eco-ATWB-H Closed Circuit Cooler
Induced draft, axial fan counterflow closed circuit cooler. The eco-ATWB-H (eco-Hybrid) is used for cooling water or water/glycol mixture. The process fluid remains without oxygen and impurities. Executed as per standard with Z-725 (725 g Zn / m²) galvanized steel panels.
The new eco-ATWB-H combines the highly efficient Ellipti-fin coils with Evapco’s new ARID Fin Pak Coils. This combination provides :
- continuous water savings, even when the spray pump is energized
- highest dry bulb switch over temperatures
- plume abatement or elimination
The eco-ATWB-H product range is CTI certified in the USA and is compliant with the International Building Code (IBC). Evapco Europe provides with each closed circuit cooler a Thermal Performance Guarantee. Eco-ATWB-H units are constructed for a maximal nominal capacity of 4.9MW.
Long-lasting corrosion protection is guaranteed with Z-725 heavy gauge mill hot-dip galvanized steel (Z-725 = 725 g/m² zinc). The galvanized steel construction withstands the most difficult environmental and operating conditions.
For special applications, Evapco can produce the units with stainless steel sump, with a water touched stainless steel construction or a complete stainless steel construction (AISI 304 or 316 are possible).
Dry Mode (Sensible Heat Transfer)
In the dry mode, the process fluid enters the ARID fin Pak™ coil through the top coil connections. The fan motor is energized, while the spray pump is deenergized. The axial fan draws air upward through the louvers and across the coils. As the air passes over the ARID fin Pak™ coil, a portion of the load is dissipated to the atmosphere through the tube walls and fins using sensible heat transfer. The warm process fluid exits the ARID fin Pak™ coil, then enters the Ellipti-fin® coil through the factory installed piping. The remaining load is dissipated through the tube and extended surface fins of the Ellipti-fin® coil utilizing sensible heat transfer. The unit will remain in the dry mode of operation until the temperature set point can no longer be met. In this mode, NO water is used and plume is eliminated.
Evaporative mode (Latent and Sensible Heat Transfer)
Once the temperature set point can no longer be met, the unit will switch to the Evaporative mode. This mode of operation in the eco-Hybrid utilizes evaporative and dry cooling simultaneously. First, the process fluid enters the ARID fin Pak™ coil through the top coil connections. The fan and pump motors are energized. A portion of the heat load is transferred through the tube walls and fins to the air passing over the ARID fin Pak™ coil. No water is evaporated during this process. The warm process fluid exits the ARID fin Pak™ coil, then enters the Elliptifin® coil through the factory installed piping. The spray system cascades water over the tubes of the Ellipti-fin® coil while heat is absorbed by the water. Air is drawn upward and over the coils by the axial fan. A small amount of the recirculating water is evaporated due to latent heat transfer through the tube and fin walls of the Ellipti-fin® coil. In this mode, water usage is reduced and plume is abated as the saturated discharge air is heated as it passes over the ARID fin Pak™ coil.