Beijing Yuanlai water Treatment equipment: The reverse osmosis process is carried out by continuously pressurizing brine with a high-pressure pump in a brine delivery device. The device consists of a pressure vessel and membrane elements. The feed water is divided into low-salinity permeate and high-salinity concentrated liquid, or called the effluent. The percentage of water supply entering the concentrate and permeate is controlled by the concentrate valve to regulate the water flow. In addition to pressure vessels, there are several groups of spiral wound membrane elements in the spiral wound membrane assembly. Inside a pressure vessel6There are many groups7Membrane element assembly. As the water supply passes through the next component, its concentration gradually increases. Then it flows out from the last group and enters the concentrated liquid control valve, where the pressure is reduced. The permeate generated by each membrane element is collected by a common permeate tube of a device and each group of elements and flows into the permeate collection tube located outside the pressure vessel. The calculation formulas for the recovery rate, salt permeability rate and desalination rate of reverse osmosis membrane modules are as follows.

Recovery rate＝Permeate flow rate/Influent flow rate*100%

Salt permeability＝Permeate concentration/Influent concentration*100%

Desalination rate＝(1--Salt transmittance*100%