In the industrial sector, filters are classified based on their function and the level of filtration they provide. We can divide them into primary filtration and fine filtration.
1. Primary Filtration (Removal of Coarser Particles)
Primary filtration is the first stage of air or fluid purification and is used to retain large particles.
- Metal mesh filters: used to block coarse impurities in liquids and gases.
- Panel filters (G2 – G4): made of synthetic or metallic fibers, often used in HVAC systems for pre-filtration.
- Coarse pocket filters (G3 – G4): suitable for industrial ventilation systems, they block larger dust and particulate matter.
- Cyclone filters: use centrifugal force to separate solid particles from an air or liquid stream.
- Basic activated carbon filters: remove odors and large volatile organic compounds (VOCs).
- Gravity or sedimentation filters: used in water treatment to separate suspended solids through decantation.
- Sand filters: employed in water treatment to remove suspended solids and organic matter.
2. Fine Filtration (Removal of Smaller Particles)
Secondary filtration removes finer particles and improves air or fluid quality, often as a second filtration stage.
- Fine pocket filters (F5 – F9): for advanced air conditioning systems, capture smaller particles.
- HEPA filters (H10 – H14): used in cleanrooms, hospitals, and industrial sectors with high purity requirements, retaining particles down to 0.3 microns with efficiency >99.97%.
- ULPA filters (U15 – U17): with even higher efficiency, used in laboratories and the pharmaceutical industry.
- Advanced activated carbon filters: used to remove gases, vapors, and volatile chemicals.
- Membrane filters: used for microfiltration of liquids and gases, typical in the pharmaceutical and food industries.
- Electrostatic filters: employed for capturing fine dust and fumes in industrial ventilation systems.
- Coalescence filters: separate oil and water aerosols in compressed air and industrial fluids.
- Ion exchange resin filters: used for water purification by removing unwanted ions.
