INFLUENCE OF DRYING PARAMETERS ON DRYING EFFICIENCY OF A RAPESEED HOT AIR CYCLONE DRYER

The purpose of this research was to investigate the influence of drying parameters such as height, diameter, ram width of the drying chamber and air speed, on drying efficiency of a hot air cyclone dryer. Experiments were run in two phases. One phase was in the field where the rapeseed hot air cyclone dryer was used to conduct physical experiments. The second and greater phase of the experiment involved mostly mathematical simulations using ANSYS Workbench software version 18.1. Two groups of simulations were conducted: single-factor simulations and multi factor simulations. The number of simulations to be run were obtained using Taguchi Orthogonal Array (TOA) design of experiments in Minitab 18 software. Regression analysis were done to determine effects of factor variations on efficiency values and to obtain a regression equation from which optimal efficiency can be predicted. We concluded that moisture content of rapeseed is directly proportional to mass of seeds and radius of gyration subsequently. Furthermore, varying drying parameters of the dryer, affected drying capacity, drying rate, temperature distribution, and drying efficiency. Ram width had the most significant influence on the numerically calculated efficiency values, followed by the height, and then diameter of the chamber. The least influence was provided by speed of incoming air. Optimal value for each variable were also suggested from analysis with 2950 mm for height, 250 mm for diameter, 90 mm for ram width, and 20 m s(-1) for air speed. Lastly, a regression equation was provided for estimation of efficiency for each parameter change. Using the optimization regression equation, drying efficiency for optimal values obtained from analysis, an efficiency of 83.9135% was obtained which is greater than the present efficiency of 80.87%.