Basic oxygen steelmaking vessels

Claim 1

IN METALLURIGAL VESSELS OF THE TYPE HAVING AN OUTER METAL SHELL, A REFRACTORY LINING IN CONTACT WITH THE INTERIOR OF THE SHELL AND AN INCLINED TAPHOLE OPENING PASSING THROUGH THE METAL SHELL, THE IMPROVEMENT COMPRISING A PREFABRICATED TAPHOLE ASSEMBLY OPENING INTO SAID TAPHOLE OPENING COMPOSED OF A PLURALITY OF MATED PAIRS OF REFRACTORY BRICK HAVING GENERALLY FACE, SIDE AND END SURFACES, EACH BRICK IN EACH OF SAID PAIRS CONTAINING A GROOVE IN A FACE SURFACE THEREOF, SAID GROOVE EXTENDING ENTIRELY ACROSS THE FACE SURFACE IN WHICH IT IS FORMED AND INTERSECTING AN ADJACENT SIDE AND END SURFACE WHICH SIDE AND END SURFACE INTERSECT TO FORM A COMMON EDGE, BOTH BRICK IN EACH PAIR BEING ARRANGED SO THAT THE RESPECTIVE GROOVE CONTAINING FACE SURFACES ARE IN CONTIGUOUS CONTACT WITH EACH OTHER WITH SAID RESPECTIVE GROOVE CONTAINING FACES COOPERATING TO DEFINE AN OPEN ENDED PASSAGE WHICH FORMS A PORTION OF AN INCLINED TAPHOLE, A SAID PAIR OF BRICK BEING ARRANGED WITH ITS SIDE SURFACES IN CONTIGUOUS CONTACT WITH AN ADJACENT PAIR ALONG A VERTICAL AXIS OF THE VESSEL WITH RESPECTIVE OPEN ENDED PASSAGES ALIGNED TO PROVIDE AN OPEN ENDED CONTINUOUS INCLINED TAPHOLE, WITH RESPECT TO SAID VERTICAL AXIS, EXTENDING THROUGH THE BRICK ASSEMBLY.