Experimental study on the suppression of coal dust explosion by silica aerogel

Abstract

Silica aerogel (SiA) is prepared using environmentally friendly material diatomaceous earth and its effect on coal dust explosion is studied. The coal dust explosion characteristics experiments are carried out in a 20 L spherical explosion tank and dust explosion flame propagation experimental system, and the coal dust explosion products are analyzed by FTIR and XPS test methods. The results showed that after adding 50% SiA, the maximum explosion pressure of coal samples decreased from 0.3813 MPa to 0.1854 MPa, (dp/dt)max decreased from 10.955 Mpa/s to 4.082 Mpa/s, weakening by 62.74%, and the flame propagation height decreased from 567.57 mm to almost no flame propagation observed; using the Coats- Redfern method to calculate the activation energy of coal and SiA in the slow reaction stage of 30.353 kJ/mol and 21.159 kJ/mol, indicating that SiA preferentially consumes oxygen in the confined space, slowing down the oxidative pyrolysis of coal; SiA attenuates the impact energy generated by the explosion, protects part of the functional groups of coal from being destroyed, and inhibits the decomposition of some C elements in coal; proposes reduce the thermal radiation effect and decompression deceleration coupling effect to describe the inhibition mechanism of SiA on coal dust explosion.