A new apparatus for flame spread experiments

In fire-PSAs of nuclear power plants, flame spread on solids, especially cables, is a significant scenario. In previous projects at VTT on fire safety in nuclear power plants, a new instrument for measuring flame spread at different ambient temperatures was proposed. This report presents the realization of the new apparatus for flame spread measurements on 2 m long samples, as well as start-up tests on the instrument describing its functionality, and flame spread experiments. Air flow and heating tests were carried out to examine the features of the new instrument. Two series of flame spread experiments were carried out, on cylindrical birch wood samples and PVC cable samples. Flame spread velocities in the range 6 ... 62 mm/s were determined in a temperature at ignition range 22...271 oC for wood samples and velocities 3...8 mm/s in a temperature at ignition range 22...187 oC for PVC cable samples. The new apparatus seems to be appropriate for determining vertical flame spread as a function of temperature.