Variations of the Lean Blowout Limits of a Homogeneous Methane-Air Stream in the Presence of a Metallic Wire Mesh

The combustion of a homogeneous lean methane-air stream was investigated in a vertical, cylindrical combustor of 150 mm diameter in the presence of a metallic wire mesh. Eight metallic materials were deposited in turn onto a stainless steel wire mesh by electroplating. The potential improvement in the lean blowout limit due to catalytic effects was established separately from those due to the thermal and aerodynamic contributions of the wire mesh and its holder ring. The effectiveness of the various metallic surfaces tested in the lean combustion of methane was in the following descending order: Pt → Cu → Ag → brass → Cr → Cd → Ni → stainless steel. Moreover, it was confirmed that hydrogen was more sensitive to catalytic effects extending to relatively lower temperatures than methane.