Technology Update: Hybrid Dryer
combined refrigeration/adsorption dryer technology.
CompAir's innovative CDT Series
of compressed air dryers from 2.5 to 34 m³/min combines
refrigerant and adsorption dryer technology deliver high quality
compressed air at low energy consumption levels. This feature
contributed by Rastgar & Co. highlights the unique technological
combination of the CDT Series, which offers lower energy
consumption compared to traditional heatless and heat
regenerative adsorption dryer technology.
Energy saving dual drying technology
The CompAir's innovative CDT Series of compressed air dryers
from 2.5 to 34 m³/min combines refrigerant and adsorption dryer
technology delivering high quality compressed air at low energy
The energy saving solution
The unique technology combination of the CDT Series offers
lower energy consumption compared to traditional heatless and
heat regenerative adsorption dryer technology.
Where high quality compressed air is
The major advantage over other compressed air drying
technologies is its contribution to energy-efficiency and
overall running-cost reduction. Less overall power consumption,
less purge-air consumption, constant and stable outlet pressure
dew points as well as reduced operating and maintenance costs
characterize this new CompAir dryer range.
Two stage drying technology
The unique combination of refrigerant and adsorption drying
technology enables high quality compressed air to be provided to
the end-user at low energy consumption levels.
In this drying process, untreated humid compressed air is
initially confronted by a pre-filter protecting a traditional
but modified refrigeration circuit. The majority of the water
vapour is effectively removed from the incoming air in this
The second stage consists of a highly compact desiccant
drying stage, protected before and after by high-performance
oil/water aerosol and particle removal filters to further reduce
the moisture content of the air to a standard dew point of
-40°C. Finally, clean, dry compressed air exits via the
patented air/air heat-exchanger to be re-heated and delivered to
the air distribution system.
This technology exploiting both PSA (Pressure Swing
Adsorption) and TSA (Temperature Swing Adsorption) brings
together an effective and economical solution to meet the needs
of the compressed air user. With the addition of a dew point
dependent switching feature for periods of intermittent load,
incorporated into the electronic controller of every CDT dryer,
initial investment costs are quickly amortised and life-time
The CDT dryers can be equipped with an optional
by-pass to meet the demands of seasonal variations of dew point
requirements above zero in summer and below zero in winter. In
such cases the dual technology can be operated solely as a
refrigeration dryer or regularly in dual combination including
Combined technology –
The unique combined package of refrigeration and adsorption
technology offers several advantages of which the most important
one is the reduced overall power consumption.
- Lower operating costs versus traditional heatless and heat
regenerative adsorption dryers (lower purge-air requirement
and lower heater consumption).
- Reduced maintenance costs due to less desiccant-fill with
extended life time.
- Reliable pressure dew point without peaks above set-point.
- Additional savings with seasonal by-pass option.
- Additional savings at partial load (dew point dependent
- Small footprint.
- Innovative digital controller.
Benefits at a Glance
- Small amount of regeneration purge air: Upto 60% lower
power versus Twin Tower heatless regeneration dryers.
- Low regeneration power consumption: Up to 30% reduced
regeneration costs versus heat regenerated solutions.
- Energy management system: Delivered air quality dew point
monitoring allows energy saving extension of drying cycle as
- Desiccant by-pass option: Avoids using more energy when
only positive dew point is required.
- Low temperature filtration: Better oil vapour filtration,
better air quality downstream.
- No need to modify desiccant bed or change orifices:
Flexible solution, fits for any working condition and