Multi-unit kiln for the production of lightweight aggregate

Claim 1

A ROTARY KILN FOR THE PROCESSING OF MATERIALS AMENABLE TO BLOATING IN THE MANUFACTURE OF LIGHTWEIGHT AGGREGATES, CEMENT OR THE LIKE, COMPRISING: (A) A CYLINDRICAL HORIZONTALLY INCLINED PREHEATING SECTION HAVING A MATERIAL FEED END AND AN OUTLET AND AT A LOWER LEVEL THAN SAID FEED END; (B) VARIABLE SPEED DRIVE MEANS TO ROTATE SAID PREHEATING SECTION TO THUS CONTROL THE RETENTION TIME OF THE MATERIAL IN SAID SECTION; (C) A HORIZONTALLY INCLINED FIRING SECTION CONNECTED IN ALIGNMENT WITH SAID PREHEATING SECTION AND HAVING AN INLET END NEXT TO THE OUTLET END OF SAID PREHEATING SECTION AND A DISCHARGE END; SAID FIRING SECTION BEING FORMED OF CYLINDRICAL END MEANS AT THE INLET AND AT THE DISCHARGE ENDS THEREOF JOINED BY A TAPERED JUNCTION MEANS; THE CYLINDRICAL END MEANS AT THE INLET END BEING SMALLER IN DIAMETER THAN THE CYLINDRICAL END MEANS AT THE DISCHARGE END, WHEREBY TO ALLOW FOR THE INCREASE IN VOLUME OF MATERIAL RESULTING FROM BLOATING THEREOF AS SAID MATERIAL MOVES FROM THE INLET END TO THE DISCHARGE END OF THE FIRING SECTION; (D) VARIABLE SPEED DRIVE MEANS TO ROTATE SAID FIRING SECTION TO THUS CONTROL THE RETENTION TIME OF THE MATERIAL IN SAID SECTION, AND (E) FIRING MEANS FIRING INTO THE LARGER DIAMETER END OF SAID FIRING SECTION.