The drier was loaded
with 80 kg of blanched chilli. The changes of moisture content
with drying time for a typical experimental run for
solar tunnel drying, improved sun drying and conventional
sun drying of red chilli is shown in Fig. 5. Moisture content
of red chilli reached to 0.05 kg kg1
(db) from 2.85 kg kg1
(db) initial moisture content in 20 h of drying in solar tunnel
drier while it took 32 h to bring down the moisture content
of similar samples to 0.09 kg kg1
(db) by improved
sun drying and 0.40 kg kg1 (db) by conventional sun drying
method. This is due to the fact that the chilli in the drier
received energy from the radiation from the sun and more
energy transported from the collector by forced convection,
while the samples dried in the open sun received energy
from only the incident solar radiation and less energy
transported from surrounding environment by n