Holder for refractory tubes e.g. mounted underneath ladle - where tube rests on air cushion, so it can rotate together e.g. with outlet tube of bottom pour rotary stopper

摘要

A refractory tube (4) must be located below a second, coaxial refractory tube (6) so that tube (4) can be replaced when necessary. Tube (4) is located in an upper ring (11) resting in a lower, outer ring (10) mounted on the end of a holder arm, which is employed to keep tube (4) in contact with tube (6), and for the removal and replacement of a worn tube (4). A cushion of pressurised fluid, e.g. air, is provided between the two rings (10,11). Due to the air cushion, tube (4) and ring (11) can rotate in ring (10), esp. when tube (6) forms the outlet of a rotary bottom-pour nozzle fitted on a ladle in a continuous casting plant. In previous designs, the rotation of a plate in the stopper created torsional stresses in tubes (4,6) so one or both cracked.