Central Rice Research Institute Annual report...2011-12

Mechanization for Rice Production and Post-harvest Systems
Product Diversification, Value Addition
and Post-harvest Technology
Development and evaluation of solar and biomass
fuelled dryer for grain and food
production
A batch dryer of 300 kg paddy holding capacity was
designed and developed. Its main components are drying
chamber (LSU type), solid fuel fired furnace with
heat exchanger and blower. The bottom sheet of the
drying chamber is hinged at one end so that it can be
lowered at the other end for removal of the grain after
drying. Provision is made to connect solar air heaters
at the suction end of the blower to supplement with
solar heat. One side of the drying chamber is provided
with a door for placing trays over the inverted ‘V’
troughs so that it can also work as a tray dryer for drying
other food materials. The bio-mass fuelled dryer
was evaluated for drying of raw and parboiled paddy.
The drying time for raw and parboiled paddy varied
from 5-7 hrs having initial moisture content in the range
of 19-26 %, where as open sun drying takes 3-4 days for
drying the same. The cost of the dryer is estimated as
approx. Rs. 40,000. The payback period of the dryer
was computed as less than one year.
Development and evaluation of greenhouse
type fish drying system for coastal region
A greenhouse type solar cabinet fish dryer was designed
for drying 15-20 kg of small to medium size (10-
15 cm long) fish. The structural frame is made of mild
steel square bars, angle and flat. Over all dimension of
the dryer is 157 x 87 x 150 (L x B x H) in cms. There are
two stainless steel sliding trays (75 x 95 cm each) which
were used for drying of fish. The aperture area is 1.44 m 2 .
The glazing material is UV stabilized polyethylene
sheet. Perforations were made at the bottom of the front
wall for entry of air and two chimneys of 15 cm diameter
and 84 cm height were made for exit of hot humid
air after drying. Two sizes of marine fish, 8-10 cm and
15-20cm were used for drying in March and May respectively.
The fish was salt treated (1 kg salt for 10 kg
fish) for overnight, then thoroughly washed, rinsed and
dried in the dryer.Under no-load condition, the stagnation
temperature of the dryer at 12.30 pm was 63 0 C in
Nov-Dec and 70 0 C in April-May. In both the cases of
fish drying, the total drying time to bring down the
moisture from around 65% to around 14% was around
12 hrs (spread over 2 days) as compared to 3 days in
open sun drying. The dryer temperature was in the
range 50-62 0 C. The ambient temperature was in the
range 30-35 0 C in March and 34-39 0 C in May. The yield
of dry fish was in the range 40.5% to 48%. Cost of drying
and value addition per kg of fish was computed to
be Rs. 2.12 and Rs. 17.90 if dried near the seashore. The
payback period of the dryer was calculated to be 132
days.
Field evaluation of 30 m 3 fixed dome type
biogas plant for power generation
Construction of a biogas plant of 30 m 3 capacity with
R.C.C fixed dome was made during 2011 at Shree Gopal
Krishna Goshala, Cuttack. Diameter and depth of digester
of the plant was 5.0 m and 3.06 m, respectively.
Dung mixing chamber was provided at the top of the
inlet pipe. The PVC inlet pipe of 250 mm was laid at
angle of 70 0 with the horizontal. The lower end of the
pipe was kept at a height of 70 cm. Outlet chamber having
dimension of 482 cm x 283 cm x 272 cm was constructed
for slurry disposal. The plant was commissioned
on November 23, 2011 and charged initially
with fresh cowdung @ 2000 kg per day and water in 1:1
ratio for fifteen days. Subsequently, 1500 kg fresh
cowdung with same quantity of water was fed to the
biogas plant for 20 days. After stabilization, normal
gas production was started from 26 th December, 2011.
Presently fresh cowdung @ 750 kg per day with 25-
30% less water is being fed daily. Digested slurry is
being used for making of vermi-compost.
During testing, the gas pressure was recorded as
57.0 mb at full capacity of slurry formation, as slurry
level decreased by 40 mm, the gas pressure decreased
from 57.0 mb to 3.0 mb. Biogas based generator was
used for generating power, the voltage varied from 220
to 450 V and current varied between 5-8 A. Power generated
from biogas based engine was also utilized to
operate a chaff cutter (with electric motor of 5.0 hp), a
submersible pump (with electric motor 2.0 hp) for irrigating
the crops. The power was also used to illuminate
40 tube lights each of 40 W for 3.0 hrs. Biogas generator
consumed biogas @ 4.90 m 3 hr -1 . The total cost
incurred towards the construction of biogas plantalong
with generator, H 2
S scrubber, moisture removal from
biogas, control panel, energy meter and generator shed
was Rs. 5,55,173. The methane production varied between
43.8 to 48.7% of total gas emission.
CRRI ANNUAL REPORT 2011-12
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