Membrane filtration module with adjustable header spacing

Abstract

A membrane filtration device has a multiplicity of hollow fiber membranes, or fibers, unconfined in a shell of a module; a first header and a second header disposed in vertically spaced-apart relationship; said first header and said second header having opposed ends of each fiber sealingly secured therein, all open ends of said fibers open to a permeate-discharging face of at least one header; permeate collection means to collect said permeate, sealingly connected in open fluid communication with a permeate-discharging face of at least one of said headers; means to withdraw said permeate; said fibers, said headers and said permeate collection means together forming an integrated combination wherein said fibers are essentially vertically disposed and ends of individual fibers are potted in closely spaced-apart relationship in cured resin; with opposed faces at a fixed distance; each of said fibers having a length from 0.1% to less than 5% greater.

1 . A membrane filtration device, for withdrawing permeate from a multicomponent liquid substrate, said membrane device comprising:
 a multiplicity of hollow fiber membranes, or fibers, unconfined in a shell of a module, said fibers together having a surface area >1 m2, said fibers being swayable in said substrate and each fiber having a length >0.5 meter;   a first header and a second header disposed in vertically spaced-apart relationship;   said first header and said second header having opposed ends of each fiber sealingly secured therein, all open ends of said fibers open to a permeate-discharging face of at least one header;   permeate collection means to collect said permeate, sealingly connected in open fluid communication with a permeate-discharging face of at least one of said headers;   means to withdraw said permeate;   said fibers, said headers and said permeate collection means together forming an integrated combination wherein said fibers are essentially vertically disposed and ends of individual fibers are potted in closely spaced-apart relationship in cured resin;   said first header being upper and disposed in vertically spaced-apart relationship above said second header, with opposed faces at a fixed distance;   each of said fibers having a length from 0.1% to less than 5% greater than said fixed distance so as to permit restricted displacement of an intermediate portion of each fiber, independently of the movement of another fiber.   
     
     
         2 . A device according to  claim 1  wherein the displacement between the first and second headers is adjustable in relation to the lengths of the fiber membranes such that, in use, the fiber membranes have a length that is between 0.1% and 5% greater than the displacement between the first and second headers. 
     
     
         3 . A device according to  claim 2  further comprising a spacer means connectable to the headers and for fixing the displacement between the first and second headers. 
     
     
         4 . A device according to  claim 3  wherein the spacer means further comprises a number of mounting holes usable to change the displacement between the headers. 
     
     
         5 . A device according to  claim 3  wherein the spacer means further comprises, mounting holes spaced apart such that:
 there is available a first connection defining a first displacement between the first and second headers at which first displacement fiber membranes have a length that is 0.1% to 5% greater than the first displacement between the first and second headers; and 
 there is available a second connection defining a second displacement between the first and second headers usable after a period of use during which the membranes have shrunk at which second displacement the shrunk membranes have a length that is 0.1% to 5% greater than the second displacement between the first and second headers. 
 
     
     
         6 . The membrane filtration device of  claim 1  wherein all of the fibers, the headers and the permeate collection means are all submersible below the surface of the substrate. 
     
     
         7 . The membrane filtration device of  claim 6  wherein the permeate collection means has a fitting or outlet for connecting to a permeate pipe extending from the permeate collection means to a point above the surface of the substrate. 
     
     
         8 . The membrane filtration device of  claim 7  wherein the permeate collection means is a permeate pan or cap covering the at least one permeate discharging face. 
     
     
         9 . A membrane filtration system comprising
 (a) a tank for holding a substrate at ambient pressure during filtration;   (b) a membrane filtration device according to  claim 1  immersed below the surface of the substrate;   (c) an aeration system for producing bubbles in the substrate which contact the fibers; and,   (d) a source of suction in fluid communication with the membrane filtration device.   
     
     
         10 . The membrane filtration system of  claim 9  further comprising a backwashing system for backwashing the membrane filtration device with a liquid. 
     
     
         11 . The membrane filtration system of  claim 10  wherein the liquid is permeate. 
     
     
         12 . A membrane filtration device, for withdrawing permeate from a multicomponent liquid substrate, said membrane device comprising:
 a multiplicity of hollow fiber membranes;   a first solid body and a second solid body;   said first solid body and said second solid body having opposed ends of each membrane sealingly secured therein, all open ends of the membranes open to a permeate-discharging face of one or both solid bodies;   permeate collection means to collect said permeate, sealingly connected in open fluid communication with the or each permeate-discharging face;   wherein,   said membranes, said solid bodies and said permeate collection means together form an assembly;   the assembly is adapted to be used with said first solid body being upper and disposed in vertically spaced-apart relationship above said second solid body, with opposed faces at a vertical distance and the fibers oriented generally vertically;   each of said fibers has a length from 0.1% to less than 5% greater than the vertical distance;   the fibers, the solid bodies and the permeate collection means are submersible below the surface of the substrate; and,   the membranes are arranged in the solid bodies such that peripheries of the membranes are bounded by an elongated rectangular shape.   
     
     
         13 . The membrane filtration device of  claim 12  wherein the permeate collection means has a port for connecting to a permeate conduit adapted to extend from the permeate collection means to a point above the surface of the substrate. 
     
     
         14 . The membrane filtration device of  claim 12  wherein the permeate collection means comprises an enclosure covering the or each permeate discharging face. 
     
     
         15 . A membrane filtration system comprising
 (a) a tank for holding a substrate at ambient pressure during filtration;   (b) a membrane filtration device according to  claim 12  immersed below the surface of the substrate;   (c) an aeration system for producing bubbles in the substrate which contact the fibers; and,   (d) a source of suction in fluid communication with the membrane filtration device.   
     
     
         16 . The membrane filtration system of  claim 15  further comprising a backwashing system for backwashing the membrane filtration device with a liquid. 
     
     
         17 . The membrane filtration system of  claim 16  wherein the liquid is permeate. 
     
     
         18 . The membrane filtration system of  claim 15  wherein the source of suction communicates with the membrane filtration device through a conduit extending from the permeate collection means of the membrane filtration device to a point above the surface of the substrate. 
     
     
         19 . The membrane filtration device of  claim 12  having 30 fibers or less across the width of the peripheral boundary. 
     
     
         20 . The system of  claim 15  having a second membrane filtration device according to  claim 12  located such that long sides of the elongate rectangular shapes are adjacent to but spaced from each other.