Abstract: In order to study influence of sealing material on explosion pressure and flame velocity in bifurcation pipes, gas explosion tests were carried out in a self-built glass pipe. Firstly, nostrils at 30, 45, 60 and 90° of bifurcation pipes were sealed with PVC film and acrylic plate. Then, parameters of gas explosion were collected by data acquisition system, and variation characteristics of pressure and flame were analyzed. The results show that the explosion pressure decreases gradually while flame velocity increases first and then decreases before it increases again rapidly in double PVC membrane pipe. And as bifurcation angle rises, both of the two factors show a trend of increase. In the straight and branch closed pipes, explosion pressure at the closed end of PVC film decreases while that at the closed end of acrylic plate increases. Flame velocity increases first and then decreases before the bifurcation angle, but it increases sharply after the angle at the closed end of PVC film, and flame oscillation at the closed end of acrylic plate appears. With the increase of the angle, explosion pressure and flame speed of straight closed pipes decrease first and then increase, while those of the branch closed pipe are decreasing.

Key words: sealing material, bifurcated pipe, gas explosion, polyvinyl chloride (PVC) film, acrylic sheet, explosive pressure, flame velocity