Harčova Nauka ì Tehnologìâ (Feb 2024)

INVESTIGATION OF REGULARITIES OF THE FILTRATION DRYING KINETICS OF COFFEE PRODUCTION WASTE

  • O. Ivashchuk,
  • V. Atamanyuk,
  • R. Chyzhovych

DOI
https://doi.org/10.15673/fst.v18i1.2715
Journal volume & issue
Vol. 18, no. 1

Abstract

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The article presents the results of a study of the kinetic regularities of filtration drying of coffee production waste in order to increase its shelf life at different process parameters ‒ the height of the stationary layer of wet material (40 mm, 80 mm, 120 mm, 160 mm), the velocity of the thermal agent (1.24 m/sec, 1.76 m/sec, 2.29 m/sec, 2.82 m/sec) and its temperature (60°C, 70°C, 80°C, 90°C). The influence of the temperature of the thermal agent and the velocity of its filtration through a stationary layer of different heights of wet coffee production waste on the kinetics of the filtration drying process is shown. The analysis of the experimentally obtained drying kinetic curves indicates the presence of two drying periods: the first period, complete saturation of the thermal agent with moisture, and the second period, partial saturation of the thermal agent with moisture. The results of the study indicate an increase in the drying time with an increase in the height of the stationary layer of the dried material, a decrease in the temperature of the thermal agent, and a decrease in its velocity. As a result of the graphical analysis of the obtained experimental data, generalized dependencies describing the intensity of the filtration drying process in the first and second drying periods were determined. These generalizing dependencies allow us to obtain equations for determining the time of the filtration drying process in both periods, which makes it possible to establish the total duration of the technological process. To assess the compliance of the experimental data with theoretically calculated ones, a graphical distribution of the obtained errors was constructed. It has been determined that the maximum absolute relative error of conformity of experimental data to theoretically calculated values is 21.78%, the average absolute relative error is 5.83%. The magnitude of the errors makes it possible to use the obtained equations for practical calculations of drying equipment.

Keywords