IMPROVING THE EFFICIENCY AND QUALITY OF DRYING MEDICINAL PLANTS

Drying of medicinal plants is one of the most important technological operations, significantly determining the quality of the finished product, also being the most power consuming operation. In this regard the development of the energy-saving technologies for drying of raw materials is a priority. The article presents a drying unit of the disc type and the results of the studies of drying of medicinal plants. A feature of this dryer is the availability of multistage perforated plates, the perforation diameter of which varies along the height of apparatus, decreasing from 15 mm on the top of plate up to 2 mm on the bottom. Thus, large particles are subjected to longer heat treatment, going through all the stages of the device. Smaller particles pass the top of the plate with large perforations and pass the length of a path which is proportional to its size. This approach allows us to dry evenly the different fractions of raw materials and to use the heat energy more rational compared with the traditional methods of drying. In addition, with the aim of reducing the energy consumption, the method of heat recovery by a heat pump is used, which ensures the temperature of the drying agent at the level of 45-47 degrees C, which also has a positive effect on the quality parameters of the dried products.