Device for treating metallic melts

Claim 1

IN A APPARATUS FOR TREATING METALLIC MELTS: A VESSEL FOR RECEIVING AND CONTAINING THE METALLIC MELT TO BE TREATED, A BELL-SHAPED MEMBERENCLOSING A CAVITY OPENING TOWARDS THE BOTTOM OF SAID VESSEL AND POSITIONED BENEATH THE LEVEL OF THE MELT IN THE VESSEL, THE INTERIOR OF SAID CAVITY BEING SUBSTANTIALLY UNOBSTRUCTED AND HAVING A REFRACTORY LINING, AT LEAST TWO CONDUITS LEADING INTO THE CAVITY IN SAID BELL-SHAPED MEMBER ABOVE THE LIQUID LEVEL THEREIN OF THE MELT, POSITIVE FEEDING MEANS FOR FEEDING MATERIAL THROUGH AT LEAST ONE OF SAID CONDITS INTO THE CAVITY IN SAID MEMBER FRO REACTION WITH THE MELT, AT LEAST ONE OF SAID CONDUITS BEING ADAPTED FOR SUPPLYING A PROTECTIVE GAS INTO THE CAVITY IN SAID MEMBER, A SOURCE OF GAS UNDER PRESSURE CONNECTED TO SAID ONE CONDUIT, AND MEANS FOR MAINTAINING PRESSURE ON THE GAS SUFFICIENT TO PREVENT MELT FROM ENTERING SAID BELL-SHAPED MEMBER TO THEREBY ESTABLISH A SECONDARY LEVEL IN THE MELT WHERE THE SAID MATERIAL COMES IN CONTACT WITH THE MELT AND IN THE PRESENCE OF THE SAID GAS.