Modern production companies need expensive and complex production equipment to meet the demands of the modern market. Equipment and machines powered by compressed air are worth nothing if the quality of compressed air is poor. Downtime and unreliability are not acceptable.
Compressed air contamination is a real problem, which cannot be ignored. Even the most simple and basic use of compressed air requires a minimum treatment, comprising the elimination of water, oil and solids.
To guarantee maximum performance and reliability, clean, dry, reliable compressed air supply is essential to maintain efficient and cost effective production. The key factor in planning an efficient compressed air system is to know all sources and types of compressed air contaminants and the required maximum levels of certain contaminants.
Contaminants come to compressed air and gas system from different sources:
- Atmospheric air, containing water vapour, dust, oil vapours and microorganisms.
- Air compressor generates oil contaminants in liquid, aerosol and vapour phase.
- Air receivers (pressure vessels) and distribution systems generates corrosion and scales.
The degree of purification of individual contaminants must be consistent with the needs of the application and the requirements of ISO 8573-1, which prescribes compressed air quality classes.
Condensate separators
Cyclone condensate separators use centrifugal motion to force condensate out of compressed air. The spinning causes the condensate to gather on walls of the centrifugal separators. When the condensate gains enough mass it moves to the bottom of the separator bowl where the blind plate calms the air flow and prevents the condensate from being sucked to the outlet. Condensate is removed out of the system by the condensate drain.
General purpose filters
Pre-filter elements are designed for efficient removal of coarse solid particles and bulk liquids from compressed air. This type of filter is generally used as a pre-filter for the coalescing filter. They are required by non-lubricated and lubricated compressors.
Oil removal filters
Coalescing filter elements are used for a highly efficient removal of solid particles, oil aerosols and water from compressed air. Oil removal filters are usually made of special coalescence material based on glass fibers. These materials enables the formation of oil drops, which are forced to the outside of the filter by air flow. When it reaches the exterior of the filter material, it is stopped in a porous foam material, which covers the filter element, and then runs down to the bottom of the filter housing. The oil is discharged by the automatic condensate drain.
Activated carbon filters
Activated carbon filters are two stage filter elements. They are required in applications, where the air is required for breathing;
mixing with food, pharmaceutical products or other similar applications. Activated carbon filter elements are designed for highly efficient removal of oil, hydrocarbons, vapors and odours from compressed air. Activated carbon is an excellent adsorbent for oil vapors and a medium suitable for the purification of compressed air. It must be in fine granulated form to generate a large surface on which the adsorption can occur. It is essential that the coalescing filter element is installed as a pre-filter upstream to the activated carbon filter.
Catalyst filters
Two stage catalyst filter elements are used for a highly efficient reduction of carbon monoxide as well as some other substances from compressed breathing air. In the first stage the Hopcalite catalyst reduces the level of these substances from the air and in the second stage the depth fiber filter media intercepts all Hopcalite dust particles. It is essential that coalescing filter element is installed as a pre-filter to the Catalyst grade filter and that relative humidity is sufficiently low.
Molecular sieve filters
A molecular sieve filters are two stage filter elements. Molecular sieve is material with pores (very small holes) of uniform size. These pores match the dimesions of small molecules, thereby preventing the adsorption of large molecules and only allowing the passage of smaller molecules.
Molecular sieve filter elements are used for separating water vapor from small flows of compressed air and therefore for air drying. In the first stage, the desiccant adsorbs water vapor from the air and in the second stage the depth fiber filter media intercepts all dust particles. The molecular sieve filtration grade is suitable for point of use applications. It is important that inlet air is free of liquid water and oil aerosols.
Sterile filters
Sterile filters eliminate micro-organisms from compressed air and they are used and are used in processes and systems which require the highest air quality. Sterile filters are made of materials that enable high temperature steam sterilization. The sterile filter element is used for highly efficient sterile filtration of compressed air, processed air and technical gasses. The depth filter medium made of borosilicate glass microfibers ensures highly efficient removal of submicron particles down to 0,01 μm including microorganisms (bacteria). The filter medium supported with NOMEX is rigidly held between two stainless steel cylinders and encapsulated between stainless steel end-caps. This results in exceptionally strong filter element that ensures highly efficient filtration and allows a large number of sterilization cycles.