AN INVESTIGATION OF EXPLOSION DEVELOPMENT IN A CHLORINATED HYDROCARBON-AIR MIXTURE IN A COMPLEX PIPE GEOMETRY

ABSTRACT The paper describes results obtained from an experimental programme to determine the explosion development characteristics of mixtures of vinyl chloride monomer (VCM) and carbon monoxide in oxygen plus nitrogen atmospheres. The main complex experimental pipe configuration and mixtures studied reproduced, as accurately as possible, a process configuration identical to that used in a real operational process plant. A commercial flame arrester device (nominal channel size 0.475 mm) was also tested on occasions. The test pipe configurations used 300 mm nominal bore steel pipe. The main test series were conducted in a configuration that included three standard 1.5 D bends, as part of on overall pipe length of ca. 20 m. In certain tests the flame arrester was placed after the third bend, furthest from the spark ignition source. Some initial commissioning tests were made using a single straight section, 4 m long. This allowed some overpressure development measurements of VCM mixtures to be compared with those for ethylene mixtures. In addition the flame acceleration characteristics of VCM/CO/O2/N2 mixture in the full 20 m geometry have been quantified and compared to the behaviour observed with propane/O2/N2 mixtures. For both fuels a distinct change in flame acceleration characteristics with reduced nitrogen content was observed. Some of the present observations give rise to some serious concerns regarding the methods used to select explosion arresters