Abstract:
Sun drying is a popular post-harvest
operation to maintain the quality of rice during the
storage period. Farmers use different treatments
and thicknesses for sun drying of paddy in Ampara
district, Sri Lanka. A study was conducted to
evaluate the drying treatments' suitability and
effectiveness as practiced by local paddy farmers
during the drying process. The grain with an
initial moisture content of 28% (dry basis) was
sun-dried with three types of drying treatment and
three levels of thickness of grain. This experiment
was conducted between 8.30 am and 4.30 pm at
the South Eastern University of Sri Lanka in
August 2020. Two dryers were fabricated, and it
was found that the duration of drying of paddy
from 28% to 13% moisture content on a dry basis
was 300 to 660 minutes depending upon the drying
treatments and thickness. The thermal storage
greenhouse dryer is reasonable at shallow
thickness with less time to reach the necessary
moisture level than other drying treatments. A
thermal storage greenhouse can be utilized for
drying paddy at 4 cm thickness for 420 minutes. It
was found that with an increase in the thickness of
paddy from 2 cm to 6 cm, the drying time
increases. A statistically significant interaction
was obtained between drying treatments and
thickness level on moisture removal of paddy.
Therefore, the moisture removal rate differs from
the paddy's drying treatments and thickness under
thermal storage passive type greenhouse.
