Osmosis filtering method for sea water and osmosis water intake unit

Abstract

The invention provides an osmosis filtering method for sea water and an osmosis water intake unit to cleanse a suspended matter or the like captured on the surface of a sand filtering layer as well as on an intermediate layer. In the osmosis filtering method for sea water, an osmosis water intake unit (11) is formed beforehand in which a water intake pipe (12) is embedded in a gravel layer (13) that is for forming a lower layer of a sand filtering layer, a reverse cleaning pipe (14) is embedded in a sand layer (15) that is for forming an intermediate layer and a surface layer of the sand filtering layer, and a water suction pipe (16) is installed above the sand layer (15). A sand filtering layer is formed by combining a required number of osmosis water intake units (11) at an installation location on the sea bed. Sea water is taken in when sea water that naturally permeates through the sand filtering layer is introduced into the water intake pipe (12). The sea water permeation speed is no faster than 400m / day. A suspended matter or the like held in the intermediate layer of the sand filtering layer is agitated by injecting water or air from the reverse cleaning pipe (14), the suspended matter is blown onto the surface layer of the sand filtering layer and recovered by suctioning the agitated water from the water suction pipe (16). [Effect] The seawater permeation speed can be maintained at the highest speed possible, i.e., no faster than 400m / day.

Description

technical field [0001] The present invention relates to a filtration method and an infiltration water intake unit. The filtration method is a filtration method for water intake of seawater permeated from the sand layer on the sea bottom. The infiltration water intake unit is used for implementing the filtration method and has the function of backwashing. Pipe, etc., the backwashing pipe removes the organisms or suspended substances accumulated on the surface of the sand layer and introduced into the middle layer to prevent the clogging of the screen mesh. Background technique [0002] As a method of taking water from seawater, most of the methods such as Figure 14 As shown, for example, a direct water intake method is used to draw water from seawater from a water intake 1 arranged on the seabed through an aqueduct 2 . also, Figure 14 3 is a pump for taking water from seawater, and 4 is a reverse osmosis membrane device. [0003] However, in the direct water intake method,...

AI Technical Summary

Problems solved by technology

This indirect water intake method does not have the problems of the direct water intake method at all, but due to the high initial cost and the problem of reduced water intake due to the clogging of the mesh on the permeable surface, the spread of the method is slow.

[0008] However, in the osmotic water intake method proposed in the above-mentioned Patent Document 1, the seawater infiltration water intake rate is 1 to 8 m / day, which is a very slow filtration rate. Therefore, in order to extract a large amount of seawater in a short time, a large area is required. Larger project scale (technical problem 1)

Therefore, it is possible to reduce the seawater infiltration rate by only removing the suspended matter accumulated on the surface of the sand filter layer.

[0014] In addition, for example, in the infiltration water intake method of Patent Document 1, a support gravel layer 5a is formed at the excavation part of the seabed, and the water intake pipe 6 is buried, and a support gravel layer 5b and filter sand 5c are formed on the top of the support gravel layer 5a. At the same time, Backfilling to the seabed surface again, the above-mentioned works are all carried out on the seabed site, so the scale of the installation project is large

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