Gas-gas quench cooling and solids separation process

Abstract

A hot raw gas stream, as produced by the partial oxidation of a solid carbonaceous fuel such as coal, is partially cooled and cleaned to remove entrained solid matter and slag. A novel gas-gas quench cooling and solids separation apparatus is employed. The apparatus comprises a closed cylindrical insulated vertical pressure vessel containing a lower quench chamber in communication with an upper solids separation chamber. The hot raw gas stream is cooled in the lower chamber to a temperature below the initial deformation temperature of the entrained slag by impingement and direct heat exchange with an oppositely directed coaxial stream of cooled, cleaned, and compressed recycle quench gas. The stream of cooled gas leaving the turbulent lower chamber passes up through a choke-ring into the comparatively calmer upper chamber counter-currently with solid slag droplets which separate out by gravity. Residual solid particles are removed from the gas stream by at least one cyclone separator located in the upper chamber. A portion of the cooled and cleaned gas stream leaving the vessel, with further cooling and with or without further cleaning downstream is recycled back to the vessel for use as said quench gas. Slag particles and other solid matter that are separated within the pressure vessel are removed at the bottom of the lower chamber.