Vacuum distn. appts. for refining of metals - where crude molten metal flows down distn. column so more volatile impurities are removed before metal reaches base of column

摘要

The appts. includes a vertical column (1) with an axial channel contg. a vertical heater; and in column (1) is a vertical stack of ring trays employed for the condensn. and removal of impurities with lower b.pts. than the crude metal being refined. The crude molten metal is located in a vessel (12) outside column (1). The base of column (1) leads to a condenser for the purified metal. Inside vessel (12) is a pot (19) with a hole (20) in its base; and a stopper rod (21) is moved vertically to open or close hole (20), so the molten metal in vessel (12) can enter pot (19). In pot (19) is the bottom end of a heated tube (13) via which molten metal travels into column (1) due to the vacuum in the latter. For continuous purificn. of molten metal, which flows down a heated distn. column (1) so vapourised impurities are condensed and removed before the purified metal reaches the base of column (1).