Abstract: Hot gases containing ash and char which pass through an undesirable viscous, sticky phase on cooling through an intermediate temperature range, are cooled in a first cooling zone including a falling film of cooling liquid and a spray of cooling liquid followed by contact with a body of cooling liquid and subsequent mixing therewith.

Abstract: The refractory lined reaction zone of a free flow vertical gas generator for the production of raw synthesis gas, reducing gas, or fuel gas by the partial oxidation of an ash-containing solid carbonaceous fuel or a high-metal-containing liquid hydrocarbonaceous fuel is preheated and deslagged by first heating the slag and ash layer on the surface of the refractory lining to a temperature in the range of about 1800.degree.-2000.degree. F. by means of an annular-type elongated burner whose downstream tip is located near the upstream roof of the reaction zone. The tip of the burner is then lowered along the central longitudinal axis of the reaction chamber to above the bottom central outlet passage of the reaction chamber, and the slag and ash layer is heated to their melting point, or above. The molten slag at the bottom of the reaction chamber and the flue gas pass out through the bottom central outlet.

Abstract: Hot synthesis gas is cooled and deashed by passage through first zone in contact with a downwardly descending film of cooling liquid, a second zone in contact with a spray of cooling liquid, a third zone in contact with a body of cooling liquid, and a fourth zone in contact with a spray of cooling liquid--at least a portion of the cooling liquid to the first zone preferably being recycled cooling liquid from which at least a portion of the solids contained therein has been removed.

Abstract: Hot gases containing ash and char which pass through an undesirable viscous, sticky phase on cooling through an intermediate temperature range, are cooled in a first cooling zone including a falling film of cooling liquid and a spray of cooling liquid followed by contact with a body of cooling liquid and subsequent mixing therewith.

Abstract: A synthesis gas cooler has concentric water walls to provide for heat transfer to a fluid in the water wall tubes. The inner water wall is concentric with the cooler shell and has a gas tight inlet connection for introducing hot synthesis gas. The inlet is located at the top of the shell. The bottom of the shell contains a body of water for quenching entrained solids which are carried with the synthesis gas, and there is a baffle to direct the flow of synthesis gas back up in the annulus between the two concentric water walls. The annulus has a closed upper end except for an outlet for the synthesis gas which is located near that end of the annulus. Also, there may be soot blowers along the length of the water walls to keep the heat transfer surfaces clean.