Compressor Air Dryers – Refrigerant and Desiccant

  • Sales, servicing & repairs on desiccant dryers, refrigerated dryers & hybrid dryers
  • Compressed air dryers prevent condensation and corrosion that damage systems
  • Flexible maintenance agreements and same day call out available

Mid-Tech’s experts are experienced in not only installing, but keeping air dryers working at peak capacity. When air is compressed, moisture and other contaminants become more concentrated in the system. If moisture is not removed, the result is corrosion which is detrimental to pneumatic equipment. Equipment failure yields production downtime and shortens the overall function and life of the equipment. Our air dryers remove water vapour before the air is ready to be used.

There are three types of air dryers – refrigerant and adsorption (or desiccant), and a hybrid of refrigerant and adsorption. Refrigerant drying cools the incoming compressed air with a refrigerant cooling agent inside a closed system, condensing the water it contains. Condensed water is separated from the air, which is then heated. With the water removed, there is no more condensation to form in the system.

CompAir F-Series refrigerant dryers operate on the direct expansion principle. The cooling circuit is continuously controlled and monitored by means of a hot gas bypass valve. The refrigerant dryer has an evaporator, compressor, condenser and expansion device.

Adsorption drying absorbs water vapour in a desiccant material. A heatless regenerative dryer uses some of the dried air, called purge air, to regenerate the desiccant material. Heat regenerative dryers uses a zero purge electric heat disk. Adsorption dryers also inhibit the growth of microorganisms. Heatless adsorption dryers, or PSA (pressure swing adsorption) dryers, are the most basic adsorption dryer type.

If you operate a small to medium flow system, a PSA dryer might be the only viable technology available. There are modular heatless dryers such as the CompAir A-Series which are reliable, more compact and lightweight which can be installed in the compressor room or at the point of use.

Hybrid dryers combine the technology of adsorption and refrigerant dryers. The biggest advantage is how this conserves energy because it uses less power, thus reducing the overall running costs. Hybrid dryers have less overall power consumption, less purge-air consumption, and constant and stable outlet pressure dew points. Not only does this reduce operating costs, it also reduces maintenance costs. PSA and TSA (temperature swing adsorption) are combined in this technology.

The first stage involves untreated, humid compressed air which goes through a pre-filter protecting a modified traditional refrigeration circuit which removes most of the water vapour from the incoming air. The next stage is a compact desiccant drying, protected before and after by high-performance oil/water aerosol and particle removal filters. These reduce the moisture content of the air to a standard dew point of -40°C. As the last step, clean, dry compressed air exits through the patented air/air heat-exchanger and is reheated and delivered to the air distribution system.

This brief overview indicates that there are efficiencies of production in using a desiccant dryer or a refrigerated compressed air dryer that must be kept running smoothly. Industrial compressors are designed for continuous operation but regular maintenance is a major part of any installation’s smooth operation.

With flexible service agreements to suit your requirements and systems regardless of the working environment, and one off service deals for your convenience, Mid-Tech have the parts, tools and expertise you need. We also offer same day call-out response for unavoidable occasions when you need us quickly. For more information on our compressor air dryers, please call 0800 028 8366 or click to contact us here.