Scheffler Reflector in Afghanistan, Solar Tandur

Scheffler-Reflector in Afghanistan

Manufacturing of the first Scheffler Reflector in Afghanistan was started in August 2005 in the Bedmoschk Solar Centre. The Solar Centre is initiated and run by our partner organisation Afghan Bedmoschk Solar Centre e.V.
Scheffler Reflectors can be used for solar cooking, solar baking, solar food processing and as well for production of steam for applications of process heat or for the requirements of hospitals (laundry , autoclaves, cooking)
The first application planed in Bedmoschk is a Solar Tandur.
The technical part of the project is done by Solare Brücke e.V.
Technical details about Scheffler Reflectors.

Manufacturing of the first Scheffler-Reflector:

steel is cut and bent, bending the metal bars requires great accuracy

the shape of the reflector frame is checked

In december 05 the first reflector was installed. It can be used for baking "Nan" and "Chapati" als well as for cooking.

A traditional tandur is installed.
The tandur weighs abuot 70kg and was built locally from clay.

The tandur is preheated.
Concentrated light falls through a glass lid into the oven. The secundary reflector (here from aluminum sheet) on top of the glass lid makes sure that all light is refelcted into the oven.

dough is prepared

baked Chapatis

Tasty!

A 30l pot is used for cooking and frying.

Developing the Solar-Tandur

Whilst the manufacturing of the first reflector is continued in Bedmoschk and further reflectors are started, first steps for developing the Solar Tandur have been taken in Ailsingen, Germany at the center of Solare Brücke e.V.

A traditional Tandur is a big clay vessel integrated into the ground:

as long as the fire is going the Tandur is used for cooking

once the fire has burnt down the flat breads are smacked against the hot clay walls of the vessel

Solar Tandur:

to develop a model that is similar to the traditional one in function and form we did the following experiments:

Assembly of the Solar Tandur


			heating up
	Insolation of 14cm rockwool


The clay walls have between 450 and 350 degree Celsius when the bread is smacked against them.
		A glass lid prevents heat losses from convection.

the result

Within the temperatur range of 450°C to 300°C we can bake about 6,5 kg of bread in one hour 50 minutes. The Tandur was preheated for 2.5 hours. The bread was then baked with the stored heat.

We are also testing a baking oven Christoph Müller devoloped in Argentina. We need to find out if it can be adapted to baking flat breads.


	The oven has a baking chamber of 60x60 cm and is heated by a air heat exchanger located underneath the baking chamber. A heat storage from gravel shall provide uniform baking temperatures, it is located under the baking chamber, too. In the background you see the 8m² Scheffler Reflektor used to heat the oven.


at 300°C tasty bread was baked. 250g of bread were ready in 8 minutes. To reach baking temperature the oven was preheated for 2 hours. For further tests we don´t have enough sunshine at the moment .

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