Abstract: This invention relates to a gas bubbler stone for metallurgical vessels having a porous, gas-permeable molded stone (1) made of a refractory material, a partial sheathing enclosing it in a gastight manner, the sheathing being made of a metal casing (2), which extends around the lateral peripheral surface of the molded stone, and a sheet metal cover (3) which covers the outer end face of the molded stone, and a gas delivery pipe (6) which extends from the under side of the sheet metal cover and is joined to the sheet metal cover in the area of a gas inlet opening (7) formed in the sheet metal cover, and which has a narrowed cross section (9) at a distance from the gas inlet opening of the sheet metal cover, and a closing body (10), which is movable at least in the axial direction of the gas delivery pipe, is situated in the pipe section between the sheet metal cover (3) and the narrowed cross section (9), its cross section being smaller than the inside diameter of the gas delivery pipe (6) and greater than the

Abstract: According to known methods for producing a composite element from a truncated cone-shaped, fire-proof ceramic insert which is enclosed by a metal jacket, the outer jacket is-heated separately and shrunk on the cold ceramic insert. Alternatively, after inductive heating of the outer jacket the ceramic insert, which is heated at the same time, is positioned in the metal jacket using a mechanical device. The invention aims to provide a new method which avoids the disadvantages associated with shrinking a separately heated hot metal jacket on to a colder ceramic insert and to provide a simple method which without inductive heating of the metal jacket and the use of mechanical devices for joining said jacket to the ceramic insert achieves an even bond between the metal jacket and ceramic insert.

Abstract: A pipe like feeder nozzle for injecting molten steel into a mold for continuous casting is constructed from a refractory material and has its lower part covered with a porous e.g. fibrous, refractory cover bonded to the feeder pipe by a refractory bonding agent.