FLAME PROPAGATION IN INDUSTRIAL SCALE PIPING

摘要

1. Flame speed and pressure generation in a pipeline deflagration are strongly dependent on fuel composition. As lower and upper flammability limits are approached, the flame can still propagate slowly but without the generation of significant pressure. This latter point is of significance when pressure is employed as the indicator of an explosion. 2. Pipe diameter has an effect on flame propagation. It is minimal in the area of L/D from 1 to ～ 50. In this section of the pipe, the flame velocity is not effected by diameter. Beyond L/D of 50, flame speed increases with pipe diameter. 3. Flame speed is proportional to burning velocity 4. Bends in the pipeline have some effect on flame propagation behavior but its is less than anticipated. With normal hydrocarbons (propane), a 90°bend causes a temporary rise in flame speed that doesn't persist. A bend at a high L/D, however, does result in significantly higher pressures. Pressure development due to bends reaches levels as high as 150 barg. 5. The Length to Distance ratios at DDT were found to be as expected. They ranged from 60 to 70, decreasing with increasing burning velocity and slightly decreasing with pipe diameter.