| 摘要 |
Improved reactors for catalytic, exothermic gas phase reactions with, as seen in the flow direction of a feed gas, which contains at least one oxidant and at least one component to be oxidized, an entry zone (1), a reaction zone (2) comprising at least one catalyst (4) and an exit zone (3) for the product gas are described. The reactors, at least in the area of the entry zone (1), have means, for example insulating jackets (6) and/or devices for the transport of cooling agents, which decrease the transport of heat produced in the reaction zone (2) into the entry zone (1) and thus decrease the risks of pre-ignition of the feed gas mixture employed or of the course of undesired side reactions in the entry zone (1) and/or wherein the inner walls of the reactor, at least in the area of the entry zone (1), are elaborated from inert material. The feed gas enters into the entry zone (1) as a homogeneous gas mixture with respect to its substance composition via one or more feed lines (30). The reactors can especially be employed for ammonia oxidation, for example in nitric acid plants, in which transition metal catalysts preferably elaborated in honeycomb form with smaller cross sections than the customarily employed platinum gauzes are used. |
