Formed sheet membrane element and filtration system
A piece of substrate material is formed under heat and pressure against a cavity into a shaped substrate sheet having one or more depressions. Two substrate sheets are bonded together to form a substrate wherein the one or more depressions form one or more interior channels. The substrate, if not formed with pre-coated substrate material, is coated with a dope and quenched to form a filtering membrane. A plurality of membranes may be placed side by side to form a bundle with permeating ends of the membrane, which are open to the one or more interior channels, separated by gaps or spacers. The bundle is connected to a header to produce a module. The module can be assembled into a cassette.
1 . A device comprising,
two sheets of a substrate material, at least one of the sheets of substrate material having depressions defined by its inner surface, the depressions extending to an edge of the at least one of the sheets of substrate material, the two sheets of substrate material having their inner surfaces bonded to a sheet form insert along outer edges of the two sheets, and along one or more lines between the depressions of the at least one of the sheets, wherein the outer surfaces of the two sheets of substrate material are coated with a filtration membrane material,
whereby the depressions form internal channels between the two sheets of substrate material, the internal channels being open to at least one of the outer edges of the at least one of the sheets of substrate material.
2 . The device of claim 1 wherein the filtration membrane material has a pore size in the microfiltration range or smaller.
3 . The device of claim 1 wherein the depressions are generally semi-cylindrical in cross section and separated by generally flat portions of the substrate material.
4 . The device of claim 1 wherein the substrate material is a non-woven textile.
5 . The device of claim 1 wherein the two sheets of a substrate material are bonded to the insert by a thermoplastic or a resin, or by welding.
6 . The device of claim 1 wherein the insert is between the entire area of the two sheets.
7 . The device of claim 1 wherein the insert is a non-woven sheet.
8 . The device of claim 1 wherein the internal channels are permeate channels.
9 . The device of claim 1 wherein the insert is a solid film.
10 . The device of claim 7 wherein the insert is a non-woven sheet of a three dimensional matrix of polyamide (PA, nylon) fibers.
11 . The device of claim 1 , wherein the insert is a rigid insert.
12 . The device of claim 9 wherein the solid film is a solid film of mylar.
13 . The device of claim 1 wherein the insert is porous.
14 . The device of claim 5 , wherein the welding is laser welding.
15 . A filtration module comprising a bundle of a plurality of the device of claim 1 .
16 . The filtration module of claim 15 wherein edges of the devices that are open to the one or more internal channels are potted into a header.
17 . The filtration module of claim 16 wherein the internal channels are generally parallel to each other and generally perpendicular to the header.
18 . The filtration module of claim 16 wherein the header is mounted in a cassette frame adapted to hold the filtration device in a tank with the header oriented vertically, the internal channels oriented horizontally, and with vertical gaps between adjacent devices.
19 . The filtration module of claim 15 wherein a filtration membrane material is coated on outer surfaces of the device.