Project Part 3: Solar Dryer
In order to remove the moisture content of the seeds, it was necessary to design and build
a dryer. Sun drying is feasible, but without assistance, this method leaves the seeds
exposed to weather and a possible higher-than-acceptable moisture content. Building a
solar dryer allowed us to protect the seeds and increase the heat and movement of air
necessary to remove water.
The design parameters therefore included the following:
- Protection of the seeds from the elements
- Increase of solar collection area
- Easy access by a woman wearing a sari
- Constructed from locally available materials
We chose to use a thin panel collector to send warm air up through the chimney which
would contain the seeds. The panel would be composed of a transparent plastic, and air
gap, and a black surface. Due to the lack of wood, the chimney was constructed with
welded steel, which is durable, cheap and largely available in the nearby town of
Keonjar. Since translating technical drawings and instructions is difficult (even from
English to English) the metal shop owner agreed to have the designer oversee the
manufacturing of the chimney to make sure nothing went wrong. A plastic that does not
yellow with time was chosen as the clear surface over the collector panel and black
painted plywood, which is available, as the backing. The only lumber in the assembly are
the 1.5 in. by 1.5 in. ribs that provide rigidity to the panel and spacing for air. The whole
assembly was puttied, plastered, and painted to protect the metal chimney and keep the
hot air from escaping before it passes over the seeds.
The original design was intended to sit on the roof of the building, but the problems with
the building made us less confidant about putting something on the roof. In the end, it
was decided to simply set the dryer on pillars in the field south of the building.
The inside of the chimney will be accessible from a door that has a foam seal around it.
A stair case rather than a ladder was chosen considering that the users would primarily be
women wearing saris. Six drawers with quarter inch mesh bottoms hold the seeds while
allowing the warm air to rise past them. Education was provided on use and cleaning of
the solar dryer as well as the times of year that it is most efficient. The only lumber in
the structure was locally milled (by hand) and all other components can by bought in
Keonjar, which is only an hour away by daily bus. Marine grade plywood was used to
ensure long life and several coats of exterior paint were applied.
Project Part 4: Agricultural Equipment
The spice grinder and rice huller were purchased in the city of Cuttack. Models was
chosen after testing various pieces of equipment in the Orissa University of Agriculture
and Technology labs. Appropriate motor sizes were chosen for the engine. In general,
when using electric motors, one must have the capacity to generate 3-5 times the actual
continuous draw of the motor, but since we were using a lister-type engine, the flywheel
will hold enough energy to start the motors. Durable, easy to maintain models were
chosen along with electric motors sized to run them.
After the generator was fully installed and the equipment running, the women were able
to see them running and being disassembled for maintenance and cleaning. They were
also educated that running everything at once uses less fuel than running everything
++Steph, I don’t know what else to say about this. Let me know briefly where I can find
more information and I’ll type more about it soon. This is a pretty rough draft, so I’ll
look over it again, but I have to head off to lab.