The principle of hollow fiber ultrafiltration membrane

The basic principle is to use the asymmetric microporous structure and semi-permeable membrane medium at room temperature with a certain pressure and flow rate, relying on the pressure difference between the two sides of the membrane as the driving force, and filter in a cross-flow manner to allow solvents and small molecules to pass , A new type of membrane separation technology in which macromolecular substances and fine particles such as proteins, water-soluble polymers, bacteria, etc. are retained by the filter membrane to achieve separation, classification, purification, and concentration.

Advantages and disadvantages of hollow fiber ultrafiltration membrane

Compared with traditional separation methods, hollow fiber ultrafiltration membrane technology has the following characteristics:

1. The filtration process is carried out at room temperature, with mild conditions and no component damage, so it is particularly suitable for the separation, classification, concentration and enrichment of heat-sensitive substances, such as drugs, enzymes, fruit juices, etc.

2. There is no phase change in the filtration process, no heating, low energy consumption, no chemical reagents, and no pollution. It is an energy-saving and environmentally-friendly separation technology.

3. Ultrafiltration technology has high separation efficiency and is very effective for the recovery of trace components in dilute solutions and the concentration of low-concentration solutions.

4. The ultrafiltration process only uses pressure as the power of membrane separation, so the separation device is simple, the process is short, the operation is simple, and it is easy to control and maintain.

5. Ultrafiltration method also has certain limitations, it cannot directly obtain dry powder preparations. For protein solutions, generally only 10-50% concentration can be obtained.

Hollow fiber ultrafiltration membrane maintenance method

1. Before the raw water is filtered, bacteria and microorganisms must be killed with a fungicide, because these bacteria and microorganisms have a strong ability to contaminate, and can produce more impurities and foreign matter by themselves, and maintain a proper amount of residual chlorine.

2. Pre-filtration removes the solid particle suspension. When the colloid content is high, use flocculation precipitation pretreatment, otherwise it will increase the working pressure of the hollow fiber membrane and cause unnecessary damage.

3. Timed backwashing and rapid washing, and regular chemical washing are beneficial to ensure the cleanliness of the membrane, the quality of membrane processing work and extend the service life of the membrane.

4. Frequent dynamic filtration is also required to discharge concentrated water. The recovery ratio depends on the quality of the raw water.

5. Slowly increase and decrease the pressure when starting and shutting down the equipment to prevent strong impact, causing excessive pressure on the membrane and causing damage to the membrane.

Various basic types of membranes have different applicability. The hollow fiber type is the most widely used in industry, especially in purification and separation applications. Hollow fiber ultrafiltration membranes can not only achieve continuous production, but also the membrane quality is easy to be uniform, and good membranes generally have no defects. Moreover, the membrane packing density in the module is large, the membrane area is large, and the volume is smaller than the tube-type and plate-type configurations, so it is widely favored by the ultrafiltration market.