Technology

Schoeneck Containers, Inc. (SCI) is a company that thinks a lot about its future – and how to continue to maintain a long track record of profitability and reliability while meeting a growing demand for its quality plastic containers for customers throughout North America. It’s the kind of thinking driving the decision to install a closed-loop adiabatic fluid cooler and central chiller with free-cooling capabilities at the company’s new 250,000-square-foot production facility in Delavan, Wisconsin.   

Industrial automation and process applications requiring a chiller or heat exchanger can come in all types of shapes and sizes, and cooling capacity demands can range from a few hundred Btu/hr. for bench top lab equipment to many million Btu/hr. for laser applications. Chiller sizing for large-scale end users such as beverage, chemical or plastics manufacturing usually will demand central systems to achieve the massive cooling capacity requirements compared with small- to medium-range point of use automation applications. These unique differences become more challenging for original equipment manufacturers (OEMs) as machine designers must anticipate a wide range of end-user operating environments and operator skill levels when specifying chillers or heat exchangers in contrast to end-user facilities where cooling capacity requirements are location specific and operator skill levels are known.  

Recent legislation is impacting the use of hydrofluorocarbon (HFC) refrigerants, both globally and nationally. On the heels of these changes is confusion about legislation and the availability of certain types of refrigerants. On a global scale, the Kigali Amendment to the Montreal Protocol provides a global phase-down schedule for the use of HFC refrigerants in multiple sectors - including R-134a and R-410A - for the HVAC/R industry. While ratified across the globe by approximately 100 countries to date, the amendment has yet to be ratified in the United States. 

“Evaporative cooling capacity for the district system is provided by a six-cell, open-loop cooling tower capable of 6,000 tons,” said Reid Olsen, USU Central Energy Plant Manager, who has been at the university for 26 years. “This tower serves the condensers of the water-cooled chillers at the heart of the district cooling system. There are four chillers in all, two of which are rated for 1,800 tons each, and the other two are 900 tons apiece. The cooling towers reject heat from the condenser water loop via evaporative cooling, allowing the chillers to supply chilled water to the campus cooling loop.”

At the company’s production plant employees manufacture a complete range of engineered, high-performance polymers. At the heart of the operation are numerous extrusion lines and related equipment that operate 24 hours a day, five days per week to produce and ship as much as five million pounds of high-performance polymer pellets each month. The process of producing pellets begins when the rotating screw on each extruder accepts a carefully calibrated mix of thermoplastic materials, as well as additives, from a hopper and pushes the mixture into the extruder’s barrel.

For U.S. Flue-Cured Tobacco Growers, Inc. (USFCTG) sustainability is a guiding practice for tobacco production from seed to delivery. So when traditional chemical water treatment had proven problematic in air washers at its plant in Timberlake, North Carolina, the company thought outside the box for solutions to address a variety of issues while also supporting its sustainability goals. 

Field-erected evaporative “wet” cooling towers, combined with heat exchangers, are an economical and efficient method to dissipate large heat loads at oil and gas refineries and chemical processing plants – as long as they’re free of harmful debris. Yet many cooling towers at these facilities are highly susceptible to poor performance and costly downtime due to problems associated with debris buildup and potential for debris to pass by traditional stationary water screens during the cleaning process, clogging heat exchangers.

Do water-cooled chiller plants still deliver lower utility bills? Today, many chiller plant energy analyses carefully account for energy costs, and even energy escalation rates – a factor that projects how fuel costs will increase over time, while ignoring water and wastewater costs associated with cooling towers. While highly effective at transferring heat, cooling towers consume millions of gallons of water each year through the process of evaporation, drift, and blowdown. With the rising cost of water and wastewater, this omission can result in an incomplete picture for the building owner.

Oil-free refrigeration compressor technology offers significant benefits in terms of efficiency and performance. Eliminating oil from the system can yield up to 40% improvement in part-load efficiency compared to fixed speed screw compressors. And, this performance improvement can be sustained over the life of the compressor since oil-free compressors incur no mechanical wear during operation.

The need to pay close attention to the university’s central chiller plant has always been a priority given the energy required to power the chillers, said Michael Bolien, Manager of Central Plant Operations, University of Tulsa. At TU, seven water-cooled chillers provide 7,000 tons of cooling capacity to all university facilities. “Over the past five years, TU has had a 17% increase in cooling load, based on the square footage of new buildings. Because our central chiller plant is our biggest energy user, optimizing its operations is our first line of defense,” said Bolien.