Mitigation of explosions in a vented vessel connected to a duct

The paper deals with the problem of mitigation of the explosion initiated in a vessel and vented through a duct. A solution has been studied which allows quiet evacuation of the explosion gases. without combustion intensification in the vessel and enhancement of explosion overpressures, characteristic in such a system. This can be obtained by retardation of the flame front penetrating into the duct by means of wire-net inserts placed at the entrance of the duct. The solution was tested at laboratory scale for two reactive stoichiometric mixtures (propane-air and ethylene-air). The results demonstrate that with correctly chosen inserts the maximum vessel overpressures as well as flame speed in the duct can be reduced approximately by half. For longer or/and more rightly rolled inserts it was possible to obtain total extinction of the flame in the duct, with only slightly higher vessel pressures. The solution is very promissing in the case of mixtures with low or moderate burning velocities. For those with high burning velocities it is still valid but the benefits may be less interesting.