| 초록 |
Bromotrifluoromethane (halon-1301) and bromochlorodifluoromethane (halon- 1211) have been widely used as a clean fire extinguishing agents due to their outstanding properties. However, production and use of halon are currently being phased out under international agreements Montreal Protocol because of global environmental concerns and HFCs have been considered as promising candidates for the replacement of halon since their ozone depletion potentials are low. The vapor-liquid equilibrium data for the systems nitrogen + clean fire extinguishing agents are essential because nitrogen is used as a pressurization gas to shorten the discharging time of the agents. This information is important because it will provide safety guidelines for the pressure vessels. The amount of nitrogen needed to pressurization gas is significant, a dangerously high pressure may result when the vessel is exposed to elevated temperature. Very few experimental data however, have been previously reported in the literature. In this work, we choose HFCs such as HFC-22, HFC-125, and HFC-134a for clean fire extinguishing agents and nitrogen as a pressurization gas for a proper jet velocity of these. Phase equilibria for binary mixtures of nitrogen + HFC-22, nitrogen + HFC-125, and nitrogen + HFC-134a were measured in the temperature range from 283.15 K to 303.15 K. For equilibrium measurement, we used a circulation type apparatus in which both vapor and liquid phases were continuously recirculated. The experimental result was correlated with the Peng-Robinson equation of state with Wong-Sandler mixing rules. The calculated values from equation of state have shown satisfactory results in comparison with the experimental data. |
