Ultrasonic Viscosity Reduction of Protein Suspensions before Spray Drying
- Ultrasonics is the solution to enhance efficiency and reduce costs for the spray drying process of whey slurries, e.g. WPC.
- Ultrasonic shear forces lower the viscosity of the whey solution and allows thereby for a higher protein concentration.
- Hielscher Ultrasonics offers various options to apply high power ultrasonics for the viscosity reduction of protein solutions.
Ultrasonic Viscosity Reduction
Powerful ultrasonic forces create cavitation, high shear forces and oscillation in liquids. Hielscher Ultrasonics uses these intense ultrasonic forces to modify the fluid dynamics of shear-thinning slurries such as protein concentrates, WPC or polymer slurries. Many slurries go through a spray-drying process to obtain the final powder product. Spray-drying is an energy-intensive process, which is often a bottle-neck in the production line, too. Ultrasonic viscosity reduction allows for a higher particle loading of the solution, which leads to a reduced volume of liquid that must be evaporated. This goes with significant energy savings. At the same time, the capacity of the spray-dryer is enhances as more product (dry weight) is be processed. The ultrasonic inline treatment of the feeding stream of the spray dryer allows for higher concentration and percentage dry solids into the dryer.
The Effects of the Ultrasonic Treatment:
- Homogenization and particle size reduction
- Remove entrained air and oxygen bubbles
- Open up the compaction layers of the proteins
- Temporarily reduce viscosity
- Create a temporary change in the protein molecule alignment
Why Ultrasonics before Spray Drying?
Ultrasonic viscosity reduction results in reduced energy consumption and higher throughput.
Additional benefits are:
- increases output by 10% or more
- reduction of overall fixed and variable cost
- reduced chilling requirements
- low investment and increased profits
- payback in less than one year
Ultrasonic Equipment
Hielscher Ultrasonics has profound knowledge of configuring and installing the suitable ultrasonic system to optimize efficiency and output of your spray-dryer. According to the production line, Hielscher offers various options to apply high power ultrasonics for the viscosity reduction of protein solutions. All of our industrial ultrasonic systems are built for heavy-duty applications under demanding conditions and can run 24/7. Due to their small footprint, they can be easily retro-fitted into existing production lines. Low maintenance and user-friendly operation are further benefits.
Contact us today to get more information about how sonication improves your spray-drying process!
Literature/References
- M. Ashokkumar, J. Lee, B. Zisu, R. Bhaskarcharya, M. Palmer, and S. Kentish (2009): Hot topic: Sonication increases the heat stability of whey proteins. J. Dairy Sci. 92:5353–5356.
- Mladen Brncic (2014): Impact of Ultrasound on Process Efficiency in Food Industry. presented at “TRENDS IN FOOD INDUSTRY” – Koprivnica, Croatia, September 5th, 2014.
About Spray-Drying Processes
Spray drying is a production technique to convert a liquid solution or slurry into a dry powder by rapidly drying with a hot gas. Especially in the food and pharma sector, the spray drying is often used to treat thermally-sensitive materials.
Spray drying is an frequently used technique in the food and pharma industry to encapsulate active compounds (micro-encapsulation).
The spray drying process consists in the following steps:
- Feeding stream: The feeeding stream is prepared to a homogenous, pumpable and impurity-free solution, suspension or slurry. Often the feedstock is concentrated before it is fed into the spray dryer.
- Atomization: During atomization, the slurry is transformed into small droplets. This is the most critical process step since the degree of atomization controls the drying rate and therefore the dryer size. The most common atomization techniques are the pressure nozzle atomization, two-fluid nozzle atomization, and centrifugal atomization. During atomization, 95%+ of the water contained in the droplets are evaporated within a few seconds.
- Drying: In a hot air or gas stream, the moisture evaporates rapidly from the surface of the particle.
- Separation: The powder particles are separated from the moist air or gas using cyclones, bag filters, or electrostatic precipitation.
Spray-dried products
Food: milk powder, coffee, tea, eggs, cereal, spices, flavorings, starch and starch derivatives, vitamins, enzymes, stevia, nutracutical, colourings, plant extracts etc.
Pharmaceutical: antibiotics, medical ingredients, additives
Industrial: catalysts, chemical products, paint pigments, ceramic materials, polymers, microalgae etc.