Patent ID: 6380517
Filing Date: 2002-04-30
Classification: F27B,F27D

Abstract:
A rotating vacuum kiln comprising:a rotating refractory metal cylindrical vessel having inner and outer walls, a cool inlet zone, a hot intermediate zone and a cool exit zone; means for charging solid particulate material for heating into said cool inlet zone while under a vacuum; a supply of additive or dopant and means for adding said supply of additive or dopant to solid particulate material in said rotating refractory metal cylindrical vessel; means for discharging said solid material after heating from said cool exit zone while under a vacuum; means for moving the solid particulate in a direction from the charging means to the discharge means; a first series of inner radiation shields in the cylindrical vessel at said hot intermediate zone, adjacent to said cool inlet zone, and a second series of inner radiation shields at said hot intermediate zone adjacent to said cool discharge zone; a gaseous exhaust conduit extending into said cool exit zone and at least partially into said hot intermediate zone for removing gases and vaporized material therefrom; means for indirectly heating said hot intermediate zone; and radiation shields surrounding the refractory metal cylindrical vessel along said hot intermediate zone.