Compact Heatless Air Dryer

Compact heatless air dryers

Working Principle

The term "desiccant dryer" refers to a broad class of dryers. Other terms commonly used are regenerative dryer and twin tower dryer, and to a lesser extent adsorption dryer.

The compressed air is passed through a pressure vessel with two "towers" filled with a desiccant material. This desiccant material attracts the water from the compressed air via adsorbtion. As the water clings to the desiccant, the desiccant "bed" becomes saturated. The dryer is timed to switch towers based on a standard NEMA cycle, once this cycle completes some compressed air from the system is used to "purge" the saturated desiccant bed by simply blowing the water that has adhered to the desiccant off.

The duty of the desiccant is to bring the pressure dew point of the compressed air to a level in which the water will no longer condense, or to remove as much water from the compressed air as possible. A standard dew point that is expected by a regenerative dryer is -40 C , this means that when the air leaves the dryer there is as much water in the air as if the air had been "cooled" to -40 C . Required dew point is dependant on application and -70 C is required in some applications.

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Bosspure 4100- Series


General Features:

  • Designed to meet the requirements of ISO 7183.
  • Dried air as per requirements of ISO 8573-1 class 3-3-4.
  • Designed for efficient working with less pressure drop.
  • Programmable timer which gives accurate cycle change over.
  • Well designed mounting bracket for wall mounting
  • Heavy duty Purge exhaust muffler for quite operation
  • Powder coated for aesthetic look and additional protection.

Advantages of compact heatless dryer:

  • Occupies no floor space as it is wall mounted.
  • Assembled in the encloser ( dust proof )
  • Easy to operate.
  • No moving parts and hence high reliability.
  • Less maintenance required.
  • Programmable electronic timer enables accurate cycle timing.


  • Each dryer is equipped with a Pre-filter to protect desiccant from free
  • water contamination, Oil,Oil aerosols,dust, scales, etc., and
  • an after-filter to avoid desiccant dust carry over.

Pressure Gauge:

  • Pressure gauges on each tower for easier illustration of working of dryer.


  • Highly reliable solenoid valves, to international standards, which act as
  • main flow and exhaust valves. Check valves with well designed orifice
  • for highly accurate purge flow.


  • Auto Drain Valve for Micro prefilters


  • Instrument and Control Air
  • Process Control Instruments
  • Textile Machines
  • Machine tools
  • Bearing air
  • Air Motors and Heavy Air motor miniature
  • Packaging machine
  • Pneumatic cylinder
  • Sensors in fluid technology
  • Sand blasting unit
  • Handling of food and beverages
  • Semi conductor manufacturing
  • Wind tunnels
  • Pharmaceutical manufacturing
  • Conveyance of hygroscopic products
  • Paint spray and Powder coating