The use of solar energy has great potential for promoting
energy efficiency and reducing the environmental impact of energy consumption
in the environment. Solar drying is a very old but continuously explored
technology that everyone can use to dry food products from meat, vegetables,
cereals and dairy products. However, over time, with increased pollution to
both the air and water, the sun drying has been deteriorating. Solar drying
provides a safe and reliable environment for the quality of the dried products
and their preservative duration. Despite the development of solar energy
technologies, high costs and competition with inexpensive fossil fuels have
historically limited their widespread adoption. Thus, interest was rekindled in
the harnessing of solar energy for heating, cooling, the generation of
electricity and other purposes. This study focuses on the design and
construction of a solar dryer device intended for drying a variety of food
products. The local and cheap materials were selected in the design so as to
help local farmers reduce the cost of drying. The principle of the dryer allows
lighter hot air to rise up the altitude and cool the surface. In the raising
process, warm air comes in contact with the food slices and draws the moisture
from them. The repeated cycle of this process makes it a very healthy, low-cost
cost long-term drying mechanism. In thermodynamic terms, the sun’s power or
heat is used to dry up the moisture content of the fruits or vegetables. The construction materials were wood,
polyurethane glass, mild steel metal sheet and the trays. The optimum
temperature of the dryer was 75°C with a corresponding ambient temperature of
28°C. The rapid rate of drying in the dryer reveals its ability to dry food
items reasonably rapidly to a safe moisture level. The capital cost involved in
the construction of a solar dryer is much lower compared to that of a
mechanical dryer. Also, from the test carried out, the simple and inexpensive
solar dryer was designed and constructed using locally sourced materials. The
temperature inside the drier was found to be about three times than that of the
outside atmospheric temperature. As per our experiment the maximum peak
temperature inside the drying chambers was 750C during the mid-day (1.00pm) and
an average of 570C in a fully sunny day (from 10:00am to 5:00pm). In seven (7)
hours continuous drying in one full sunny day under the same climatic condition
and in the same time the solar drier can remove maximum moisture contents from
the food contents inside the drier for low moisture content food products.
Experimental observation shows that the solar drier can be used as an
alternative in case of food preservation and the efficiency is also acceptable.
The people can make it on their homes especially in the developing countries
where the energy demand is high.This chapter of the book is significant because
it advocates the sustainable preservation of food using renewable energy. The
creation of a passive solar dryer provides a cheap and environmentally
beneficial way to lower post-harvest losses. It promotes further research in
sustainable energy and agricultural technologies and helps ensure food
security.
Author(s) Details
Yusuf Ismail Koleleni
Physics Department, Muslim University OF Morogoro, P.O. Box 1031, Morogoro,
Tanzania.
Please see the book here :- https://doi.org/10.9734/bpi/mono/978-93-47485-78-7/CH5
