Atlas Copco CD Heatless Desiccant Dryers

Atlas Copco Cerades Desiccant Dryers

The CD 20⁺-335⁺ is the first dryer to use the revolutionary Cerades™
desiccant developed and patented by Atlas Copco. Compressed air
is channelled straight through the solid desiccant, as opposed to
pushing its way through loose desiccant beads. As a result, you enjoy:
• Lower energy costs and a minimal pressure drop thanks to the
straight, no-resistance air flow.
• Better air quality and longer service intervals because Cerades™
lasts longer than loose desiccant, which decays significantly
over time.
• Environmental and health protection, lower operational costs,
and less downtime as Cerades™ eliminates desiccant dust and
the need to filter it out to reach ISO 8573-1:2010 Class 2 for
• Trouble-free installation and continuous operation as Cerades™
can be mounted horizontally.
• A smaller dryer size as Cerades™ can handle a higher air flow.


Cerades Ceramic Core


Conventional CD Dryer Scope of Supply

  • Extruded, compact modular design
  • Twin desiccant towers
  • Towers contain desiccant cartridges filled with activated alumina desiccant
  • Pre-filtration to 0.01micron/0.01ppm (PD filter)
  • Dust removal after-filtration to 1 micron (DDp filter)
  • Dewpoint sensor
  • Pressure dewpoint(PDP) control
  • 4 / 5.5 / 8 / 10 bar purge nozzles supplied



  • -70ºC/-100ºF molecular sieve desiccant option
  • Remote monitoring ready
  • IP65 Electrical Protection

The drying process

Wet air passes through the inlet filter and enters the drying tower of the dryer (tower A). The water-adsorbing desiccant removes the water vapour from the air as it passes up the tower. The air then leaves the tower through the integrated filter to remove any desiccant particles.


The regeneration process

A small portion of the dried air (know as ‘purge air’) is fed back into tower B to regenerate the desiccant. During regeneration the dry air is allowed to expand through the desiccant tower, in the process taking the moisture from the desiccant. The desiccant regeneration process takes several minutes and once this is complete the towers switch operation based on the dewpoint being achieved at the dryer outlet.



    • Modular extruded design in either simplex, duplex, triplex configuration
    • Base, heads, panels, valves and extrusions corrosion protected


  • Spring loaded desiccant cartridge– less dusting, horizontal installation possible
  • Large internal diameter for low air speed, better drying and low pressure drop
  • Overfilled with desiccant to allow for overflow peaks
  • Up-sized silencers for better regeneration and reduced noise levels


Control and Monitoring

  • Sophisticated, microprocessor based controller with a digital display
  • Digital display showing outlet dewpoint
  • Pressure dewpoint control reduces running costs by extending the dryer cycle times and thereby reducing the purge air requirement
  • Purge stop function which allows the dryer cycle to be paused during periods of no flow (connection required to suitable signal)
  • CAN Bus connectivity as standard
  • AirConnect compatible
  • Voltage free contacts for warning and alarm output included as standard
  • IP54 Protection