Apparatus for degassing molten metal

Claim 1

IN A VACUUM DEGASSING VESSEL INCLUDING A METALLIC NOZZLE EXTENDING FROM ITS LOWER END FOR DRAWING MOLTEN METAL INTO SAID VESSEL FOR DEGASIFICATION AND HAVING LINING SUPPORT MEANS AT ITS LOWER END AND EXTENDING INWARDLY TOWARD THE AXIS OF SAID NOZZLE, THE IMPROVEMENT COMPRISING A REFRACTORY LINING FOR SAID NOZZLE INCLUDING A PLURALITY OF REFRACTORIES ARRANGED IN COURSES SURROUNDING THE LONGITUDINAL AXIS OF SAID NOZZLE, EACH OF THE REFRACTORIES DEFINING THE LOWERMOST OF SAID COURSES LYING IN SIDE-BY-SIDE ABUTMENT AND EACH HAVING A TRANSVERSE GROOVE EXTENDING ACROSS ONE SIDE AND BETWEEN A PAIR OF LONGITUDINAL EDGES, EACH OF SAID GROOVES EMBRACING SAID LINING SUPPORT MEANS TO SUPPORT THE REFRACTORIES THEREABOVE IN SAID LINING, EACH OF SAID GROOVES BEING LOCATED A PREDETERMINED GREATER DISTANCE FROM ONE OF THE ENDS OF SAID REFRACTORIES THAN THE OTHER, SAID GROOVES BEING SYMMETRICAL IN CROSS SECTION SO THAT SAID LINING SUPPORT MEANS MAY BE EMBRACINGLY ENGAGED WITH EITHER OF THE ENDS OF SAID REFRACTORIES BEING IN AN UPRIGHT POSITION, WHEREBY VARIATIONS IN THE LENGTHS OF THE REFRACTORIES IN SAID NOZZLE LINING RESULTING FROM NORMAL MANUFACTURING TOLERANCES MAY BE COMPENSATED BY REVERSING THE REFRACTORIES IN SAID LOWERMOST COURSE.