Geelen Counterflow developed the Counterflow Recovery Unit (CRU) with the goal of recovering as much energy and water as possible from its counterflow dryers. These dryers are designed for extruded petfood, aquafeed and food.
Two years of thermodynamic and Computational Flow Dynamics (CFD) modelling lead to a prototype which was tested full-time during 8 months in a commercial production line.
The Geelen Counterflow Recovery Unit is a top-down vertical heat exchanger in stainless steel that recovers up to 75 percent of the energy and water from a counterflow dryer’s exhaust air, whilst avoiding the excessive fouling by fines and fats that often make the use of industrial heat exchangers so difficult.
Dryers are the biggest energy consumers of any extrusion process. Typically, up to 60 percent of the energy consumption of an extrusion plant is used to generate hot air to evaporate moisture from the product. After passing the product, the dryer’s warm exhaust air with high relative humidity transports the moisture out of the dryer. It makes a lot of sense to recover the latent energy in that warm air through condensation before it is discharged. Condensing the air will also significantly reduce the number of odor particles in the air.
Together with an electric heat pump and heat exchangers for the drying air, the Counterflow Recovery Unit can eliminate the need for fossil fuels for drying of extruded petfood, aquafeed and food products.
During 2021, Counterflow Recovery Units will be installed in petfood and aquafeed plants in South Korea, China and Norway by customers that plan to eliminate their CO2 emissions in the next few decades.