The replacement cycle of the high-efficiency filters (commonly H13/H14 grades) in the automatic double-door material shower room should be comprehensively judged based on the usage environment, pressure difference changes, and filtration efficiency. The core reference standards are as follows:
I. Regular Replacement Cycle (Basic Reference)
Standard usage scenarios (entrance of clean areas, low dust concentration, daily usage duration 8-12 hours, such as electronic and pharmaceutical clean workshops) : 1-2 years.
High-dust scenarios (areas with large amounts of dust such as chemical engineering, building materials, and mechanical processing, or where the material shower is used for more than 16 hours a day) : 6 to 12 months.
For special clean requirement scenarios (such as biosafety laboratories, aseptic pharmaceutical workshops, etc., where particulate matter control is extremely strict) : The longest period shall not exceed 18 months, or the cycle shall be shortened in accordance with industry standards.
Ii. Key Judgment Basis (Prior to Regular Cycles)
Differential pressure gauge monitoring (core indicator
The initial pressure difference of the high-efficiency filter (in a brand new state) is usually 100-300Pa. It needs to be replaced immediately when any of the following conditions is met:
The actual operating pressure difference is ≥ 1.5 times the initial pressure difference.
If the pressure difference remains persistently above 500Pa (even if it does not reach 1.5 times the initial value, it indicates that the filter material is severely clogged, affecting the air-blowing efficiency);
The pressure difference is less than 50Pa (it may be due to damaged filter material or loose installation causing air leakage. It needs to be inspected and replaced).
Filter integrity detection
Every quarter, scan the air outlet surface of the high-efficiency filter with a particle counter. If particulate matter leakage is detected (exceeding the clean area grade requirements), or if the filter material is damaged or deformed, it should be replaced immediately without waiting for the regular cycle.
Auxiliary judgment signal
The air velocity in the air shower room has significantly decreased (the air velocity at the outlet is lower than 15m/s, and after ruling out the fan failure and the blockage of the primary filter).
The environmental cleanliness test in the clean area failed to meet the standards (after excluding other pollution sources, it is suspected that the high-efficiency filter has failed).
Iii. Key Factors for Extending Service Life
Strictly implement the maintenance of the primary filter (G3/G4 grade) : clean it weekly and replace it every 3 to 6 months to prevent large particles of dust from directly clogging the high-efficiency filter material.
Control the dust concentration at the entrance of the material shower room (such as setting up a pre-cleaning area outside the material shower room) to reduce the load on the high-efficiency filter.
Avoid frequent start-up and shutdown of the equipment or rough handling to prevent the filter material from being damaged due to air flow impact and vibration.
Core principle
The replacement of high-efficiency filters should be based on the core pressure difference monitoring data. The regular cycle is only for reference. The final determination should be made in combination with the actual usage scenario and test results to ensure the dust isolation effect of the material shower room on the clean area and guarantee that the cleanliness of the production environment meets the standards.