Memtec America Corporation

Other

Pall Corporation

Usf Filtration & Separations Group Inc.

Usf Fultration and Separations Group Inc.

Charles S Hoffman

Robert J Schmitt

Clinton V Kopp

Steven D Barboza

Anthony C Shucosky

Timothy W Yingling

Norman F Robillard

Andrew Lewis Wright

Jonathan R Beckwith

Charles C Schuyler

Robert H Sumner

Colin Manoil

Ralph R Isberg

Michael Syvanen

A filter cartridge comprises a length-adjustable end cap attached to an end of a filter body. The end cap includes an annular seal, a spacer coaxially positioned in spaced relationship with the seal, and a connection member including a cylindrical neck in moveable sealing contact within the seal and in a snug sliding fit within the spacer and an imperforate flange including a seal on a radial outer region thereof. A method of joining an end cap to an end of a generally cylindrical filtration medium comprises positioning an annular spacer ring in a recess of a connection flange of an end cap; melting an exposed portion of the connection flange; contacting the melted exposed portion of the flange and an end of a filter body; and allowing the melted exposed portion to cool and bond the filter body to the end cap.

Length-adjustable filter cartridge end caps, filter cartridges employing, and methods of making, the same

A filter cartridge assembly includes a filter cartridge having a generally cylindrical filter medium which defines a cylindrically shaped core space, and a pair of end caps fixed to opposite ends of the filter medium. Most preferably, the filter cartridge is 'coreless' in that it is not provided with an integral support core structure. At least one of the end caps (e.g., the proximal end cap) is annular and has an interior cylindrical surface defining an interior space in alignment with the core space. A truncated generally conically shaped seal skirt is operatively associated with the annular end caps. The filter cartridge is sleeved over reusable support core structure which includes a base having a truncated conically shaped seal skirt, and a tubular perforated rigid core element fixed at one end to the base. The annular end-cap and the base of the support core structure are removably mechanically coupled to one another, most preferably by being threadably interconnected. In such a manner, the seal skirt is sealingly engaged with the seal skirt of the base. The base of the support core structure most preferably is provided with a protruding seat boss which carries seal rings (e.g., conventional O-rings). The seat boss is thereby adapted to being removably, but sealingly, seated within an internal seat cup structure of a conventional filter housing.

Filter cartridge assembly having a reusable support core structure

Substantially constant tension is maintained on a melt-blown nonwoven fibrous sheet by mounting the sheet take-up roller for longitudinal movements relative so as to accommodate the increasing diameter of the sheet material being wound convolutely on the take-up roller. Sheet tension during production is thereby maintained substantially constant by virtue of a continual increase in the longitudinal distance (in relation to the machine direction) between the fiber collection mandrel and the take-up roll. Preferably, tension control is achieved by a pneumatic pressure-regulating system which includes at least one rotatable press roller which is longitudinally fixed in position relative to the collection mandrel and is in contact with the sheet material being wound around the take-up roll. The take-up roller is pneumatically advanced toward the press roller by the pneumatic actuation of at least one air cylinder. Thus, as the diameter of the sheet material being wound around the take-up roll increases, the pneumatic ram of the air cylinder will cause the pneumatic pressure of the air cylinder to correspondingly increase. This increase in pneumatic pressure is sensed by a pneumatic pressure regulator which vents sufficiently to decrease the pneumatic pressure acting on the air cylinder to a predetermined set point pressure. In this manner, the pressure exerted on the sheet material between the positionally fixed press roller and the longitudinally movable take-up roller is maintained substantially constant during production of the nonwoven sheet material.

Apparatus and method for making melt-blown nonwoven sheets

Filtration medium is formed of a mass of nonwoven melt blown support and filtration fibers which are integrally co-located with one another. The support fibers have, on average, relatively larger diameters as compared to the filtration fibers which are integrally co-located therewith. Preferably, the filtration medium is disposed within at least one annular zone of a filtration element, for example, a disposable cylindrical filter cartridge having an axially elongate central hollow passageway which is surrounded by the filtration media. A depth filter cartridge in accordance with the present invention may thus be formed having one or more additional filtration zones (which additional filtration zones may or may not respectively be provided with integrally co-located support fibers) in annular relationship to one another. As a result of the melt blown, nonwoven fiber structure in accordance with the present invention whereby at least one filtration zone is comprised of relatively larger diameter support fibers integrally co-located with relatively smaller diameter filtration fibers, a filter cartridge having a wide range of 'engineered' physical properties (e.g., in terms of filtration, pressure drop tolerance and the like) can be provided.

Method of making filtration media having integrally co-located support

The apparatus is provided to make a melt blown fibrous medium and includes first and second melt blowing dies for respectively issuing first and second streams of melt blown fibers along first and second melt blown paths. The first and second streams are issued on a forming surface where the streams are collected to form a melt blown fibrous medium. A movable transfer surface is interposed between the first die and the forming surface in the first path so that the first stream of melt blown fibers impinges on the transfer surface in advance of the forming surface such that the first stream is transferred to and brought into contact with the second stream of melt blown fibers on the forming surface.

Apparatus for making melt-blown filtration media having integrally

Melt-blown filtration media having integrally co-located support and

An export sequence of export DNA can be identified by transforming a population of cells with a vector having a transposon that includes a structural gene encoding a detectable compound, positioned between insertion sequences. The structural gene encodes a detectable compound that, in wild-type organisms, is translated with an export peptide effective to export the compound. Since the transposon lacks DNA coding for an export sequence capable of exporting the detectable gene product, transformants that export the gene product include a DNA fusion of the transposon to export DNA from the parent cell, in a position to allow expression of the fused DNA. The transformants are analyzed to locate the export DNA or a gene comprising it, and the position of the export DNA in the cell's genome is determined; the orientation of the insertion also is determined. Having identified cell genes that naturally contain export DNA, the export DNA is cloned and fused to a gene encoding a product whose production and export are desired. For example, a cell is engineered to produce and export a desired product, to enable easier substance recovery and to improve cell tolerance for high levels of the desired product.

Export of intra-cellular substances

Growing community of inventors

Baltimore, MD, United States of America

Charles S Hoffman