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Indexed by:期刊论文

Date of Publication:2019-09-01

Journal:JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES

Included Journals:SCIE、EI

Volume:61

Page Number:89-93

ISSN No.:0950-4230

Key Words:Flammability limit; Refrigerant; HCFC-22/air mixtures; Elevated pressure

Abstract:Even if HCFC-22 is no longer considered acceptable due to the Montreal Protocol, it still has potential explosion hazards as an intermediate material for fluorine industry. This paper conducts a research on the flammability limits of HCFC-22/air mixtures at elevated pressures which gradually rise up to 1.0 MPa. A 1.5 L cylindrical vessel was designed to perform the experiments. Experimental data obtained by using two kinds of ignition sources (coiled nichrome wires and chemical igniters) were compared. Results show that HCFC-22/air mixtures can be flammable under ignition energy of hundreds of joules at elevated pressures. The range of flammability limits widened obviously with the increasing initial pressure when the mixtures were ignited with chemical igniters, while flammability limits had a narrow and irregular range when the mixtures were ignited with coiled nichrome wires. Algebraic functions which satisfy the variations of flammability limits obtained with chemical igniters were presented. In addition, explosion pressure curves with three peaks were found when the initial pressure was higher than 0.9 MPa. Key reactions of a possible explosion mechanism are proposed.