Induction cookers: technical characteristics, operation principle, energy saving, advantages, disadvantages, tips
This innovative technology of cooking, by the generation of an electromagnetic field, has resulted in an improvement in performance, a reduction in consumption, a total absence of heat loss, and an increased safety in the kitchen. Suffice it to say that the induction cooktops make the most of the absorbed energy with an efficiency of 90% while traditional stoves, by the nature of their operating principle, make only 40-60% dispersing about half 'of energy into the surrounding environment.
Approximate yields of the various hobs:
• Induction 90%
• Halogen 58%
• Electric 47%
• Gas 40%
It is known as the induction hobs are able to transform a very high percentage of useful heat energy used in the heating of the food, while the other hobs have a large dispersion in the environment for which the expenditure of energy is twice as about half of the energy used is wasted.
It is clear that to heat the same content, through the use of a gas cooker will take more time, and the heat will not be irradiated uniformly over the whole pot, this is because while a gas transfers heat through the fire ON POT, the induction hob will generate an electromagnetic field that transfers heat into the pot.
But how does the kitchen electromagnetic induction?
The principle is really quite simple. When laying a ferrous metal container on the plate, an underlying electric inductor creates a magnetic field inside. The magnetic field created in the container generates ferrous metal of the currents that turn inside the magnetic energy induced in caloric energy causing it to heat. The electromagnetic field that gives rise to heating of the cooking zone in fact, arises only in contact with the container and remains confined to the surface of the same, this allows to keep cool the surface of the floor around the cooking zone in function ensuring greater safety and ease of cleaning in the event of accidental spillage of liquids, avoiding the formation of scale.
Particular characteristics necessary for the operation
- Current variable in time, to create a magnetic field variable in time and therefore an induced electromotive force.
- Materials with low electrical resistance, to facilitate the passage of the eddy currents and to increase the intensity. So metallic materials or conductors are generally good for this type of applications, while the electric insulators are bad.
- Materials whose shape favors the flow of eddy currents. Since these flows circularly, ideal forms for the materials to be heated are those circular or circular symmetries (disks, bulls), while the square shapes are less efficient (squares, rectangles, triangles), instead linear forms or "combed" are very bad .
- Materials whose electrical resistance is not too low, because the currents induced in the material dissipate thermal energy only in the presence of a resistance. For which the superconducting materials would not fit. The compromise is in the fact of being able to find a material with an electrical resistance not high, but not too low. For this purpose, the metals are the perfect materials.
What are the advantages of induction hobs?
Using the induction system, the cooking time of some foods, such as pasta or sauces, are greatly reduced. Just think for example that the boiling time for two liters of water almost halved: a cup of tea? Only a few seconds! We recommend in particular older people as it is very unlikely that this system can burn through the pots, we can burn, or take the current (be careful, however, unlikely does not mean impossible). It 's very unlikely that you can also start fires allowed: in fact, this system avoids the risk of the danger of gas leaks and the risks associated with open flame (logically, as in all things, in spite of the high reliability of these systems, a fault can happen).
Among the benefits of the use of induction cookers compared to conventional include:
- Reduced cost of ownership compared to traditional gas or electric;
- Economic: only consumes energy when the container is resting on the plate;
- High efficiency and minimum heat loss: efficiency of 90% as against 40-50% of traditional stoves;
- Immediate heating of the pan;
- Immediate control of the temperature variation of the pot to instantly freeze boiling, cooking or for very bright or very sweet;
- Quick cooking often comparable to that of the microwave (from one third up to 50% compared to a traditional stove): two liters of water are brought to a boil in about 5 minutes compared to 8 minutes using a gas stove. This consequently reduces the consumption of electrical energy required;
- The heat remains constant and homogeneous avoiding foods that stick to the bottom right, you can then reduce the seasonings and fats, foods retain a better look;
- Safety: the pot is raised and the area goes off, you can not forget turned on, not activated accidentally in contact with metal objects such as small silverware, rings, bracelets, etc..;
- Safety: the glass ceramic surrounding stays cool;
- Security: avoid the risk of the danger of gas leaks and risks associated with open flame;
- Easy to clean: the floor is completely smooth and sealed, a gust of damp cloth and clean again, there is nothing sticks;
- Greater comfort during cooking and an average saving of 30% in time
- Silent: the cooktop does not generate noise;
- Technologically advanced;
- Offers aesthetic appeal.
Disadvantages
- For intensive use requires a connection over 3Kw normally supplied to private users in Italy. A connection from 4kW or 6kW is possible but involves a considerable increase in costs, especially for consumers with residential facilities in Italy has limited the supply of 3kW.
- High cost of cooktops. In recent years, however, are made available induction hobs at prices comparable to those in gas.
- Requires the use of suitable cookware (usually on the bottom is the symbol of the solenoid), flat-bottomed and made of ferromagnetic material. Those ceramic can be used as long as plugging through an adapter or panel ferromagnetic: since, in the latter case, the transmission for heat occurs by contact, is lost, however, the transfer efficiency due to electromagnetic fields.
- The operation depends on the presence of mains voltage: the appliance can not work, for example, during a power outage. It should be said that even some modern gas ranges depend, to some extent, from the mains voltage, such as, for example, for the devices of ignition.
- Electromagnetic fields can interfere with electrical equipment (such as, for example, the cardiac pacemaker): subjects carriers should avoid close contact or rather should discuss with your doctor the opportunity to use an induction cooker. Radio receivers placed nearby may experience electromagnetic interference.
- And 'advisable not to use utensils, cookware and cutlery metal (used for example to turn the food in pots) to prevent derivative current flow through the body.
10/10/2010
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Translated via software
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Source:
Italian version of ReteIngegneri.it