Trisep Corporation

Peter H Knappe

Matthew Tanner

Daniel Franklin Quigg

Michael Snodgrass

Seymour S Kremen

Hans A Thomason

Ronald Paul Magnani

Sanitary elements and cartridges of high performance are described which utilize a thin surrounding tubular shell with an exterior textured surface. Through the use of an overwrap material of particular design and by wrapping an assemblage of sheets of semipermeable membrane material, permeate carrier material and feed spacer material using a high tension, a spirally wound crossflow filtration element is constructed which has a substantially cylindrical outer surface of closely controlled OD that smoothly fits within such shell and which resists telescoping as a result of its radial compression.

Sanitary spiral wound filtration cartridge

High flow, low-pressure ultrafiltration or microfiltration spiral wound membrane cartridges are used in filtration of liquid feedstocks having high suspended solids. Applications may utilize either vacuum or pumping for transmembrane drive pressure (TMP), and gas may optionally be bubbled up through the cartridges with certain feedstocks. Water permeate flux rates as high as 90 gallons per square foot per day (gfd) can be obtained at TMPs below 5 pounds per square inch. By locating each spiral wound cartridge in its own casing and supplying liquid feedstock to an open lower end of the casing, as opposed to submerging such cartridges in a tank filled with feedstock, overall low pressure performance is greatly improved. High permeate flow can be maintained for long periods of time between shutdowns for intensive cleaning. TMP is gradually increased to maintain a substantially constant rate of permeate discharge until a target is reached, indicative of solids accumulation on the membrane surface to an undesirable extent; then backflushing is effected for a short time. Discarding the hold-up volume of feedstock in the cartridge, the backflushing fluid and dislodged solids, allows production to be promptly resumed with fresh feedstock at performance at near original levels.

Low pressure filtration

A spiral wound membrane filtration element capable of being back-flushed has a permeate carrier sheet; a permeable membrane filter layer sheet adhesively bonded to the permeate carrier sheet, and a feed spacer sheet. The membrane filter layer sheet folds over the feed spacer so that the feed spacer sheet is sandwiched between two layers of the membrane filter layer sheet. The sandwich positions over the permeate carrier sheet such that the adhesive seal bonds the membrane filter layer sheet to the permeate carrier sheet. The permeate carrier sheet, the membrane filter layer sheet, and the feed spacer sheet are wrapped around a permeate collection tube. The filter element is cleaned by pressurizing the feed solution or by creating a vacuum in the permeate collection tube, and periodically introducing a pressurized back flush fluid into the permeate collection tube of the filtration element to back-flush the membrane, under a pressure and for a time sufficient to dislodge a substantial portion of the retained solids on the surface of the membrane. The membrane filter layer sheet is made by placing a casting a casting solution of a certain thickness on a passing support substrate having a Frazier air permeability between 0.1 and 10 cfm/ft . The thickness of the casting solution on the support substrate is controlled through use of a mechanical device for dispersing the casting solution. The substrate with the casting solution is then immersed into a quench bath, to allow removal of casting solution, after an air quench time that allows formation of a thin membrane film on the support substrate.

Back-flushable spiral wound filter and methods of making and using same

A novel rigid, nonporous shell for use with a spiral wound membrane filtration element that allows a controlled bypass flow between the outside of the element and the inside of an enclosing pressure housing while maintaining structural mechanical properties and tight tolerances on the outside diameter of the element allowing easy installation and removal of the cartridge.

Growing community of inventors

Santa Barbara, CA, United States of America

Peter H Knappe