How to deal with dust falling on the surface of chemical filter?

After the chemical filter has been running for a period of time, it is common for dust to accumulate on the surface. But the processing method cannot be applied to the habits of ordinary filters.

Direct answer: Do not wash, beat or blow with high pressure directly. First confirm the degree of dust accumulation, front-end pre-filtration status and product maintenance instructions before deciding whether to clean the surface or replace the filter material. Removing dust does not equal restoring gas handling capabilities.

Investigate the cause of dust accumulation

When you see dust falling, don’t rush to clean it up. First, ask: Where did the dust come from?

Whether pre-filtering is invalid. If the primary and medium-efficiency filters are damaged, installed with bypasses or have not been replaced for a long time, dust will directly enter the chemical filtration section. The root cause of many ash problems lies in pre-filtration. Please refer to the specific division of labor Discussion on the division of labor between chemical filters and primary filters .

Check whether the installation has a bypass. The frame is not tightly sealed, the access door is not closed tightly, and the interface is loose, which will also allow dusty air to bypass the filter material and deposit on the surface. For specific inspection methods, please refer to Discussion on how to check frame bypass after chemical filter installation .

Whether the environmental load changes. Are there any recent construction, maintenance, process adjustments, or changes in external pollution sources? These factors may increase the amount of dust entering the filter section.

Treat the source first, then the surface. If the front-end problem is not solved, dust will accumulate on the surface soon after cleaning. For detailed investigation, please refer to Discussion of what to check if the pressure difference before and after the chemical filter suddenly rises .

Distinguish between frame and medium

When cleaning, the outer frame and filter material should be treated separately.

Outer frames and frames. Floating dust on the metal frame, box surface, and access door can be cleaned with a dry cloth or vacuuming according to the maintenance instructions. Be careful not to use a rag with water or solvent to avoid moisture or chemicals coming into contact with the filter material.

filter surface. Filter material is the core functional part of chemical filters. It is not recommended to pat, brush or blow away dust on the surface. Slapping and brushing may allow dust to enter the media, and blowing may push dust into the filter material or cause dust to rise. For specific maintenance requirements, please refer to whether chemical filters can be washed and reused . Discussion on

Seals. The dust accumulated on the sealing gasket and card slot can be cleaned gently, but do not pull or use sharp tools to avoid damaging the sealing surface.

The scope of cleaning must be clear. What can be safely cleaned and what cannot be moved at will should be clearly stated in the maintenance procedures to avoid relying on experience on site.

Review drag and gas targets

Dust falling on the surface may affect the operating status, so two indicators need to be reviewed.

Differential pressure and air volume. When the dust accumulation is heavy, the resistance of the filter section may increase and the air volume may decrease. Record the pressure difference and air volume to determine whether it exceeds the allowable range of the system. For specific pressure difference investigation, please refer to Discussion on whether the chemical filter can be replaced based on the pressure difference .

outlet concentration. The surface dust itself does not necessarily directly affect the gas handling capacity, but if the dust is accompanied by moisture, hardening of the medium or blockage of the channel, the outlet concentration may change. Test the outlet concentration according to project requirements to confirm whether the protection objectives are still met. For specific sampling methods, please refer to Discussion of sampling points for chemical filter performance verification .

The two items are judged separately. Normal resistance does not mean that the gas processing capacity is normal, and normal outlet concentration does not mean that the pressure difference is OK. For specific differences, please refer to Discussion on whether the chemical filter can be replaced based on the pressure difference .

Follow maintenance instructions

For specific processing methods, please refer to the product description of the model.

Models that allow cleaning. If the product instructions clearly permit cleaning, follow the instructions, tools, and drying conditions. After cleaning, verify the outlet concentration and sealing status according to project requirements.

Models that do not allow cleaning. Most chemical filters are treated as replacement. If dust on the surface affects the pressure difference or outlet concentration, evaluate the replacement of the filter material. For specific life span judgment, please refer to Discussion of how long chemical filters last .

When replacing the filter material, check the front end simultaneously. If the ash falling is caused by the failure of pre-filtration, the pre-filtration problem should be dealt with while replacing the chemical filter material to avoid recurrence.

Record the process. The date, reason, handling method and retest results of cleaning or replacement should be recorded. Please refer to the specific inspection records Discussion of what items should be checked during daily inspection of chemical filters .

Project judgment example

The dust on the surface of the chemical filter in a certain project was obvious, and the air volume dropped slightly. Operation and maintenance personnel are preparing to rinse the filter element with water.

During the investigation, we first checked the pre-filtration and found that the medium-efficiency filter was seriously dusty and the installation frame had a bypass. Dust enters the chemical filter section, causing surface dust to fall and resistance to rise. Treatment method: Replace the medium-efficiency filter, repair the seal of the installation frame, clean the outer frame and floating dust on the surface of the frame, and do not wash the chemical filter material. After retesting, the air volume and pressure difference returned to normal, and the outlet concentration did not change.

Ashfall from another project is accompanied by an increase in outlet concentration. Check to confirm that the media has become solidified and that cleaning the surface will not restore processing capabilities. After the evaluation, the filter material was replaced and pre-filtration maintenance was strengthened.

These two cases illustrate: first check the source of dust on the surface, then determine whether it affects gas treatment, and finally decide whether to clean or replace it. involving When selecting a chemical filter product series , it is recommended to provide the front-end configuration, operating data and maintenance requirements to the supplier for verification.

Key points for selection and acceptance inspection

About the maintenance and support of Aili Industry

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 projects that need to deal with surface dust, the front-end pre-filtration configuration, operating data, product maintenance requirements and replacement criteria can be combined to assist in checking the treatment plan.

Related products:Chemical filter product series、MAU box chemical filter、FFU comes with chemical filter . Provide usage conditions and maintenance requirements when enquiring, which will help confirm the appropriate solution. The specific selection is subject to the technical documents and test results confirmed by the project.