How to determine whether the membrane of ultrafiltration equipment needs cleaning?
Ultrafiltration membrane pollution refers to the physical and mechanical interaction between particles, organic matter and microorganisms in the liquid and the membrane resulting in adsorption and precipitation on the surface of the membrane or in the membrane hole to make the membrane hole small or blocked, resulting in the membrane water permeability or separation capacity decreased, so the membrane of the ultrafiltration equipment is to be cleaned, so how do we judge whether the ultrafiltration membrane needs to be cleaned?
(1) According to the change of the pressure drop at the inlet and outlet of the ultrafiltration device, in most cases, when the pressure drop exceeds the initial value of 0.05MPa, it indicates that the fluid resistance has increased significantly. As a daily management, the isobaric high-flow washing method can be used to wash, if ineffective, chemical cleaning method can be used.
(2) According to the change of water permeability or water permeability quality, when the water permeability or water permeability quality of the ultrafiltration system decreases to an unacceptable degree, it indicates that the water flow path is blocked, or the separation performance of the membrane is affected by the phenomenon of concentration polarization. In this case, the combination of physical and chemical cleaning method is used, that is, the physical method is quickly washed away a large number of polluting substances. It is then cleaned with chemical methods to save chemicals.
(3) Periodic cleaning. The ultrafiltration system in operation can adopt periodic periodic cleaning according to the law of membrane contamination. Can be manual cleaning, for industrial large devices, it is appropriate to set the time by automatic control system according to the sequence of cleaning.
