Compressed Air Treatment Solutions

Ideal for Applications Requiring Extremely Low Dewpoint

Sullair Desiccant Compressed Air Dryers are engineered for the most critical applications — providing dry compressed air where you need it most.

• Flow Range: 3 to 7500 + cfm
• Dew point range: −4 to −100°F (−20 to −73°C)
• ISO 8573-1:2010 Air Quality Class Range: Classes 1, 2 and 3

How Desiccant Air Dryers Work

Sullair Desiccant Dryers have a dual tower design in which both vessels are filled with desiccant material. Moisture migrates to the driest material available. Desiccant material adsorbs moisture—separating it from saturated compressed air. (As long as the desiccant material is drier than the air entering the dryer.)

1. Saturated, compressed air passes through vessel one where the desiccant adsorbs moisture. This helps lower the dewpoint to expel dry compressed air 
2. Once vessel one reaches a set level of saturation, the air switches to pass through vessel two 
3. While the air is passing through vessel two, vessel one dries and regenerates the desiccant material
4. When vessel two reaches a set level of saturation, the air switches to pass through vessel one

Types of Desiccant Dryers

Desiccant dryers are classified by regeneration methods.

Heatless Dryers

Uses an average of 15% of process air during the regeneration process

• Heatless dryers divert a small amount of dried process air from the drying vessel to regenerate the opposite vessel.

Heated Dryers

Uses an average of 8% of process air during the regeneration process

• Heated dryers use an additional heat source—reducing process air loss during the regeneration process. The additional heat source helps enhance the drying and regeneration process while saving energy.

Heated Blower Purge Dryers

Uses an average of 2% of process air during the regeneration process

• Heated Blower Purge dryers use a combination of an additional heat source, air from a blower and little to no process air. The three-tiered method helps optimize drying and regeneration processes while reducing energy consumption — maximizing energy cost savings over the lifecycle.

Benefits of Desiccant Compressed Air Dryers

• Operation in subzero temperatures
• Can achieve higher air purity—ISO ISO 8573-1:2010 Air Quality Classes 1, 2 and 3

Sullair Refrigerated Air Dryers reliably remove harmful moisture and contaminants from compressed air, helping protect your compressed air system, machinery and downstream tools.

• Flow Range: 10 to 6000 cfm
• Dew point range: 37 to 45°F (2.8 to 10°C)
• ISO 8573-1:2010 Air Quality Class Range: Classes 4 - 5

How Refrigerated Dryers Work

1. Saturated compressed air enters the system and is precooled in the air/air heat exchanger.
2. Then, the precooled air moves downstream through the air/refrigerant heat exchanger, where it’s chilled to a set dewpoint, causing condensate to separate from the air.
3. To reliably prevent separated droplets from re-entering the airstream, condensate collects in a large reservoir with subsequent recirculation where flow velocity is significantly reduced.
4. Accumulated condensate is then discharged from the dryer via drain.

The dried, cool process air passes back through the heat exchanger to be reheated and help prevent condensation outside of the downstream distribution piping.

Types of Refrigerated Dryers

Non-Cycling
Ideal for running at full capacity 

• Maintains constant energy consumption no matter flow or air demand.
• Hot gas bypass maintains a stable dew point in varying operating conditions and controls refrigerant amount circulating.

Cycling
Ideal for operations with variable flow rates

• The refrigeration circuit runs intermittently—cycling on and off based on the heat load. This helps to increase energy efficiency and match supply to demand.

Benefits of Refrigerated Dryers

• Economical
• Energy efficient
• Low maintenance