Hollow fiber ultrafiltration membrane is a structure that is widely used in ultrafiltration professional technology. Because the production of hollow fiber ultrafiltration membrane is continuous, the quality of the membrane is convenient and uniform, the excellent membrane is generally defect-free, the membrane filling density in the component is large, and the total membrane area is large, so the volume is smaller than other configurations.
1. Judgment of the pros and cons of hollow fiber ultrafiltration membrane
①Under the working pressure of 0.1-0.2MPa air pump, there is absolutely no air bubble leakage on the surface of hollow fiber uf membrane. If there are air bubbles, the defect of the membrane is marked, and the interception characteristic is bound to be poor.
②At a certain temperature, the pure water flux (0.1MPa, 25℃) should be moderate, about 120-200L/m2/h, too high a film is easy to block, too low output power is low.
③ The compressive strength (surface pressure difference) of hollow fiber uf membrane should be above 0.3 MPa. In order to develop the water flux, reduce the thickness and looseness of the membrane, it is not enough to give up the compressive strength of the membrane.
④ The interception characteristics are judged by measuring the air pollution index (SDI) value of the water. Basically, the SDI value of general turbidity should be zero, but it is limited to sampling, testing equipment and environmental pollution of the natural environment. Generally speaking, the SDI value should be at least lower than 2, and the standard value should be lower than 1.0.
2. Factors affecting the service life of hollow fiber ultrafiltration membrane
①High-quality ultrafiltration membrane parts, with no defects in pressure resistance and diameter, and the membrane surface is moisturized.
②The production process is appropriate. Uf membrane filter, especially large and medium-sized equipment, must be equipped with pipelines such as backwashing, rapid washing, organic chemical washing, air pumping washing, etc. and a fully automatic control system. The simple piping system software with one inlet and two outlets has the lowest mechanical equipment cost, but it obviously endangers the service life of the membrane.
③Excellent operating standard must be set according to the sewage water body, such as operating pressure, ultrafiltration membrane water concentration, backwashing, rapid washing frequency, compressive strength, time, organic chemical washing cycle, medicine Selection, operation steps, etc.