A single vacuum tube based solar cooker

Abstract

A new type of solar cooker based upon the use of a single glass vacuum tube (1) and plane mirror strips (2) is being reported as shown in figure 04. The cooker utilizes a number of parallel rectangular mirror strips fitted inside a rectangular bed (18). Each strip is capable of rotating on its individual axis for one dimensional solar tracking. The mirror strips (2) are individually pre-aligned with the help of laser beam to reflect the incoming solar radiation onto the secondary curved reflector (4) and finally onto the vacuum tube. A tracking device (5) with a motor (6) forces a synchronized rotation of the rectangular mirror strips to follow the sun as it moves on the sky. A primary cooking pot (8) is fitted on top of the vacuum tube through a rubber pipe (9). The vacuum tube (1) and the primary pot (8) are filled with a high boiling point thermal fluid that circulates between them through natural convection. The primary cooking pot (8) and its lid (10) are well insulated from outside to minimize the leakage of heat. A secondary cooking pot (11) with its lid (12) is placed inside the primary pot. The secondary pot contains the actual stuff (food) to be cooked. The cooker can be either installed over the roof top of a house or near a south facing window, thus allowing its operator to stay inside a shade. Two threaded rods (13) are provided at the rear edge of the rectangular bed (18) to incline the whole collector apparatus at a suitable angle with respect to the horizon to maximize the incident solar radiation. Temperatures of up to 300 degree Celsius are easily attainable.