After the clean room is expanded, will the original chemical filtration capacity be enough?

Clean room expansion does not end with making the area larger. The original chemical filter section was selected based on the pollution load and air volume of the old area. After expansion, the amount of fresh air may increase, the return air path may change, and new equipment or processes may also bring new sources of gaseous pollution.

Direct answer: Whether the original chemical filtration capacity is sufficient cannot be judged by feeling. The treatment air volume, gas load, regional sensitivity and air path need to be rechecked. The increase in area is not necessarily proportional to the pollution load, but the risk of directly following the original plan is relatively high.

First record the changes brought about by the expansion

The first step in an expansion project is to clearly outline 'what has changed.'

Added new areas and workstations. What process is the extension used for? Are cleaning agents, solvents, adhesives or other materials that may release gaseous contaminants used? For specific pollution source investigations, please refer to whether to do air sampling before choosing a chemical filter . Discuss

Fresh air volume and return air volume. Will the total air volume of the system increase after expansion? Will the newly added area be provided with independent air supply or exhaust, or will it be connected to the original system? If connected to the original system, the air volume borne by the original chemical filtration section may increase. Please refer to the specific air volume diameter. Discussion on whether the chemical filter air volume should be selected based on the total air volume of the system or the air volume of a single unit .

Changes in equipment and materials. The addition of material release, lubricants, and seals from the new equipment itself may also bring new gas components. If the process is adjusted after expansion, the pollution components may also change.

Personnel and logistics changes. The increase in personnel and the frequent entry and exit of materials may affect local airflow and diffusion of pollutants. For specific impacts, please refer to Discussion of whether chemical filter validation is required to maintain consistent production loads .

Check system allocation and capacity

After the changes are clearly listed, check whether the original filter section can still be covered.

Total air volume changes. If the total air volume of the system increases after expansion, the air volume passing through the original chemical filtration section will also increase. When the air volume increases, the contact time between the gas and the medium is shortened, and the treatment effect may be reduced. For specific impacts, please refer to Discussion on whether the chemical filter air volume should be selected based on the total air volume of the system or the air volume of a single unit .

Is the media capacity sufficient? The capacity of the original filter material is selected based on the old area load. If the pollution load increases after expansion, the consumption of filter media will accelerate and the replacement cycle may be shortened. For specific life assessment, please refer to Discussion of how long chemical filters last .

Single module flux variation. If the original system has multiple parallel modules, the air volume borne by each module may change after expansion. Check the module flux one by one to avoid overloading some modules. For specific allocation methods, please refer to Discussion on whether the chemical filter air volume should be selected based on the total air volume of the system or the air volume of a single unit .

Is the original filter material still suitable for new contamination? If expansion introduces new processes or materials, the target gas composition may change. The original filter material is aimed at old components and may not be suitable for new components. For specific selection principles, please refer to Discussion on why chemical filters should be selected according to target gases .

Verify with new working conditions

After the expansion is completed, the original filtration capacity must be verified under new operating conditions.

Preserve pre-expansion records. The inlet concentration, outlet concentration, air volume, pressure difference and replacement cycle before expansion are the benchmarks for subsequent comparisons. Please refer to the specific inspection records Discussion of what items should be checked during daily inspection of chemical filters .

Tested under normal new operating conditions. After expansion, the inlet and outlet concentrations will be detected based on actual production status, actual air volume and actual personnel activities. Cannot only measure static or low load conditions. For specific sampling methods, please refer to Discussion of sampling points for chemical filter performance verification .

Cover new areas. Sampling points should include key locations in the expansion area and the original area. You can't just test old areas, and you can't just test new areas. For specific protection scope, please refer to Discussion on how to judge whether chemical filtration is effective when the clean shed is open all around .

The original acceptance report cannot be used to prove the new area. The expansion changed the system conditions, and the original detection data corresponded to the old working conditions. It needs to be reconfirmed according to the new working conditions. For specific differences, please refer to Discussion of the difference between initial efficiency and lifetime efficiency of chemical filters .

What to do when there is not enough

If the verification finds that the original chemical filtration capacity is insufficient, there are several treatment directions.

Add filter section. Add a chemical filter section to the newly added area or return air path to share the load of the original filter section. For specific configuration, please refer to Discussion on why MAU needs to configure chemical filtration section .

Expand the area of ​​the original filter section. If space at the original location allows, switch to a chemical filtration section with a larger effective area to reduce the passing wind speed at the same air volume and improve the treatment effect. Please refer to the specific thickness restriction plan. Discussion of how to determine configuration when chemical filter thickness is limited .

Change filter material type. If expansion introduces new contaminants, the original filter material may no longer be suitable. It is necessary to re-select according to the new target gas. For specific principles, please refer to Discussion on why chemical filters should be selected according to target gases .

Adjust system air volume distribution. Through air valve or branch adjustment, the original filter section can bear a reasonable air volume, and the newly added area will be processed separately. For specific balancing methods, please refer to whether chemical filtration modification requires re-doing the air volume balance . Discuss

Reevaluate replacement cycles. As the load changes after expansion, the original replacement cycle may no longer be applicable. The maintenance plan needs to be adjusted based on new detection data. For specific management methods, please refer to Discussion on why the chemical filter replacement cycle cannot be calculated as half a year .

Project judgment example

After the expansion of a clean room, a new cleaning process was added, and the total air volume of the system increased by about 20%. The original chemical filtration section continues to be used.

After running for a period of time, it was found that the outlet concentration of the original area was still normal, but the odor could occasionally be smelled in the newly added area. The test confirmed that the organic vapor released by the new cleaning process was the main reason. The original chemical filtration section still processed the air in the old area and did not cover the new sources.

Adjustment plan: Add a chemical filtration section for organic vapor to the return air path of the newly added area, and review the air volume and capacity of the original filtration section. After adjustment, the outlet concentrations of both areas met the requirements, and the replacement cycle of the original filter section was also re-evaluated.

This case illustrates: After expansion, whether the original chemical filtration capacity is sufficient depends on whether the air volume, load and pollution components have changed, and it cannot be used directly. involving When selecting chemical filter product series , it is recommended to provide the expanded working condition data and target gas to the supplier for verification.

Key points for selection and acceptance inspection

About Aili Industrial’s expanded filtration package

Aili Industrial has independent manufacturing capabilities in filters, motors, fans, control systems and sheet metal processing, and can provide chemical filter product series and supporting air supply equipment. For clean room expansion projects, we can assist in checking the chemical filtration section expansion or supplementation plan based on the new area, air volume changes, pollution load and system conditions.

Related products:Chemical filter product series、MAU box chemical filter、FFU comes with chemical filter . Providing the expanded operating condition data and target gas when inquiring will help confirm the appropriate solution. The specific selection is subject to the technical documents and test results confirmed by the project.