Waste treatment with anaerobic digestion

Claim 1

THE METHOD OF DISPOSAL OF A SUSPENSION OF PUTRESCIBLE WASTE MATTER THROUGH ANAEROBIC DIGESTION, WHICH COMPRISES SUBJECTING THE SUSPENSION TO CONTINUOUS SEDIMENTATION TO FORM A SLUDGE BED SUBJACENT TO A BODY OF SEPARATED LIQUOR; MAINTAINING A BODY OF DIGESTING SLUDGE; FEEDING SLUDGE FROM SAID SLUDGE BED TO SAID BODY OF DIGESTING SLUDGE AT A RATE ADAPTED BO PRODUCE INCOMPLETELY DIGESTED SLUDGE FOR DISCHARGE FROM THE DIGESTER; SUBJECTING INCOMPLETELY DIGESTED SLUDGE DISCHARGED FROM SAID BODY OF DIGESTING SLUDGE TO CENTRIFUGAL SEPARATION TREATMENT CONTROLLED FOR DELIVERING A CAKE AMTERIAL SUBSTANTIALLY CONTAINING THE DIGESTED SOLIDS, AND AN OVERFLOW SUBSTANTIALLY CONTAINING THE UNDIGESTED SOLIDS; AND INTRODUCING SAID OVERFLOW DIRECTLY INTO SAID BED OF SLUDGE TO EFFECT ENTRAPMENT AND RETENTION THEREIN OF UNDIGESTED SOLIDS.