Lödige’s Druvatherm® vacuum shovel dryer: a total mixing and drying solution

For many years the Druvatherm® vacuum shovel dryer patented by Lödige has been successfully manufactured at the Paderborn/Germany location. The diverse portfolio of Druvatherm® fluidised bed reactors from Lödige offer the perfect solution for each type of application. These range from “simple” solid material mixers to drying systems and a pressure vessel for reactions subject to overpressure. Dryer sizes vary from small laboratory devices with 5-litre drum volume to production machinery with volumes of more than 50,000 litres.

These machines can be used for batch operation. In these reactors the solid particles move in a mechanically created fluid bed, generated by the input of energy via a horizontally arranged shaft equipped with mixing elements. Thermal energy is supplied or discharged via a heat transfer medium such as water, steam, thermal oil or molten salt. Temperature ranges of up to 600°C are achieved by means of electrical heating. High heat transfer coefficients are realized using a mixing drum equipped with a double jacket. The shaft can optionally be included in the heating or cooling circuit. Additional rapidly rotating choppers in the reaction chamber introduce shear forces to the product, enabling additional procedural options. The creation of a vacuum or the use of carrier gas enhance the performance range of the Lödige mixing reactor with drying systems known as shovel dryers. The selection of material qualities, mixing elements and sealing technology is varied according to the respective process.