HDPE cooling towers from Delta Cooling protect one manufacturer’s plant operations.
HVAC systems play a crucial role in industrial cooling applications. Made of cooling towers, chillers, and air handlers, these are used to cool areas where high heat loads can shut down critical processes. This could stem from machinery that generates extensive heat, or where cooling and ventilation are required to protect temperature- and humidity-sensitive equipment.
In the case of a large paper mill operated by one of the leading makers of tissue, pulp, paper, and packaging products, a primary cooling tower and other HVAC apparatus is vital to keeping the electrical equipment rooms cooled. These enclosures hold heat-sensitive instrumentation used to monitor and control essential plant operations.
The Mississippi plant is one of the U.S.’s largest producers of container boards, used in the fabrication of durable cardboard boxes. The mill recently needed to replace the cooling tower used for the electrical rooms along with an additional tower that supplied comfort air to the building’s offices. Both cooling towers were the classic metal-clad design framed with wood and were beginning to disintegrate. “Our cooling towers were maintenance-intensive and getting to be unreliable,” says Brian Lloyd, an electrical and instrumentation planner for the mill. “We decided to immediately replace the two that were integrated with the HVAC equipment.”
Cooling towers have undergone serious design changes over the years. To evaluate options, Lloyd consulted with experts like Russell Cready of Tencarva Machinery Company. “In addition to all of the standard functional necessities, there were a few other specific requests the mill’s engineers stressed would be required,” he says. “Those included lower maintenance costs, longer lifespan, and operational cost savings.”
Avoiding the Pitfalls of Metal
Cready knew the drawbacks of metal-clad cooling towers, like costly maintenance due in part to their susceptibility to corrosion. They often require repeated, expensive repairs like re-sheeting and welding and expensive water treatment chemicals, too. “Servicing some metal-clad cooling towers can be a nightmare,” Cready says. “Some models have thousands of nuts and bolts that can slow repairs to sometimes weeks.”
Cready proposed using engineered plastic cooling towers made of high-density polyethylene (HDPE). These are impervious to weather, caustic conditions, and water treatment chemicals and won’t rust or corrode. Cready recommended and the facility engineers installed towers made by Delta Cooling, who pioneered the HDPE design in the 1970s and offers a 20-year factory warranty.
Ensuring a Longer Lifespan
The second requirement, a long lifespan, is an inherent benefit of HDPE. The mill selected Delta’s TM Series, an induced-draft, counter-flow design available in single unit capacities from 250 to 2,500 cooling tons. The TM Series offers a modular design that allows the towers to be assembled in multiple configurations of up to six units. “It makes it easier for them to add on to the existing towers to meet future cooling needs,” Cready says.
The new cooling towers are self-contained and factory assembled, so installation was easier and less intrusive. “Installation didn’t require a big crew, so we had only a few people coming in and out of the facility, which helped reduce any disruptions to plant operations,” Cready says. It took just a few hours.
Adding Convenience and Savings
The new design promises to add substantial savings to the plant. For example, in addition to the HDPE structural material, the tower’s “plumbing” has enclosed, non-corroding PVC pipe and non-clog spray nozzles to further reduce maintenance costs.
The old metal-clad tower had an exterior containment pond, which is no longer required because the new towers are self-contained. “That eliminates a troublesome chore, keeping the pond free of dust and debris that often traveled from our equipment into the containment water,” says Lloyd. “Also, we no longer have the need to treat that water with expensive chemicals.”
Lloyd says the new cooling towers also consume less power, and the blowers are independent. The old metal-clad tower had one big fan on top, so they’d have to shut the tower down and deal with a big 60hp motor with a large fan on top. With the smaller independent fans, if you have one go out they are simple to replace, saving time and material costs.
Project: Mississippi paper mill
Project Manager: Brain Lloyd
Specifier/Installer: Russell Cready, Tencarva Machinery Company
Cooling Tower Manufacturer: Delta Cooling Towers