| 摘要 |
<p>PURPOSE:To keep activity of catalytic assemblies for a long period of time and prolong their lives by using a first catalytic assembly carrying a catalytic composed mainly of an oxide of noble metal and a second catalytic assembly carrying a catalytic composed mainly of an oxide of transition metal. CONSTITUTION:A cylindrical flow passage 1 has, in part thereof, a catalytic assembly 31 having a honeycomb structure and carrying a catalyst composed mainly of an oxide of noble such as palladium, which is disposed on the upstream side of the interior of said flow passage, and a catalytic assembly 32 having a honeycomb structure and carrying a catalyst composed mainly of an oxide of transition metal such as manganese, which is disposed on the downstream side of the interior of the flow passage, each catalytic assembly being provided at two places separately along a direction 5 in which inflammable gas flows. Further, a gap 8 is provided between these catalytic assemblies, and a porous solid layer 71 made of a heat-resistant material is provided in the gap 8. Accordingly, the catalytic assembles 31, 32 can be usually used at temperatures suitable to their respective capabilities, and a mixed gas can be burned even when it is preheated at a relatively low temperature. Since the catalytic assembly 31 composed mainly of an oxide of noble metal is disposed om the upstream side and permits the mixed gas having a relatively low temperature to pass there through, its life can be prolonged.</p> |
