Reduction furnace provided with superstructure

Claim 1

AN ELECTRIC REDUCTION FURNACE FOR HIGH TEMPERATURE PROCESSING, OF THE TYPE HAVING A CRUCIBLE INTO WHICH ELECTRODES EXTEND DOWNWARDLY, CHARACTERIZED BY: (A) A HOOD FOR THE CRUCIBLE HAVING SUBSTANTIAL HEIGHT AND HAVING (1) A CHARGING INLET OF SUBSTANTIAL SIZE, AND (2) AN OUTLET OF SUBSTANTIAL SIZE THROUGH WHICH HOT GASES AND DUST CAN BE WITHDRAWN FROM THE SPACE BENEATH THE HOOD; (B) MEANS SUSPENDING THE HOOD OVER THE CRUCIBLE WITH THE LOWER EDGE OF THE HOOD SPACED ABOVE THE UPPER EDGE OF THE CRUCIBLE TO PROVIDE AN INLET ALL AROUND THE RIM OF THE CRUCIBLE THROUGH WHICH AIR CAN BE DRAWN INTO THE SPACE BENEATH THE HOOD; (C) MEANS FOR WITHDRAWING HOT GASES AND DUST THROUGH SAID OUTLET; (D) COOLING COILS SUBSTANTIALLY COVERING THE INSIDE OF THE HOOD AND THROUGH WHICH FLUID COOLING MEDIUM CAN BE CIRCULATED; (E) A PLURALITY OF ELECTRODE HOLDERS SUPPORTED BY THE HOOD AND PROJECTING A SUBSTANTIAL DISTANCE DOWNWARDLY INTO THE SPACE THEREBENEATH; AND (F) COOLING MEANS THROUGH WHICH FLUID COOLING MEDIUM CAN BE CIRCULATED SURROUNDING ALL OF THAT PORTION OF EACH ELECTRODE HOLDER WHICH IS IN THE SPACE BENEATH THE HOOD.