Solar parabolic dish concentrator concentrates radiations of sun on receiver all the day from 9 a.m. to 6 p.m. It tracks the radiations of Sun through automated tracking device, which rotates the parabolic dish along axis of rotation of Sun. Parabolic dish consists of set of solar grade mirrors of rectangular shape or high reflective Solar grade Mirror. Normally, parabolic dish for industrial applications has an area of 16 or 32 sq. m. of elliptical shape.
SOLAR STEAM COOKING SYSTEM
Technology – Parabolic Concentrators
Each parabolic concentrator of the system has a reflector frame fitted with reflecting Solar Grade mirrors, rotating support and a stand. The concentrators are installed in such a way that they focus the sunlight on to the receivers while in operation which will be attached to a steam header/ tank. The concentrators are tracked automatically with the help of suitable tracking arrangement. The concentrators are installed in series and parallel combination connected to different steam headers/ tanks depending on the size of the system. Each unit of concentrators is connected in series and has its own tracking arrangement. The stands of the concentrators are properly grouted. The tracking arrangement is such that once adjusted in the morning with the help of drive motor, the concentrators will automatically track the Sun at least in one direction i.e. in E-W, thereby focusing all the Sun light exactly on the receivers connected to the header.
For cooking application water is supplied to the receiver through thermo-siphoning process and with the help of solar heat steam is generated. The steam from all the receivers is collected in steam header with the pressure of more than 2 bars. Once the steam is accumulated there after it is used for cooking application.
Steam Header/ Drum Assembly and Instrumentation
Each steam header assembly is connected to a group of concentrators that consists of a steam header/ tank connected to receiver (circular in shape), pressure reducing station, steam and feed water pipelines and necessary valves. The designs of the receivers are such that they work on thermo- siphon principle and the water stored in the header is slowly converted into steam when the system is put into operation. It has a drain arrangement for cleaning against scale formation. The pressure reducing station is so designed that it reduces the pressure of steam generated in the header from 10 Kg/cm2 to 2-4 Kg/cm2 so as to ensure safety of the user while using the steam. The system pipelines, receivers and steam header are insulated with glass wool/ rock wool covered by aluminium cladding to minimize heat losses. The system is hydro tested for any leaks before insulating its various components. Feed water tank of suitable capacity, instrumentation e.g. pressure gauge and water level and temperature indicators, level controller, safety valves, steam separators are installed with the system for safety and measuring different parameters.