Our equipment needs to use reverse osmosis membrane. The reverse osmosis process is driven by the pressure difference on both sides of the membrane, so the working pressure level applied to the concentrated water side of the membrane element becomes an important technical indicator. The working pressure of the early aromatic polyamide composite membrane was 200PSI, and the working pressure of the low-pressure and ultra-low pressure composite membranes that have been released in the past 20 years has dropped to 150PSI and 100PSI. The reduction of the working pressure can not only reduce the design pressure of the feed pump and the rated pressure of the pipeline, but also reduce the equipment investment; it can also directly reduce the electrical power loss of the membrane system, fully demonstrating the low energy consumption advantage of the membrane technology. The reduction of working pressure is based on the specific water flux (also known as water flux, membrane flux or flux), so another way to reduce the working pressure is to increase the water flux of the membrane body under the specific working pressure. .
When the working pressure of the membrane is lower than 1.0MPa, the osmotic pressure of the concentrated water in the system will be in the same order of magnitude as the pure driving pressure. In the low-pressure membrane system, under the conditions of high system yield, high feed water salinity and long system flow, the flux of each membrane element in the system flow will be seriously unbalanced. Therefore, the advantages of ultra-low pressure membranes are mainly reflected in the limited environment of commercial and residential small systems or low-salt water supply.