Process and apparatus for the drying of coal in power stations, especially for the drying of water-containing brown coal

摘要

The object on which the invention is based is to afford a solution for the drying of coal in power stations, especially for the drying of water-containing brown coal, in which a proportionate coal combustion for the expulsion of coal moisture is dispensed with and, instead, smoke gas is used for this purpose within a temperature range in which acid dew points are crossed. This is achieved, according to the invention, in that a part stream of the raw fine coal is introduced into the smoke-gas cooler constructed from acid-resistant tube bundles, is heated by the smoke gas conveyed in countercurrent and is dried, the vapour occurring is discharged for the preheating of machine condensate and/or combustion air, and the vapour condensate obtained is used as a service-water substitute for the suspension treatment of the smoke-gas desulphurisation plant. The apparatus according to the invention for coal drying is characterised in that the smoke-gas cooler is arranged in a vertically guided portion of the smoke-gas conduit and is constructed from acid-resistant tube bundles known per se, which are guided on the one hand through a ceiling and on the other hand through a smoke-gas conduit bottom having an acid-resistant lining, there being [lacuna] above the smoke-gas conduit ceiling a coal feed connected to the acid-resistant tube bundles and having a vibrating and/or distributing grid and, below the smoke-gas conduit bottom, a collecting trough with an outlet device for the dried coal and with a conduit for the vapour discharge [lacuna] Original abstract incomplete. IMAGE