Abstracts of Recent Patents In the UK British Patent s~eciflcatians can be or&fed km:

Casting of polymer bead seals in filter housings

In GB 2290243 lntersep Ltd describes a filter housing in the form of a centrifugal concentrator filter unit, It is designed to be fully contain- able in a conventional cen- trifuge tube when sealed with a cap to provide a closed system centrifugal concentrator adapted to concentrate solution with- out creating external aero- sol or fluid contamination. The filter housing com- prises two mating parts which retain a filter ele- ment. The endwall forma- tion of the two housing parts defines a capillary channel into which a watery free- flowing cyanoacrylate poly- mer adhesive or sealant can be introduced from a ledge through an aperture. The adhesive will flow around the channel by ca- pillary action, to form a bead seal between the filter element and the two parts. The principle of the inven- tion is applicable to two-part filter housings generally. Date of printing by UK Of- fice: 20 Dec. 1995.

Concentrating macro- molecules in solution

In GB 2290244 V. Vassarotti describes a device for re- moving or replacing solvent in a liquid sample contain- ing macromolecules. It comprises a concentration chamber having at least one rigid wall and the oppo- site wall formed from a membrane. The membrane is permeable to the solvent. An aperture adjacent to the upper part of the chamber is provided for introduction and removal of liquid. A

pocket in the lower portion of the chamber retains a fixed volume of a concen- trated sample. An absorp- tion container is provided with absorbent material which is arranged closely adjacent to the membrane in the concentration cham- ber and is capable of ab- sorbing the solvent. The improvement in this device is that the aperture adjacent to the upper end of the concentration chamber is arranged to received and tightly fix the outlet from a detachable auxiliary upper reservoir. Inventor: V. Vas- sarotti, Date of publication: 10 Jan. 1996.

Regenerative adsorption filter bed for extractor hood

In GB 2290727 E. de Ruiter and J. Tornblom describes an odour filter for extractor hoods. It includes an ad- sorption filter bed which is regenerable by washing. The filter bed is made of a highly air-permeable sub- strate material, and has 50 to 400 g/l of adsorbent. The adsorbent has a mean par- ticle diameter between 0.2 and 2 mm. Preferably the bed is made of open-pore reticulated polyurethane foam, and the adsorbent material is activated char- coal. The adhesive may consist of organic cross- linkable polymers or alter- natively the adhesive may be a hot-melt type. Inven- tors: E. de Ruiter and J. Tdrnblom, Date of pub- lication: 10 Jan. 1996.

Fluid filtering unit

In GB 2290726 Longwail Roof Supports Ltd de- scribes a fluid filtering unit, which comprises a filter element through which fluid being filtered must pass, and a means for cleaning the filter element in situ without interruption of the filtering process. The clean- ing comprises a collector which is movable between two positions on the up- stream side of the filter element during cleaning. There is a means for urging the collector in use towards its first position, and for moving the collector on to

its second position against the pushing force. There is also a means for automati- cally connecting the collec- tor to dump filtrate at a pressure less than that of the fluid being filtered as the collector moves from its first position towards its second position. Inventors: C. Oziem and P. Elliott- Moore, Date of publication: 10 Jan. 1996.

Purifying water

In GB 2290985 Solar Dy- namics Ltd describes a mul- ti-stage apparatus for continuous wastewater fil- tration. It comprises a tank provided with a wastewater inlet pipe to supply water containing suspended so- lids to the tank, and a large-diameter outlet pipe. A second tank receives the mixture from the outlet pipe; this tank is sufficiently large to allow settling of the lar- ger suspended solids. It is provided with a lower, openable port for discharge of settled solids, and has an upper weir for discharge of partially cleared water. The surface of a continuously driven, perforated belt is positioned to receive a stream of the discharged, partially cleared water. The belt perforations are sized to enable the passage of clear water while retaining fine solids on the surface for subsequent discharge. A water collection trough is provided for water passing through the belt perfora- tions. A solids collection bin collects particles falling off the belt. Inventor: E. Sharir, Date of publica- tion: 17 Jan. 1996.

Filter assemblies

In GB 2290486 Pall Corpora- tion describes a filter as- sembly. It comprises a base, a filter element mounted on the base, and a housing connected to the base so as to enclose the filter element. The filter is connected to the housing in such a way thatthe filter is retained with the housing when the housing is re- moved from the base on disassembly. The connec- tion is such that rapid and

simple removal of the filter element from the housing can be achieved by pulling the element from the housing. Inventors: R.F. Cassidy and R.E. Short, Date of publica- tion: 3 Jan. 1996.

Filtering and shut-off valve

in VVO 96/03193 Big ‘0’ Inc describes a method and apparatus for removal of organic liquids (including liquid hydrocarbons) from an aqueous stream passing through a conduit. It com- prises interposing in the conduit a housing with a cavity of a predetermined volume, through which the aqueous stream must flow. In the cavity is a discrete, organic liquid swellable polymer absorbent having a maximum volume on swelling greater than the predetermined volume of the cavity, so that the ab- sorbent cannot reach 100% saturation. This volume lim- itation of the cavity prevents dissolution of the polymer absorbent, and permits the use of non-cross-linked polymers. The polymer pre- ferably will swell to at least four times its volume; and not be soluble in less than 20 times its volume. Inven- tors: K. Daly and R.A. Fen- ney, Publication date: 8 Feb. 7 996.

ulti-stage separation of immiscible fluids

in WO 96/02309 P. Costinel describes a compact multi- stage oil/water separator, which has applications in removing oil contaminants from bilge water in ships. The oil/water separator has two toroidal mechanical se- paration stages on the suc- tion side of a feed pump, and cyclone separation and filtration stages on the out- put side of the pump. The cyclone separation and fil- tration stages are located inside the mechanical se-, paration stages for com- pactness. The oil/water separator has built-in fail- safe operation to prevent the accidental discharge of water. Inventor: P. Costinel, Publication date: 1 Feb. 1996.