Fire Safety Science Digital Archive

Flame tip height, width, and height to base of a lifted flame were observed based on eye observation using a ejected fuel gas through a pipe. Fuel gas was supplied through regulators at the rate of 1001/min, 2001/min, and 4001/min which was ejected from a pipe of 1/8B, 1/4B, 3/8B, 1/2B, 3/4B, and IB, respectively. Pipe heights from the top surface of a dummy bomb were set at 200mm, 700mm, and 1700mm, respectively in order to measure the effect of stand-off distance which reduced the feed back of radiative heat flux to the dummy bomb. Radiative heat flux were also measured at 0.1m, 0.27m, 0.71m, 1.1m, 1.27m, 1.71m, 1.9m, 2.9m from the pipe at the same horizontal level of the dummy bomb. Temperatures in the dummy bomb and on which surface, as well as in a flame along the flame axis (center line of the flame) were measured. Dimensionless flame height, Ha/D, and dimensionless flame width, Wf/D \were correlated well by 1/3 power of dimensionless heat release rate, Q*1/3. Radiative heat fluxes to the dummy bomb were also estimated using the view factor, and center-line temperature, assuming translucent and mufti-ring flame configuration piled up. Estimated radiative heat flux to the dummy bomb were compared with the measured ones and good conformation between them was obtained. This implies that the estimation method on radiative heat flux to the foot of the flame ejection pipe is useful to assess the radiative heat flux for fire safety design of propane gas bomb.