May 27, 2014
Dinnissen introduces new spray drying unit
Dinnissen Process Technology has developed a new method for the final drying stage of pre-dried products using the Pegasus® Drying Unit.
The huge initial investment costs and high energy consumption of spray drying towers make the drying of liquid products such as milk extracts, whey, flavour concentrates, and wet-mix products into a very costly proposition. To increase the capacity of spray drying towers and reduce the energy consumption and cost of drying powder-like materials, Dinnissen therefore developed the Pegasus Drying Unit.
In order to dry liquids and wet-mix products and convert them into powders with a long shelf life, producers generally have to resort to using capital and energy intensive spray drying towers.
The drying of wet-mix products in such towers requires large volumes of air, high air pressures, and high temperatures of up to 200°C. The Pegasus Drying Unit serves to meet the requirements of companies that need to increase the capacity of their expensive spray drying towers and/or wish to avoid or delay the need to invest in an additional spray drying tower.
Wet-mix products first go through a conventional pre-drying process, after which they undergo a final low-temperature drying stage in the Pegasus Drying Unit. This not only saves a great amount of energy but also ensures optimum retention of colour, aroma, flavour, and heat-sensitive components such as vitamins.
During the final drying process, the double-shafted paddle mechanism built into the Drying Unit gently suspends powders, granules, and granulates in the air, creating a so-called fluid bed. Precisely at the moment that the ingredients are gently suspended, air is injected at a temperature of between 80°C and 140°C into the Drying Unit. The suspended powder-like or particulate ingredients are brought into very close contact with the hot, dry air, resulting in a very fast and even drying process.
Mixing hot, dry air with particles in the fluidised zone does not require any extra pressure and consumes much less energy. An additional advantage is that particles being dried in the Drying Unit do not run the risk of clumping or being damaged. The Drying Unit is also a very efficient tool for spray-drying a wide range of liquids onto dry carriers such as tea, muesli, and cocoa powder.
The control program built into the Drying Unit allows producers to easily and quickly adjust drying settings, such as drying time and moisture content, to suit their own requirements. In addition, products can be subjected to several processes at the same time in the Drying Unit, for example drying the product while at the same time spraying and impregnating liquids onto the product.
Its modular construction means that the Pegasus Drying Unit can also be integrated into the overall production process or production line.