SEAWATER INFILTRATION METHOD AND WATER INFILTRATION INTAKE UNIT

摘要

To clean sediments and the like trapped not only in a top layer of a sand filtration layer, but also in intermediate layers. A seawater infiltration method which uses a water infiltration intake unit which is formed in advance and provided with a water intake pipe embedded in a gravel layer which forms a deep layer of the sand filtration layer, and a backwashing pipe embedded in a sand layer which forms an intermediate layer and a surface layer of the sand filtration layer, and a water suction pipe which is disposed above the sand layer. A desired number of water infiltration intake units are combined to form a sand filtration layer at an installation site on an ocean floor, and they intake seawater from the sea which has undergone natural infiltration in the sand filtration layer and this is introduced into the water intake pipe. The seawater infiltration rate is set at less than 400 m/day. Water or air is injected from the backwashing pipe to agitate and blow upward from the surface layer living organisms or sediments trapped in intermediate layers of the sand filtration layer, and the agitated water is sucked in by a suction pipe and recovered. The seawater infiltration rate can be maintained as high as possible under 400 m/day.

主权项

1. A seawater infiltration method which uses water infiltration intake units combined to form a sand filtration layer at an installation site on an ocean floor, wherein each of the water infiltration intake units comprises a water intake pipe embedded in a gravel layer which forms a deep layer of the sand filtration layer, and a backwashing pipe embedded in a sand layer which forms an intermediate layer and a surface layer of the sand filtration layer, and intakes seawater from the sea which has undergone natural infiltration in the sand filtration layer and been introduced into the water intake pipe, comprising:
setting a seawater infiltration rate at less than 400 m/day, and injecting water or air from the backwashing pipe to agitate and blow upward from the surface layer living organisms or sediments trapped in intermediate layers together with living organisms accumulated in the surface layer, thereby preventing clogging of the sand filtration layer.