What should I pay attention to about microfiltration of large flow water filter?

When a large flow filter element is used for filtering, the filtering process mainly comes from the driving force, which is the pressure on the fluid formed by the pressure difference, and the fluid is filtered by applying pressure through the pressure difference. A large flow filter element is used to filter the liquid, which can filter out the small particles in the liquid through the membrane, and these small particles are intercepted by the filter membrane and collected for centralized treatment. The retention and filtration of the impurity particles in the fluid is mainly determined by the nature of the filter membrane. Its filtration is mainly based on whether there is a connection between the filter membrane and the performance of the particles, whether there is an interaction performance, so as to filter out the impurities. The main principle of filtration and sieving is to use the filter membrane with a larger pore size than the size of the impurity particles, and then block the impurity particles from the outside so that they cannot pass through the filter membrane, thereby separating and filtering them out. If the size of the impurity particles is smaller than the pore size of the filter membrane, then they can pass through the filter membrane to enter the membrane pores. These fine particulate impurities will adhere to the pore wall in the membrane pores and be filtered out. This kind of filtration The method is realized inside the membrane body, so this separation filtration is also different from the basic separation filtration, which can be called deep filtration. Large-flow filter element microfiltration can be divided into two types, which are mainly distinguished according to the flow direction of the main liquid and permeate on both sides of the membrane. The two processes are co-flow and cross-flow respectively. When conducting experiments in the laboratory, filter paper and funnels are generally used to separate the precipitates in the liquid. The filtered liquid is filtered through the filter paper by means of static pressure or through the vacuum on the side of the liquid. When the filtered liquid and the permeate flow in parallel, the process is called co-current microfiltration. In this process, the impurity particles filtered and trapped by the filter membrane will gradually accumulate as the filtration progresses. The filter cake layer is formed. Depending on the filter membrane used, the trapped impurity particles will also accumulate in different places. If a surface filter membrane is used, the impurity particles will be trapped and accumulated on the surface of the membrane; if a deep filter membrane is used, Then the impurity particles will be trapped and accumulated in the membrane. No matter what kind of filtration, it will increase the filtration resistance. After all, the impurities are intercepted and accumulated in the filter element. This will cause the filtration efficiency to decrease, the filtration flux will be affected, and the pressure drop will change. Therefore, the co-flow microfiltration needs to remove the impurity particles trapped on the membrane from time to time, and the filter element can also be replaced regularly to avoid clogging the filter element and becoming unusable. When the filtered liquid flows tangentially to the membrane surface, the impurity particles in the liquid are intercepted by the membrane, and the liquid passes vertically through the membrane surface and flows out through the membrane. This process is another method of microfiltration, called Cross-flow microfiltration or tangential microfiltration. Similarly, the trapped impurity particles will also form a filter cake layer on the surface of the membrane. Because the main fluid is tangential to the membrane performance under the influence of pressure, it will cause a higher shear force, which will The filter cake layer accumulated on the membrane surface is effectively removed, making the filter cake layer accumulated by the impurity particles relatively thin. This cross-flow microfiltration method can effectively control the filter cake layer accumulated by the impurities and prevent it from clogging the filter element. The service life of the product is prolonged, and its use effect will be gradually strengthened.