Project in the spotlight: Condenser drying system
Certainty of quality and lower energy costs
In their new storage for organic products, Maatschap Van Stee in Swifterbant opted for condensation drying 3 years ago. In addition to the lower energy costs, the higher storage yield was also an argument. “If I had to do it over again, I would do it the same way,” says Frans van Stee.
The arable farm of Maatschap Van Stee consists of 70 hectares. Frans runs the company together with his brother. 4 years ago they opted for a gradual switch to organic farming. Onions, carrots and potatoes are their main crops. In addition, the crop plan consists of spinach, beans, fodder beets, sweet corn, peas and oats. With a gradual transition to organic, they created time to adapt the machinery and to get used to organic cultivation. They also realized that the long-term storage of organic products would become difficult with the traditional technique in the existing storage areas. That is why they initially thought of converting to condensation drying. However, because the storage areas could not be closed 100%, that plan was shelved and new construction was given all the attention.
It was clear from the start that the storage had to consist of 3 cells. In addition, it had to be possible to dry independently without fossil fuels. Because of their good experiences with Tolsma-Grisnich, it was a matter of great importance to Van Stee that their storage adviser Paul den Engelsen would guide them through the new construction process. Based on the size of the company and the construction plan, the advice was to set up 2 cells for condensation drying and 1 cooling cell specifically for carrot storage.
With the condenser drying installation, Van Stee can dry the onions 24/7 and provide them with a heat treatment to combat mildew. The cooling system uses propane, a natural product that is not harmful to people and the product. In addition, glycol is a simple and robust refrigerant with which both the hot and cold circuits are carried out at Van Stee. The cooling ensures a constant temperature of the product, so that unwanted germination is also under control.
” We enjoy and benefit from this investment every day. If we had to do it over, we would do it this way again.”
Air Control Max fans
For the ventilation, the choice fell on the low-noise and energy-efficient Air Control Max fans. “I am very happy with that,” says Van Stee. If he turns on 4 fans of 2.2 kW at 60%, the energy consumption increases by only 3 kW. This makes a significant difference in energy costs. And the lower noise level? “In the storage you can’t hear whether the fans are on. And even in the pressure chamber I can have a normal conversation with someone.”
The new storage is controlled by the Vision Control storage computer. Initially, Van Stee had to get used to it. Still, he wanted to make maximum use of all the options offered by the storage computer. That is why he finds the guidance from Tolsma-Grisnich very pleasant. “They can log in, watch and make adjustments to the settings if necessary. Thanks to the service and coaching of Tolsma-Grisnich, I have learned a lot and I can now also work well with this user-friendly storage computer.” There are 550 solar panels on the roof of the storage facility. These are linked to the energy module of the Vision Control. The use of the self-generated electricity is therefore optimal. In addition, it provides a good overall overview of energy production and consumption.
Whether the new storage meets the wishes of Van Stee: “Absolutely. Last year, we were able to get the carrots from 12 to 3 degrees Celsius within two weeks. And when you see the ware potatoes which are still in the boxes, it is as if they were harvested yesterday. The soil still won’t let go. In short: product quality is maintained and storage costs are lower.”
In the carrot cell, Van Stee is cooling against the frost line. However, he has not yet seen ice on the evaporator. “I really thought that electrical defrosting was necessary. Paul advised against it because it also produces heat and then has to be cooled again. A waste of valuable energy. His advice has been of great value in the choices we have made.”