| Popis: |
The purpose of the articleis to improve the heat transfer equipment for the production of concentrates from vegetable raw materials, namely a vacuum-evaporator apparatus with a mixing device. System analysis, namely simulation modeling, has been chosen as a tool to determine the advantages of the proposed technical solutions. Research methods. The main heat exchange process of the proposed method for the production of concentrated products from vegetable raw materials is the boiling of the juice in a vacuum evaporator apparatus of periodic action with an improved design of a steam mixer. The mixer is a spiral metal tubular constructor with the possibility of supplying steam into its cavity. As a result of the experiments the dependence of the heat transfer coefficient on the rotation frequency of the developed mixer was investigated, the analysis of which allowed to determine the efficiency of using the new design of the mixing device. This became a practical basis for system-dynamic modeling of temperature field changes during vegetable juice boiling. Results.A new method of processing of vegetable raw materials has been proposed. For its implementation, a vacuum-evaporator apparatus with advanced mixing device was developed. Experimental studies were conducted to determine the heat transfer coefficient during juice concentration. The simulation of changes in the temperature field in the apparatus and the overall working cycle of the evaporator are carried out. Simulation results were obtained using the Vensim system analysis software package. The duration of real steadystate heating was controlled experimentally with the use of a vacuum-evaporator apparatus. Conclusions. The dependence of the heat transfer coefficient on the number of revolutions of the stirrer during the boiling of vegetable juice in the developed vacuum-evaporator apparatus is determined. A system-dynamic model of the heat transfer process has been created, namely the changes in the temperature field in the apparatus are determined, and that makes it possible for further computer experimentation on the basis of the practical studies of the complex heat transfer system relations. |
