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INVENTIONSINFILTRATIONANDSEP Abstracts of British Patents Filter screen assembly In GB 2245191 United Wire Ltd describes a filter screen assembly. It comprises a main frame of moulded plastics material, which is subdivided by crosspieces to form sub-areas. A screen mesh is stretched over the main frame and secured around each subarea. Each sub-area incudes a snap engagement for receiving a module comprising a sub-frame bridged by mesh. If part of the main mesh is damaged, the damaged part is cut away and one or more modules are snapped into the corresponding sub-area(s). Eventually all the mesh may be replaced by modules. It is possible to patch a damaged mesh with metal sheet patches or, in the case of a multiple mesh assembly, to bond the two meshes together onsite. However, the former procedure results in diminished throughput, while the latter results in reduced efficiency of the so-called ‘blinding’ action, whereby the differential vibrations of the two meshes serve to dislodge material, tending to clog the upper mesh. (2j?.gures, 1500 words)
Particulate/liquid separation In GB 2245504 William Baguley and Timothy J. Clamp describe a means of separating particulate material from a liquid. Particulate materials, such as carbon or resin granules, are separated from a liquid - such as a slurry of ore from which the granules have absorbed metal values by pumping the mixture up a pipe and onto a frustoconical screen. The liquid then passes through the screen to a collector, and the granules Eow down the screen, either back into a tank or into a second collector for recycling. The pumping is effected by a rotary impeller or by an air lift. Vanes inhibit or allow limited rotation of the rising mixture, and a bafEe directs it down onto the screen. The pipe may have a wider portion at the top to reduce the flow velocity. (3mres, 2000 words)
Oil separation from refrigerant gas flow In GB 2245507 Savant Instruments Inc describes a means of separating oil from a refrigerant gas flow. Oil is separated from refrigerant gas downstream of a compressor by a separator. The gas is first retarded by the increasing cross-section of the lateral inlet before impinging on an internal tube, and finally reverses its direction of flow up inside the tube to the Filtratlon 81 Separation
January/February
condenser and evaporator stages. The oil thus separated is returned to the upstream side of the compressor through a filter and a coil of capillary tubing. The separator is used in singleor two-stage refrigerators. (3 figures, 3500 words)
Filter assemblies In GB 2245843 British Nuclear Fuels describes a filter module comprising a parallelepipedal housing, divided by a partition into two compartments. At least one hollow cylindrical filter element is housed in each compartment, with each filter element fitting about opening(s) in the partition. Several modules may be located in a row with openings connecting their respective compartments. End compartments and opposite end compartments are connected into a Euid Eow line, with the filter elements acting in parallel. (3Jzgures, 1250 words)
Multi-sample filtration plate In GB 2246081 Bio-Bad Laboratories describes a plate assembly for performing multiple filtration using a vacuum. It comprises an upper plate with apertures forming sample wells; a membrane sheet forms the Eoor of each well. A collection plate with individual wells is situated underneath the membrane sheet, aligned with the upper plate apertures. A drop guide plate between the membrane sheet and the collection plate guides small quantities of filtrate downward from the membrane into the collection wells. The guide plate comprises individual tubes < 2.5 mm in diameter, which project into wells and raised islands clamping the membrane sheet against the underside of the upper plate around each aperture. A first plate enables a second plate to be clamped to a third plate by screws, to form an assembly which may be latched to a lower support plate. (46 fIgu?-e.s, 4000 words)
Filter device In GB 2254800 Maschinenfabrik Hennecke GmbH describes a filter device. In the manufacture of filled plastics materials from melts or several liquid reaction components, coarse components of the fillers can be filtered out by means of a filter. This consists of a fixed housing containing a rotor. The peripheral surface forms at least one filter gap with the inner circumferential face of the housing. An inlet enters the filter gap at the side, and there is a sump outlet. Another outlet is arranged
1993
on the other side of the filter gap. Agitator blades are arranged on the rotor to clear those areas through which there is otherwise no Eow of liquid, to prevent deposits. The rotor has a circumferential groove defined between walls, the outer edges of which are toothed. Filtered plastics flow between the teeth and face of the housing, which may be formed on a replaceable living sleeve. Openings allow Eow axially through the rotor to an outlet. The sump outlet has a valve which opens periodically to discharge rejects. (3 figures, 1500 words)
Magnetic separator filters In GB 2255031 GEC Alsthom describes a filter for removing magnetic particles from a fluid stream. It comprises successive subsections along the length of the filter, each having a distributed pattern of permanent magnet particle collectors and Euid Eow apertures. This pattern is different in some subsections, so that collectors in the successive subsections together cover the whole cross-sectional area of the filter, and the apertures of the successive subsections together define meandering Euid Eow paths through the filter. In another version, a number of magnetic cubes set in aluminium discs are distributed randomly within a housing. The magnets are of high coercivity, e.g. barium hexaferrite or Sm-Co. (8jIgures, 4000 words)
