Scalable immersed-filtration method and apparatus

Abstract

A method and apparatus for filtering a large volume fluid intake system using a modular immersed-filtration array that can be easily scaled for use in a wide variety of immersion filtering applications. The immersed-filtration array is composed of a plurality of individual filtration modules. Each filtration module has a mating end that allows the module to be coupled with a base unit or plenum via a common interface port located on the base unit. The array can be scaled in a plurality of ways.

1 . A scalable filtration array for immersion in fluid containing ichthyoplankton, comprising:
 a base configured to receive a plurality of filtration modules, wherein said base has common interface ports configured to accept a mating end of said filtration modules, and said base has corresponding numbers of common interface ports and filtration modules, and said mated common interface ports and filtration modules form a corresponding number of fluid connectors for filtrate discharge said plurality of filtration modules being configured to reduce entrainment and impingement of ichthyoplankton in said fluid.   
   
   
       2 . The scalable filtration array of  claim 1  wherein the shape of said base is selected from the group consisting of circles, rectangles, polygons, spheres, cubes, and polyhedra. 
   
   
       3 . The scalable filtration array of  claim 1  wherein said common interface ports are threaded to allow mating of said filtration modules containing a complementary threaded mating end. 
   
   
       4 . The scalable filtration array of  claim 1  wherein each of said plurals of filtration modules, comprises:
 a plurality of filter elements;   a stacking core configured to allow assembly of said filter elements into a filter stack, wherein said stacking core has a first end configured for mating to a base, and a second end configured to accept an end piece, and said filter elements form a fluid connector for filtrate discharge when said filter stack is assembled between said first end and said second end, and said fluid connector discharges said filtrate from said first end of said stacking core, and;   an adjustable compression means, wherein said compression means is located between said filter stack and said cap attachment.   
   
   
       5 . The scalable filtration array of  claim 4  wherein said adjustable compression means comprises:
 a compression plate that sits against said stack of filter elements;   a spring that sits against said compression plate, and;   an anti-torsion washer located between said spring and said end piece.   
   
   
       6 . The filtration module of  claim 1  wherein said first end is threaded to allow mating to said base. 
   
   
       7 . A method of reducing entrainment and impingement of fluid-borne ichthyoplankton, the method comprising the steps of:
 providing an immersed filtration array;   filtering fluid through a plurality of filtration modules of said immersed filtration array, wherein said filtration modules contain filter elements having a groove size of about 10 times to about 1,000 times less than the average lower diameter limit of ichthyoplankton, and;   filtering at a V i  such that the ratio of V w  to V i  is between about 2 and 25.   
   
   
       8 . The method according to  claim 7  wherein said filter element pore size is about 40 microns. 
   
   
       9 . The method according to  claim 7  wherein the ratio of V w  to V i  is about 5. 
   
   
       10 . The method according to  claim 7  wherein V i  is about 0.2 cubic feet per second.