Abstract: In a slagging gasifier the slag quenching chamber is provided with means having a plurality of equispaced outlet ports disposed around the inside of the upper region of the chamber, each outlet port communicating with a venting control which may be used selectively to vent the normally pressurized quenching chamber to atmosphere during a slag-tapping operation.

Abstract: The quench chamber of a slagging pressure gasifier is provided with a perforated tubular air ring remote from the slag tap main burner of the gasifier and arranged, in use, to supply the burner with a secondary air supply and, at the same time, to set up an air circulation adjacent the walls of the chamber above the normal water level therein, thereby to cool the walls. There is further provided a nozzle mixing ring burner for use in a slagging gasifier comprising a body having two integrally formed chambers each having respectively a gas inlet and outlet and an air/oxygen inlet and outlet. The outlets are directed toward a shaped annular portion on the inner periphery of the ring body.