Fire Safety Science Digital Archive

A new metal foam material was examined for its effectiveness in absorbing the pressures formed by gas explosions in a sealed 2.8 litre (1/10 ft3) cubic vessel. A range of different porosity grades of the metal foam were examined in conjunction with (a) Propane, (b) Ethylene and (c) Hydrogen/air flammable gas mixtures. The finest grade (porosity 80) when present to the extent of 50 per cent by volume, reduced the explosion pressure from approximately 620 kN/m² (90 psi) to 83 kN/m² (12 psi) for all three gases tested. The results obtained were found to be very lose to the values predicted by a theoretical expression derived. This effect is considered to be valuable in the protection of electrical equipment used in flammable atmospheres.