Reverse-flow-free nanofiltration apparatus or reverse osmosis apparatus and shutdown method thereof

Abstract

The present invention discloses a reverse-flow-free nanofiltration apparatus or a reverse-flow-free reverse osmosis apparatus, and in particular relates to a shutdown reverse-flow-free nanofiltration apparatus or a shutdown reverse-flow-free reverse osmosis apparatus. The shutdown reverse-flow-free nanofiltration apparatus or the shutdown reverse-flow-free reverse osmosis apparatus includes an adjusting tank and a filter film unit which is connected with the adjusting tank, the filter film unit is provided with a water inlet and two water outlets, the two water outlets are respectively connected with a production water tank and a concentration water tank, the concentration water tank and the production water tank are respectively provided with water discharge ports, the production water tank is provided with two water discharge ports, and one of the water discharge ports is connected with the water inlet of the filter film unit. When in shutdown work, water in the production water tank is led into the water inlet of the filter film unit by a pipe to replace water in the adjusting tank for sustained input, the phenomenon of reverse flow, which is caused by internal high osmotic pressure due to sudden shutdown of a high-pressure pump, of production water of a film to a concentration water side can be effectively avoided, filtrationfilm surface wrinkling and damage can be avoided, filtrationfilm desalination performance and system stability can be ensured, and the service life of the reverse-flow-free nanofiltration apparatus or the reverse-flow-free reverse osmosis apparatus can be prolonged.

Description

technical field [0001] The invention relates to a water purification device, in particular to a nanofiltration device or a reverse osmosis device without reverse flow when shut down. [0002] The invention relates to a shutdown method of a non-reverse flow nanofiltration device or a reverse osmosis device. Background technique [0003] In wastewater zero discharge projects, nanofiltration or RO is usually installed in the front of the evaporation crystallizer to re-concentrate the wastewater. The salt content of wastewater entering nanofiltration or RO is relatively high, reaching 40,000-50,000mg / L. We found that in actual projects, if the high-salt nanofiltration device or reverse osmosis device is shut down in the traditional way, the high-pressure pump suddenly stops working, because the main driving pressure of the inner membrane of the permeation tube disappears, and the high-concentration on the concentrated water side Na 2 SO 4 Or high TDS will generate high osmoti...

AI Technical Summary

Problems solved by technology

We found that in actual projects, if the high-salt nanofiltration device or reverse osmosis device is shut down in the traditional way, the high-pressure pump suddenly stops working, because the main driving pressure of the inner membrane of the permeation tube disappears, and the high-concentration on the concentrated water side Na 2 SO 4 Or high TDS will generate high osmotic pressure, which will cause the permeate water of the membrane to flow back to the concentrated water side, which will cause wrinkling damage on the surface of the NF / RO membrane, and cause large irreparable damage to the nanofiltration membrane / reverse osmosis membrane. Physical damage, which seriously affects the desalination performance of the membrane and system stability, and reduces the service life of the nanofiltration device or reverse osmosis device

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