2026-09-21T13:47:44Zhttps://dspace.unza.zm/server/oai/requestoai:dspace.unza.zm:123456789/80482023-07-06T11:20:30Zcom_123456789_18col_123456789_91
Tambe, Achalle Joseph
2023-07-06T09:20:25Z
2023-07-06T09:20:25Z
2022
Thesis
The agricultural sector in most developing countries encounters a lot of post-harvest
losses due to a lack of appropriate drying and storage facilities for preservation. Though
many drying technologies have been developed, there is an increasing demand for
automation in drying. Concerning this limitation, this work presents the design and
fabrication of an intelligent solar-photovoltaic hybrid tunnel dryer for tomatoes with
automatic temperature control and air recirculation. The entire dryer assembly consists
of the main dryer itself, a solar photovoltaic system, and a control unit. The dryer was
tested through the performance of seven experiments; three experiments where done for
the sake of testing and making adjustments on the control unit to check if the current
from the Arduino digital pins is sufficient enough to energise the relay coils in which in
the course of these three experiments, a current booster was designed and fabricated.
The fourth experiment was the no-load experiment where the average drying chamber
temperature was obtained to be 59.95℃. The fifth experiment was a load experiment, the
sixth experiment was to determine the collector efficiency which was 67.06%, and the
seventh experiment was another Load experiment whose main purpose was to determine
the energy consumed by the electric heater for drying tomatoes and dryer performance.
The dryer performance was determined using the two load experiments. In the Load
experiments, freshly bought tomatoes from the local market were washed and sliced to a
700g mass and placed in the drying chamber. For the first and second load experiments,
the tomato was dried from an initial moisture content of 95% (wet basis) to a final
moisture content of 5.30% and 9% (wet basis) respectively. The respective drying
chamber efficiencies were 10.24% and 16.16%, the drying efficiency of 31.53% and
41.41%, the drying rate of 66.31g/h and 73.51g/h for an average solar irradiance of
0.678KW/ ��2
and 0.572kw/m2 average ambient temperature of 22.706 ℃ and
31.482℃, ������ average drying chamber temperature of 60.33℃ and 60.27℃, for 9 hours
and 8 hours respectively. The total energy consumed by the heater in the second load
experiment was 1562.87 kJ.
http://dspace.unza.zm/handle/123456789/8048
en
The University of Zambia
Food--Preservation.
Food--Drying.
Canning and preserving.
Tomato drying.
Design and fabrication of an intelligent solar-photovoltaic hybrid tunnel dryer for tomatoes with automatic temperature control and air recirculation.
Thesis