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Author
Edwards, R. J.
Title
Propane Inerting Concentrations of Two Halon Replacement Gases.
Coporate
Worcester Polytechnic Inst., MA
Report
Thesis
December 1993
118 p.
Keywords
halons | propane | inerting | halon alternatives | flammability | nitrogen | experiments
Identifiers
HFC-227 ea; HFC-23
Abstract
There are many candidate halon replacement gases available, but CF₃CHFCF₃, (heptafluoropropane) also known as HFC-227ea; and CHF₃ (trifluoromethane), also known as HFC-23, are two of the most promixing agents. The objective of this thesis has been to determine the propane inerting concentrations for HFC-227ea and HFC-23, and the propane inerting concentrations for blends of the agents with nitrogen. The experiments were run with near stoichiometric propane-air mixtures, in a 6 liter spherical vessel with an ignition spark discharge energy of 11 joules. The conditions inside the vessel were monitored during ignition with a pressure transducer and a K-type thermocouple. A 1.0 psig pressure was the primary criterion to delineate inerting, but temperature rise criteria were also explored. The data resulted in a CH₃CHFCH₃ inerting concentration of 11.7 volume%, which closely correlates with the Heinonen and Skggs (NMERI) value of 12.0 volume%. The data also resulted in a CHF₃ inerting concentration of 20.2 volume%, which also closely correlates with the Heinonen and Skaggs value of 19.8 volume%.