Microfiltration membrane is the process of sieving and concentrating insoluble materials under the action of pressure difference. It is commonly used to filter out suspended particles ranging from 0.02 to 10 μm in liquid mixtures. This technology is widely used in the pharmaceutical industry for filtration and sterilization, high-purity water preparation for the electronics industry, food industry, drinking water production, and urban sewage treatment.
Requirements for cleaning solution: The concentration of the cleaning agent should be appropriate to avoid chemical damage and corrosion to the membrane. The water used for cleaning must be impurity-free water. Otherwise, impurities in the water will contaminate the microfiltration membrane and make it difficult to clean. Suspension of operation: When the microfiltration membrane device is stopped, it must be thoroughly cleaned and then sealed for storage. If it is temporarily stopped, the microfiltration equipment used for processing liquor can be soaked in unblended liquor for preservation. If it is stopped for a long time, the microfiltration membrane should be removed, dried, and sealed for storage. When it is restarted, it should be cleaned according to the cleaning method of the microfiltration membrane before it can be put into use.
After the UF membrane is produced, it needs to be stored. There are two methods for storing the UF membrane: wet state and dry state. The purpose is to prevent membrane hydrolysis, microbial erosion, freezing and shrinkage deformation, and the failure of the UF membrane.
Storage method of wet state UF membrane: The main point of storing the wet state UF membrane is to keep the membrane in a moist state. The commonly used formula for membrane preservation liquid is: water: glycerol: sodium bisulfite = 79:20:1. This type of UF membrane is generally soaked in protective liquid for seal storage before use to prevent membrane shrinkage, pore reduction, and membrane structure damage caused by dehydration, which will cause a decrease in water flux.
Short-term storage: If the UF membrane is temporarily stopped, it should be sterilized and backwashed once with HY-240 bactericide added to the backwash water. Then, the inlet valve, discharge valve, and regulating valve of the UF membrane should be closed to maintain sealing and sterilization effect. Long-term storage: If the UF membrane is stopped for a long time (more than 10 days), it should be sterilized and backwashed once, and then HY-310 protection liquid should be injected into the UF membrane and sealed for storage.
Storage method for dry state membrane: Natural dehydration and drying of the UF membrane will cause the collapse of membrane pores, seriously affecting the membrane permeability and mechanical strength. Therefore, the membrane needs to be treated in a dry state. Currently, commercially available UF membranes are mostly in the form of dry state membranes. This is not only conducive to storage and transportation, but also necessary for making membrane components.