| 摘要 |
PURPOSE:To dissolve away the poisonous materials on the surface of the catalyst while mounting said catalyst in an automobile by introducing steam from the exhaust system to the upper stream side of the catalyst whose activity has decreased, thence ammonia gas to said catalyst. CONSTITUTION:When poisonous materials such as phosphorus and lead deposite on the surface of the pellet catalysts 4 coated with Pt-Rh on alumina carriers and the activity of the catalysts have decreased, steam- and NH3 gas feeders 8, 10 are connected to an exhaust pipe 5 communicating an exhaust manifold 2 and catalyst chamber 3. First, an on-off valve 12 is opened to introduce an amount of steam by which water drops deposit on the surfaces of the catalysts 4 to said catalysts from the feeder 8. Thence, an on-off valve 13 is opened to introduce an amount of NH3 by which the water deposited on the catalysts 4 is saturated to the catalysts from the feeder 10. NH3 gas dissolves in the deposited water to farm and deposit aq. ammonia, thereby dissolving phosphorus, lead, etc. Thereafter, the feeders 8, 10 are removed and when an engine 1 is operated, the poisonous materials removed from the catalyst surface are discharged together with aq. ammonia, whereby the activity of the catalysts is restored. |
