19 Oct 2009 --- It is commonly known that evaporation equipment is cheaper and requires far less energy than drying equipment. Therefore it is common sense to increase the dry matter content prior to drying. However, the maximum dry matter content obtained with standard falling film evaporators is limited, due to the resulting increase of viscosity at higher dry matter content. Moreover, viscous liquids are difficult to spray dry, often resulting in powders of unsatisfactory quality.

Contract research company NIZO food research can now produce high solid liquids and adjust and test the subsequent spray drying processes. By delivering a representative sample of the end product and a clear procedure to adjust the current equipment, NIZO provides a risk free recipe for its clients to expand their drying capacity and to reduce energy consumption.

To provide this service, NIZO has purchased evaporation equipment that enables concentration up to a very high dry matter content. In addition is has installed a range of different atomization systems to its industrial spray dryer to investigate the most favorable configuration and process conditions. In this manner NIZO can produce high solids concentrates which are subsequently atomized and dried. The evaporation equipment may also be used to produce high solids feeds for either drum dryers or freeze dryers, which are also available at NIZO.

The systems can be used to obtain powder samples, which are representative for those obtained at large scale drying operations. Moreover, the data obtained can be applied to adapt current evaporation and drying systems to the high solids drying system. Customers can thus expand their drying capacities while retaining a high powder quality and reduce energy consumption.

Senior expert Coen Akkerman explains that NIZO has the complete infrastructure available to test the modifications in the evaporation and the drying process and show the consequences for the quality of the end product. ‘After testing the changes on 25 kg powder per hour scale we can directly translate the improvements to, say, 5 tonne/hr scale. The tests can therefore be done with limited amounts of raw materials, while at the same time the process parameters for large scale operation are obtained.’