UPGRADE OF SOLAR INDIRECT DRYING PLANT WITH NATURAL VENTILATION UDC: 662.997

Abstract

This article presents the results of research work on a modernized solar drying plant with indirect heat pipes and natural air ventilation. The dependences of temperatures, moisture content of the steam-air mixture and on the surface of the dried grapes, the drying speed on the time of the drying process were established, and were also compared with the results of the kinetics of the grape drying process, obtained in a direct-acting solar drying installation.
The complete physical characterization of the structural model and its elements is established by semi-empirical calculation methods and calculated on the basis of relevant concepts and experimental results.
The high drying temperature of the hard layer (crust formation) that forms on the surface makes it difficult for liquid that has not yet been removed from the inside to escape and prevents drying. This problem was solved by changing the drying conditions and were implemented through a solar drying installation with a heat pipe and natural air convection in the solar collector, with the following efficiency factors: heat pipes 34%, heat exchangers 25% and drying cabinet 11%.
Based on a comparative analysis of the results of experimental studies, it was found that the size of the dried grapes (capillaries) does not matter at the initial stage of drying, while at later stages it affects the drying rate. Also, due to the high drying temperature, the hard layer (crust formation) that forms on the surface makes it difficult for the liquid that has not yet been removed from the inside to escape and prevents drying. The formation of a crust should be avoided as this affects the drying speed and quality of the product to be dried. This problem can be solved by monitoring or changing the drying conditions. Such a problem can be solved by monitoring or changing the drying conditions. In this scientific work, the drying conditions were undoubtedly realized by installing a heat pipe in the solar collector.