AN IMPROVED CONCENTRATOR TYPE SOLAR COOKER, REFLECTOR OF WHICH IS FORMED OF THREE SEGMENTS OF A PARABOLOID DISH TO GIVE INCREASED REFLECTOR AREA AND HIGHER CONCENTRATION OF SOLAR ENERGY ON HOT PLATE TO BAKE ROTI

摘要

A concentrator type solar cooker developed by one of the inventors of this application was patented in 1980. This cooker had a paraboloidal circular concentrator to focus sun rays on the bottom of a hot plate on which a Phulaka could be baked. The reflector was mounted on a trolley for tracking sun. At present, this is the only solar cooker on which baking can be done. In order to bake a thicker ROTI on this cooker, it was necessary to increase reflector area by 50% keeping focal length same. The newly improved concentrator type solar cooker achieves this requirement in the following manner. In the old design, a circular dish of 1200 mm dia was used. For the improved cooker, dish is cast on same mould. But only a central portion segment 900 mm wide is cut. In the second casting, this 900 mm wide piece is cut in two segments each 450 mm wide. Thus, three segments of reflector are formed. While forming a large reflector, central segment is kept in its original position. The two smaller segments are vertically displaced and inclined as obtained from computer studies to concentrate solar rays at the same focal point below the hot plate. Thus, with reflector area increased by 50%, a thicker ROTI is baked on hot plate, keeping the trolley design and sun tracking arrangement, substantially the same.