With improved, multi-mode controls that conserve electricity while dramatically reducing water consumption, the latest EarthSmart™ adiabatic cooling towers (ESTW Series) from Conair provide a cost-efficient process-cooling solution. The new adiabatic towers eliminate the constant water consumption and treatment requirements of conventional evaporative towers, utilizing closed-loop cooling that isolates process water from contamination, cycling it through finned heat exchangers where ambient air absorbs process heat and cools it for recirculation.
Like conventional evaporative towers, adiabatic towers take advantage of evaporative cooling, but do so in a different and more resource-efficient way. During periods where ambient air is warmest and maximum cooling capacity is needed, adiabatic towers use top-mounted fans to draw warm air through wetted adiabatic panels located in front of the finned heat coils. As air passes through these panels, the water within them evaporates, pulling latent heat energy from the passing air. The tower’s controls automatically manage this adiabatic process, varying water volume and fan speed to reduce the temperature of the ambient air passing through the heat exchangers and provide the additional cooling capacity required.
The advanced controls in EarthSmart adiabatic towers offer multiple modes that also save energy and water in conditions when less than full cooling capacity is required. In normal mode, the system runs without using any water and the smart control regulates fan speed, air flow, and process coolant flow to achieve the desired process cooling set-point. No adiabatic cooling water is used.
When conditions require additional cooling, it operates in either of two wet modes and gives processors the flexibility to choose whether to conserve water or power, depending on changing utility and resource costs:
- In water-saving mode, the control minimizes water consumption in favor of increased airflow to achieve the desired process-cooling set-point. In this mode, the tower makes maximum use of fan speed and ambient air flow to provide process cooling capacity. The control system allows for use of water on the adiabatic cooling pads only if airflow at maximum fan speed is insufficient to achieve or maintain the process cooling set-point.
- In energy-saving mode, the control system reduces electrical consumption by activating use of adiabatic cooling as soon as power consumption reaches a user-defined set-point. Adiabatic cooling is then increased until process cooling needs are satisfied or adiabatic capacity is up to 100% before power consumption is increased.
These innovative, resource-saving features are why EarthSmart adiabatic towers cut water consumption up to 80% compared to conventional evaporative tower systems. EarthSmart controls are built around an advanced, application-specific PLC. All towers feature variable-speed, electrically commutated fans and circulating motors that enable the controls to precisely match changing cooling-load requirements by varying fan/motor speeds, controlling the release of adiabatic cooling water, and regulating the speed of process-coolant flow.
The closed-loop design of Earth Smart adiabatic tower chillers not only minimizes water consumption, but dramatically reduces the possibility of coolant contamination and fouling, as well as the added costs of water monitoring and chemical treatment. Instead of using 100% water as a process coolant, processors may adopt a 35% ethylene glycol mix, which will also help prevent freezing during cold weather. The dramatic reduction in water consumption by the EarthSmart tower also means lower sewage costs.
Conair offers eleven models of EarthSmart adiabatic tower chillers (ESTW Series), available to handle nominal process coolant flow rates from as little as 45 gal/min (170 l/min) up to 510 gal/min (1930 l/min), with cooling capacities ranging from 17 tons to 195 tons.
The Conair Group (www.conairgroup.com) is a leading global supplier of auxiliary equipment for plastics processors, including resin drying systems, blenders, feeders and material-conveying systems, temperature-control equipment and granulators. Extrusion solutions include line-control systems, film and sheet scrap-reclaim systems and downstream equipment for pipe and profile extrusion. Over 450 individual products solve problems, save energy, cut waste and are easy to use. Conair is also an international company, with long-standing operations in Europe, Asia and Latin America. The industry’s most complete product line, top-flight engineering and unbeatable service, all combine to give processors the confidence they need to succeed in today’s competitive global marketplace.