Tool could enhance spray drying process
The Denmark-based spray dryer equipment manufacturer demonstrated its predictive spray drying tool, Drynetics, at the Anuga FoodTec trade show last week.
According to Michael Wahlberg, manager at GEA Niro, the dynamic behind the development of Drynetics is that if you improve the method you improve the results.
Not all feeds the same
He said that the GEA tool differs from existing spray drying process simulation techniques in that it does not assume that all feeds are essentially alike: “Some feeds are sticky, some take longer to dry than others and some can form deposits on dryer walls, thus leading to impaired performance.”
He also claims that conventional simulation programmes use the Rans-Marshall model for the drying kinetics, which leads to too optimistic drying times, whereas the GEA tool depicts the drying process as it really is.
Experimental approach
In the Drynetics method, continued Wahlberg, tests are undertaken on individual droplets of a feed to determine its actual drying properties or to detect the accumulation of deposits on dryer walls with the results then transferred to computation fluid dynamics (CFD) software to simulate the drying process with unprecedented precision.
“Spray dryers are very large and expensive equipment. Using accurate stimulation in the design process improves the result, cuts costs and saves time,” he argues.
Design optimisation
According to Wahlberg, the predictive tool has enabled GEA to optimise the design of its spray drying equipment as well as allowing it to make improvements to its existing equipment.
He told FoodProductionDaily.com that GEA is using the Drynetics tool to assist food processors in terms of innovation as new formulations can now be tested under realistic conditions and drying properties of different feeds can be fine tuned.
Pilot plant
GEA TDS also showcased its pilot UHT pasteurization plant at the Cologne trade show.
The company said that depending on the viscosity of the product, the plant is suitable for the heat treatment of liquid foodstuff at flow rates between 500 and 1,000 litres per hour. The plant, claims GEA, can be used for indirect heating, and also for cooling, with a modular design allowing these processes to be implemented using plate heat exchangers or tubular heat exchanges, or a combination of both types.
By comparing various suitable cross-sectional areas in the tubes and plates, reference data can be obtained for subsequent production under real conditions, added GEA.
