Abstract: A monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath, including a first portion, a second portion integrated with the first portion, and a bore passing through the first portion and communicating with the second portion for supplying gas to the second portion, wherein at least the second portion has a network of interconnected pores that provides preferential gas flow from the bore through the second portion to inject gas into the molten metal bath.

Abstract: A method of forming a monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath includes the steps of: preparing first and second batch materials, depositing the batch materials into a mold to form different portions of the diffuser, and firing the casting to obtain the monolithic diffuser. Various embodiments of the method include vibrating the mold at least while the second batch material is deposited therein, partially freezing a first portion of the casting, and freezing the entire casting prior to firing.

Abstract: A monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath, including a first portion, a second portion integrated with the first portion, and a bore passing through the first portion and communicating with the second portion for supplying gas to the second portion, wherein at least the second portion has a network of interconnected pores that provides preferential gas flow from the bore through the second portion to inject gas into the molten metal bath.

Abstract: A monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath, including a first portion, a second portion integrated with the first portion, and a bore passing through the first portion and communicating with the second portion for supplying gas to the second portion, wherein at least the second portion has a network of interconnected pores that provides preferential gas flow from the bore through the second portion to inject gas into the molten metal bath.

Abstract: A monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath, including a first portion, a second portion integrated with the first portion, and a bore passing through the first portion and communicating with the second portion for supplying gas to the second portion, wherein at least the second portion has a network of interconnected pores that provides preferential gas flow from the bore through the second portion to inject gas into the molten metal bath.

Abstract: A refractory brick particularly suited for constructing a diffusor wall for an industrial heat source. The brick includes a substantially tubular body having a first end, a second end opposed to the first end, an inner surface defining a passageway extending in the longitudinal direction of the body from the first end to the second end, and an outer peripheral surface extending from the first end to the second end. The outer peripheral surface has a complementary shape that allows mating of a plurality of the bricks to form cooperatively a diffusor wall. Mating means is formed on or in the outer peripheral surface for engaging corresponding mating means formed on or in outer peripheral surfaces of adjacent bricks when assembled as a diffusor wall.

Abstract: A ceramic ferrule, an array of ceramic ferrules, and a ceramic ferrule refractory wall, all for shielding a tube sheet/boiler tube assembly of a heat exchanger connected to an industrial heat source. The head portion of each ferrule replaces conventional cast refractory walls, and has an outer-peripheral shape that allows the ferrules to mate at the operating temperature of the industrial heat source. The mated ferrules expand and contract substantially independently of one another, but form a substantially gas-tight barrier for shielding the tube sheet/boiler tube assembly from the waste gas of the industrial heat source.