Effect of aluminum silicate wool on the flame speed and explosion overpressure in a pipeline

Problems of decreasing the flame speed resulting from pre-mixed gas explosions and attenuating explosion overpressures are discussed. A cylindrical test pipeline with an 89 $\times$ 4.5 mm cross section is used to study flame propagation characteristics of an acetylene–air mixture both in the empty pipeline and in the presence of aluminum silicate wool attached to the internal wall of the pipeline. Experimental results show that aluminum silicate wool, which is a kind of a fibroid porous material with a high specific surface area, decreases the increment of the outlet flame speed and attenuates drastically the explosion overpressure if the length of the porous insert exceeds the critical length.