Effectiveness of an active dust and gas explosion suppression system

Abstract

The research aimed to test the effectiveness of gas and  dust explosion suppression by means of a super fast explosion suppression system with a volume of 5 dm3. Smokeless powder as an explosive charge and sodium bicarbonate as a suppressing material were used. The experiments were carried out using a prototype device – a 5 liter steel container, closed by means of an aluminum membrane. Approximately 1.75 kg of extinguishing powder was placed in the container. The membrane was ruptured by exploding a specially developed charge located inside a perforated steel combustion chamber and mounted over the suppressing powder surface. The system was triggered by a signal from the protected volume, sent by a pressure transducer or by a photodiode reacting to a developing flame. The investigations into the efficiency of the active explosion suppression system were carried out in the 1.3 m3 explosion chamber. The explosion was initiated in a corn starch-air mixture of 0.2 kg/m3 concentration, or in a methane-air mixture of 7.5% and 8.5% CH4 concentration. The explosion suppression process occurred through the action of the extinguishing powder blown out from the extinguisher after the compressed combustion products perforated the membrane.