Cargill-Ewos, a world-leading Norwegian producer of feed and nutrition for the aquaculture industry, is committed to use sustainable and responsible practises to support increasing global consumption of fish and seafood, protect the environment, and help farmers succeed.
In 2022, the company has integrated an electric feed drier supplied by Geelen Counterflow at its Norwegian Bergneset feed mill to substantially reduce energy consumption by 15,000 MWh/a, to cut carbon emissions by 3,000 t/and make the factory one of the world’s first zero-emission feed factory.
Heat pump demonstrator
Two Counterflow Recovery Units from Geelen Counterflow are installed to recover 75% of the waste heat from the dryer by means of condensation. The water from the heat exchanger serves as a source for the four electrically powered high temperature heat pumps (HWW 2/9583I and HWW 3/9583I) which generate hot water at a maximum temperature of 120 °C in a second water circuit.
This heat is used via heat exchangers to generate hot air, required to dry the moist product. CSH2T screw compressors from BITZER, which enable condensation temperatures of up to 125 °C, are implemented. These compressors are especially designed for high-temperature heat pumps using either R1233zd(E) or R245fa as refrigerants.
At maximum design capacity the average COP across the entire dryer is ca. 2.8. Around two-thirds of this value derives from the high temperature drying zones, which operate with a temperature lift of 80 °C (from 40 °C heat source to 120 °C heat sink) and a COP of around 2.4. Another third of the heating capacity is provided with a temperature lift of 50 °C from 40 °C to 90 °C and a COP of around 4.0.
Most of the time, the dryer is not running at maximum design capacity. This allows the temperature lifts to be reduced, resulting in an average COP across the dryer of ca. 4.0.
Figure 1: Geelen Counterflow, Vertical Feed Dryer with 15 floors
A video from this first-of-a kind installation is provided here.
Key facts
| Dryer type | Electric counterflow dryer |
| Drying product(s) | Extruded aquafeed |
| Drying medium | Hot air |
| Operation | Semi continuous batch flow |
| Product conveying | Vertical gravity flow through multiple decks |
| Heating medium temperature | Hot air, max 115C |
| Heat sources | Electricity |
| Heat pump capacity | 3.3 MWth (4 high temperature heat pumps) |
| Flow temperature heat pump | Max. 120°C |
| Refrigerant | R1233zd(E) |
| Drying time | 30-80 minutes |
| Start of operation | 04/2022 |
| Capacity | 4400 kg/h water evaporation |
| Dryer dimensions | One of the worlds largest counterflow dryer incl. 15 drying decks |
| Direct heat recovery | Yes |
| Heat source for heat pump | Hot water after latent heat recovery from dryer’s air exhaust |
| Challenges | The installation was a complex undertaking, with dozens of international experts involved in the design and integration of the advanced systems. The main challenges include: 1) New electrical connection to power station several kilometres away 2) Covid-19 necessitated system assembly by local team with remote guidance |
| Tracked parameters | Temperature, relative humidity, product moisture, power consumption, and COP. |
More information
This information is based on publicly available data and insights provided by Geelen Counterflow.
This first full-electric dryer started up its operations after 8 years of brainstorming, designing, engineering and pilot testing. Two more Electric Counterflow Dryers will start up operation in South Korea and China in the next few months.
For further details, please contact Geelen Counterflow, the manufacturer of this dryer.