DEVELOPMENT AND PERFORMANCE EVALUATION OF A SOLAR  BUBBLE PARBOILED RICE DRYER THROUGH EXPERIMENTS AND  COMPUTATION

Milliyon, Abebe Mekuria

dc.contributor.author	Milliyon, Abebe Mekuria
dc.date.accessioned	2024-01-12T06:59:52Z
dc.date.available	2024-01-12T06:59:52Z
dc.date.issued	2023-06
dc.identifier.uri	http://ir.bdu.edu.et/handle/123456789/15568
dc.description.abstract	Through experimental tests and simulation, this work examined the drying characteristics, and performance of forced convection Solar Bubble parboiled rice dryer. For the drying characterizations and behavior of the parboiled (Shaga) rice variety, twelve thin-layer drying models were used to analyze and fit the experimental data with the utilization of nonlinear regression. Experimental tests by considering the effects of drying mode (solar bubble versus open sun), loadings (thin, medium, and thick layer), and mixing conditions of (two and three hours) on the drying time and moisture losses using a three-way ANOVA. Additionally, computational fluid dynamics simulation is employed for predicting drying air velocity, temperature distribution for validation, and drying kinetics simulation by considering the parboiled rice as a porous media. The results show that the drying process occurred in the falling rate period. The Diffusion Approach model with the goodness of fitting R 2 =0.998421, RMSE=0.004696, SSE=2.205E-5 and (modified Lewis) model with the goodness of fitting R 2 =0.992191, RMSE=0.012265, SSE=0.000181 accurately described the drying characteristics for the two- and three-hours mixing interval respectively. Safe milling moisture content of 14% was achieved within 10, 16, and 23 hrs for the two-hour mixing conditions and within 12, 25 33 hrs for three hours of mixing with the respective loadings. The magnitude of effective moisture diffusivity is in the range of 1.5×10-9 - 2.3×10-9 an activation energy value of 23.2 KJ/mol. the simulation also accurately predicts the drying air distributions. The inlet air heating zone and the parboiled rice drying zone temperatures were in the range of 32-47 0 C and 36-52 0 C with (1.3 0 C) 0.4% deviation from the experimental respectively. Moreover, a drying kinetics simulation predicts the performance of the solar bubble dryer without considering the mixing conditions. The modified solar bubble parboiled rice dryer with its simulation model was utilized as a kind of perspective for solar drying applications for parboiled grain crops as well as to optimize the SBD. Keywords: parboiled rice, moisture diffusivity, solar bubble dryer, activation energy	en_US
dc.language.iso	en_US	en_US
dc.subject	Energy Center	en_US
dc.title	DEVELOPMENT AND PERFORMANCE EVALUATION OF A SOLAR BUBBLE PARBOILED RICE DRYER THROUGH EXPERIMENTS AND COMPUTATION	en_US
dc.type	Thesis	en_US