Experimental study on the characteristics of overpressure wave to ventilation facilities during gas explosion and automatic shock relief devices

Ventilation facilities could easily be destroyed by gas explosion in a coal mine and usually lead to the cascade collapse of the entire ventilation system. Altering the ventilation facilities could increase the value of the overpressure peak and the propagation speed of the shock waves. The attenuation law for blast waves in restricted roadway networks was analysed, and calculation models for the blast wave overpressure and attenuation of the smoke flow velocity in tunnelling roadways were derived. An overpressure relief air door with a magnetic lock was then designed. This air door is opened by the action of the blast overpressure to relieve the pressure in a large section. The air door is automatically reset after the shock wave passes and closes under its load force and body weight. The system has the function of continuous automatic pressure relief and reset, providing support for efficient emergency rescue operations. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.