Compressed Air Dryers

Refrigeration dryers are used to remove water vapour from compressed air used in applications where the quality of air required is suitable for general purpose applications such as factory air tools inside factories and process buildings. They are not for use in applications where the compressed air pipe work is exposed to low ambient temperatures.

These type of dryers lower the temperature of the compressed air to condense the water vapour which is then collected and discharged. The pressure dew point produced by refrigeration dryers is positive, typically +3Deg C to prevent water from freezing in the pipework. This type of dryer will not prevent bacteria from growing inside the air supply pipe work and is not suitable for applications where air quality is critical such as respiratory protection.

The Buran range is designed for small to medium volume flows of compressed air up to 1650 m3 / Hr providing a pressure dew point of 3 Deg C. The range features a microprocessor based controller allowing energy savings of up to 90%, (From DC 0150 AE) automatic level controlled condensate drain, dew point display and aluminium heat exchanger which prevents internal corrosion due to wet air. The refrigerant is R134a which does not deplete the ozone layer.

Safewell supplies adsorption dryers from the Donaldson range including Ultrapac 2000, Oilfreepac and HED / ALD / MSD Heatless Adsorption Dryers.

Adsorption dryers are used to remove water vapour from compressed air used in applications where the air has to be very dry to prevent bacterial growth, corrosion and disruption to production processes involving air actuated equipment e.g. valves or instrumentation.

These type of dryers contain desiccant, a media used to adsorb water from air. Air is passed through the media and the water vapour is retained by the desiccant. For continuous long term operation, it is necessary to regenerate the desiccant media when is becomes wetted to ensure that its drying efficiency is sustained.

Desiccant dryers are typically manufactured with duty and standby desiccant chambers. The duty chamber is used to provide a flow of dry air while the standby chamber is being regenerated. A small stream of dry air from the duty chamber flows in reverse through the standby chamber to exhaust drying the wetted desiccant. Following regeneration the chambers swap duty and the other chamber is then regenerated. Regeneration control can be electronically or pneumatically controlled.

The performance and efficiency of desiccant dryers is validated by measuring the pressure dewpoint of the treated air. The pressure dewpoint indicates the temperature when condensation of water vapour present in the compressed air supply will occur. Typically adsorption dryers will produce a dewpoint of -20 to -70 Deg C providing very dry air at normal ambient temperatures.

It has been demonstrated that bacteria will survive in compressed air down to a pressure dewpoint of -26 Deg C. A desiccant dryer is, therefore, essential when drying compressed air used in critical applications involving food and pharmaceutical production or applications where the air is used for respiratory protection or medical therapy.

ULTRAPAC 2000

The Ultrapac 2000 heatless adsorption dryers come in two main ranges, the Mini version which covers volume flow rates from 5 to 25 m3 / Hr (1 bar, 20 Deg C) and the Midi version which covers flow rates from 35 to 100 m3 / Hr (1 bar, 20 Deg C). The Ultrapac 2000 is a complete purification package including the dryer, pre-filter, after-filter and condensate drain in a compact space saving design offering a range of benefits including energy efficiency and ease of maintenance. The desiccant is contained in easy to replace cartridges. The dryer will provide a pressure dewpoint of -40 Deg C at 100% load. Operating pressure is up to 16 bar (g)

ULTRAPAC HED / ALD / MSD

This range of dryers offers a complete purification package including heatless adsorption dryer with pre-filter, after-filter and electronic condensate drain. The range covers flow rates from 5 to 1000 m3 / Hr (1 bar, 20 Deg C).ALD/HED/MSD dryers provide dewpoints from -20 Deg C to -70 Deg C. Operating pressure is up to 16 bar (g).

HIGH PRESSURE ADSORPTION DRYERS

For processes where the air pressure is greater than 16 bar (g) we can supply a range of safe and efficient heatless regenerating dryers suitable for operation at max pressures of 25, 40 100, 250 and 400 bar (g). Volume flow rates (1 bar, 20 Deg C) range from 40 to 1130 m3 / Hr for the 25 bar (g) unit, 50 to 1200 m3 / Hr for the 40 bar (g) unit, 55 to 655 m3 / Hr for the 100 bar (g) unit, 90 to 1050 m3 / Hr for the 250 bar (g) unit and 115 to 870 m3 / Hr for the 400 bar (g) unit. The dryer includes pre and after filters.