Gas separator In GB 2255033 Baker Hughes describes a gas separator for an electric submersible centrifugal pump for a well. It separates the gas from the liquid components such as water and oil in the well fluid. The gas separator has a driven rotor, which has an outer cylinder, an inner hub and one or more longitudinal vanes that extend between the inner hub and the outer cylinder. Notches are formed in the upper edges of the vanes. A stationary discharge member mounted above the rotor has a skirt that extends into the notches. This defines a separate inner flow path for gas to Eow out of the separator into the well. The unseparated portions (liquid) of the well Euid Eow into a gap between skirt and housing into a second separator stage, and then into a pump intake. Supports extend radially from the discharge member, securing the discharge member in the housing. (4 $gums, 2500 words) @I
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Particulate/liquid separation In GB 2245504 William Baguley and Timothy J. Clamp describe a means of separating particulate material from a liquid. Particulate materials, such as carbon or resin granules, are separated from a liquid - such as a slurry of ore from which the granules have absorbed metal values by pumping the mixture up a pipe and onto a frustoconical screen. The liquid then passes through the screen to a collector, and the granules Eow down the screen, either back into a tank or into a second collector for recycling. The pumping is effected by a rotary impeller or by an air lift. Vanes inhibit or allow limited rotation of the rising mixture, and a bafEe directs it down onto the screen. The pipe may have a wider portion at the top to reduce the flow velocity. (3mres, 2000 words)
Oil separation from refrigerant gas flow In GB 2245507 Savant Instruments Inc describes a means of separating oil from a refrigerant gas flow. Oil is separated from refrigerant gas downstream of a compressor by a separator. The gas is first retarded by the increasing cross-section of the lateral inlet before impinging on an internal tube, and finally reverses its direction of flow up inside the tube to the Filtratlon 81 Separation
January/February
condenser and evaporator stages. The oil thus separated is returned to the upstream side of the compressor through a filter and a coil of capillary tubing. The separator is used in singleor two-stage refrigerators. (3 figures, 3500 words)
Filter assemblies In GB 2245843 British Nuclear Fuels describes a filter module comprising a parallelepipedal housing, divided by a partition into two compartments. At least one hollow cylindrical filter element is housed in each compartment, with each filter element fitting about opening(s) in the partition. Several modules may be located in a row with openings connecting their respective compartments. End compartments and opposite end compartments are connected into a Euid Eow line, with the filter elements acting in parallel. (3Jzgures, 1250 words)
Multi-sample filtration plate In GB 2246081 Bio-Bad Laboratories describes a plate assembly for performing multiple filtration using a vacuum. It comprises an upper plate with apertures forming sample wells; a membrane sheet forms the Eoor of each well. A collection plate with individual wells is situated underneath the membrane sheet, aligned with the upper plate apertures. A drop guide plate between the membrane sheet and the collection plate guides small quantities of filtrate downward from the membrane into the collection wells. The guide plate comprises individual tubes < 2.5 mm in diameter, which project into wells and raised islands clamping the membrane sheet against the underside of the upper plate around each aperture. A first plate enables a second plate to be clamped to a third plate by screws, to form an assembly which may be latched to a lower support plate. (46 fIgu?-e.s, 4000 words)
Filter device In GB 2254800 Maschinenfabrik Hennecke GmbH describes a filter device. In the manufacture of filled plastics materials from melts or several liquid reaction components, coarse components of the fillers can be filtered out by means of a filter. This consists of a fixed housing containing a rotor. The peripheral surface forms at least one filter gap with the inner circumferential face of the housing. An inlet enters the filter gap at the side, and there is a sump outlet. Another outlet is arranged
1993
on the other side of the filter gap. Agitator blades are arranged on the rotor to clear those areas through which there is otherwise no Eow of liquid, to prevent deposits. The rotor has a circumferential groove defined between walls, the outer edges of which are toothed. Filtered plastics flow between the teeth and face of the housing, which may be formed on a replaceable living sleeve. Openings allow Eow axially through the rotor to an outlet. The sump outlet has a valve which opens periodically to discharge rejects. (3 figures, 1500 words)
Magnetic separator filters In GB 2255031 GEC Alsthom describes a filter for removing magnetic particles from a fluid stream. It comprises successive subsections along the length of the filter, each having a distributed pattern of permanent magnet particle collectors and Euid Eow apertures. This pattern is different in some subsections, so that collectors in the successive subsections together cover the whole cross-sectional area of the filter, and the apertures of the successive subsections together define meandering Euid Eow paths through the filter. In another version, a number of magnetic cubes set in aluminium discs are distributed randomly within a housing. The magnets are of high coercivity, e.g. barium hexaferrite or Sm-Co. (8jIgures, 4000 words)
Gas separator In GB 2255033 Baker Hughes describes a gas separator for an electric submersible centrifugal pump for a well. It separates the gas from the liquid components such as water and oil in the well fluid. The gas separator has a driven rotor, which has an outer cylinder, an inner hub and one or more longitudinal vanes that extend between the inner hub and the outer cylinder. Notches are formed in the upper edges of the vanes. A stationary discharge member mounted above the rotor has a skirt that extends into the notches. This defines a separate inner flow path for gas to Eow out of the separator into the well. The unseparated portions (liquid) of the well Euid Eow into a gap between skirt and housing into a second separator stage, and then into a pump intake. Supports extend radially from the discharge member, securing the discharge member in the housing. (4 $gums, 2500 words) @I
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71