The Influence Of Porous Materials On Channel Flame Propagation

Pipeline Safety has always been the concerned object of the domestic and foreign security workers, the works about explosion prevention and control have vital significance to the industrial production of the country and people's living. Beacause of its small size,light weight and low cost, porous material gradually becomes the common structure to prevent and control explosion in the pipe. High-frequency data picking board and pressure sensor, together with flames probe were used in this paper to discuss the flame's law of development in the pipe, a number of experiments were also conducted at the same time to study the inhibitory effects of the porous material to the flame in the pipe.(1)The length of the Aluminium silicate wool showed distinct dual character to the inhibition of the flame propagation in the pipe. For DN80, when the length of the wool was less than 400mm, porous areas played a role in the growth of pressure and speed of the flame propagation,however,as the length was more than 400mm, it restrained the propagation of flame.(2)The position of the passage formed by porous material placed in the length setting device had dual character for the inhibition of flame propagation in the pipe. From the numerical detection of the measuring point near the out part. It could be seen when aluminium silicate wool was placed nearby the initiation point, it exerted a tremendous influence on the flame propagation, the velocity and pressture decreased compared to the smooth tube values;With the increasing of Lx, the velocity and pressture at the measuring point both rised, aluminium silicate wool absorbed energy, moreover, it was used as the variable cross-section obstacle.(3)Regardless of the length of aluminium silicate wool and the setting parameters of porous passage, porous materials represented by aluminium silicate wool had limitation to restrain the flame propagation in the pipe. The porous passage formed by aluminium silicate wool could not quench the burning flame.There was a limiting length of the passage and the restraining effect were nearly the same while the lengths were above and under the limition.(4)The characteristics of the flame propagation control with fiber porous materials represented by aluminium silicate wool are as follows:â‘ There will be a mitigate area after the poprous area and in this area,the trend of flame speed and pressture decreases obviously. It indicates that the flame inhibition of the aluminium silicate wool reflects in the inhibition of the subsequent flame propagation increasing trend. â‘¡The flame propagation control with fiber porous materials represented by aluminium silicate wool is first to decrease the flame propagation pressture,then reduces flame energy and finally decelerates the flame.â‘¢When the length of the wool is less than 400mm, the flame with high speed,high pressture and high energy has a greater increase amplitude in the poprous area; As the length is more than 400mm, the inhibitory effect of the flame with high speed and high energy is better compared to low speed and low energy flame. The pressure inhibition is special and the inhibition effect is better when the pressure is low.â‘£The influence of aluminium silicate wool to the flame in the pipe is the combinable effects of the absorption and damping to the flame,obstacle effect and energy increase caused by chemical reaction.