Saving energy in spray drying applications
3 ways in which KROHNE can significantly improve the efficiency of your drying process:
Precise temperature set point measurement to minimise unused energy
Measurement of shear rate und reduction of tolerances
Improvement of particle delivery to atomiser
Spray drying transforms liquids into dry powders. This process involves spraying a liquid, such as slurries or concentrated emulsions, into hot air. The technique uses atomisers or spray nozzles to create smallest possible droplets. The method stands out in the food industry, especially for making any kind of powders that are shipped around the world like chocolate, fruit, cereal, flavor, milk or, more recently, products like algae concentrate. Process instrumentation can play the disruptive role in significantly optimising the spray drying process, that certainly exceed the improvements attempted by control algorithms. The implementation of the most appropriate measurement for the most homogeneous size of particles by the atomiser now enables unmatched precise control and adjustment of the process parameters, ensuring efficient and consistent product quality while lowering the excess heat in GJ/t. This is of course particularly interesting in terms of significantly reducing the amount of energy used per tonne of finished product.
How can KROHNE help with these challenges?
KROHNE provides the special instrumentation for measuring steam, coolants, gases, and everything that is necessary in order to produce food products. A large contribution lies in drying applications, where industrial scaling has made precision crucial. Traditionally, only process density could be measured for liquids undergoing drying. KROHNE has revolutionised this through modifications to the Coriolis measurement principle, enabling shear rate measurement.
How KROHNE measurement solutions can increase energy efficiency in drying applications:
Precise temperature set point measurement to minimise unused energy
According to studies, the energy consumption of spray dryers (evaporation rates ranging from 0.1 to 12 t/h) varies from about 3 to 20GJ/t of evaporated water. The average fuel-to-electricity consumption was about 27. It is estimated that around 29 % of the energy supplied to the dryers was being wasted. By better performance specification of precision measurement instrumentation for density, mass flow and temperature, there is significant potential to reduce energy consumption per tonne of finished product. But are current set-ups for spray dryers really based on the best parameter that has recently become available on an industrial scale?
Measurement of shear rate und reduction of tolerances
Shear rate offers a more reliable metric than density alone, addressing changes in viscosity that impact atomisation during spray drying. With advancements of KROHNE OPTIMASS flowmeters, we can now measure the shear rate accurately, reduce tolerances and even lift the overall results. This would be the key to saving gigajoules of energy in spray drying processes.
Improvement of particle delivery to atomiser
If density alone is used, the size of the atomised droplets won't be uniform. Industry experts agree that shear rate and viscosity are the most accurate methods of process control. Density is the current KPI to maintain the feed of concentrated fluid to the atomizer as homogeneous and repeatable as possible. Correlating density to viscosity though shows that viscosity values might be significantly different, while the value for density remains constant.
Example: By reducing excess heat and tightening PID control, the highest process efficiency and quality can be achieved. Expect savings in GJ/t.
Contribution to Sustainability
Precise energy management: Saving gigajoules of energy by reducing particle size tolerance and the need for excess heat
Ensuring optimal process performance, less variation and consistent product quality
Further Benefits
Gaining valuable process insights and optimisation of production efficiency and return on investment
Ensuring hygienic production processes and preventing contamination
Evolution of your spray drying applications towards energy efficiency
Reducing energy consumption is an immensely important issue today, and not just because of sustainability aspects. By saving energy, companies can of course also save considerable costs and expenses. KROHNE understands the significance of precise process instrumentation in boosting the efficiency and performance in food production. Effective monitoring allows precise control, ensuring consistent product quality and energy savings. KROHNE supports these challenges with a broad portfolio for measuring steam, coolants, and gases. In addition, our Coriolis flowmeters enable accurate shear rate measurement, reducing tolerances and providing valuable insights for optimising spray drying applications.