Combustion system

Claim 1

IN APPARATUS FOR HEATING PARTICLES OF ORE TO AN ELEVATED TEMPERATURE, SAID APPARATUS INCLUDING WALL MEANS DEFINING A CYLINDRICAL KILN HAVING AN INTERNAL SURFACE, AN INLET END, AND AN OUTLET END, SAID KILN, BEING DISPOSED WITH SAID OUTLET END LOWER IN ELEVATION THAN SAID INLET END; CHARGING MEANS ADJACENT THE INLET END OF SAID KILN FOR CHARGING A STREAM OF ORE PARTICLES THEREINTO TO FORM A BED OF PARTICLES THEREIN COVERING A PORTION OF THE INTERNAL SURFACE OF SAID KILN; MEANS FOR ROTATING SAID KILN TO CAUSE SAID BED OF PARTICLES TO PASS FROM SAID INLET END TO SAID OUTLET END; BURNER MEANS FOR PROMOTING THE COMBUSTIBLE REACTION OF A STREAM OF FUEL AND COMBUSTION-SUPPORTING AIR, SAID BURNER MEANS BEING LOCATED ADJACENT THE OUTLET END OF SAID KILN AND BEING ADAPTED TO DELIVER THE PRODUCTS OF SAID COMBUSTIBLE REACTION TO SAID KILN TO FLOW THERETHROUGH IN COUNTER-FLOW HEAT TRANSFER RELATIONSHIP WITH SAID BED OF PARTICLES; AND FURTHER INCLUDING THE IMPROVEMENT IN MEANS FOR ADDING A STREAM OF HEATED AIR LADEN WITH ORE PARTICLES OF THE KIND BEING HEATED IN SAID KILN IN A MANNER TO UTILIZE AT LEAST A PORTION OF THE HEATED AIR STREAM AS COMBUSTION-SUPPORTING AIR FOR SAID BURNER, SAID IMPROVEMENT COMPRISING, IN COMBINATION: AN AIR INLET TUBE ADJACENT THE OUTLET END OF SAID KILN AND BEING DIRECTED TOWARD A REGION OF THAT PORTION OF THE INTERNAL SURFACE OF THE KILN WHICH IS COVERED BY SAID BED OF PARTICLES; CONDUIT MEANS FROM A SOURCE OF HEATED AIR LADEN WITH ORE PARTICLES OF THE KIND BEING HEATED IN SAID KILN; SAID CONDUIT MEANS LEADING TO SAID KILN AND INCLUDING SEPARATING MEANS FOR SEPARATING THE STREAM OF HEATED AIR INTO TWO PORTIONS, THE FIRST OF SAID TWO PORTIONS BEING LESS HEAVILY LADEN WITH ORE PARTICLES THAN THE SECOND OF SAID PORTIONS AND BEING DELIVERED BY SAID CONDUIT MEANS TO SAID BURNER TO SERVE AS COMBUSTION-SUPPORTING AIR, THE SECOND OF SAID PORTIONS BEING DELIVERED BY SAID CONDUIT MEANS TO SAID AIR INLET TUBE OF SAID KILN TO PASS THEREINTO, WHEREBY THE PARTICLES CONTAINED IN SAID SECOND PORTION WILL PRECIPITATE THEREFROM ONTO SAID BED.