurality of metallic wires are jacketed with a tube for providing a cladding. The cladding is drawn for reducing the outer diameter thereof. The cladding is removed to provide a remainder comprising the coating material with the plurality of metallic wires contained therein. The remainder is drawn for reducing the diameter thereof and for reducing the corresponding diameter of the plurality of metallic wires contained therein. The coating material is removed for providing the plurality of fine metallic fibers.

Abstract: A back-flushable filter cartridge includes a cylindrical exterior fluid-permeable filter media cage, a cylindrical interior fluid-permeable core element coaxially disposed within the filter media cage so as to establish therebetween an interior space, and longitudinally pleated filter media surrounding the core element and disposed in the interior space such that individual pleats thereof extend substantially radially outwardly from the core element. An annular space is established between outer longitudinal folds of the pleated filter media and the filter media cage. The pleated filter media is radially expandable into the established annular space to allow individual adjacent pleats of the pleated filter media to circumferentially separate from one another in response to fluid flowing in a radial direction from the core element toward the filter media cage.

Abstract: Highly asymmetric polyethersulfone membranes prepared from a stable, clear, homogeneous solution or stable colloidal dispersion of polyethersulfone are described. The membranes have a porous skin possessing a high density of skin pores with an average diameter of from about 0.001 micron to about 20 microns. In addition, the membrane has a porous support with an asymmetric region of gradually increasing pore diameters so that the opposite face of the membrane has an average pore diameter that is from about 50 to about 10,000 times the diameter of the skin pores.

Abstract: An electrochemical cell comprises a porous membrane (8) of electrically insulating composition, the membrane having pores (not illustrated) communicating from one side of the membrane to another, a working electrode (5) disposed on one side and a counter or pseudo-reference electrode (7) disposed on the other side. A target area (11) of one electrode is liquid permeable and extends over the surface of membrane (8) without blocking underlying pores of the membrane. Optional insulating layers (9,10) cover the electrodes (5,7) and opening defines the target area (11). Preferably, the porous membrane is impregnated with reagents, for example GOD/Ferricyanide.

Abstract: The present invention relates to the field synthetic polymeric membrane materials formed from casting polyvinylidene difluoride (PVDF) polymer solutions and/or dispersions. Membranes formed in accordance with the present invention are all highly porous. Both internally isotropic membranes and highly asymmetric PVDF membranes are disclosed. The membranes of the invention are useful in a variety of microfiltration and ultrathin applications.