Method for the combustion of partially dewatered sewage sludge as well as improved furnace incorporating grate firing for carrying out the aforesaid method

Claim 1

A COMBUSTION FURNACE OF THE TYPE UTILIZING A MULTIZONE GRATE FIRING FOR THE DESTRUCTION OF PREVIOUSLY PARTIALLY DEWATERED SLUDGE POSSESSING LOW CALORIFIC VALUE AND HIGH CONTENT OF NON-COMBUSTIBLE CONSTITUENTS, PARTICULARLY FOR THE COMBUSTION OF SEWAGE SLUDGE, SAID FURNACE INCLUDING: A PRE-DRYING COMPARTMENT; SAID PRE-DRYING COMPARTMENT BEING DEFINED ALONG TWO SIDES BY FIRST AND SECOND GAS-TIGHT INTERMEDIATE WALLS AND ALONG THE BOTTOM BY A GAS-PERMEABLE SUPPORT MEANS; DELIVERY SHAFT MEANS COMMUNICATING WITH SAID FIRST GAS-TIGHT INTERMEDIATE WALL AND SEPARATED FROM SAID PRE-DRYING COMPARTMENT THEREBY, SAID DELIVERY SHAFT MEANS BEING ADAPTED TO RECEIVE SAID PREVIOUSLY PARTIALLY DEWATERED SLUDGE AND DISPOSED TO FEED SAID SLUDGE UPON SAID GAS-PERMEABLE SUPPORT MEANS; SUPPLY MEANS FOR SUPPLYING A GASEOUS HEATING MEDIUM TO A LOCATION BENEATH SAID GAS-PERMEABLE SUPPORT MEANS, SAID SUPPLY MEANS PRE-DRYING SAID SLUDGE UPON SAID GAS-PERMEABLE SUPPORT MEANS BY EXPELLING VAPORS THEREFROM; A REGULATING SLIDE MEANS SHAPED AS A GAS-TIGHT SLIDE AND DISPLACEABLY MOUNTED WITHIN SAID SECOND GAS TIGHT INTERMEDIATE WALL; A COMBUSTION COMPARTMENT, SAID COMBUSTION COMPARTMENT BEING ADJACENT SAID PRE-DRYING COMPARTMENT AND SEPARATED THEREFROM IN A GAS-TIGHT MANNER BY SAID SECOND INTERMEDIATE WALL AND SAID REGULATING SLIDE MEANS; SAID COMBUSTION COMPARTMENT INCLUDING A FEED GRATE MEANS DISPOSED AT THE BOTTOM OF AID COMBUSTION CHAMBER, SAID FEED GRATE MEANS BEING ADAPTED TO RECEIVE SAID SLUDGE DISPOSED UPON SAID GAS-PERMEABLE SUPPORT MEANS, SAID REGULATING SLIDE MEANS REGULATING THE THICKNESS AND QUANTITY OF SLUDGE RECEIVED BY SAID FEED GRATE MEANS; SAID FEED GRATE MEANS INCLUDING, IN SUCCESSION, A DRYING ZONE COMPRISING AN INITIAL GRATE PORTION, A PRIMARY COMBUSTION ZONE, AND A BURN-OUT ZONE, WITH RESPECT TO THE DIRECTION OF FEED OF SAID SLUDGE;