FARMER'S NOTEBOOK
Bio-waste gasifier
that works out cheaper than grid power
M.J.PRABU
| Fuel consumption is almost 30-40 per cent less than that
of other designs |
— Photo: Special Arrangement
Different uses: Rai
Singh Dahiya of Rajasthan with his invention.
Many ingenious innovations in agriculture do not require an
IITian’s brain, but are by humble, poor peasants across the country.
From Kashmir to Kanyakumari, several hundreds of these innovators
endowed with their curiosity, traditional knowledge and skills have
made farming easier for themselves and their ilk.
Mr. Rai Singh Dahiya in Rajasthan never stepped into a school,
but it did not stop him from receiving an award from the local
District Collector for building a unique biomass gasifier for
operating modified diesel engines.
The biomass-based gasifier unit processes about 20 kg of
bio-waste to run an engine of 30 HP for an hour. So far about 50
gasifiers have been sold in the village.
Shape of the unit
The gasifier is conical in shape, compact in design and
surrounded by a water jacket with the capability to handle multiple
fuel sources.
Fuel wood or agricultural residues are fed into it. An air inlet
is provided at the bottom. The system comprises two stages, one for
removing ash, and the other, for charred residue and tar.
The primary filter unit comprises a series of rows of filtration
units. Perforation becomes progressively smaller from the first to
the third filtration unit.
The filter can be easily cleaned and is surrounded by a water
jacket. The secondary filter has layers of different sizes of sieves
ranging from 2 inches to a fine size with the cleaning gate at the
bottom.
Detailing its operation the farmer says, “first, the bio-waste
must be deposited from the top. This unit acts as a furnace and
heats up to 200 degree centigrade to generate gas.
The gasifier is monitored and fed continuously first for about 30
minutes. An aspirator is turned on for sucking producer gas until
the flame appears.
Water cooling
“Next, the air supply from the bottom is cut off. The produced
gas is made to pass through the first cyclone where water-cooling is
done; the gas is cooled and partial cleaning is also achieved.
“The gas then passes through the second cyclone, which removes
carbon and ash based residues, and enters the filtration unit
consisting of sieve grills and cloth.” This cleans up the gas
completely. After cleaning, the gas is fed into the mixer unit,
which mixes the gas with air in the right “fuel-air ratio”, which is
set for the engine and power rating.
Calibration mark
There is a calibration mark for optimal ratio set by the
innovator, but the user can override that and choose his settings.
Alternatively, the nature of the knocking sound, which changes at
optimal ratio, can also be used as a cue for optimal mixing ratio.
The fuel mixer then feeds the fuel-air mixture into the modified
engine, which runs on this clean fuel.
The furnace in the gasifier unit can be built to different
capacities as per availability of biomass and agricultural residue.
“Considering the cost of machine, fuel-biomass and local labour,
this arrangement is estimated to cost less than half the cost per
unit of power when compared to normal electricity grids costing 4 Rs
per unit.
“It can be used to operate pump sets in remote fields, pump up
water in homes, operate basic machines such as saw mills, flour
mills and generate electricity by charging an alternator,” explains
Mr. Dahiya.
Fuel consumption
He claims that the fuel consumption to be almost 30-40 per cent
less than other available designs. The prices vary from Rs. 1,25,000
for 10 kW unit to Rs. 3,25,000 for 35 kW unit.
For more details contact Mr. Rai Singh Dahiya, Thaldak village,
Taluka Bohar, Hanumangarh, Rajasthan 335 524, 09414535665.
Printer friendly page
Send this
article to Friends by E-Mail
Sci
Tech
