Abstract:
In this thesis the design of the equipment for determining
the, drying rates of agriculture products was presented. The first
part was the design and testing of the equipment and the second
parts was the experiment to determine the prying rates and the
drying rate equations.
The equipment consisted of a humidifier, a dehumidifier, a
drying unit and a heating wire with a temperature control. The
operation of the equipment was by mixing moist air from a
humidifer with dried air from a dehumidifier and by controlling
the air temperature. For testing of the equipment 11 experiments
were carried out in a temperature range of 49-71 C, relative
humidity of 14-62% and with air velocity between 0.7-1.3 m/s. It
was found that (for 95% limit of confidence) the maximum error of
the controlled temperatures was +- 4.55 F (+- 2.53 C) and of the
controlled relative humidity was +- 3.03%
The results of the drying of coconut chips showed that the
drying rates increased with temperature and decreased with
relative humidity, but the effects of air velocity was not
significant. It can be explained that the drying rates were
dependent on the internal movement of moisture inside the coconut
chips.
A semi-theoretical, modified-semi-theoretical and empirical
equations were selected to fit the experimental data. The
empirical equation was found to give the best fit.