Apparatus for withdrawing permeate using an immersed vertical skein of hollow fibre membranes

Abstract

A membrane module has a first solid body having a plurality of passages extending through it and a second solid body. Hollow fiber membranes extend between the solid bodies. A permeate manifold communicates with the lumens of the membranes through their ends. The membranes are arranged into a plurality of spaced bundles in the first solid body. A passage is located between adjacent bundles. An apparatus for withdrawing permeate from a substrate has a membrane module immersed in a tank containing a substrate at ambient pressure. The module is oriented such that the solid bodies are generally vertically aligned with the second solid body above the first solid body. A source of suction is connected to the permeate manifold for withdrawing permeate. A gas distribution system supplies a gas to the passages through the first solid body. The gas may be provided continuously or intermittently during permeation.

1 . A membrane module comprising, 
 a first solid body having a plurality of passages extending through it;    a second solid body;    a plurality of hollow fiber membranes extending between the solid bodies, each of the membranes having a wall surrounding a lumen, each of the membranes having an end potted into the first solid body and another end potted into the second solid body; and,    a permeate manifold in communication with the lumens of the membranes through one of the ends of each of the membranes;    wherein,    the membranes are potted in the solid bodies so as to substantially prevent any liquid outside of the membranes from entering the permeate manifold other than through the walls of the membranes;    the membranes are arranged in the first solid body into a plurality of bundles such that adjacent bundles are spaced apart from each other in the first solid body; and,    the passages through the first solid body are arranged to include a passage between adjacent bundles.    
     
     
         2 . The membrane module of  claim 1  wherein the bundles each have a cross section having two generally parallel sides and the bundles are arranged such that the generally parallel sides of adjacent bundles are generally parallel to each other.  
     
     
         3 . The membrane module of  claim 2  wherein the passages through the first solid body are arranged to include a passage between each pair of adjacent bundles.  
     
     
         4 . The membrane module of  claim 3  wherein the passages through the first solid body are arranged to also include a passage beside an outer one of the two generally parallel sides of each of two outer bundles, wherein the outer bundles are bundles which are each adjacent to only one other bundle.  
     
     
         5 . The membrane module of  claim 1  wherein proximal faces of the solid bodies are spaced by a distance and the length of the membranes between the proximal faces of each of the membranes is between 1.001 and 1.05 times the distance.  
     
     
         6 . The membrane module of  claim 1  wherein proximal faces of the solid bodies are spaced by a distance and the length of the membranes between the proximal faces of each of the membranes is between 1.001 and 1.01 times the distance.  
     
     
         7 . The membrane module of  claim 1  further comprising a plenum connected to the first solid body in communication with the passages.  
     
     
         8 . An apparatus for withdrawing permeate from a substrate comprising, 
 a tank for containing a substrate at ambient pressure during permeation;    a membrane module of  claim 1  immersed in the tank such that the solid bodies are generally vertically aligned with the second solid body above the first solid body and such that both solid bodies are immersed in the substrate;    a source of suction connected to the permeate manifold for withdrawing permeate; and,    a gas distribution system for supplying a gas to the passages through he first solid body.    
     
     
         9 . A process for producing permeate comprising the steps of, 
 providing an apparatus according to  claim 8;     operating the source of suction while the substrate is at ambient pressure to withdraw permeate; and,    operating the gas distribution system to flow a gas through the passages.    
     
     
         10 . The process of  claim 9  wherein the gas flows generally continuously while permeate is withdrawn.  
     
     
         11 . The process of  claim 9  wherein the gas flows intermittently while permeate is withdrawn.