With the continuous improvement of industrial production technology, water treatment is getting closer and closer to our daily life. Ultrafiltration technology has been widely used in drinking water treatment, wastewater industrial sewage treatment, RO reverse osmosis pretreatment and other fields.
1. Ultrafiltration membrane principle
Uf filter membrane is a whole screening process related to the diameter of the membrane. The pressure difference on both sides of the membrane is used as the driving force, and the uf filter membrane is used as the filter material. Under a certain working pressure, when the raw liquid passes through the membrane surface. , many microplates covered on the surface of ro uf membrane only allow water and small molecular water materials to pass through the liquid, while the raw liquid material whose volume exceeds the microdiameter of the membrane surface is intercepted to the leakage side of the membrane to become the extraction liquid, so as to achieve The purpose of purifying, separating and dissolving the stock solution.
2. Filtration method of uf filter membrane
①. Internal pressure filtration:
The raw liquid first enters from the inner thread of the membrane wire, is pushed by the pressure difference, and penetrates into the hollow fiber from the inside to the outside along the axial direction, and is filtered by internal pressure through the liquid. The radial direction passes quickly, so that the pollutants attached to the surface of the inner pores of the membrane can be washed away and the water diffusion coefficient of the membrane can be repaired.
②. External pressure filtration:
The raw liquid penetrates into the membrane wire from the outside along the axial direction through the pressure difference and becomes the through liquid. When the intercepted material gathers outside the hollow wire, it is filtered by external pressure. The external pressure ro uf membrane is sealed in the membrane shell, and there are many blind spots in the flowing water. The pollutants attached to the membrane surface cannot be removed by a rapid impact method, and the pollutants cannot be completely removed.
③. Dead end filtering:
All the moisture in the stock solution penetrated into the uf filter membrane, and no extract was discharged. When the concentration of substances separated in the raw liquid is very low, in order to better reduce energy consumption, dead-end filtration is generally selected.
④. Cross-flow filtering:
During filtration, some of the concentrated liquid is discharged from the other end of the uf filter membrane . When the concentration of substances that can be cut off by the membrane in the original solution is high, the frictional resistance of the membrane will increase rapidly. At this time, cross-flow filtration is commonly used.
3. Characteristics of uf filter membrane
①. The separation is realized at normal temperature and low voltage, so the energy consumption is low, thereby reducing the operating cost of the equipment.
②. The mechanical equipment is small in size, simple in structure and low in project investment cost.
③. The whole process of membrane separation technology is simple pressurized transportation of liquid, the production process is simple, and the actual operation, maintenance and management methods are convenient.
④. The water diffusion coefficient is large, the filtration precision is high, and the water utilization rate is high.
⑤. Low product cost and low operating cost.