Canneberges Bécancour is one of the most productive cranberry farms in North America. The farm is located on 450 acres in the Bois Franc region of Quebec. It has 80 cranberry bogs and processes about half a million pounds of cranberries per day during a typical harvest, lasting four to six weeks in late fall.
Once cranberries are harvested, they need to be delivered over significant distances in a short time frame. Unfrozen cranberries that face long transit times can pose serious challenges and risks to the distributors. However, if the berries could be frozen at the site of harvest before being shipped across North America, the risk is significantly reduced.
Canneberges Bécancour wanted to develop a freezing facility to support the original 17,000-square-foot processing plant. The new freezing facility could not use halocarbons, due to environmental concerns. It needed to use CO2 instead of ammonia, because a refrigerant leak could ruin an entire crop of cranberries. It needed fully automated controls so it could be run without skilled refrigeration operators. Finally, it required maximum energy efficiency, including minimal time in supercritical mode and maximized heat recovery.
The team decided on a 400-ton 100% CO2 refrigeration system from Carnot Refrigeration. Transcritical CO2 has a well-established place in the food retail industry, and the design was similar to a rack system used in supermarket refrigeration. In this case, three rack systems were developed for the cranberry freezing facility. Each rack contains 13 reciprocating compressors and includes high-side and low-side components. The system also depends on Danfoss ICM TS expansion valves to expand the high-pressure supercritical CO2 gas to a cold lower pressure two-phase fluid.
The system’s RC Intelligent Recovery System enables heat recovery for underfloor heating, space heating, and process water. In addition, each unit can be run as a convertible system, so the room can be changed from a cooler to a freezer or vice versa.
When the next cranberry harvest rolled around, the Canneberges Bécancour team was delighted with the results and planned to expand the plant again, using a similar 100% CO2 refrigeration system — more than doubling its production capacity to exceed 60 million pounds of cranberries per harvest.