METHOD OF REGULATING WATER CONTENT OF SLURRY IN PRODUCTION OF COAL-WATER SLURRY

PURPOSE:To attain desired flow and combustion characteristics through an exact regulation of the water content of a slurry with high accuracy, by conducting wet pulverization and cooling of a coal-water slurry having a temperature raised by heat generated accompanying pulverization with an air stream, wherein the amount of supply of water is controlled through detection of a change in the humidity of the air stream. CONSTITUTION:A predetermined amt. of coal 2 is passed from a coal storage tank 1 through a coal weighing and feeding device 3 and fed into a wet ball mill 4. At the same time, predetermined amts. of water and a dispersant are fed from each feed pipe 5, 8 with a valve 7 for controlling the flow rate of water. Wet pulverization is conducted, and coarse particles are separated and removed from the atomized slurry 10 with a vibrating screen 11. The slurry is introduced into a cooling chamber 12 and then brought into direct contact with an air stream from an inlet air pipe 13 to cool the slurry having a temp. raised by heat generated accompanying pulverization. In this case, the humidity of an air stream in the pipe 13 and that of an air stream in an outlet air pipe 26 are measured with hygrometers 14, 27, respectively, and the signals are input into a main controller 31. The amount of evaporation of water is determined based on the degree of a change in the humidity obtained by composition, and the amount of supply of water is controlled so that the amount of supply of water is one corrected by the amount of evaporation of water of the slurry in the necessary amount of water of the slurry product. At the same time, the amount of coal fed is also controlled to exactly regulate the water content of the slurry.