| 摘要 |
PROBLEM TO BE SOLVED: To reduce construction cost; and to shorten a construction period by reducing a flow speed of sewage flowing in a de-energizing pipe by the de-energizing pipe itself for the sewage, and dispensing with a manhole and de-energizing work used for reducing the flow speed of the sewage. SOLUTION: A projecting part 20 projecting inside from the left and right is formed except for a range of a prescribed circular arc angle (for example, about 30°) of a bottom surface 12b of the de-energizing pipe 10 for the sewage and a range of a prescribed circular arc angle (for example, about 90°) of an upper surface. In a flow rate of a degree of colliding the sewage with the projecting part 20 (when the flow rate is relatively large), since flowing-down energy of the sewage can be diffused and de-energized by this collision, the flow speed of the sewage can be reduced. In a flow rate of not colliding the sewage with the projecting part 20 (when the flow rate is relatively small), reduction in the flow speed of the sewage can be prevented. COPYRIGHT: (C)2004,JPO
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