| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for effectively preventing seal water of a water seal part of a water seal type drain trap from reducing by sewage side negative pressure.SOLUTION: When waste water is not expected to flow to a drain trap such as in the case of long-term absence, the seal water is stabilized by inputting an additive A (a low mobility realizing agent) such as converting the seal water into high viscosity or low mobility to the seal water. While, the seal water is converted into low viscosity or high mobility by inputting an additive B (a high mobility realizing agent) before making the waste water flow to the drain trap when returned from the long-term absence. Thus, a resident can cope with reduction in the seal water by the negative pressure in the absence. Thus, a role of the seal water can be maintained even in the absence, and use can also be immediately started when coming home. |
