Abstract:

 In this paper, an experimental system was designed and set up to investigate the relationship between the filling pressure of FK-5-1-12 and the response of suppressing class B fire, which composed of a experimental device of suppressingclass B fire with FK-5-1-12 and collection device of exhaust.The pressure in fire-extinguishing bottle, pressure at nozzle, mass flow of FK-5-1-12, fire-extinguishing time and the exhaust composition were measured respectively at the different filling pressure of fire-extinguishing bottle. The HF content in the exhaust was measured by Ion chromatography method and the other gas component was measured by GC-MS. The results showed that the mass flow rate increased as the filling pressure was increased from 1.5 MPa to 4.2 MPa.The increment of mass flow was about 30% when the filling pressure was between 1.5 MPa and 2.5 MPa. That growth rate was about 5% when the filling pressure was between 2.5 MPa and 4.2 MPa.The HF quantity inexhausted was decreased by 40% at the same time. Besides，the hexafluoropropylene, heptafluoropropane, perfluoropropane, perfluoroheptane were detected inexhausted.

Key words:  , filling pressure, Class B fire, FK-5-1-12, fire-extinguihing time, discharge mass flow, HF content