Apparatus and method for the manufacture of product gas

In an apparatus for producing gas by oxidation of finely divided fuel in a reactor with concomitant formation of liquid slag, a combination comprising a vessel having an upper part and a lower part for containing a water bath;

• a vertically oriented straight discharge tube extending downwardly from said upper part and having a lower open end immersed in the water bath, said tube also having double walls which define between themselves an annular clearance and an upper inlet for receiving a stream of product gas from the reactor and a stream of liquid slag which is within and surrounded by the gas stream so that the gas stream prevents contact between the slag and the discharge tube;
• means for circulating a cooling liquid through the annular clearance in counterflow to the gas and slag streams;
• means for admitting said cooling liquid at an upper end portion of the discharge tube from the annular clearance onto an inner surface of the discharge tube, for gravity descent on and along the inner surface as a liquid film which prevents local overheating or destruction of the tube;
• means for discharging from the lower part of the vessel the slag which has become cooled and granulated on entry into the water bath;
• and means for withdrawing from the upper part of the vessel the cooled product gas which has ascended from the lower open tube end through the water bath.