Coal gasification plant

Claim 1

In a coal slagging gasifier comprising: a gasifying vessel; means for introducing coal into said vessel for gasification thereof in said vessel; means for introducing oxygen and steam into said vessel to effect gasification of coal therein; a hearth located at the bottom of said vessel and including a slag removal orifice for removing slag therefrom; burner means located beneath the slag removal orifice for directing a flow of hot combustion products up the slag removal orifice to retain the slag in a molten condition on said hearth; a quenching chamber positioned below said slag removal orifice for receiving slag discharged through said slag removal orifice; and means for reducing or stopping said flow of hot combustion gases for discharging slag through said slag removal orifice; the improvement wherein said slag-removal orifice is located centrally within said hearth and is formed as a substantially vertical passageway through a removable slag tap member, said slag tap member comprising a solid cast mass of high thermal conductivity metal having an integrally formed metal tube for circulating a coolant liquid through said cast mass, and having an upper tundish surface across which discharged slag flows, said upper surface sloping downwardly and inwardly and merging with said slag removal orifice, said coolant tube being capable of retaining its shape without any appreciable distortion during the casting of the surrounding metal mass, extending through said cast mass and forming a coolant conduit adjacent to said tundish surface and to the surface of said orifice passageway and spaced from said surfaces a distance of 0.25 to 1.5 inches, the ends of said tube projecting exteriorly of the surrounding cast metal mass to provide a coolant inlet and outlet.