Catalytic pre-mixed fibre burners

The performances of three pre-mixed fibre burners (maximum rated power: 30 kW), based on the same FeCrAlloy porous support, were tested in a specific pilot plant. The first one was a commercial FeCrAlloy panel (the reference burner); the other two were catalytically activated by deposition onto the fibres of the LaMnO3 perovskite, according to two different procedures:'dir ect' and 'indirect route'. The latter, in which an LaAlO3 layer was placed between the catalyst and the fibres to prevent deactivation, should be pref erred for the presumably major stability and constant performance in the lo ng term. The flue gas temperature, the NOx, CO and HC flue gas concentratio ns and the emission intensity of the panel surface, were measured as a func tion of E-a (excess of air) and Q (specific heat power). Besides, the opera ting combustion regimes (radiant, transition and blue-flame) were identifie d by direct observation of the burner surface. As compared to the non-catal ytic burner, the two catalytic ones enabled, with nearly unchanged NOx prod uction, up to about 5 times lower CO and HC emissions, particularly in the radiant combustion regime. As a result, a wider rangeability of the burner (down to about 10% of the maximum specific operating power, where non-catal ytic burner failed), with environmentally acceptable flue gas composition, was achieved. (C) 1999 Elsevier Science Ltd. All rights reserved.