. REFLECTOR COOKERS
.
THE PAPILLON (Butterfly)
| DEUTSCH | ENGLISH | FRANCAIS | ESPANOL |
| How does our
Papillon work?
The Papillon is a concentrating solar system which works with direct solar radiation. The radiation entering the mirrors is concentrated in a point (Focus) where the cooking equipment stands. In order to keep the focus, the mirrors
are followed up the sun.
|
 Papillon without
wings
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A parabolic reflector casts sunlight
onto the dull black pot lying at its focal point.The black pot absorbs
the sun generated energy and cooking process takes place. A part
from being used for cooking, the reflector also helps in distilling water,
baking, frying and industrial use such as dye-works.
The biggest solar oven is found in
the Montepellier in the Pyrenees and its centre heats to a temperature
of 3.800 degrees centigrade.
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| The Box cooker is made of a highly
insulated box where inner walls are black. It’s double glazed window
allows sun rays penetrate. For additional power, it is equipped with a
reflector which directs sun rays into the mirror space. It is specialized
for boiling and baking but not frying or browning. One can prepare
different dishes at the same time in the box although the time required
for cooking becomes longer.
The Box Cooker has an advantage over the reflector cooker in that it can be used for cooking even during cloudy days. It retains warmth for a long time. Think of a motor vehicle standing in the sunshine whose temperature rises up to 80 degrees centigrade. What about this special apparatus which is even able to store the generated heat energy for hours. To maximize the box-cookers power, we should collect into it as much heat as possible. Because it is highly insulated it hardly releases heat and temperature goes up to 180 degrees centigrade during good weather. A further advantage of the box cooker is that it doesn’t require much technology to produce. Its raw materials are readily available. This means cost of production is relatively cheaper and will be very useful to the poor people. Its very special advantage is that nothing can overcook in it or burn. Which means the cooking process doesn’t need to be closely monitored. This is a considerable advantage it has over all other cooking systems. . 
Box Cooker fabricated in Burkina Faso |
| Reservoir cooker is an
appliance which collects solar energy during the day and is able
to store it in a medium like crude oil (petroleum) for later use. The oil
is kept in a highly insulated container for it to store the heat energy
for a long time, normally 24 hours. This makes it possible for the
system to be used even at night in the rooms.
When cooking, the isolation plate should be removed so as to place the cooking pot on an iron plate lying below it. It can be built with at least three reservoirs and three pot spaces at disposal. These appliances are so far better with only one disadvantage of a high cost of production. |
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| This appliance is build with a large
surface area for collecting sunshine which is transformed into steam.
The steam produced spreads upwards into the uppermost space where the cooking pot is placed on a highly insulated container. The construction allows maximum solar energy collection because the collector is quite open. However the energy absorption of this appliance is relatively low and its maximum temperature is 100 degrees centigrade. |
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| Fixed-focus solar cookers have fixed
parabolic mirrors placed parallel to the earth’s axis. The focal length
lies out of the mirror and when the curve is well calculated the focal
point will fall on the area where the pot is placed.
The metabolic lies on a particular system and will adjust automatically to the sunshine. The pot space is protruding such that some other fuel can be used to heat the cooking pot incase the sun fails. Here the power produced is directly dependent on the size of the mirror. |
Solar cooker installation in India, built by Dipl. Ing. Scheffler |