| 摘要 |
PURPOSE:To prevent dust explosion, by previously purging the interior of a coal storage tank with nitrogen, and then both throwing coal into the tank and detecting concentration and pressure of oxygen in ambient gas, then controlling a supply quantity of nitrogen gas on the basis of the detected pressure. CONSTITUTION:Before coal is stored in a coal storage tank 1, nitrogen gas is supplied from a nitrogen gas injection port 14 to perform nitrogen purge internally of the tank 1. In this way, for concentration of oxygen if not higher than a prescribed value, for instance, 10%, a discharge port 3 is closed and a filling port 2 is opened to throw coal into the tank. When internal pressure exceeds a prescribed level by filling of the coal, a vent valve 5 is operated to release gas. Further in a case with the internal pressure abnormally high or low, a supervisory device 13 generates an alarm. While the atmospheric gas is always picked from a sampling port 14 to perform gas analysis, if concentration of oxygen at least a prescribed level is recorded, an alarm is generated from the supervisory device 13, and a feed amount of nitrogen gas is increased. |
