Cleaning Requirements for Ceramsite Filter Media before Filling
Briefly introduces the screening and cleaning requirements for ceramsite filter media before filling.
Cleaning Requirements for Ceramsite Filter Media before Filling
During transportation and storage, ceramsite filter media may generate debris, dust, or a small amount of substandard particles. If directly filled without screening and cleaning, these impurities will clog the filter heads, increase the initial pressure drop, and affect the quality of the effluent. Proper screening and cleaning are essential preparatory steps before filling.
Screening Requirements
Screening Purpose: To remove excessively large or small particles and debris, ensuring the filter media particle size meets the design gradation requirements and guarantees uniform filtration performance.
Screening Method:
Use a standard screening machine or manual screening.
Select a screen with the appropriate mesh size according to the design particle size requirements.
After screening, the particle size distribution should be re-checked to ensure proper gradation.
Sieving Category | Percentage Passing Requirement |
Larger than the design upper-limit particle size | ≤5% |
Smaller than the design lower-limit particle size | ≤3% |
Within the design particle size range | ≥92% |
Cleaning Requirements
Cleansing Purpose: To remove dust, debris, and surface ash generated during transportation and storage, preventing filter head clogging and water contamination after loading.
Cleansing Methods:
Water Washing (Recommended): Place the ceramic filter media in a washing tank or pool, soak and stir with clean water until the water is clear. Suitable for small to medium batches.
Sieving + Water Washing Combined: Directly rinse with water after sieving. This is standard operation.
Backwashing Method: Clean by backwashing after loading into the filter bed. Suitable for already loaded filters.
Recommended Process: Soak and stir with clean water → Drain (remove fine powder) → Repeat until the effluent is clear → Drain and set aside.
Post-Cleansing Inspection
Inspection Item | Acceptance Criteria |
Wash water | No visible turbidity |
Surface dust | Non-sticky to the touch; no floating dust on the water surface |
Debris content | ≤1% |
Precautions
Do not store for extended periods after cleaning: Filling should be completed within 2-3 days after cleaning to avoid secondary contamination.
Screening equipment cleaning: Prevent cross-contamination between different batches and specifications of filter media.
Cleaning water volume: Sufficient water volume improves efficiency; a water-to-material ratio of ≥3:1 is recommended.
Wastewater discharge: Cleaning wastewater should be treated by sedimentation before discharge.
Summary
The screening and cleaning of ceramsite filter media before filling can be summarized as follows: screening removes impurities and ensures proper gradation; washing removes dust and prevents clogging. Screening ensures that the particle size distribution is within acceptable limits (≥92% within the design particle size range); washing removes dust and debris until the effluent is clear. Filling should be done as soon as possible after cleaning to avoid secondary contamination. Proper screening and cleaning are crucial prerequisites for ensuring the initial operational effectiveness of the filter.