When replacing the filter material of the aluminum frame combined filter, attention should be paid to the standardization of operation, safety and the guarantee of filtration effect. The following are detailed precautions:
I. Preparations Before Replacement
System shutdown and safety protection
First, turn off the ventilation and air conditioning system where the filter is located. Make sure the machine is shut down before operating to prevent dust from spreading due to air flow or causing accidental contact by personnel.
If the filtration environment contains harmful gases or dust (such as in chemical workshops), protective masks and gloves should be worn. If necessary, protective clothing should be worn to prevent pollutants from coming into contact with the skin or being inhaled into the body.
Preparation of tools and new filter materials
Prepare appropriate disassembly tools (such as screwdrivers, wrenches, snap-on screwdrivers, etc.), and check in advance whether the tools are in good condition to avoid damaging the aluminum frame during operation.
Confirm that the specifications (size, filtration grade, material) of the new filter material are consistent with those of the original filter material and meet the system design requirements (such as air volume compatibility) to avoid a decrease in filtration efficiency or loose installation due to non-compliant specifications.
Prepare cleaning supplies (such as rags and compressed air tanks) to remove the residual dust inside the aluminum frame.
Ii. Precautions for Disassembling Old Filter Materials
Avoid the diffusion of pollutants
When disassembling, handle it gently. Do not pull the old filter material forcefully to prevent the dust and debris adhering to the surface from scattering into the surrounding environment (especially in clean areas, the old filter material should be wrapped in a plastic bag before being taken out).
If the filter material is severely damaged or has adsorbed harmful substances, it should be sealed and packaged and disposed of in accordance with the hazardous waste treatment process. It must not be discarded at will.
Check the condition of the aluminum frame
After removing the old filter material, immediately check the integrity of the aluminum frame: whether there is deformation, rust, weld point detachment, and whether the sealing rubber strip is aged, broken or fallen off.
If there is slight rust on the aluminum frame, it can be gently sanded with sandpaper and then coated with anti-rust paint. If the deformation is severe or the seal fails, the aluminum frame should be repaired or replaced first, and then a new filter material should be installed.
Iii. Key Points for Installing New Filter Materials
Make sure the filter material matches the aluminum frame
Before installation, check whether the size of the filter material matches the inner cavity of the aluminum frame. The edge of the filter material should be closely attached to the inner side of the aluminum frame without wrinkles or misalignment (especially for pleated filter materials, it is necessary to ensure uniform wrinkles to avoid excessive local force causing damage).
If the filter material needs to be fixed with glue, an environmentally friendly glue compatible with the filter material (such as silicone) should be selected. It should be applied evenly and of moderate thickness to prevent the glue from overflowing and contaminating the filter material or affecting its air permeability.
Sealing performance guarantee
When installing, pay special attention to checking the sealing surface between the filter material and the aluminum frame to ensure there is no gap. If the original sealing rubber strip ages, a new one should be replaced (the material is recommended to be nitrile rubber or ethylene propylene diene monomer rubber, which has better heat resistance and aging resistance).
For multi-group combined filters, it is necessary to check whether the joints between adjacent filters are sealed to prevent unfiltered air from leaking through the gaps.
Fixed method specification
Fix the filter material according to the original structure (such as clips, bolts, and pressure strips) with moderate force: if it is too loose, it may cause the filter material to shift; if it is too tight, it may break the filter material or deform the aluminum frame.
If bolts are used for fixation, they should be tightened in diagonal sequence to ensure uniform force distribution.
Iv. Inspection and Testing after Replacement
Appearance review
After installation is completed, visually inspect whether the filter material is flat and undamaged, whether the aluminum frame is firmly fixed, and whether the sealing rubber strip is fully attached.
System trial operation
Turn on the ventilation system and run it for 5 to 10 minutes to observe if there is any abnormal noise from the filter (it may be due to the offset installation of the filter material causing airflow turbulence).
Measure the initial resistance with a differential pressure gauge and record the data as the reference value for subsequent maintenance. If the resistance is abnormal (much higher or lower than the design value), the machine should be stopped to check whether it is improperly installed (such as clogged filter material or poor sealing).
Clean the site
Clean up the garbage generated during the replacement process (such as packaging materials and old rubber strips), wipe the surface of the aluminum frame and the surrounding areas to ensure there is no residual dust.
V. Other Matters needing Attention
Storage requirements for filter materials: Unused new filter materials should be sealed and stored in a dry and well-ventilated place, avoiding moisture, direct sunlight or heavy pressure to prevent premature aging of the filter materials.
Record replacement information: Record in detail the replacement date, filter material model, initial resistance, operator and other information, establish a maintenance file, and provide a reference for subsequent replacement cycles.

By strictly following the above precautions, it can be ensured that the filtration efficiency of the replaced filter meets the standards, the service life of the equipment can be prolonged, and at the same time, secondary pollution or system failure caused by improper operation can be avoided.