Expansion to Unilever's Covington ice cream plant uses CO2/NH3 system 

By Robert Davidson, Oct 26, 2015, 17:16 2 minute reading

On 7 October, US Cold Storage opened its distribution centre, an expansion to the Unilever ice cream plant in Covington, Tennessee. The warehouse utilises a CO2/NH3 cascade refrigeration system with glycol defrost and is looking to secure LEED Silver status.

Originally announced in August 2014, the newly-opened 336,500 square foot facility in Covington will include a new freezer conveyor that will move finished ice cream products from the Unilever plant to the storage facility where the temperature will be maintained at -20oC. The expansion cost a total of US$48 million (€43.5 million) and will serve as the third-party logistics provider for Unilever, with two other Tennessee locations in Smyrna and La Vergne.

CO2/NH3 cascade system keeps ice cream cool

To ensure that the warehouse refrigerates both efficiently and responsibly, US Cold Storage opted for a CO2/NH3 cascade system to refrigerate the 170 pallets per hour that the ice cream plant will produce. The new freezer conveyor will help transport the Unilever brands such as Ben & Jerry’s, Klondike and Popsicle through the refrigerated warehouse. The CO2/NH3 cascade system keeps the temperature at 20oC inside the warehouse and the pallets are put inside a refrigerated truck where it is taken to the storage facility. To keep up with production, the automated vehicles will operate 24 hours a day, 7 days a week.

In a CO2/NH3 system, NH3 is used in the high stage to reject heat to the outside, whereas CO2 is used in the low stage to reject the heat to the ammonia high stage. This separation of refrigerants in the refrigeration process means that ammonia can be uninvolved in more sensitive locations where there are safety concerns, such as when food is present. The ammonia is instead located in a central mechanical room or a rooftop compartment.

US Cold Storage helps Unilever continue its use of natural refrigerants

Unilever is one of the most forward-thinking global companies with regards to the displacement of harmful fluorinated gases for efficient and environmentally friendly natural refrigerants. With over 1.8 million point-of-sale hydrocarbon cabinets refrigerating its ice cream, Unilever is deploying more and more natural refrigerants in the rest of its supply chain, particularly ammonia. US Cold Storage has helped Unilever on its journey in the United States and when announcing the Covington expansion, George Cruz, US Cold Storage vice president and area manager had this to say on their continued partnership:
“United States Cold Storage and Unilever work together across the country, and we are all very excited to expand our growing relationship at a USCS facility that embraces automation by maximizing on efficiencies of being a plant attached to this very significant Unilever ice cream production facility. We know that working together with the community that this project will be successful.”


By Robert Davidson

Oct 26, 2015, 17:16

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