| 摘要 |
PROBLEM TO BE SOLVED: To clean the inside of a pipeline by dredging even earth and sand built up in a large-sized or zigzag pipeline definitely and efficiently. SOLUTION: A high air-tight tubular envelop 5, which is connected to a compressor 7 (a compressed air supply source), is inserted into a pipeline 1. Then, a compressed air is supplied to the tubular envelope 5, thereby expanding the tubular envelop 5. The inside of the pipeline 1 is blocked with the expanded envelop 5 so that water may be accumulated in the upstream area of the tubular envelop 5. When a specified amount of water is accumulated, the compressed air is vented gradually from the tubular envelop 5 so that the accumulated water may flow in a clearance between the tubular envelop 5 and the pipeline 1, thereby carrying downstream the water with earth and sand 3 built up the bottom of the pipeline 1. The earth and sand 3 is dammed up with a sandbag (weir) 13 provided on the downstream side and pumped up to the ground together with the water by means of a sand pump 12. Since the tubular envelop is insertible easily into a large-sized or zigzag pipeline due to this construction and functions as one type of a valve, it is possible to carry downstream even the earth and sand 3 built up in the pipeline and dredge the earth and sand 3 definitely. |
