Kaeser refrigerated air dryer from 162 to 1130 scfm

Thanks to cycling control mode and high storage density, the new generation of SECOTEC refrigerated dryers requires very little electrical power, almost regardless of load.

In contrast to other typical systems on the market, excess cooling power is not wasted, but rather used to cool down a thermal mass. Once cooled, it supplies cooling for compressed air drying, eliminating the need for additional electric power.

Furthermore, the new design ensures minimal maintenance requirement and service work is made quick and easy.

Want to find out more about how KAESER is reducing life-cycle costs?

• Life-Cycle-Cost Management

The load on a refrigerated dryer doesn't just depend on the volume of compressed air to be dried (grey area), but more importantly depends on how much water the incoming compressed air contains. The volume of water (moisture) increases as the temperature rises, so the load on refrigerated dryers increases dramatically when ambient temperatures are high, such as during summer (yellow curve).

Conversely, when the temperature drops during the winter (turquoise curve), there is less load on refrigerated dryers. To maintain a stable pressure dew point throughout these fluctuations, refrigerated dryers should be designed to provide sufficient performance during peak load times, and have additional reserve capacity.

Like the flow rate and temperature range, refrigerated dryers are always operating within the load range of 0 to 100%. Because SECOTEC storage control ensures energy is only used as needed across this entire load range, users benefit from exceptional savings.

The use of small volumes of the future-proof R-513A refrigerant provides security of supply for maintenance work throughout the entire life of the refrigerated dryer.

Innovation:

• The use of greenhouse gases is becoming ever more strictly regulated throughout the world. Installation of highly compact heat exchangers - such as SECOPACK LS and micro-channel condensers - considerably reduces refrigerant demand.
• The greenhouse gas potential of R-513A is significantly lower compared to the refrigerants that have commonly been used in refrigerated dryers up until now.
• R-513A is equivalent to R-134a. It is neither toxic nor flammable.

The duty-cycle of refrigerated dryers is always fluctuating between 0 and 100%. Unlike conventional partial-load control systems, SECOTEC storage control precisely adjusts electrical power consumption during all load phases.

This allows SECOTEC refrigerated dryers to save almost 60% of energy costs compared to refrigerated dryers with hot gas bypass control running at an average of 40% of capacity.

In contrast to conventional systems, the thermal mass in SECOTEC dryers always remains cool. This means compressed air can be dried effectively even during start-up phases. The high-quality insulation around the thermal mass also helps to keep energy use to a minimum. With SECOTEC refrigerated dryers, compressed air drying takes place with outstanding energy efficiency and it's especially gentle on the equipment thanks to the high thermal mass capacity.

SECOTEC refrigeration dryers efficiently maintain pressure dew points of up to +38°F during full load operation. Thanks to their narrow fluctuation range, pressure dew points are also more stable during partial load operation than is the case with conventional refrigeration dryers. 

Conventional refrigeration dryers with switching operating modes, but without an additional thermal mass, use the heat exchanger material itself as a thermal mass. In these dryers it is therefore necessary to switch the refrigerant compressors and fan motors on and off much more frequently, in order to maintain the required cooling performance. 

To reduce switching frequency and wear, the refrigerant circuit therefore only switches on at much higher pressure dew points. The resulting fluctuations in the pressure dew point negatively affect drying performance. This can be risky, since corrosion can take hold even with relative compressed air humidity of 40% – corrosion can therefore occur even without condensate formation. 

SECOTEC refrigerated dryers, on the other hand, ensure long-life operation thanks to their high thermal mass storage capacity. Once the thermal mass has been charged, the refrigerant compressor and fan motor can remain switched off for much longer without impacting pressure dew point stability.

Refrigerant circuit

Refrigerant circuit includes:

• Scroll compressor
• Aluminum micro-channel condenser with fan
• Safety pressure switch
• Thermal mass
• Filter dryer
• Thermostatic expansion valve
• SECOPACK LS aluminum heat exchanger system
• Temperature and pressure transducer

SECOPACK LS

• Air/air and air/refrigerant heat exchanger in aluminum block design
• Integrated thermal mass chamber with phase change material
• Condensate separator
• Heat insulation

SIGMA CONTROL SMART

Floating relay contacts

• "Fault" and "Refrigerant compressor running" service messages 
• "Maintenance/warning" and "High pressure dew point" warning messages
• Operating hours counter
• Maintenance timer

Condensate drainage

• Eco-Drain 31 Vario electronic condensate drain with tap on condensate inlet, incl. insulation of cold surfaces

Enclosure

• Powder-coated housing
• Removable panel for straightforward electric connection
• Efficient condenser cleaning
• Removable side panel serves as main access point to the interior
• Machine mounts

Connections

• Corrosion-resistant compressed air piping
• Bulkhead pipe fitting for external condensate line connection
• Cables for mains connection on rear panel (cut-outs in the unit's top metal panel for alternative connection from above)

Electrical equipment

• Electrical equipment and testing to EN 60204-1 "Safety of machines"
• Control cabinet to protection rating IP 54

Options and accessories

• Refrigerated dryers for use in ambient temperatures up to 122°F (standard for TD models)
• Water-cooled refrigerated dryer (TF series)
• Compressed air connections left (TF series)
• Replacement pipework kit TF 173, 203, 251 (pre-assembled) (TF series)
• Adjustable machine mounts
• Integrated transformer with primary voltage of 200 V – 440 V (external for TD models)
• Integrated transformer with primary voltage of 500 V / 3 Ph / 50 Hz and 575 V / 3 Ph / 60 Hz (external for TD models)
• Silicon-free design (VW Plant Standard 3.10.7)

TD, TE and TF series refrigerated dryers are equipped with the innovative SECOPACK LS heat exchanger system. Its latent heat thermal mass is composed of a phase change material. Compressed air warms the material until its melting point (thermal mass discharge), absorbing latent melting heat in the process. This is significantly greater than the amount of heat that it can absorb based on its normal specific heat capacity (without phase change). The latent thermal mass in these dryers therefore has a significantly higher thermal storage density and requires 98% less storage material to achieve the same capacity as conventional storage media.

The key advantages: high thermal capacity for stable pressure dew points and material-friendly operation combined with dramatically reduced unit footprint.

The technical specifications can be found in this brochure:

• Secotec TD-TG Series (PDF, 1.86 MB)