Patent ID: 6319411
Filing Date: 2001-11-20
Classification: B01D,B01F,C02F

Abstract:
A method for removing concentrated solids from within a vertical skein of shell-less, immersed hollow fiber membranes used for the filtration of water containing suspended solids, said method comprising;i) assembling multiple skeins in side-by-side relationship in a cassette in an unrestrictive reservoir, each skein comprising multiple generally parallel arrays of vertical fiber membranes;ii) concentrating solids within skeins of the cassette by creating a differential pressure across walls of the hollow fibers to filter the water flowing in tangential flow, parallel to the surface of the membranes; and,iii) generating an oscillating movement of the cassette about its central transverse axis located above the skeins causing the cassette to travel in an arc, at a frequency sufficient to renew water around the skeins by inducing a substantially vertical flow of the water upwards or downwards through the skeins, and flow of permeate through the fibers parallel to the bubble-generated flow when the angulating vertical axis of the oscillating cassette passes through the central vertical axis.