Effect of CaCl2, Al(OH)3 and NH4H2PO4 on the explosion sensitivity of pulverized coal

Abstract

ABSTRACT In this paper, the effects of 30 wt%, 50 wt% aluminum hydroxide, calcium chloride and ammonium dihydrogen phosphate three explosion inhibitors on the two sensitivity parameters of the minimum explosion concentration and the minimum ignition energy of pulverized coal were investigated. It was found that for the same explosion inhibitor, the higher the content of explosion inhibitor, the higher the increase of MEC and MIE of pulverized coal-explosion inhibitor. At the same time, dust reduction measures should be taken in time when the coal dust concentration will be close to 70 g/m3. It was found that for the same explosion inhibitor, the higher the content of explosion inhibitor, the higher the increase of MEC and MIE of pulverized coal-explosion inhibitor. In the meantime, dust reduction measures should be taken in time when the coal dust concentration will be close to 70 g/m3. Furthermore, 150 g/m3 was the critical concentration of the ignition energy of pulverized coal. In order to prevent the occurrence of coal dust explosion accidents, it was necessary to resolutely prevent the concentration of pulverized coal from approaching this value on site. In addition, when the pulverized coal-explosion inhibitor concentration was 100 g/m3-250 g/m3, whether it was 30 wt% NH4H2PO4 or 50 wt% NH4H2PO4, the ignition energy required for mixing with pulverized coal was greatly increased. Overall, in the concentration range of 30–50 wt%, 50 wt% NH4H2PO4 was more advantageous in the suppression of coal dust explosion.