Parker Domnick Hunter DTA Twin Tower Desiccant Air Dryer

Parker Domnick Hunter DTA Series Heatless Twin Tower Desiccant Air Dryers effectively remove contaminants in compressed air systems using pressure swing adsorption (PSA) technology.


Parker Domnick Hunter DTA Series heatless desiccant air dryers remove water vapour from compressed air through a process known as pressure swing adsorption. Pressure dewpoints ranging from -40°F (-40°C ) to -100°F (-70°C) are attained by directing the flow of saturated compressed air over a bed of desiccant.

The physically tough and chemically inert desiccant 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 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 low-pressure dry 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 Domnick Hunter DTA Series 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. Counterflow purging ensures optimum performance by keeping the driest desiccant at the discharge end of the dryer.

Moisture load, velocity, cycle time and contact time determine tower size and the amount of desiccant. To ensure dewpoint, each tower is carefully sized to allow a minimum of 5.5 seconds of contact. To prevent desiccant dusting and bed fluidization, airflow velocities are kept below 50 feet per minute. The dryer can cycle for years without changing the desiccant. In general, heatless dryers are the most reliable and least expensive of all desiccant type dryers. Parker Domnick Hunter DTA Series are the most energy-efficient thanks to standard features like, “variable cycle control”, compressor inter-lock and purge flow regulator.


  • Highest quality air
  • Clean, oil-free and dry compressed air in accordance with all editions of ISO8573-1, the international standard for compressed air quality
  • Energy-efficient – giving maximum savings
  • Dry air eliminates microbiological growth
  • Preventing product spoilage, recall and litigation
  • Dry air means zero corrosion
  • Preventing product spoilage and damage
  • Smaller, more compact and lightweight
  • Small footprint means less than half the size of conventional dryers

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