Filtering apparatus and process

Claim 1

APPARATUS FOR FILTERING CONTAMINATING SOLIDS AND RECLAIMING HEAT FROM A HEATED AQUEOUS EFFLUENT IN THE COURSE OF CONDITIONING THE EFFLUENT IN SUBSTANTIAL PART FOR REUSE, SAID APPARATUS COMPRISING A PLURALITY OF FILTER UNITS EACH OF WHICH COMPRISES AN ELONGATE CYLINDRICAL HOUSING HAVING A TUBULAR FILTER CARTRIDGE DISPOSED IN FIXED RELATION COAXIALLY AND SUBSTANTIALLY COEXTENSIVELY THEREIN AND PROPORTIONED IN CROSS SECTION TO LEAVE AN ANNULAR CIRCULATION SPACE ABOUT SAID CARTIDGE WITHIN SAID HOUSING, MEANS FOR SUPPLYING SAID EFFLUENT CONTINUOUSLY TO SAID FILTER UNITS IN PARALLEL, SAID SUPPLY MEANS BEING ARRANGED FOR DELIVERING EFFLUENT TRANGENTIALLY INTO SAID CIRCULATION SPACE AT A PLURALITY OF POINTS SPACED LENGTHWISE OF THE HOUSING OF EACH FILTER UNIT, MEANS FOR CARRYING OFF FILTERED EFFLUENT FROM THE OUTLET SIDE OF EACH FILTER UNIT OF SAID PLURALITY, MEANS FOR RECIRCULATING RESIDUAL UNFILTERED EFFLUENT FROM THE INLET SIDE TO SAID FILTER UNIT SUPPLY MEANS WHICH COMPRISES A DRAIN LINE FROM EACH FILTER UNIT CONNECTED TO A COMMON MANIFOLD HAVING A RECIRCULATING LINE RUNNING THEREFROM TO SAID FILTER UNIT SUPPLY MEANS AND HAVING A COMMON DRAIN LINE FITTED THEREAT, SAID COMMON DRAIN LINE BEING VALVED FOR THROTTLING TO FORCE RECIRCULATION OF A PREDOMINANT PORTION OF UNFILTERED EFFLUENT DRAINING FROM SAID CIRCULATION SPACE, MEANS FOR SELECTIVELY CLOSING THE MEANS FOR CARRYING OFF FILTERED EFFLUENT FROM THE FILTER UNITS OF SAID PLURALITY OF SO THAT ANY OF SAID FILTER UNITS MAY BE REGENERATED BY THE CLEANSING ACTION OF EFFLUENT CIRCULATION THERETHROUGH ONLY AT SAID INLET SIDE WHILE THE REMAINDER OF SAID FILTER UNIT PLURALITY CONTINUES IN OPERATION, AND A HEAT EXCHANGER, TOGETHER WITH MEANS FOR SUPPLYING CLEAR AQUEOUS MAKE-UP THROUGH SAID HEAT EXCHANGER, AND MEANS FOR BLEEDING A CORRESPONDING PORTION FORM SAID RECIRCULATING EFFLUENT THROUGH SAID HEAT EXCHANGER IN HEAT EXCHANGE RELATION WITH SAID MAKE-UP SUPPLY.

Claim 3

The method of filtering contaminating solids from a heated aqueous effluent comprising the steps of supplying said liquid continuously to a plurality of filter units in parallel, each of Said filter units comprising an elongate cylindrical housing having a tubular filter cartridge disposed in fixed relation coaxially and substantially coextensively therein and proportioned in cross-section to leave an annular circulation space about said cartridge within said housing at which said liquid is supplied tangentially, carrying off filtered liquid from the outlet side of all but one of the filter units of said plurality, recirculating unfiltered liquid from the inlet side of all filter units of said plurality to said liquid supply, sequentially alternating the filter unit of said plurality from which no filtered liquid is carried off so that all of the filter units are periodically regenerated by the cleansing action of liquid circulation therethrough only at said inlet side while the remainder of said filter unit plurality continues in operation, and supplying clear aqueous make-up in an amount sufficient to bulk the filtered effluent carry-off to equality with the supplied effluent while first passing the make-up supply in heat exchange relation with a corresponding amount of unfiltered effluent bled from said filter units for this purpose.

Claim 4

The method of filtering contaminating solids from a heated aqueous effluent comprising the steps of supplying said liquid continuously to a plurality of filter units in parallel, each of Said filter units comprising an elongate cylindrical housing having a tubular filter cartridge disposed in fixed relation coaxially and substantially coextensively therein and proportioned in cross-section to leave an annular circulation space about said cartridge within said housing at which said liquid is supplied tangentially, carrying off filtered liquid from the outlet side of all but one of the filter units of said plurality, recirculating unfiltered liquid from the inlet side of all filter units of said plurality to said liquid supply, sequentially alternating the filter unit of said plurality from which no filtered liquid is carried off so that all of the filter units are periodically regenerated by the cleansing action of liquid circulation therethrough only at said inlet side while the remainder of said filter unit plurality continues in operation, and supplying clear aqueous make-up in an amount sufficient to bulk the filtered effluent carry-off to equality with the supplied effluent while first passing the make-up supply in heat exchange relation with a corresponding amount of unfiltered effluent bled from said filter units for this purpose.