The wind speed of the FFU air outlet surface is qualified, why is there still a weak airflow area on the process table?
Qualified air outlet surface does not mean qualified countertop
During FFU acceptance, the wind speed is usually measured on the air outlet surface. If the average wind speed on the outlet surface reaches the target value, the equipment itself may be judged qualified. However, in actual production, it was found that there were still weak airflow areas at certain locations on the process table, and particle control was not ideal.
If the air outlet surface is qualified, it only means that the airflow sent by the FFU meets the requirements near the air outlet surface. The air flow still needs to pass a certain distance from the air outlet surface to the craft table. During this distance, equipment, fixtures, tools, heat sources, and lateral disturbances can all affect airflow. By the time it reaches the countertop, the airflow may have deflected, slowed down, or created a weak zone.
Therefore, when verifying the air flow on the process table, you cannot just look at the wind surface data, but must measure it at the location of the protected object. Aili Industrial has complete production capabilities in FFU complete machine and airflow design, and can cooperate with the project to analyze table airflow issues. For the basic structure of the FFU machine, you can refer toAili Industrial FFU fan filter unit。
Why should the measuring plane be separated?
The separation of measuring planes is the basis for understanding the weak areas of airflow. The measurement plane of the air outlet surface is close to the FFU and reflects the equipment output. The process surface measurement plane is close to the product, reflecting actual protection. The airflow conditions in the two planes may be different.
It is recommended to record the wind speed and air flow direction of the air outlet surface and process table respectively during acceptance or commissioning. If the air outlet surface is qualified but there is a weak area on the table, you can analyze the reason from the difference between the two planes.
How equipment occlusion affects countertop airflow
Equipment obstruction is a common cause of weak countertop airflow areas. Equipment, fixtures, tools, displays or pipelines, if located between the FFU and the product, may block or redirect airflow. The larger the obstruction is and the closer it is to the product, the more obvious the impact will be.
Blocking may also cause airflow to deflect, causing wind speeds to be lower in some areas. If the product is behind or to the side of a barrier, protection may not be adequate.
During the inspection, you can mark the position and height of the obstruction, and measure the wind speed in front of, behind, and around the obstruction. If the impact of occlusion is large, the FFU position, air supply direction or equipment layout can be adjusted.
How does the air supply distance affect
As the air supply distance increases, the airflow may spread or slow down. If the installation height of the FFU is high and the distance from the air outlet surface to the countertop is large, the airflow may have attenuated when it reaches the countertop. If the tabletop position deviates from the FFU air supply center, the wind speed may be lower.
The influence of the air supply distance is related to the wind speed of the FFU outlet surface, the airflow direction and the surrounding environment. For workstations with a large air supply distance, you can confirm whether the FFU layout covers key positions on the table, or whether local air supply needs to be increased.
How heat sources and lateral disturbances affect
The heating of process equipment will generate upward airflow, which interacts with the FFU downward air supply. When the heat source is strong, the upward airflow may change the direction of the downward air supply, forming a weak airflow area or vortex near the table.
Lateral disturbances result from movement of people, movement of equipment, material handling, or airflow in adjacent areas. Side airflow may deflect the clean airflow, causing the wind speed to decrease at certain locations on the tabletop.
During the inspection, you can observe the air flow changes when the equipment is running, and record the location of the heat source and personnel operation conditions.
How to optimize layout
If there are weak airflow areas on the countertop, they can be optimized from several directions. Adjust the position of the FFU so that its air supply covers key operating positions. Adjust the air supply direction or air outlet structure to reduce the impact of occlusion. Increase local air supply or enclosure structures to protect key areas. Adjust equipment layout to reduce occlusion and heat source interference.
For equipment end workstations, please refer toEquipment end fan filter unit andCustomize the EFU equipment-end fan filter unit to understand the equipment supporting air supply scheme. For workstations that require complete enclosure, please refer toClean workbench。
Verify and document how to do it
After adjustment, it should be verified under actual operating conditions. Measure the wind speed and airflow direction at key locations on the process table to confirm improvements in weak areas. Record the measurement location, method and results, and compare them with those before adjustment.
If the project has cleanliness requirements, particle data can be measured simultaneously. Verification records can aid in subsequent maintenance and replication to other workstations.
Issues that should be confirmed in advance during project communication
During the FFU countertop air flow investigation and optimization stage, it is recommended to confirm the following with the FFU manufacturer and process side: air outlet surface and countertop measurement location; equipment occlusion and heat source conditions; air supply distance and FFU layout; personnel operation and material movement methods; target wind speed and air flow direction; layout optimization plan; verification method and judgment standard.
If you are dealing with the problem of weak airflow areas on FFU countertops, you can visitAi Li Industrial FFU fan filter unit to understand the complete machine configuration, you can also contact Ai Li Industrial for air flow optimization support.
in conclusion
If the wind speed of the FFU outlet surface is qualified, it does not mean that the airflow still meets the requirements after it reaches the process table. Equipment occlusion, air supply distance, heat sources, and lateral disturbances can all create areas of weak airflow on the countertop. The measuring planes should be separated and verification should be done where the protected object is located. Layout optimization and local air supply can improve weak areas.
Aili Industrial has complete production capabilities in FFU complete machine and airflow design, and can cooperate with the project to analyze table airflow issues. If you need to know more about FFU airflow optimization, you can visitAili Industrial FFU fan filter unit , you are also welcome to contact Aili Industrial for project support.
