Experimental Investigation of Vessel Volume and Equivalence Ratio in Vented Gas
An experiment of vented gas explosions involving two
different cylinder vessel volumes (0.2 and 0.0065 m3) was reported,
with equivalence ratio (Φ) ranged from 0.3 to 1.6. Both vessels were
closed at the rear end and fitted at the other side with a circular
orifice plate that gives a constant vent coefficient (K =Av/V2/3) of
16.4. It was shown that end ignition gives higher overpressures than
central ignition, even though most of the published work on venting
uses central ignition. For propane and ethylene, it is found that rich
mixtures gave the highest overpressures and these mixtures are not
considered in current vent design guidance; which the guideline is
based on mixtures giving the maximum flame temperature. A strong
influence of the vessel volume at constant K was found for methane,
propane, ethylene and hydrogen-air explosions. It can be concluded
that self- acceleration of the flame, which is dependent on the
distance of a flame from the ignition and the ‘suction’ at the vent
opening are significant factors affecting the vent flow during
explosion development in vented gas explosion. This additional
volume influence on vented explosions is not taken into account in
the current vent design guidance.
[1] European Standard : Gas Explosion Venting Guidance EN 14994:2007,
2007.
[2] D. Bradley and A. Mitcheson, The venting of gaseous explosions in
spherical vessels.II-Theory and experiment , Combustion and Flame, 32,
1978b, pp. 237-255.
[3] S. Chippett, Modelling of Vented Deflagrations. Combustion and Flame,
55, 1984, pp.127-140.
[4] V.V. Molkov, Theoretical Generalization of International Experimental
data on Vented Gas Explosion Dynamics, Physics of Combustion and
Explosions, 25, 1995, pp. 165-181.
[5] V.V. Molkov, Unified correlations for vent sizing of enclosures at
atmospheric and elevated pressures, Journal of Loss Prevention in the
Process Industries, 14, 2001, pp. 567-574.
[6] NFPA 68: Guide for Venting of Deflagrations: 2007, National Fire
Protection Association, 2007.
[7] D.M. Razus and U. Krause, Comparison of empirical and semi-empirical
calculation methods for venting of gas explosion, Fire Safety Journal,
36, 2001, pp. 1-23.
[8] E. Runes, Explosion venting, Plant Operations & Loss Prevention, 6,
1972, pp. 63-71.
[9] R. Siwek,Explosion venting technology, Journal of Loss Prevention in
the Process Industries, 9(1), 1996, pp. 81-90.
[10] W. Bartknecht, Explosions-Schultz. 1993, Berlin: Springer-Verlag.
[11] R.M. Kasmani, Willacy, S.K., Phylaktou, H.N. and Andrews, G.E., Selfaccelerating
gas flames in large vented explosions that are not accounted
for in current vent design, 2nd International Conference on Safety and
Environment in Process Industries, Naples, Italy, 2006.
[12] European Parliament and Council Directive 1994/9/EC, The Explosive
Atmosphere Directive (ATEX), 94/9/EC, 23.3.1994
[13] G. Ferrara, Benedetto, A.Di, Salzano, E and Russo, G., CFD analysis of
gas explosions vented through relief pipes, Journal of Hazardous
Materials, 137, 2006, pp. 654-665.
[14] R.M. Kasmani, Andrews, G.E. and Phylaktou, H.N., Experimental study
on vented gas explosion in a cylindrical vessel with a vent duct, Process
Safety and Environmental Protection, In Press, Corrected Proof,
Available online 1 June 2012.
[15] G.E. Andrews and Bradley, D., Determination of burning velocity: A
critical review, Combustion and Flame, 20, 1973, pp. 77-89.
[1] European Standard : Gas Explosion Venting Guidance EN 14994:2007,
2007.
[2] D. Bradley and A. Mitcheson, The venting of gaseous explosions in
spherical vessels.II-Theory and experiment , Combustion and Flame, 32,
1978b, pp. 237-255.
[3] S. Chippett, Modelling of Vented Deflagrations. Combustion and Flame,
55, 1984, pp.127-140.
[4] V.V. Molkov, Theoretical Generalization of International Experimental
data on Vented Gas Explosion Dynamics, Physics of Combustion and
Explosions, 25, 1995, pp. 165-181.
[5] V.V. Molkov, Unified correlations for vent sizing of enclosures at
atmospheric and elevated pressures, Journal of Loss Prevention in the
Process Industries, 14, 2001, pp. 567-574.
[6] NFPA 68: Guide for Venting of Deflagrations: 2007, National Fire
Protection Association, 2007.
[7] D.M. Razus and U. Krause, Comparison of empirical and semi-empirical
calculation methods for venting of gas explosion, Fire Safety Journal,
36, 2001, pp. 1-23.
[8] E. Runes, Explosion venting, Plant Operations & Loss Prevention, 6,
1972, pp. 63-71.
[9] R. Siwek,Explosion venting technology, Journal of Loss Prevention in
the Process Industries, 9(1), 1996, pp. 81-90.
[10] W. Bartknecht, Explosions-Schultz. 1993, Berlin: Springer-Verlag.
[11] R.M. Kasmani, Willacy, S.K., Phylaktou, H.N. and Andrews, G.E., Selfaccelerating
gas flames in large vented explosions that are not accounted
for in current vent design, 2nd International Conference on Safety and
Environment in Process Industries, Naples, Italy, 2006.
[12] European Parliament and Council Directive 1994/9/EC, The Explosive
Atmosphere Directive (ATEX), 94/9/EC, 23.3.1994
[13] G. Ferrara, Benedetto, A.Di, Salzano, E and Russo, G., CFD analysis of
gas explosions vented through relief pipes, Journal of Hazardous
Materials, 137, 2006, pp. 654-665.
[14] R.M. Kasmani, Andrews, G.E. and Phylaktou, H.N., Experimental study
on vented gas explosion in a cylindrical vessel with a vent duct, Process
Safety and Environmental Protection, In Press, Corrected Proof,
Available online 1 June 2012.
[15] G.E. Andrews and Bradley, D., Determination of burning velocity: A
critical review, Combustion and Flame, 20, 1973, pp. 77-89.
@article{"International Journal of Chemical, Materials and Biomolecular Sciences:50337", author = "Rafiziana M. Kasmani and Gordon E. Andrews and Herodotos N. Phylaktou and Norazana Ibrahim and Roshafima R. Ali", title = "Experimental Investigation of Vessel Volume and Equivalence Ratio in Vented Gas", abstract = "An experiment of vented gas explosions involving two
different cylinder vessel volumes (0.2 and 0.0065 m3) was reported,
with equivalence ratio (Φ) ranged from 0.3 to 1.6. Both vessels were
closed at the rear end and fitted at the other side with a circular
orifice plate that gives a constant vent coefficient (K =Av/V2/3) of
16.4. It was shown that end ignition gives higher overpressures than
central ignition, even though most of the published work on venting
uses central ignition. For propane and ethylene, it is found that rich
mixtures gave the highest overpressures and these mixtures are not
considered in current vent design guidance; which the guideline is
based on mixtures giving the maximum flame temperature. A strong
influence of the vessel volume at constant K was found for methane,
propane, ethylene and hydrogen-air explosions. It can be concluded
that self- acceleration of the flame, which is dependent on the
distance of a flame from the ignition and the ‘suction’ at the vent
opening are significant factors affecting the vent flow during
explosion development in vented gas explosion. This additional
volume influence on vented explosions is not taken into account in
the current vent design guidance.", keywords = "Equivalence ratio, ignition position, self-acceleration
flame, vented gas explosion.", volume = "6", number = "10", pages = "899-5", }