Methods and apparatus for removing solids from a membrane module

Abstract

A method of operating a membrane filtration module, the module including one or more membranes extending longitudinally between vertically spaced upper and lower headers into which the ends of the membranes are potted. The membranes have a permeable wall which is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall. At least one of the upper and/or lower headers has one or more openings therein and the method including flowing the feed, at least in part, through the one or more openings for application to the membrane wall. Apparatus for performing the method is also disclosed.

What is claimed is: 
     
         1 . A membrane filtration module comprising:
 one or more filtration membranes located in a vessel and extending longitudinally between vertically spaced upper headers and lower headers into which the ends of the one or more filtration membranes are potted, at least one of the upper and the lower headers having one or more openings defined therein; and   an open-ended plenum chamber positioned at a base of the membrane filtration module below the lower header and having an open lower end spaced from a port in the base of the vessel without any intervening structures therebetween, wherein the one or more openings of the at least one of the upper and the lower headers, the open lower end of the open-ended plenum chamber, and the port in the base of the vessel are vertically aligned to the one or more longitudinally extending filtration membranes.   
     
     
         2 . The membrane filtration module of  claim 1 , wherein the one or more openings are provided in the lower header and the membrane filtration module further comprises a permeate chamber in fluid communication with the upper header. 
     
     
         3 . The membrane filtration module of  claim 2 , wherein the one or more openings in the lower header, the open lower end of the open-ended plenum chamber, and the port in the base of the vessel are configured to define an uninterrupted flow path for dislodged contaminant matter to exit the membrane filtration module in a direction substantially parallel to the one or more filtration membranes. 
     
     
         4 . The membrane filtration module of  claim 3 , further comprising a source of pressure configured to apply pressure to a feed liquid within the module. 
     
     
         5 . The membrane filtration module of  claim 2 , further comprising a source of backwash fluid in fluid communication with the permeate chamber. 
     
     
         6 . The membrane filtration module of  claim 2 , further comprising a gas supply manifold configured to supply a gas to the one or more openings in the lower header. 
     
     
         7 . The membrane filtration module of  claim 5 , wherein the gas supply manifold is positioned adjacent the one or more filtration membranes and is further configured to direct gas downward into the open-ended plenum chamber. 
     
     
         8 . The membrane filtration module of  claim 7 , wherein the gas supply manifold includes a port vertically aligned to the open lower end of the open-ended plenum chamber and the port in the base of the vessel. 
     
     
         9 . The membrane filtration of  claim 8 , wherein the port is positioned below the one or more openings in the lower header. 
     
     
         10 . The membrane filtration module of  claim 1 , wherein the vessel is open to atmosphere. 
     
     
         11 . A membrane filtration system, comprising:
 a plurality of filtration modules located in a vessel, each of the plurality of filtration modules including one or more membranes having permeable walls and extending longitudinally between vertically spaced upper headers and lower headers into which the ends of the one or more membranes are potted, the lower headers having one or more openings defined therein;   a single open-ended plenum chamber in fluid communication with the one or more openings in the lower headers and having an open lower end spaced from a port in the base of the vessel without any intervening structures therebetween; and   a gas supply manifold disposed between the plurality of filtration modules and configured to direct gas downward into the single open-ended plenum chamber between the plurality of filtration modules.   
     
     
         12 . The membrane filtration system of  claim 11 , wherein the one or more openings in the lower headers, the open lower end of the single open-ended plenum chamber, and the port in the base of the vessel are vertically aligned to the one or more longitudinally extending filtration membranes. 
     
     
         13 . The membrane filtration module of  claim 12 , wherein the one or more openings in the lower headers, the open lower end of the single open-ended plenum chamber, and the port in the base of the vessel are configured to define an uninterrupted flow path for dislodged contaminant matter to exit the membrane filtration system in a direction substantially parallel to the one or more membranes. 
     
     
         14 . The membrane filtration system of  claim 13 , further comprising a source of pressure configured to apply pressure to a feed liquid in the plurality of filtration modules. 
     
     
         15 . The membrane filtration system of  claim 11 , further comprising at least one permeate chamber in fluid communication with the upper headers. 
     
     
         16 . The membrane filtration system of  claim 15 , further comprising a source of backwash fluid in fluid communication with the at least one permeate chamber. 
     
     
         17 . The membrane filtration system of  claim 11 , wherein the gas supply manifold includes a port vertically aligned to the open lower end of the single open-ended plenum chamber and the port in the base of the vessel. 
     
     
         18 . The membrane filtration module of  claim 17 , wherein the port is positioned below the one or more openings in the lower headers. 
     
     
         19 . The membrane filtration system of  claim 11 , wherein the vessel is open to atmosphere.