Cooking or preparation of food is such an integral part of our everyday lives. Anytime we need to do some cooking, heating of food we simply light the cooking medium mostly gas stove in the kitchen, place the vessel on top of the burner and get started. Did we ever try to know what is happening under the cooktop, the energy which is actually doing the work?
In most of the Indian kitchens, cooking is done on a cook top which has a burner and uses LPG, butane, propane as fuel. This gas stove and fuel, which came to be used in the early 1800's, has evolved over time, in terms of design and ignition mechanism. One of the earliest of the gas stoves used a pilot light which would have a gas flame continuously burning under the cooktop. This type of gas stoves had the advantage of being free of any outside energy source, but had the disadvantage of using fuel even if the stove was not in use.
But the gas stoves before the one with pilot light had to be lit using outside flame. Using this type of gas stove had the chances of filling the stove and kitchen with gas if it was left on by mistake. The slightest spark from switching on lights would trigger the gas and cause violent explosion. To prevent such accidents, manufacturers starting installing a flame failure device for gas stoves.
Though gas stoves have advantages of easy use, safe and fuel efficient it has some disadvantages which led to alternate methods for cooking purposes. The other most used source of energy for cooking purpose is electric energy. The use of electric energy for cooking purposes uses different methods of electric heating such as coil element, halogen heater and induction.
The use of electric energy for this purpose, heats up the vessel which is in contact with the hot surface and the heat energy from the vessel is transferred for cooking to happen. This enables easy handling of food, which may be in liquid or any other form and also allows uniform and gradual application of heat for cooking purposes. Did we ever try to know how electric energy is converted to heat energy for cooking purpose?
On a gas stove what would be a burner, the induction-cooker element is simile in an induction cooker. The element is a powerful, high frequency electromagnet; electromagnetism is generated by complex electronics in the €element€ below the cooktop. To understand the working of an induction cooker, if a cast iron skillet is placed in the magnetic field of the element, the energy is transferred to the metal. The transferred energy causes the cooking vessel to become hot, which is passed on to the food for cooking. The amount of heat transferred to the cooking vessel can be controlled by the strength of the electromagnetic field. http://www.soyerappliances.com/
Thus induction cooker can be said to have a four step process to produce the required heat energy for cooking to happen. The electronics of the induction cooker element powers a coil which produces a high frequency electromagnetic field, the electromagnetic field penetrates the material of the cooking vessel and sets up an circulating electric current which generates heat, the heat from the vessel is transferred to the vessel for cooking purposes, and there is no electromagnetic field outside the vessel as soon the vessel is removed from the surface or the element turned off heat generation stops. The cookware for induction cookers is normally the same as for other stoves.