Spray Dryers Danish Joint Research on Spray Dryers
A joint research cooperation by GEA Niro and the Danish Technical University (DTU) investigates the behaviour of bulk flows within spray dryers – with laboratory scale simulation and state of the art CFD technology the partners aim for a better understanding of turbulent flow processes.
Soeborg/Denmark – Research partners combine their energies: Danish GEA Niro joins a cooperation with the Technical University of Denmark (DTU) to simulate spray drying processes. To investigate large scale industrial processes in DTU's laboratory, a scaled down apparatus that uses water currents instead of air is used. The data gathered helps GEA Niro refine the development of its spray drying equipment and ensures that its technology keeps pace with, and sometimes drives, its customers’ production needs.
The laboratory apparatus, financed by GEA and operated by the DTU, uses laser scanning to analyse the bulk flow of microscopic particles. Professor Knud Erik Meyer from the DTU explains these experiments: “We let the water run through the container and then create vertically aligned laser light. We shoot twice in a row and record each laser pulse. As the particles in the water move from the first to the second picture we can see how fast and in which direction the particles move.”
Understanding Turbulent Flow Processes
“This research collaboration makes it possible for GEA Niro to optimize our systems to be as compact and energy efficient as possible. At the same time, it makes it possible to improve the drying process, allowing the systems to produce better products by controlling the temperature of the particles during the drying process,” says Thorwald Ullum, Fluid Mechanics Manager at GEA Niro. “Today, we dedicate resources to understand, in detail, what happens locally in the different parts of the spray dryer. We can now make computer simulations of the spray drying process very accurately. By using CFD (Computational Fluid Dynamics) we can predict how the air moves and thereby how the particles dry. It is essential to know how close the simulations are to reality."
"Simulations are only part of the evaluation process," Ullum comments on the validity of simulations. "Although the simulation results are very accurate, every assumption has to be tested and validated on production equipment.”
Building a Better Spray Dryer
With these experiments both partners try to get a better understanding of the complex flow patters of turbulent currents within spray dryers. GEA expects to use the experimental results in the development of new simulation methods for future spray dryers. According to Ullum, DTU is a perfect partner for researches like this: “DTU has the most advanced equipment, and the researchers at DTU have the knowhow we need,” he said."