Effectiveness of Fire Control Agents on Chemical Fires. Phase I. Test Methodology and Baseline Hexane Tests

摘要

A basic test method for comparing relative effectiveness of fire control agents on fires from liquid chemicals was set and modified through developmental tests. The methodology was then demonstrated in a test series intended to produce baseline data for comparison with future test data using other chemicals as fuels. Fuel for the baseline test series was high purity hexane. Tests were run in concrete pits with and without sheet steel wall linings and with and without steel obstructions. Pit (fuel) surface areas were 25, 100, 400 and 1600 sq ft. Foam fire control agents used were low expansion protein, AFFF, and alcohol and a saltwater high expansion foam. Dry chemical agents were used in the three smaller pit sizes and were sodium bicarbonate and potassium bicarbonate, and a urea-potassium bicarbonate reaction product. Agents were applied through fixed systems, with a few manual tests for comparison. Data collected include burning rates; fuel, wall and obstruction temperatures; radiant fluxes; agent flow rates and nozzle pressures; preburn, control, and extinguishment times; and meteorological information. Times were taken by instrumentation or observation and stopwatch. Tentatively, the best data element for comparison appears to be a plot of application rate versus control time for foams and versus extinguishment time for dry chemical agents. Future tests should establish scaling parameters to allow use of smaller surface areas for the comparative effectiveness tests.