Dewatering e.g. raw brown coal - comprises preheating feed material, sealing in steam-tight pressure chamber, subjecting to steam injection and applying mechanical pressure

摘要

In a process for reducing the amt. of capillary water in the fibre cells of carbonaceous, finely divided solids and/or slurries (esp. raw brown coal), the feed material is preheated to ca. 60[deg]C at the beginning of the cycle, sealed in a substantially steam-tight pressure chamber which has been preheated to over 100[deg]C, and subjected on both sides to superheated steam at >= 150[deg]C. The pressure mechanically applied to the surfaces of the feed material is greater the static pressure, and, as a max., corresponds to the pressure of the steam (5-8 bar). After the feed material reaches >= ca. 125[deg]C, the steam injection is stopped and a mechanical pressure of up to 75 bar (depending on the grain size of the feed material) is applied to reduce the residual water content to 20 wt.%. Also claimed are a plant and a press for the process.