A non-reverse flow nanofiltration device or reverse osmosis device and its shutdown method

Abstract

The invention relates to a non-reverse flow nanofiltration device or reverse osmosis device, in particular to a device for shutting down the non-reverse flow nanofiltration device or reverse osmosis device. The present invention includes a regulating tank and a filter membrane unit connected with it. The filter membrane unit is provided with a water inlet and two water outlets, and the two water outlets are respectively connected to a water production tank and a concentrated water tank. The concentrated water tank and The water production tanks are respectively provided with water outlets, and the water production tanks are provided with two water outlets, one of which is connected to the water inlet of the filter membrane unit. The device of the present invention, during shutdown, introduces the water in the water production tank into the water inlet of the filter membrane unit through the pipeline to replace the continuous input of water in the adjustment tank, effectively avoiding the sudden stop of the high-pressure pump, resulting in internal The phenomenon that the produced water of the membrane flows to the concentrated water side caused by high osmotic pressure avoids the wrinkling and damage of the membrane surface, ensures the desalination performance of the membrane and the stability of the system, and prolongs the nanofiltration device or reverse osmosis device. service life.

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

Images