Abstract: A method and apparatus of producing industrially usable gas is disclosed wherein hot detarred gas produced in conventional manner is passed through a plate type precipitator adapted to remove from the gas at least some of the remaining contaminants, mainly the solid and fluids of relatively low volatility.

Abstract: A steam generating system for a gas producer of the type including a combustion chamber and an annular water jacket surrounding the chamber is disclosed characterised in that the upper part of the jacket is of larger diameter than the lower part thereof, the lower part being heated through substantially direct contact with the combustion chamber and the upper part being insulated from the chamber preferably by means of a skin of fire bricks or the like; an open upwardly directed vent pipe communicating with the lower part of the jacket; and a steam exhaust line communicating with the upper part of the jacket. The system also includes a venturi arrangement for introducing the generated steam to the air blast as well as a safety valve in the steam line which is adapted to respond to temperature changes in the air blast.