Parker Airtek TW Series Heatless Desiccant Air Dryers remove water vapor from compressed air through a process known as Pressure Swing Adsorption. A standard pressure dewpoint of -40°F (-40°C) is attained by directing the flow of saturated compressed air over a bed of desiccant.

The most commonly used desiccant is activated alumina, a spherical shaped, hygroscopic material, selected for its consistent size, shape and extreme surface to mass ratio. This physically tough and chemically inert material is contained in two separate but identical pressure vessels commonly referred to as “dual” or “twin” towers.

As the saturated compressed air flows up through the “on line” tower, its moisture content adheres to the surface of the desiccant. The dry compressed air is then discharged from the chamber into the distribution system.

A solid state controller automatically cycles the flow of compressed air between the towers, while the “on line” tower is drying, the “off line” tower is regenerating. Regeneration, sometimes referred to as purging, is the process by which moisture accumulated during the “on line” cycle is stripped away during the “off line” cycle. As dry low pressure purge air flows gently through the regenerating bed, it attracts the moisture that had accumulated on the surface of the desiccant during the drying cycle and exhausts it to the atmosphere.

To protect the desiccant bed from excess liquid, all Parker Airtek TW Series Heatless Air Dryers are designed to work with the natural pull of gravity. By directing the saturated air into the bottom of the “on line” tower and flowing up through the bed, liquid condensate caused by system upset, is kept away from the desiccant and remains at the bottom of the tower where it can be easily exhausted during the regeneration cycle. Counter flow purging ensures optimum performance by keeping the driest desiccant at the discharge end of the dryer.

Heatless dryers in general are the most reliable and least expensive of all desiccant type dryers. Parker Airtek TW Series Heatless Desiccant Air Dryers are the most energy efficient thanks to standard features like, “Variable Cycle control”, “CycleLoc™” and purge flow regulator.
Features/Benefits
Basic Controller
• Allen Bradley® PLC
• Nema 4X enclosure
• LCD user interface
• Four line digital display features:
o Tower drying indication
o Tower regenerating indication
o Run status
o Time remaining in cycle
• Selectable cycle settings
• Programmable drain timer (drain on, time and test)
• Compressor demand via external dry contact
(CycleLoc®)
• Power ON/OFF switch
• Step-through regeneration for maintenance

Advanced Controller
• Allen Bradley® PLC
• Powerloc™ Energy Demand System
• Nema 4X enclosure
• 3.5” LCD user interface
• Dew point sensor input (-148 to 68°F)
• Optional 4-20 mA output for remotely monitoring dew point
• Tower pressure sensors
• Inlet pressure and temperature sensors
• Compressor demand via external dry contact (CycleLoc®)
• Modbus/TCP communications via standard ethernet port
• Modbus RTU communications via optional RS232/485 port (Using external gateway device)
• SD card slot for accessing historical data and alarm information
• Selectable cycle settings
• Programmable drain timer (drain on, time and test)
• User selectable alarms with common alarm relay
o High inlet temperature
o Low inlet pressure
o Tower failed to blow down (switch failure)
o Tower failed to pressurize
o High dew point
o Sensor failure for all sensors
• Filter maintenance & alarm
• Clogged muffler maintenance and alarm
• Power ON/OFF switch
• Alarm log stores most recent alarms
• Flashes green when in energy savings mode
• Flashes red when an alarm is present
• Dry contact for common alarm