Flammability limits of combustible gases and vapors measured by a tubular flame method

Development of an automated flammability burner system

“…Since the tubular burner system is very simple and has the potential to give results which closely resembte an actual situation, NRLFD (Liao et al, 1996;Satio et al, 1995 and1997;Ogawa et al, 1998) They concluded that the flammability limits are independent of burner size when the flame stretch rate is kept constant. This important conclusion will be used later in Chapter 4 to validate the selection of the working range of mass flow controllers.…”

“…Where: In the case of the tubular bumer with the 30-mm diameter, an injection velocity of 5 c d s was employed as a standard injection velocity in the NRIFD study (Liao et al, 1996;Satio et al, 1995 and1997;Ogawa et al, 1998). Under this injection velocity, not only was the flame securely stable, but a wide and repeatable flammability range could be obtained (Satio et al, 1995 and1997).…”

“…Increasing injection velocity causes the fiammability range to narrow due to a larger flame stretch rate (Kobayashi and Kitano, 1989). If the injection velocity is smaller than 5 c d s , a larger amount of heat loss from the flame to the bumer wall may result in narrow ranges, and the unstable flame rnay lead to unrepeatable results (Liao et al, 1996). Therefore al1 measurements of the limits were Saito et al (1997) at NRiFD also built a 7.9-liter explosion vesse1 to compare the results obtained from t h e tubuiar flame burner system.…”

“…( (2) A larger range of flammability limits was obtained because of less heat loss from the flarne zone (Liao et al, 1996).…”

“…Figure 2.8 Schematic diagram of tubular flame bumer system used by NRlFD (Liao et al, 1996;Satio et al, 1995 and1997;Ogawa et al, 1998) …”