Memtec America Corporation

Usf Filtration & Separations Group Inc.

Anthony C Shucosky

Steven D Barboza

Clinton V Kopp

Robert J Schmitt

William P Seeley

Charles S Hoffman

Lillo C Brocato

Charles Hoffman, Jr

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.

Back-flushable filter cartridge and method of back-flushing same

A pleated, all poly(tetra-fluoro ethylene) filter element (20) incorporating a poly(tetra-fluoro ethylene) filter membrane (24) is shown and described. The membrane is supported by an all poly(tetra-fluoro ethylene) paper (26) and (28), which permits filtrate to pass through the paper and across the poly(tetrafluoro ethylene) membrane. A sandwich is formed by placing a layer of poly(tetra-fluoro ethylene) filter membrane (24) between the two layers of poly(tetra-fluoro ethylene) support paper, (26) and (28), and the sandwich is then pleated prior to assembly around a core (14) and between end caps (12) and (18), which are bonded to the poly(tetra-fluoro ethylene) paper and poly(tetrafluoro ethylene) filter membrane by a hot-melt process.

Pleated poly(tetra-fluoro ethylene) filter cartridge

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

Filter cartridges having nonwoven melt blown filtration media with

In critical filtration applications, filter cartridges are employed to replace ion exchange resin precoat filters to minimize the waste produced. The filter cartridges are backwashed with all gas and the liquid in the filter housing provides an active scouring effect as a result of the high levels of turbulence produced. The liquid, with entrained debris from the filter is minimized in volume.

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Timonium, MD, United States of America

Anthony C Shucosky