METHOD FOR PREVENTING SPONTANEOUS IGNITION IN COAL STORAGE SILO, AND COAL HUMIDIFIER USED THEREFOR

PROBLEM TO BE SOLVED: To provide a spontaneous ignition preventive method for reliably preventing spontaneous ignition while maintaining the heat generation of coal and the handling property of coal by the necessary minimum humidification without excessive increasing the equipment cost in a coal storage silo, and a coal humidifier used therefor. SOLUTION: In the spontaneous ignition preventive method, when coal landed from a coal carrier 1 is humidified by a water sprinkling device 4 on a belt conveyor 3 in advance, and charged in a coal storage silo 5, the humidification amount ΔW required for the entire water content in coal after the elapse of the required storage days t2not to be below the specific water content WIBis set by the formula (1): ΔW=WIB+VD*t2-WTB, where WTBis the total water content at the loading port which is the total water content before humidification, WIBis the specific water content, and VDis the drying rate in the coal storage silo 5 according to the brand of coal. If ΔW