Process for the improvement of the conditioning of gasification agents utilized in an underground coal-gasification process

摘要

1. Method of improving the conditioning of gasifying agents, used in methods for the underground gasification of coal, and consisting of water in the liquid state, by an oxygen-containing gas and by a low dosage of a tensio-active agent promoting the production of foam, characterized in that the production of foam is performed at the bottom of the injection wells, equipped with two concentric casings (1, 3), the outer casing (1), used for the injection of the oxydizing gas, terminating in one or more filtering sieves (2) with meshes of approximately one or two millimetres diameter, and the inner casing (3), used for the injection of the mixture of water and a foaming agent, terminating in one or more vaporisers (4) or by a device made from perforated sheet metal dispersing the water in fine droplets.