IMPROVING THE AERODYNAMIC CHARACTERISTICS OF THE DRYING PROCESS BASED ON THE LOCAL APPROACH

Abstract

In modern conditions, energy-saving technologies are widely used in various technological processes, including drying processes. Energy saving is achieved in various ways, including through the recycling of waste from the original product, in particular, dried plant waste. The object of this study is the coolant supply system of the installation for drying and technological conditioning of plant waste. The purpose of the work is to develop methods for improving the aerodynamic characteristics of the coolant supply system based on local control of thermophysical parameters in characteristic zones of the working environment. Physical modeling is a traditional method used in IET NAS of Ukraine to study the transfer processes typical for heat power equipment. The research was carried out in a specially made experimental sample of the installation, which completely reproduces the operating conditions of the full-scale installation in terms of geometric parameters and air supply system. The main difference was that the experiments were performed without heating the coolant (air) and using a fixed working line. The material to be dried was placed on a horizontal working line in the form of a thin layer and was blown by vertical air jets. To assess the uniformity of the velocity field, the hot-wire method of measurements was used. Simultaneously with the values of the time-averaged velocity, the method makes it possible to determine the value of longitudinal fluctuations, which have a significant effect on the intensity of heat and mass transfer processes. Based on the local control of the measurement results in the characteristic zones of the working space of the installation, measures were developed aimed at improving the uniformity of the flow velocity fields due to design changes in the air supply system. When performing the work, eight modifications were implemented, differing both in design features and for information received. Because of the measures taken to improve the aerodynamic characteristics of the coolant supply system, it was possible to achieve optimal values of the average velocity and its non-uniformity coefficient, which ensure the required quality of material processing.