| 摘要 |
PROBLEM TO BE SOLVED: To prevent at a low cost backflow of sewage from a sewage basin that accommodates rainwater into a source of sewage in a house.SOLUTION: An excess water drainage port 11 that opens toward the outside of a house 1 is formed on a flow channel at a location lower than a source of sewage 6 of the house 1, and made to communicate with a rainwater lead-in pipe 4 connected to a sewage basin 2 that stores and drains sewage from the house 1. The excess water drainage port 11 may be provided with a cover 16 that normally closes the excess water drainage port 11 and opens the excess water drainage port 11 automatically by water pressure from the rainwater lead-in pipe 4, before sewage inside the sewage basin 2 reaches the source of sewage 6. Furthermore, a flow amount throttle device 24 may be provided on the rainwater lead-in pipe 4 at a location closer to a clear water tank 2 than the excess water drainage port 11, the flow amount throttle device restricting amount of rainwater flowing into the sewage basin 2.SELECTED DRAWING: Figure 1 |
