By implementing proper maintenance measures, the lifespan of sanitary grade microporous filters can be extended while maintaining high filtration accuracy. Today, the editor will take you to understand the correct maintenance methods for sanitary grade microporous filters.
1、 Core component maintenance
1. Filter/membrane maintenance
Regularly inspect the surface of the filter element for damage or blockage. If impurities are found to accumulate on the coarse filter screen (stainless steel wire mesh), it should be washed in a timely manner. For precision filter membranes (such as mixed cellulose ester and polyether sulfone), the replacement cycle should be evaluated based on the residual amount of the medium;
When cleaning the filter element, it is forbidden to use hard brushes. It is recommended to use clean water with a pressure of ≤ 0.2MPa for reverse flushing or compressed air for reverse blowing to avoid deformation of the filter material;
The installation of the filter membrane should ensure that the light surface is facing upwards and the edges are free of wrinkles. Use sterile tweezers to prevent contamination.
2. Sealing system inspection
Confirm the integrity of the O-ring after each disassembly, and wet the sealing components with process fluid during installation to ensure airtightness and prevent the risk of liquid leakage;
The bolts of the filter housing need to be evenly tightened to avoid sealing failure caused by uneven force.
2、 Operating standards
1. Start stop control
Before starting, all valves should be closed to confirm the correct direction of the pump body. Slowly open the inlet valve to exhaust and adjust the flow rate to the rated value;
When shutting down, first turn off the pump power and wait for the residual liquid to drain before cutting off the valve to prevent damage to the filter membrane caused by reverse flow impact.
2. Operation monitoring
Real time monitoring of pressure difference changes. When the inlet and outlet pressure difference exceeds 0.1-0.2 MPa, the filter element needs to be cleaned or replaced immediately;
It is recommended to use three-stage filtration pretreatment for high viscosity media (such as alcohol and polymers) to reduce the load on the main filter.
3、 Disinfection and storage
1. Disinfection process
Stainless steel components can be sterilized using high-temperature steam at 121 ℃ for 15 minutes, while plastic parts need to be soaked in 70% ethanol or 2% hydrogen peroxide for disinfection;
The sterilization of filter membranes should be selected according to the material: mixed cellulose ester membranes are suitable for ethylene oxide gas, and polytetrafluoroethylene membranes can withstand radiation disinfection.
2. Long term storage
When not in use, the filter element should be soaked in pure water containing antibacterial agents (such as 10ppm sodium hypochlorite) to prevent biofilm growth;
The filter membrane needs to be dried and stored in a dedicated filter membrane box to avoid moisture or mechanical compression.
4、 Special working condition handling
1. Crystalline containing medium: Dissolve residual crystals in the corresponding solvent (such as dilute hydrochloric acid) after each use to prevent clogging of micropores;
2. Biological product filtration: The entire process is operated in a biosafety cabinet, and after filtration, the filter membrane is immediately transferred to the culture medium to avoid secondary contamination;
3. High temperature liquid: Acetic acid fiber membrane with explosive strength>0.5MPa should be preferred to avoid membrane rupture caused by thermal expansion and contraction.