Aluminum Alloy Stable Rotary Vane Pumps , Practical Blower Purge Desiccant Dryer

ATLAS COPCO CD25-260 DESICCANT AIR DRYERS AIR TREATMENT

How do desiccant dryers work?
Desiccant dryers consist of two towers filled with desiccant. Wet compressed air passes directly through the substance, which adsorbs the moisture. The desiccant has a finite adsorption capacity before it must be dried out. Hence the twin tower design. While one tower is drying air, the other is being regenerated.

Atlas Copco offers two types of desiccant dryers, the BD+ rangeof blower (zero) purge dryers and the CD(+) series of heatless desiccant dryers. The difference lies in their regeneration process.

1. Drying
Wet compressed air flows upward through the adsorbent desiccant from bottom to top (1).

2. Regeneration
Heatless desiccant dryers – CD+:
Dry air from the drying tower outlet is expanded to atmospheric pressure and sent through the saturated desiccant, forcing the adsorbed moisture out (2 and 4).
After desorption, the blow-off valve is closed and the vessel is re-pressurized.

Blower (zero) purge desiccant dryers – BD+:
The blower (5) takes ambient air and blows it across the external heater (6). The heated air is then sent through the saturated desiccant (2), forcing the adsorbed moisture out.

3. Cooling (BD+)
BD+ with purge:
After the heating phase, the desiccant is cooled by expanding dry compressed air from the outlet of the adsorbing vessel over
the hot reactivated tower.

BD+ with zero purge:
After the heating phase, the blower takes in ambient air and sends it through the reactivated tower from bottom to top.

4. Switching
After regeneration, drying switches from the saturated tower to the regenerated tower (3).

CD 25-260 Competitive investment & superb reliability

1 , Reliable operation
Designed to perform reliably at continuous operation of100% airflow, whereas most dryers on the market are only built to work at 70% to 80%. This includes a constant pressuredew point of -20°C/-5°F or -40°C/-40°F as standard. The pressure dew point can also be adjusted for seasonal or application changes.

2 , Unique manifold/valve design
• Large pipe diameter minimizes pressure drop for advanced energy savings.
• Electronically operated 3/2 valve reduces risk of breakdowns and offers reliable control during airflow fluctuations. With this new design, vessel switching operates unfailingly even in rough conditions.

• Service openings ensure easy service of the moving parts of thevalve system.
• Clever strainer design minimizes pressure drop, regeneration times and energy consumption. Its “swirl” technology ensures optimal distribution of the airflow and decreases wear of the desiccant.

3, Advanced controland monitoring system

• 4-line display in 23 languages.
• Service alarms and general alarm relay.
• Monitors all parameters to ensure maximum reliability.
• Allows for synchronization with the compressor, turning on/off when the compressor does.
• Service indications (4,000, 8,000 and 40,000 hours) and warnings.
• Optional pressure dew point sensor for Dew Point Dependent Switching.

4 , Service andmaintenance-friendly
• Desiccant bags allow for quick replacement without spilling adsorbent material.
• A spring covers the bags to prevent damage by desiccant moving due to pressure pulsations.5 Attached filters
• A durable PD pre-filter prevents oil contamination to increase desiccant lifetime and is included for installation in the air piping.
• A DDp after-filter protects the airnet from desiccant dust and network contamination and is included for installation in the air piping.
• To be installed in the air piping.
• Easy to assemble and maintain.

6 , Nozzle purge set
Offers flexibility in optimizing regeneration pressure for lowest purge air consumption. Standard is 7 bar; 4 and 10-bar nozzles come as separate parts.

7, Advanced options
• Pressure dew point sensor required forDew Point Dependent Switching.

• Wall mounting kit.

Technical Specifications

Reference conditions BD + : Performance data per ISO 7183:2007.
Compressor air inlet temperature: 35°C/100°F.
Inlet relative humidity: 100%.
Reference conditions BD + ZP (Zero Purge):
Performance data per ISO 7183:2007.
Ambient air temperature: 25°C/77°F.
Ambient air relative humidity: 60%