PRACTICABILITY OF FLAME ARRESTER FOR PETROLEUM REFINING AND PETROCHEMICAL PLANT

对陶瓷型避雷器和金属丝网型避雷器的灭火特性进行了试验研究，设计了避雷器的安装位置，并对陶瓷型避雷器的灭火特性进行了分析，得出了在丙烷-空气系统中，以火焰通过避雷器时的最小火焰速度来评价陶瓷型避雷器的灭火能力。在此临界速度下，陶瓷避雷器比不锈钢卷边带式避雷器具有更好的熄弧能力。等效直径和长度是影响避雷器熄焰能力的重要参数，尤其是等效直径小于2 mm的避雷器，其熄焰能力随厚度的增加而显著提高。结果表明，材料对火焰熄灭性能无影响，但表面粗糙度对火焰熄灭性能有影响，并讨论了火焰熄灭器位置对火焰熄灭性能的影响。在管道弯曲区域，火焰速度会加快，因此，不应在弯曲区域或其后面设置阻火器。由于沿着火焰传播，火焰温度升高，所以避雷器应设置在较短的起燃长度内。当火焰向下传播时，火焰往往在阻火器处停滞，有时停滞的火焰经过一定的停滞时间后才通过。在这种情况下，临界速度不是评价避雷器灭弧能力的一个好因素。因此，避雷器不应设置在火焰向下传播的地方。

Experiments were conducted on flame quenching characteristic of ceramic type arrester and on wire gauze type arrester to design arrester set up position.For flame quenching characteristic of ceramic type arrester, it was shown that quenching ability was evaluated by the minimum flame velocity at which the flame passed through the arrester in propane-air system. With this critical velocity, good quenching ability was obtained for ceramic arrester compared with stainless steel crimped ribbon type arrester. Equivalent diameter and the length were important parameters, in flame quenching ability of these arresters especially for the arrester with smaller size of equivalent diameter than 2 mm, flame quenching ability increased with increase of the thickness remarkably. There were no material effect but surface roughness effect on quenching ability was obtained.The effect of position of arrester on flame quenching characteristic was also discussed. At curved region in piping flame velocity would be accelerated, and therefore arrester should not set up at curved region or just behind there. Because along with the flame propagation the flame temperature was increased, the arrester should be set up within short run up length. When the flame propagates downward, the flame often stagnates at the arrester, and some times the stagnated flame passed through after a certain stagnation time. In this case, the critical velocity is not a good factor to evaluate the quenching ability of arrester. Therefore, the arrester should not set up where the flame propagates downward.