I. Basic Structure of Air Filters
1. Filter Media
- Fiber Materials: Such as glass fiber, synthetic fiber, etc., which have high filtration efficiency and long service life.
- Activated Carbon: Mainly used to adsorb harmful gases and odors in the air, often used in combination with other filter media.
- Electrostatic Materials: Capturing tiny particles in the air through the principle of electrostatic adsorption, with significant filtration effects.
2. Support Structure
- To ensure the stability and durability of the filter media, air filters usually have a support structure. The support structure can be a metal frame, plastic frame, or other materials, serving to fix and protect the filter media.
3. Sealing Device
- The sealing device is used to prevent unfiltered air from leaking from the edges of the filter, ensuring that all air passes through the filter media. Common sealing devices include rubber sealing strips, foam sealing strips, etc.
4. Enclosure
- The enclosure of the air filter is used to protect the internal structure and prevent the external environment from affecting the filter. The enclosure material can be metal, plastic, or other durable materials.
II. Working Principles of Air Filters
1. Mechanical Filtration
- Screen Filtration: Using the pore size of the filter media to trap particles larger than the pore size on the surface of the filter media.
- Inertial Impaction: Due to inertia, particles in the air cannot follow the airflow to bypass the filter media and are forced to collide with the media surface and be captured.
- Diffusion Effect: Tiny particles in the air, due to Brownian motion, exhibit irregular motion and are eventually captured by the filter media.
2. Electrostatic Adsorption
- Electrostatic adsorption captures particles in the air through electrostatic force. Electrostatic filters usually charge the filter media to attract particles with the opposite charge, thus achieving the filtration effect.
3. Chemical Adsorption
- Chemical adsorption is mainly used to remove harmful gases and odors from the air. Activated carbon filters are common chemical adsorption filters. Activated carbon has a large number of microporous structures that can adsorb harmful gases and odor molecules in the air.
4. Biological Filtration
- Biological filtration uses microorganisms to degrade harmful substances in the air and is often used to treat organic exhaust gases and malodorous gases. The biological filter is filled with microbial carriers. When air passes through, harmful substances are degraded by microorganisms, achieving the purpose of purifying the air.
III. Types and Applications of Air Filters
|
Type |
Features |
Applications |
|
Pre-filter |
Captures larger particles such as dust and pollen |
Commercial building ventilation systems |
|
Mid-efficiency filter |
Provides medium-level filtration |
Office air conditioning systems |
|
HEPA |
Captures extremely fine particles, including bacteria and viruses |
Hospital operating rooms, clean rooms
|
IV. Key Performance Indicators of Air Filters
1. Filtration Efficiency: The ability of the filter to remove particles of different sizes.
2. Pressure Drop: The pressure loss of air passing through the filter.
3. Dust Holding Capacity: The total amount of particles that the filter can hold before reaching a certain pressure drop.
V. Maintenance and Care of Air Filters
1. Regular Filter Replacement: Replace the filter according to the usage environment and frequency to ensure filtration effectiveness.
2. Clean the Enclosure: Regularly clean the filter enclosure to prevent dust accumulation that may affect performance.
3. Check Sealing Devices: Ensure that the sealing devices are intact to prevent unfiltered air from leaking.
Through this article, we hope you have gained a deeper understanding of the working principles and maintenance tips of air filters. Choosing the right air filter products can not only improve air quality but also protect our health.
