There are several types of compressed air filters
Compressed air inline filters are divided into four categories: coalescing filters, vapor removal filters, dry particulate filters, and catalytic oxidation oil removal filters. While each type ultimately produces the same result (removal of contaminants), the four types work in different ways:
Coalescing filter
Coalescing filters remove water, oil and aerosols from the air while preventing contaminants from re-entering the air. These filters also remove particulates from compressed air that trap them in the filter media, but can cause pressure drops if not replaced regularly. Coalescing filters remove most contaminants well, reducing particle concentrations to 0.1 microns and liquid concentrations to 0.01 ppm.
Steam removal filter
Vapor removal filters work by adsorption. They typically use activated carbon granules, carbon cloth or paper to remove lubricants. Aerosol vapor removal filters work well after coalescing filters because they capture and remove gaseous lubricants that will pass through the coalescing filter.
Dry particulate filter
Dry particle filters are typically used after adsorption dryers to remove desiccant particles. Dry particulate filters work in the same way as coalescing filters.
Catalytic oxidation oil removal filter
Catalytic oxidation oil removal filter uses the catalytic action of catalyst to remove oil pollution impurities in compressed air. It is usually a special filter for oil pollution in compressed air, so that the oil pollution removed in this way can reach grade 0 oil-free state. , is a relatively mature degreasing technology.
Classification of compressed air filter elements
S-class filter (pre-filter), which can filter solid particle impurities of 3μ and above, and the oil mist concentration is controlled at 1ppm/wt;
U-class filter (preliminary filter), which can remove solid particle impurities of 1μ and above, and the oil mist concentration is controlled at 0.5ppm/wt;
Class H filter (pre-filter), which can remove solid particle impurities of 0.1μ and above, and control the oil mist concentration at 0.1ppm/wt;
Class F filter can remove solid particle impurities of 0.01μ and above, and the concentration of oil mist is controlled at 0.01ppm/wt; it can effectively filter ultra-fine dust.
The precision filter is generally used in conjunction with the compressed air dryer, and the configuration of the first 3 and the last 1 is often used;
S, U, H three-stage filters are installed at the front end of the compressed air dryer to protect the stable and long-lasting operation of the dryer, also known as security filters.
The F-class filter is installed at the back end of the dryer to effectively filter ultra-fine dust and ensure the quality of the compressed air outlet.
When do you need a compressed air filter
Not every compressor needs a compressed air filter. Whether a filter is required depends on the purpose of the compressed air, inflating tires or driving pneumatic tools. The quality of compressed air is not high, but in pharmaceutical and food production enterprises , the quality of compressed air will have high requirements. If tiny dust, moisture, and oil droplets will adversely affect the production of the enterprise, then you need to install a compressed air filter immediately.
When to replace the compressed air filter
Determining when a filter needs to be replaced depends on the operating hours of the air compressor and the quality of compressed air required:
A drop in pressure may also indicate that the filter needs to be replaced. When considering whether to replace your compressed air filter, consider the following questions:
Has the equipment life expired?
Does the air audit show air quality below acceptable limits?
Does the pressure drop exceed acceptable levels?
Does the pressure drop exceed the manufacturer's variation point?
If one of the above conditions is met, it means that a new filter needs to be replaced.
