This study presents a newly developed system to utilize solar energy to dewater
the sludge in a semicontinuous mode. The semicontinuous dryer mainly consists
of a moving belt on which aluminum bars are fixed to hold the sludge and a fan is
used to drive the air at the required speed. The effects of operating conditions,
such as air velocity, belt speed, and mode of contact between the sludge and air,
on the drying rate of water were investigated. The drying rate of water was
measured under the effects of different operating conditions, including air
velocity, belt speed, and mode of contact between the sludge and air. The
experimental results proved the technical feasibility of the developed solar
drying system to efficiently evaporate water. The achieved drying rates were
2.02 kg water/m2 h and 0.49 kg water/m2 h in September and February,
respectively. Under a given insolation rate, a high evaporation rate is achieved at
large air velocity and slow motor speed. An empirical relationship to predict the
mass transfer coefficient (drying flux constant) was derived by conducting a
well-designed experiment using a tray dryer. The data obtained successfully
described the mass transfer coefficient expressed as JD¼15.1Re0.72.

Title

JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY

Publisher

AIP Publishing

Publisher Country

United States of America

Publication Type

Online only

Volume

7

Year

--

Pages

--