Detonation-Flame Arrester Devices for Gasoline Cargo Vapor Recovery Systems.

An experimental program was carried out to 1 develop empirical data on the deflagration-to-detonation run-up distance for flowing mixtures of gasoline and air in 15.2-centimeters- 6.0-inches- diameter piping simulating a vapor recovery system, and 2 evaluate the quenching capability of eight selected flame control devices subjected to repeated stable detonations. The deflagration-to-detonation run-up distance was found to be 11.2 m 36.7 ft, or a length-to-diameter ratio of 74. The relative roughness of the run-up length of piping was 0,010 to 0.015. The stable detonation downstream of the transition point has a velocity of 1800 ms 5906 fts with a stable peak pressure of 1900 knm2 to the 2nd power 275 psia. There appeared to be no discernable correlation between the initial flow velocity used in testing and the resulting run-up distance. Detonations were obtained only at equivalence ratios greater than 0.8 however, there was no correlation between equivalence ratio and run-up distance for equivalence ratios ranging from 0.9 to 1.4. The successful detonation-flame arresters were 1 sprial-wound, crimped aluminum ribbon, 2 foamed nickel-chrome metal, 3 vertically packed bed of aluminum Ballast rings, and 4 water-trap or hydraulic back-pressure valve.