How to check the pressure difference of FFU filter? What parameters should be paid attention to during selection and operation?
Direct answer: FFU filter pressure differential should be judged together with air volume, filtration efficiency and fan operating point. First confirm the initial pressure difference of the filter at the target air volume, and then check whether the FFU can maintain the required air supply when the pressure difference rises during operation; pressure difference monitoring and replacement conditions should be determined based on project conditions, filter data and technical agreements.
Filter pressure difference is the pressure difference generated before and after the air passes through the filter. For clean room and equipment-side FFU, it is directly related to the resistance that the fan needs to overcome. However, the pressure difference value will be affected by the air volume, filter material, filter size and usage status. It is easy to draw wrong conclusions when comparing two numbers without measuring conditions.
First confirm the filtration requirements and measurement conditions
SelectWhen using HEPA or ULPA air filters , process particle control requirements, filtration efficiency, target air volume and installation size should first be clarified. When requesting initial differential pressure data from the supplier, confirm the test air volume and measurement method at the same time. The pressure difference of the same filter under different air volumes may be different, so the comparison should be based on the project design air volume.
On-site monitoring also requires confirmation of the pressure tapping location. Whether the measured pressure difference is the pressure difference before and after the filter , or the system pressure difference including the resistance of the box, air inlet structure, etc., should be clearly stated in the technical agreement and debugging records.
How will the increase in pressure difference affect FFU air supply?
As the filter resistance increases, the operating status of the FFU may change. When running at a fixed speed, the actual air volume may decrease; when speed regulation is used to maintain the air volume, the fan operating gear, power consumption and noise may change accordingly. Therefore, judging whether the filter is suitableFor the FFU fan filter unit , you should not only look at the initial pressure difference of the new filter, but also check whether the target air volume can be maintained after the resistance changes.
If the project is switched to a more efficientFor ULPA filters , the filter pressure difference and fan performance data should be rechecked, and the filter sealing and replacement methods should be confirmed. Filtration efficiency, resistance and actual air supply effect need to meet the requirements at the same time.
How to set pressure difference monitoring and replacement conditions?
After the FFU is installed and debugged, the project can record the initial pressure difference, actual air volume and operating status under the agreed air volume or operating gear, as a benchmark for subsequent comparisons. During inspections, data should be recorded under similar working conditions as much as possible; if the pressure difference is found to be abnormal, the air volume, control gear, sealing condition and measuring point status should be combined for investigation.
The filter replacement conditions should not be determined solely by a universal pressure difference value. The allowable final resistance of the filter, the FFU's ability to maintain the target air volume, cleanliness test results, and project maintenance requirements should be combined to clearly define the monitoring and disposal methods in the technical agreement.
How does Aili Industry cooperate with project verification?
Aili Industrial can combine the target air volume, filter efficiency and resistance, box structure and control method to check the operating performance of the FFU machine under project conditions. For batch projects, it is recommended to confirm the filter installation and sealing, air volume and pressure difference data through a prototype, and then conduct the complete machine or on-site test according to the agreed method. The specific configuration and replacement conditions are subject to the project technical agreement and actual test results.
Before technical communication, it is recommended to prepare the cleanliness requirements, design air volume, filter specifications, installation dimensions, operation mode, pressure difference measuring point requirements and estimated quantity. This information helps determine whether the filter matches the FFU, and also facilitates the establishment of a baseline for later maintenance.
Q: Is the lower the filter pressure difference, the better?
Answer: The filtration efficiency and process requirements should be met first, then the pressure difference should be compared under the same air volume and test conditions, and the sealing and overall machine performance should be checked.
Q: Do I need to replace the filter immediately if the pressure difference increases?
Answer: It should be judged according to the replacement conditions agreed on the project, and the air volume, cleanliness and measurement status should be checked at the same time to find out the reason for the increase in pressure difference.
Q: Can the filter pressure differentials of different FFUs be directly compared?
Answer: Only if conditions such as filter configuration, test air volume, and measurement location are comparable, can differential pressure data be meaningful.
