When does a ULPA system require airflow pattern testing? Layout changes and working condition confirmation

the ULPA filter system needs to confirm the impact of air paths, layout changes, or pollution migration, airflow pattern testing can be performed according to project requirements. When Testing should serve a specific problem and control the impact of the tracer method on the environment. Airflow pattern testing is not a routine testing item and does not need to be done regularly. Its value lies in answering specific questions: whether the airflow follows the designed path, whether the protected area is affected after the layout is changed, whether local eddy currents will bring contaminants to the workpiece. There are no clear questions in the flow pattern test, and the images taken are difficult to use for judgment. Aili Industry isFFU fan filter unit andThe EFU equipment end fan filter unit can be equipped with flow pattern testing according to project requirements.The FFU computer group control system records the operating status during testing so that the flow pattern image corresponds to the actual working conditions.

1. Clarify the phenomenon to be observed: backflow, short circuit, obstruction or door opening influence

Such as backflow, short circuit, obstruction, door opening or equipment movement, determine the observation position, operating mode and recording method.

The first step in flow pattern testing is to define the problem. What needs to be observed is whether the airflow is vertically downward above a certain workstation, whether there is backflow in the protective area when the equipment is in operation, whether outside air enters when the door is opened, or whether a wake is formed downstream of an obstacle. Different problems correspond to different observation positions, operating modes, and recording methods. Aili Industry isIn the HEPA/ULPA filter matching plan, the airflow organization design intention is explained according to the protection area and equipment layout.The non-standard ULPA filter project can confirm the key positions that need to be observed according to the equipment structure. The relationship between grade and airflow requirements can be found inISO cleanliness level comparison。

2. Select the applicable method: the tracer medium must be compatible with the process materials

The tracer medium and operation should be compatible with the process materials and cleanliness requirements to avoid introducing contamination that is difficult to remove for the purpose of observation; it should be implemented in accordance with the approved procedures.

Flow pattern testing typically uses fume or other tracer media, which themselves may be particles or chemicals. In areas with high cleanliness requirements, the selection and dosage of tracer media need to be evaluated: whether the media will affect the product, whether it is easy to remove, and whether it is compatible with process materials. The test plan should be implemented after project approval. Aili Industry isIn the EFU equipment end fan filter unit equipment end flow pattern test, it is recommended to select the tracer method according to the internal space and process requirements of the equipment.For flow pattern observation of compact models such as ultra-thin EFU , the observation window can be determined according to the cavity structure. For the selection of test methods, please refer toHEPA FAQs and Selection Guide。

3. Interpret in conjunction with other data: the image should correspond to air volume, pressure and process boundaries

The flow pattern image should correspond to the air volume, pressure and process boundaries. One static image cannot be regarded as the conclusion of all operating states.

The flow pattern image is instantaneous and local, and must be interpreted in conjunction with air volume, pressure and process status. The same airflow pattern has different meanings under high air volume and low air volume; the same image represents different states when the equipment is stationary and running. Aili Industry isThe air volume and pressure parameters are simultaneously recorded in the FFU fan filter unit flow pattern test package.The FFU computer group control system records the operating mode and partition data during testing, and the flow pattern images and operating data are archived accordingly. For the relationship between flow patterns and operating data, please refer toULPA ultra-high efficiency filter FAQ and selection guide。

4. When the automatic mechanism moves, the protected area is suspected of backflow, and the complete action process should be recorded.

When the automatic mechanism is in motion, there is suspected backflow in the protected area. The complete action process should be recorded instead of just taking pictures of the flow pattern when the equipment is stationary. The movement of the equipment will change the local air flow, and the flow pattern in the static state cannot represent the operating state.

Aili Industry isNon-standard ULPA filters andIn the EFU equipment end fan filter unit equipment end flow pattern test, the observation nodes are determined according to the equipment action sequence, covering the status of mechanism movement, door opening and closing, and carrier entry and exit;The FFU computer group control system records action time points and operating parameters, and flow pattern records can correspond to actions in time sequence. For the relationship between device actions and flow patterns, please refer toEFU FAQ and technical support。

5. Related questions and answers

Does the fact that the flow pattern looks smooth mean that the cleanliness is acceptable?
Project-specified particle and other performance verification still needs to be completed, and observations cannot replace all testing.

Do flow pattern tests need to be done regularly?
Usually it does not need to be done on a regular basis and is done when layout changes, process adjustments, or when specific airflow issues need to be identified.

Will tracer media contaminate clean areas?
It is necessary to evaluate the compatibility of the medium and the process and the removal method, implement it according to the approved procedures, and control the dosage and residues.

6. Related articles

ULPA ultra-high efficiency filter FAQ and selection guide

Ultra-thin EFU

FFU computer group control system

HEPA FAQs and Selection Guide

7. Key points for selection and acceptance inspection

8. Product matching and technical support from Aili Industrial

Aili Industry isFFU fan filter unit andThe EFU equipment end fan filter unit can be equipped with flow pattern testing according to project requirements.The FFU computer group control system records the operating status, operating mode and partition data during the test, allowing the flow pattern image to correspond to the actual working conditions.The HEPA/ULPA filter matching plan explains the airflow organization design intention according to the protection area and equipment layout.The non-standard ULPA filter project confirms the key positions that need to be observed according to the equipment structure;EFU equipment end fan filter unit equipment end flow pattern test selects the tracing method according to the internal space and process requirements of the equipment.Ultra-thin EFU flow pattern observation determines the observation window according to the cavity structure.The FFU fan filter unit flow pattern test is equipped with a synchronous recording of air volume and pressure parameters, and the equipment action timing and flow pattern records are archived in time series. Provide process objectives, installation drawings, operating conditions and acceptance requirements, and can further communicate ULPA standard specifications, non-standard interfaces, samples and batch matching. The specific parameters and test range are based on the confirmed model and technical documents.