How does EFU form clean air supply at the equipment end? Air flow path and working process description
Direct answer: The basic process of EFU forming clean air supply is 'air entry-fan pressurization-box flow equalization-filter filtration-clean air reaches the process area'. What really affects the effect of the equipment is not just the filter efficiency, but also whether the air inlet is blocked, whether the pressure in front of the filter is uniform, whether the air outlet surface is blocked by the equipment structure, and whether the air can form a reasonable backflow.
Step 1: Air enters from the air inlet side
The EFU can draw air from the top, side or designated return air area of the equipment. If the air inlet is close to the wall panel, cable trough or equipment shield, the fan inlet will produce a biased flow, which may lead to a decrease in air volume and a change in noise. The air inlet space should be reserved based on the fan inlet form during design.
Step 2: The fan builds pressure and pushes air through the filter
The fan needs to overcome the air inlet resistance, the resistance inside the box, the filter resistance and the additional resistance on the outlet side of the equipment. As the filter accumulates dust, the system resistance will rise and the operating point will change accordingly. Therefore, speed regulation margin and pressure difference monitoring are more meaningful than a single rated air volume.
Step 3: Improve the air distribution in the static pressure space
The velocity distribution of air after it leaves the fan is not naturally uniform. Reasonable cabinet height, fan position and space in front of the filter can help reduce local high-speed areas. The ultra-thin EFU has limited space and needs to be jointly optimized through the fan, diversion and filter structures. It cannot just compress the box height.
Step 4: Filter completes particle control
As air passes through the filter material, particles are trapped by the filter media. Filtration efficiency should match process objectives, test particle size, and project acceptance methods. The seal between the filter and the box must also be reliable, otherwise bypass air leakage will bypass the filter material.
Step 5: Clean air covers key process areas
Robotic arms, beams, trunking and process modules below the air outlet surface change the direction of the air flow. Equipment-side verification should measure wind speed and uniformity at key points under actual or equivalent structures, rather than just measuring the filter surface in the no-load state.
Project confirmation checklist
Confirm items |
What needs to be clarified |
Installation conditions |
Available length, width and height, air inlet and outlet directions, interfaces and maintenance space |
Air parameters |
Target air volume, wind speed, static pressure and uniformity |
Filtering requirements |
Efficiency ratings, resistance, sealing and testing methods |
Electrical control |
Power supply, speed regulation, communication, linkage and abnormal logic |
Acceptance conditions |
Test conditions, measuring points, instruments and judgment standards |
FAQ
Does the clean air outlet of the EFU mean that all locations inside the equipment are clean?
Not equal to. Equipment structure, sources of contamination, return air paths, and human or institutional movement can all affect local airflow.
Why does the same EFU have different air volumes when installed on different devices?
Different equipment has different air inlet space, air outlet resistance and structural shielding, and the system resistance curve will change.
How to verify that device-side airflow is effective?
Comprehensive judgment should be made based on wind speed, uniformity, particle detection and air flow visualization results at key process points.
How does Aili Industry cooperate with equipment-side EFU projects?
Aili Industry carries out R&D and production around EFU complete machines, fans and motors, control systems, sheet metal structures and air filters. For equipment-side projects, configuration can be carried out based on equipment drawings, target air volume, static pressure, filtration efficiency, installation interface and control logic. When it comes to ultra-thin, small size or special interfaces, it is recommended to confirm the drawings and agreed working conditions first, and then test the curing parameters through the prototype so that the configuration can be consistent in subsequent mass production.
During project consultation, the available internal length, width and height of the equipment, target cleanliness, air supply area, air volume or wind speed requirements, filtration efficiency, power supply and communication methods can be provided to facilitate quick judgment of whether standard products are suitable or whether non-standard design is required.
Related content
EFU FAQ and technical support EFU equipment fan filter unit 70mm ultra-thin EFU
Conclusion: EFU inhales the air around the equipment or the designated return air area, and then sends clean air to the key process area after being pressurized by the fan, equalizing the flow in the box, and trapping particles in the filter. The airflow effect also depends on the internal structure of the equipment and the return air path.
