Zenon Environmental Inc.

Robert W Langerak

Paul B Koehler

Hamid R Rabie

Fernando A Tonelli

Steven Kristian Pedersen

Pierre C&ocirc;t&eacute;

Denis Guibert

Radu Apostolache

Christian Gungerich

Marshal Deane

An element of immersed, suction driven, filtering membranes has a plurality of hollow fiber membranes suspended between upper and lower headers. The lower header is movable between a first position in which the fibers are substantially elongated and second position in which the two headers are closer to each other by between 1 and 4% of the un-potted length of the membranes. The weight of the lower header is sufficient to keep the lower header in the first position in substantially quiescent water while allowing the lower header to rise to the second position in upwardly flowing water. Aerators are mounted generally below the elements and supply scouring bubbles to each element at a higher rate and then at a rate less than one half of the higher rate in repeated cycles. The cycles are preferably between 10 seconds and 60 seconds in duration. The lower header rises to the second position when bubbles are supplied at the higher rate and falls to the first position when bubbles are supplied at the lower rate.

Aerated immersed membrane system

To pot membranes in a header, a dense, viscous liquid, suspension or, preferably, a thixotropic, water soluble gel, is placed in a header pan in space reserved for a permeate channel. A plurality of hollow fiber membranes are collected together and their open ends are inserted into the gel. A fixing liquid, typically a resin, is placed over the gel. The fixing liquid surrounds each membrane and then solidifies, simultaneously sealing the outer surfaces of the membranes and forming a plug in the opening of the header to complete the permeate channel. After the fixing liquid has solidified, the gel is removed by various means. The space initially occupied by the gel becomes part of the permeate channel after the gel is removed. In one embodiment, membranes are grouped by a cushioning adhesive which later surrounds the membranes where they exit the completed header.

Gel potting method and method to reduce twinning for filtering hollow fiber membranes

A tubular membrane module for example for use in ultrafiltration has a tubular shell made of standard PVC pipe provided with moulded PVC end fittings that are secured to the pipe by epoxy resin adhesive. A membrane tube within the shell extends between the end fittings and is secured by a similar adhesive in respective sockets within the end fittings. Each socket has a blind end that receives the end portion of the membrane tube so that the tube is protected from shear effects due to fluid entering the tube under pressure in use.

Tubular membrane module

A tubular membrane module for example for use in ultrafiltration has a tubular shell made of standard PVC pipe and moulded PVC end fittings. A series of membrane tubes within the shell extend between coupling members at both ends. The coupling members fit closely inside the shell and end fittings and are secured in place using epoxy adhesive. A transverse wall in each coupling member is provided with sockets which receive the ends of the tubes and in which the tubes are secured by a similar adhesive. Each socket has a blind end that receives the end portion of the tube so that the tube is protected from shear effects due to fluid entering the tube under pressure in use.

A tubular membrane module for use in ultrafiltration or microfiltration has a bundle of membrane tubes that extend between inlet and return headers. The inlet header is fixed to one end of a tubular housing having a permeate outlet while the return header is free to float longitudinally of the housing to accomodate dimensional changes in the tubes with respect to the housing. The tubes are sealed at their ends in sockets in respective potting collars but are mechanically secured and sealed to the headers. The sockets are undercut to protect the membranes from stripping due to fluid shear.

Growing community of inventors

Burlington, Canada

Robert W Langerak