The maintenance of backwash self-cleaning filters requires a combination of physical cleaning, chemical treatment, and system inspection. The specific methods are as follows:
1、 Filter cleaning and replacement
1. Physical cleaning: Use a high-pressure water gun (0.6-1.0MPa) to backwash the filter element from the outlet for 3-5 minutes, with a recommended oblique angle of 45 ° to avoid damage to the filter. Metal filter cartridges can be cleaned of hard dirt with copper scrapers, while activated carbon filter cartridges should avoid detergent to prevent micro pore blockage.
2. Chemical cleaning: For stubborn impurities, the activated carbon filter can be soaked in 0.5% -1.0% citric acid solution (pH 4.5-5.5) for 30 minutes, and the metal filter can be soaked in 3% -5% hydrochloric acid solution (heating at 50 ℃ is more effective). After cleaning, it needs to be thoroughly rinsed until neutral.
3. Replacement standard: If the filter element is deformed or cracked by more than 2 millimeters, it should be replaced immediately. Coating with food grade silicone grease during installation can improve sealing performance.
2、 System component inspection
1. Backwash system: Regularly check valves, sensors, and pipeline connections to ensure no water leakage and avoid resource waste.
2. Sealing test: After resuming operation, a 0.1MPa pressure test is required. If there is no leakage within 30 minutes, it is considered qualified.
3. External cleaning: Use a mild cleaning agent to wipe the surface of the housing to prevent the reinforcing agent from corroding the equipment materials.
3、 Cleaning frequency and water quality monitoring
1. Cycle recommendation: It is recommended to clean once a month in environments with poor water quality or high frequency use, and every 1-3 months under normal circumstances. In northern hard water areas, it needs to be shortened to 2-3 months per occurrence.
2. Effect verification: After cleaning, the turbidity of the effluent should be<0.5NTU, the suspended particles should be<2 particles/liter, and the flow rate attenuation should not exceed 5%.
4、 Precautions
1. Operation safety: Before cleaning, the inlet valve must be closed and the residual pressure in the pipeline must be released. Electric equipment must be powered off.
2. Error avoidance: Avoid damaging the filter screen due to water hammer caused by quick valve opening and closing, and disable acidic cleaning agents for siphon filters.
By standardizing maintenance, the filtration efficiency of the equipment can be restored to over 85%, extending its service life by 3-5 years.