Drying products independently of the outside air while preserving quality

Drying independently of the outside air

Date
07-06-2017

ENGIE Refrigeration has now developed a condensation drying system that you can use to dry your crops independently of the outside air conditions, and the operational costs are lower than with conventional systems.

For a long time, the agricultural sector depended on the outside air to dry and refrigerate crops. Climate change now means that farmers can no longer store their onions over the winter without sacrificing quality. However, ENGIE Refrigeration has developed a condensation drying system for onions that means you are no longer dependent on the weather. What are the benefits for you? Better preservation of the quality of your onions and significantly lower energy costs. Or to put it another way, higher profits.

Onions must be dried as soon as they are harvested. This is usually done using the outside air. However, the quality of the outside air almost never fully meets the requirements for safeguarding the quality of the onions during the drying process. To resolve this problem, the outside air is heated with gas heaters so that the air can absorb more moisture. But this requires a huge amount of gas. And it has the extra disadvantage that 1.6 kilos of moisture is released for every kilo of propane gas that is burned. This moisture also has to be removed, and that costs another 10% extra gas consumption.

Moreover, it is not practical to heat the air, because the temperature of the onions actually needs to be stable. Continuing to heat the air results in an unwanted temperature increase, while stopping the process means that the onions can no longer be dried.  

ENGIE Refrigeration has now developed a condensation drying system that you can use to dry your crops independently of the outside air conditions, and the operational costs are lower than with conventional systems.  

How does it work?
With condensation drying – also called refrigeration drying – outside air and gas heaters are a thing of the past. The condensation dryer is actually a refrigeration and heating system in one. That is what makes the system unique. With condensation drying, the air is brought under the condensation point, which means that a great deal of moisture can be removed and the onions can be dried. We then use the heat released during the refrigeration process to keep the onions at the right temperature. Added to this, the system is fitted with a heat pump to heat consignments of onions. The entire system runs on an operating system developed by ENGIE in-house, which can be controlled both on-site and remotely using a PC or smartphone.  

Existing technology used in a new way
The technology isn’t new, says Marcel Bennink, Project Manager at ENGIE Refrigeration. “We’ve been using this technology for years in cheese warehouses and climatic chambers. The results in those sectors got us thinking and ultimately led to the development of an effective approach for storing onions. Our wealth of experience in multiple sectors means we can continue to take innovative steps. This is inspiring us to translate technologies that work well elsewhere to other markets, and the condensation drying of onions is an excellent example of that.” 

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