Abstracts of Recent Patents

Filter assembly

In WO 97/07870 Pall Cor- poration describes a filter for a subterranean environ- ment. It has an inner sup- port, and a filter body containing a filter medium fitted around the inner sup- port. There is at least one endcap welded to the inner support member, and con- nected to a lengthwise end of the filter body. The weld is substantially free of marten- site; a method is included for welding a filter with a weld bead which is substantially free of martensite. Inventor: M.B. Whitlock.

Ultrahigh efficiency filter

In WO 97/07871 Camfil de- scribe a frame made of a geopolymer. It is essentially comprised of a U-shaped section with the concavity turned inwards. The body of the filter is encased in a cast mass of geopolymer, which adheres to the inter- nal wall of the section. Such a construction provides for excellent tightness at the fixing interface of the filter body, despite the very high temperature variations that the filter may undergo. In- ventors: D. Bertin and J.-M. Boivinet.

Gas filter

In GB 2305138 Erhard Charles Andreae describes a gas filter. It has a perfo- rated rigid platform element on which is supported, in a superimposed manner, a number of flexible arc-like filter elements. A chamber is located between adjacent elements and at least some of the arc-like elements are perforated in such a way

that the gas stream passing through the filter is forced to change direction sharply when going from one cham- ber to the next. Inventor: E. C. Andreae. Date of publica- tion: 2 April 1997.

A grease trap with a filter

In GB 2305617 John Swan describes an apparatus for filtering fat/grease/other solids from waste water. It comprises a hollow hous- ing, a water permeable fil- ter unit, an inlet and an outlet for enabling filtered waste water to flow out of the housing. An air trap is provided in the housing such that a liquid seal is formed at an upstream end of the air trap so as sub- stantially to prevent air from the outlet from entering the fluid passage. The filter may be in the form of a U- shaped trough supported by two end plates. The filter may be made of wire mesh. Inventor: John Swan. Date of publication: 16 April 1997.

Glass fibre filter composite and method of making it

In GB 2305618 Jack Ray- mond Pfeffer describes a filter composite. It com- prises a first layer of glass fibres having random orien- tation, the layer being por- ous to gas flow. There is a porous mat of sufficient stiffness to support the glass filter layer during use as a filter. The mat consists of compacted glass fibres, and an additional porous layer carried by the mat to block escape of glass fibres or particles from the filter composite during gas flow. The first layer fibres have diameters between about 0.000035 and 0.00015 inch (8.9-38 x lO%m). The first layer may be tufted to increase the surface area. Inventor: J. R. Pfeffer. Date of publication: 16 April 1997.

Membrane filter unit and process of producing it

In G!3 2305619 FSM Technol- ogies Ltd describes a unit wherein at least two outer casing portions are sealed

together around a mem- brane. The unit is formed from a process whereby the two casing portions are pro- vided. A membrane is lo- cated within the casing and the casing portions are sealed together, with a blue light or UV light-curing ad- hesive. The membrane may be in the form of hollow fibre(s) and a preliminary step involving the formation of a plug of adhesive around the fibre may be present in the process. The plug of adhesive may be trimmed and then placed into the outer casing portions for sealing. Inventor: Robert Gordon Hood. Date of pub- lication: 16 April 1997.

An oil-water-gas separator with an impact deflector

In GB Patent 2305933 Na- tional Tank Co. describes an oil-water-gas separator with an impact deflector. The momentum impact ab- sorber, located in a vessel for separating an oil-water- gas mixture, comprises an inlet nozzle and a dish- shaped deflector. A number of cylindrical posts are ar- ranged circumferentially around the nozzle axis de- fining a dispersion area. The mixture passes through the nozzle and is deflected backwards to impinge against the vessel inner wall and subsequently through cylindrical posts which create tortuous flow paths. The nozzle is prefer- ably surrounded by a cy- lindrical shroud. The cylindrical posts are free of sharp edges to minimise shearing of oil droplets. The deflector absorbs the high kinetic energy of the inlet fluid and thereby mini- mises droplet shearing and damage by ‘slugs’ to the interior of the vessel. Inven- tor: M. Ft. Brown. Date of publication: 23 April 1997.

Support base for deep bed filter

In GE 2306121 Tetra Europe Ltd describes a support base for a waste liquid filter, suchasadeepbedsewage filter. It comprises a number

of metal trays filled with concrete. The trays are po- sitioned over a channel set in the filter base with small gaps between them to aliow filtered liquid to flow through them into the chan- nel. The trays may be held in place by anchors. Inven- tors: N. Dodsley and Ft. Hanson. Date of publication: 30 April 1997.

Filter with variable iiiquid head

In GB 2306122 Tetra Europe Ltd describes a waste liquid filter. It comprises a vessel having a base arranged to support a particulate media column in the vessel. Means are provided to sup- ply gas and liquid to flow along the column during normal and backwashing operation of the filter, The vessel has a first outlet ar- ranged to maintain a liquid head at a first level in the vessel during norma! op- eration and a second outlet arranged to maintain a li- quid head at a second level in the vessel during back- washing operation. The head at the second ievel may be greater to contain the media in the column during backwashing. Inven- tor: H. Rundle. Date of pub- lication: 30 April 1997.

Filter press

in WO 97/14492 JWI Inc. describes a shifter mechan- ism for a filter press. A shifter mechanism incorpo- rates a vibrating mechan- ism for effecting bumping of individual filter plates dur- ing their separation from the closed stack to assist in dislodgement of the filter cake from the individual filter plates. The vibrating device can selectively vi- brate or bump the individual filter plates responsive to the weight of the filter plate. The vibrating device will be activated only upon sensing a filter plate having a weight greater than a predeter- mined value. This indicates an undesired quantity of filter cake. Inventor: D. M. Higgins. Date of publication: 24 April 1997.