| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve engine power by raising the efficiency of purification by increasing a quantity of exhaust gases in contact with a catalyzer, while simplifying the structure of this device, and preventing it from becoming an obstacle to the propagation of a pressure wave. SOLUTION: In this device, a downstream end of a convergent cone part 15 constituting an exhaust pipe 10 of a surface traveling boat 1 is blocked up, and a double-pipe structural catalyst holding pipe 16 is joined to a pheripheral surface of a straight part constituting the exhaust pipe 10, having a catalyzer 22 built in an upstream part of the inner pipe. Since this catalyzer 22 is fitted in the inner pipe of this catalyst holding pipe 16 free of detachment, a quantity of an exhaust gas in contact with this catalyzer 22 is increased, whereby the efficiency of purification can be improved, while a workability for maintenance and inspection operations over the catalyzer 22 can be improved as well. In addition, since the catalyzer 22 is directly fitted in the inner pipe, a catalyst keeping holder or the like can be omitted, and thus a reduction in the number of component items and structural simplification or the like can be expected.</p> |
