Hollow fiber filter device

A hollow fiber filter device comprising:

• a filter casing, a separating plate extending across said casing for separating the casing into a filtering chamber defined on one side of said plate and a filtered liquid chamber on the other side of said plate, an inlet port extending through said filter casing and in communication with said filtering chamber, and an outlet port extending through said filter casing and in communication with said filtered liquid chamber;
• a plurality of filter modules each extending from said separating plate into said filtering chamber,
• each of said filter modules comprising a fiber bundle plate supported on said separating place, a plurality of elongated hollow fibers connected to and extending from said fiber bundle plate into said filtering chamber, said fibers having respective open first ends open to said filtered liquid chamber and respective open second ends opposite said first ends, a space forming means enclosing said second ends of said fibers and spaced therefrom for establishing a space open to said second ends that is sealed from said filtering chamber, a single pipe operatively connected to said fiber bundle plate and extending through a central portion of said plurality of fibers and between said fibers bundle plate and said space forming means for placing said space in communication with said filtered liquid chamber, and an air pipe extending through said single pipe;
• an air injection pipe in said filtering chamber for introducing air into said filtering chamber;
• an air distributor plate disposed in said filtering chamber between said modules and said air injection pipe for distributing the air introduced into said filtering chamber by said air injection pipe over an area at which said modules are disposed;
• and
• said air pipe having a closed first end, an open second end extending through said space forming means and through said air distributor plate, and plural air injection nozzles extending through and open at the exterior of said single pipe.