Treatment of metal melts

Claim 1

APPARATUS FOR THE VACUUM TREATMENT OF METAL MELT COMPRISING A CLOSED VESSEL, MEANS FOR EVACUNATING SAID VESSEL, A CONTAINER FOR THE MELT DISPOSED BELOW SAID VESSEL AND UNDER ATMOSPHERIC PRESSURE, A RISING PIPE FORMING THE SOLE CONNECTION BETWEEN SAID VESSEL AND SAID CONTAINER, THE UPPER END OF SAID PIPE BEING CONNECTED TO SAID VESSEL AND THE LOWER OPEN END EXTENDING INTO SAID CONTAINER, AND A GAS INLET PIPE WITH ITS OUTLET DISPOSED BELOW, IN ALIGNMENT WITH, AND SPACED FROM THE LOWER OPEN END OF SAID RISING PIPE, SAID GAS INLET PIPE HAVING A PLURALITY OF OUTLET NOZZLES OF SMALL SIZE RELATIVE TO THE CROSS-SECTION AREA OF SAID RISING PIPE, SAID NOZZLES BEING UNIFORMLY DISTRIBUTED OVER AN AREA THE SHAPE AND SIZE OF WHICH EQUALS SUBSTANTIALLY THAT OF THE INTERNAL CROSS-SECTION AREA OF SAID RISING PIPE, WHEREBY THE GAS IS DISTRIBUTED OVER THE CROSSSECTION AREA OF SAID RISING PIPE.