Solar food processor

Abstract

Cooking is one of the unavoidable activities that consumes huge amount of conventional fuel. If this state continues then all the fuel left will get depleted in about 20-30 years. This problem was identified many years ago and solar cookers were introduced. In different parts of the world solar cookers are made, studied and patented but it is not being used at homes like other conventional cookers. The necessity of the use of solar cookers in order to reduce the consumption of firewood or conventional fuel is well recognized by various National and International Organizations. In spite of various efforts made by those organizations the wide spread use of solar cookers has not become possible. Drawbacks in conventional solar cookers are they are single use based models, i.e. if one buys a cooker one can use it only for cooking but it can't be used for drying, distillation of water etc. and if one buys a solar dryer it can be used only for drying but not for cooking or distillation of water and so on. The reason is that each operation requires a different design, for cooking the cabin should be air tight, but holes should be present for drying (ventilation system) and in the case of distillation of water the glass placed on top of the cooker should be slanting, for the water to drain into the container. Another big drawback is that as one is cooking food in the solar cooker if the climate changes suddenly and if it becomes cloudy then the food will be half cooked. These cookers can't be used at night and during the period lacking sufficient sunshine. They are huge in size making it very inconvenient to use. The above mentioned problems can be overcome using the Solar Food Processor. The Solar Food Processor is a multi-purpose device unlike the conventional solar cooker; it can be used for cooking, heating/pasteurizing water (to inactivate microbes), distillation of a small quantity of water (to remove different minerals) and drying domestic products (fruits, vegetables, herbs etc.). All the activities can be performed in a single device called Solar Food Processor (SFP). If SFP is used for cooking only seven months a year and for heating water and drying for another 4 months a year, one can save on the average, 1160kWh of electricity, 650 kg of fire-wood or 205 liters of kerosene (or LPG) per year. SPF can be used during the period lacking sufficient sunshine. Copper tubes filled with water are placed at the bottom of the cooker and thus solar energy will be stored in the water. The heat can be retained for a period of 2 hours and hence when the sunlight is not sufficient the heat stored in the water can be used to warm food. The heat energy is used for cooking but the light energy is wasted hence solar panels that can produce 20W of energy is fitted to the cooker. The energy thus produced is stored in a battery. SFP can be used to cook and warm food even at night using stored solar energy. The energy stored in the battery from the solar panel can be used to power an electric heating plate placed inside the cooker, on which the vessel to be cooked or warmed can be placed. This way SFP can also be used at night and the period lacking sufficient sunshine. If the food is not cooked properly due to the unstable climate, it can be placed on the electric plate powered by the battery and food can be cooked properly. It can also be used as a hot case as it can retain heat for a longer time. Thus the SFP is very efficient, economical and convenient due to reduced size when compared with the conventional solar cookers.