Modeling of the spray drying process of green protein suspension concentrate (PGC)

Development and implementation of high-tech and energy-efficient methods of feed production is important and appropriate due to the fact that enterprises are not able to provide the market of feed consumers with high quality products at affordable prices. To solve this problem, an alternative technology for the production of protein green concentrate (PGC) from the cormophyte mass of high protein plants was developed. The most energy-intensive process of obtaining PGC is spray drying. At the same time the problems of energy saving, and the product quality are solved by modeling. The drying model developed in this study is based on the falling edge of evaporation, which is used in many studies of drops drying. The problem of obtaining the basic equations of heat and mass transfer during the periods of constant and decreasing drying rate was to be solved. It is also supposed that the drying takes place during the periods of constant and decreasing drying rate. Basic equations of heat and mass transfer for both periods of drying were obtained. Changing of thermophysical characteristics were determined by statistical methods in the range of PGC humidity of 10... 75% and a temperature of 20... 100%. The model is solved by finite difference method with an accuracy of modeling results of 12%. Method of finite differences is a numerical method for solving differential equations based on the replacement of derivative differences schemes and is the grid method. Identification of model parameters to experimental data obtained in the experimental spray dryer was carried out. The solution allows the mathematical model to determine the change in moisture content (DS concentration ) and drop radial temperature in the spray drying of the PGC concentrate that is necessary both to select the geometrical sizes of the dryer and the drying process parameters controlling.