Comparative Experimental Investigation Between Parabolic Dish and Flat Plate Collector Based Solar Dryer for Saw Dust Briquette Production
No Thumbnail Available
Date
2019-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
From different types of briquette drying technology, the open sun drying system is the most widely
used,
which
is
found
in
many
developing
countries
including
Ethiopia.
For
this
type
of
convectional
drying
process,
the
time
required
to
remove
moisture
from
the
product
is
too
long.
In
average
it
requires
3
to
4
days
with
available
sufficient
solar
radiation.
Beside
that
the
recent
improved
type
solar
driers
(flat
plate-based
driers)
have
still
inefficiency
regarding
to
the
drying
time.
This
happened
due
to
the
low
drying
air
temperature
effect
that
limits
the
drying
time
and
efficiency.
The
main
objective
of
this
project
was
to
design,
construct
and
test
more
efficient
solar
drier compare to the recent developed dryer type. To prove the new type of drier performance,
the
experiment
has
been
done
by
comparing
the
performance
of
the
parabolic
dish
based
drier
(PDSCD)
with
the
Flat
plate
based
drier
(FPSCD).
The
comparative
assessment
has
been
done
with scientific experiment using different measuring methods and tools discussed in this
paper.
The experiment was conducted in the Addis Ababa Institutes of Technology compound free field
area for both solar driers. The drying air temperature has been increased using concentrator
collectors. The PDSCD and FPSCD absorber surface temperature, drying air temperature, air
speed at the outlet of the drying chamber, moisture content variation, the relative humidity at
ambient and inside the drying chamber were measured with unloaded and loaded setup using
direct and indirect measuring methods. The amount of moisture removed from the drying chamber
of
PDSCD
and
FPSCD
is
0.039
kg
and
0.022
Kg
respectively.
The
measured
result
indicates
that
performance
PDSCD
has
a
better
moisture
removing
capacity
rate
than
FPSCD.
After
analysis
of
the
measured
result,
the
thermal
efficiency
parabolic
dish
collector
and
Flat
plate
collector
is
determined
31.55%
and
8.95
%
respectively.
And
the
overall
drying
system
efficiency
of
the
PDSCD
and
FPSCD
is
31.55
%
and
8.95
%
respectively
where
the
PDSCD
has
better
performance
than
FPSCD.
Description
Keywords
Solar thermal Energy, Solar dryer, parabolic dish solar collector, Drying chamber