Browsing by Author "Mutumba, Raymonds"

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    Arduino based control of the Food and Water Conveyance Systems of a Refractance Window Dryer
    (International Journal of Scientific Advances, 2021) Mutumba, Raymonds; Kigozi, Julia; Tumutegyereize, Peter; Ssenyimba, Shaffic; Muyonga, John
    A refractance window dryer with a 14.5kg/hr throughput capacity was developed to effectively dry food product of 3mm on the conveyor belt. For efficient dryer performance an automated system for the conveyor belt movement and water conveyance system was designed. The automated system comprised of an ARDUINO centered control system, an arrangement of sensors, water pump and the conveyor motor. A computer program was written in Arduino environment, successfully compiled and uploaded on to the controller board to process all commands. The system was fi rst simulated successfully in ISIS Proteus environment and connected onto a bread board for testing before attaching the motor onto the main circuit board. Performance tests done at 85°C revealed that there was no movement of the belt as temperature built steadily from 31.19°C until it reached a temperature of 92.0°C in the boiler. The maximum recorded water temperature was 98.06°C and the system had an operating range of 95±3°C. Achieving this led to an automated food conveyance system that was reliable and ensured high product quality. The Arduino based system worked well and is recommended for the refractance window dryer and can be up scaled to a bigger similar machine.
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    Performance Analysis of An Arduino Based Calibration and Temperature Control System for A Refractance Window Dryer
    (African Journal of Biotechnology, 2011) Mutumba, Raymonds; Kigozi, Julia; Tumutegyereize, Peter; Ssenyimba, Shaffic; Muyonga, John
    Automated control of temperature in fruit dryers is important for product quality and retention of nutrient content. In this study, the continuous refractance window dryer (RWD) was calibrated for drying temperature to enable the dryer to be set to dry a wide range of products. The drying operation in a RWD is carried out over a bed of hot water. The calibration system comprised of a computer program, calibrated knob, arrangement of sensors and output components. A computer program was successfully written in Arduino environment and a circuit board connected. A DS18B20 sensor was used to read the hot water temperature and a 5V potentiometer employed to vary the voltage as it corresponds to the desired water temperature. The system calibration focused on drying temperatures for mango, tomato and pineapple, but it can be applied to any other food products since the optimum drying temperature for most food products falls within the considered range. A calibration equation relating potentiometer voltage and temperature was formulated with the potentiometer maximum angular sweep found to be 295°. This angular sweep corresponded with 94.9996°C as the maximum calibration temperature. The system was found to be 97.6% accurate at attaining the desired temperature. A calibrated label was developed and marked accordingly. The developed system was simple to operate and robust throughout the testing hence it can be recommended for similar machines.
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    Plastic Packaging: A Study on Plastic Imports in Uganda
    (Int. J. Sci. Adv, 2022) Wandeka, Cynthia M.; Kiggundu, Nicholas; Mutumba, Raymonds
    Plastic packaging is crucial in preserving the quality of products. It has become ubiquitous, and an inseparable part of daily life and the food industry due to its aesthetic attributes, strength, affordability and convenience of use. This has thus led to the increase in demand and imports of plastics in the country. However, plastic packaging alone accounts for 47% of global plastic waste amidst documented threats of plastic waste to the environment-water-food-health nexus. Several reports indicate that between 1994 and 2017, Uganda imported a total of 1.9 million tons of plastic in both raw and finished form compared to 117 million tons across Africa. Imports and use of plastics in Uganda have increased by six-fold within the last three years hence extrapolating the growing challenge for sustainable plastic imports, product packaging, and waste management. The objective of the review therefore was to explore the future trend and impact of plastic imports and packaging in Uganda by analyzing plastic imports and the associated waste. The study further reviews the challenges arising from the growing demand for plastic packaging and presents a discussion on the solutions and potential ways forward for win-win benefits. Several strides to curb the menace of plastic waste are presented, which are manly from the private sector and plastic recycling businesses. A conclusion is made that if these efforts are to meet the intended leaps of change, the government of Uganda has to support the private organisations through grants, space allocation for collection centers and media access across the country. Furthermore, stricter regulations on excess plastic importation have to be implemented by the government as the country develops locally grown solutions to plastic packaging and use.
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    Techno economic analysis of refractance window drying of fruits:
    (International Journal of Scientific Advances, 2021-10) Namayengo, M. Faith; Mutumba, Raymonds; Aliga, Alex; Muyonga, John H.
    Uganda produces a variety of fruits, vegetables and herbs with much of it going to waste because of limited post-harvest processing methods. Refractance window drying technology (RWDT) has a potential of producing high quality dried food products from fruits, vegetables and herbs. A techno economic analysis (TEA) was conducted to compare the processing potential of a new hybrid RWD model to existing fruit drying technologies in selected districts of Uganda. Technical and economic data was collected using in-depth interviews with small and medium scale dried fruit processors, farmers and exporters. Comparisons of the technical and economic parameters of the currently used dryers and the hybrid RWD were done to ascertain the competitiveness of hybrid RWD in the local market. Economic analysis was conducted using the cost benefit analysis and payback period tools. Findings indicated the solar box dryer was the commonest and cheapest dryer at USD. 163, while the UNIDO solar hybrid dryer model was the most expensive at USD. 58,378. The UNIDO solar hybrid dryer (USHD) had the highest loading capacity of 1,250 Kg compared to the hybrid RWD and solar box dryer that both had a loading of 30 Kg of whole pineapple per batch. The throughput for the different dryers was found to be 60 Kg, 7.5Kg and 0.5 Kg for the USHD, RWD and solar box dryers respectively for a 10-hour production cycle. The drying time for the solar box dryer was 48 hours compared to 2 hours for the hybrid RWD and 10 hours for the USHD for pineapple flakes per batch. Additionally, the hybrid RWD presented more opportunities for producing a variety of high-quality dried products, including fruit dices, powders, leather and flakes. A recommendation is made for design modification for the hybrid RWD to increase effective drying surface area and throughput. Keywords: Refractance window drying; technoeconomic analysis; fruit dying; loading capacity