Why Compressed Air Filters Are Needed
Compressed air contains contaminants such as particulate matter, suspended matter, and oil vapor, which can negatively impact end users. The right filters can remove these harmful substances. The number and type of filters required depends on the air quality required by the application.
Ideal Air Quality
Different applications and processes require different levels of compressed air filtration, requiring an assessment of quality requirements, production processes, and flow requirements. Standard dry dust filters (with a filtration level of 1 to 0.01 microns) are generally sufficient for pneumatic equipment, while activated carbon filters are required to eliminate oil vapor. Understanding the three key contaminants—particulate matter, suspended matter, and vapor—from both ambient air and the air system is essential.
Compressed Air Contaminants
1. Particulate matter: Dust, dirt, pollen, metal shavings, and other particles can damage finished products, leading to production delays, quality control issues, and customer satisfaction.
2. Suspended matter: These particles consist of small droplets in compressed air systems, such as those in oil-injected machines, originating from lubricants. Improper handling can harm both the product and health. 3. Vapor: Composed of liquids such as gaseous lubricants, it requires an activated carbon filter to remove.
Filtration Methods
1. Dry Dust Removal: Compressed Air Line Filter remove solid particles through three mechanisms: inertial impaction (particles are captured due to their weight; larger particles are easier to separate), interception (particles larger than the filter media's pores are captured, making larger particles easier to remove), and diffusion (small particles moving erratically are intercepted, making smaller particles easier to remove).
2. Suspended Matter and Vapor Removal: Charcoal air filter can remove liquids and some particulate matter by coalescing small droplets into larger droplets that fall into a water collector, making the airflow cleaner and drier. However, they cannot effectively remove vapor. Vapor filters use adsorption, allowing vapor to bind to the adsorbent surface. Activated carbon filters are commonly used, but over time, oil vapor will coat the surface, requiring replacement of the filter media before saturation. A dust removal filter should be installed to prevent carbon particles from entering the airflow.
The Impact of Lubricating Oil
To assess the impact of oil on compressed air systems, it is important to understand the equipment and industry requirements. Strict industry health regulations or equipment sensitive to oil/vapor require appropriate filtration. Lubricants can come from both ambient air and the compressor. Oil-injected air compressors release lubricants, increasing costs. Industries like electronics and semiconductors are susceptible to contamination, leading to product loss and other issues.
The Importance of Proper Filtration
Improper filtration can cause pipe corrosion, increased pressure drop, and equipment damage, resulting in downtime and high repair costs. It can also strain the compressor, causing high energy consumption and excessive component wear. Proper filtration is crucial when meeting stringent regulations.
