Various Methods of Heating

Various Methods of Heating

Heating of the material can be carried out by using different methods. Out of all these methods electrical heating method is most convenient and clear method.
The heat can be controlled accurately so electrical heating is widely used in many industrial applications.
In electrical heating electrical energy is converted into heat energy. Different electrical parameters are used such as resistance of the material, frequency of the electrical signal and speed of the electrons or ions in order to convert the electrical energy to heat energy.

Types of Heating Method :

Depending upon these parameters there are different types of electrical heating methods :

1. High resistance heating :

High resistivity of the material is used in this type of heating.
When the current is passed through such material, the heating takes place due to the power dissipation I Reg. Electrical cooking stove, Electrical furnace.

2. Infra red heating :

Electromagnetic radiation at infra red frequencies is focused on the object to be heated and heating of the material is carried out.
E.g. It is used in quick and uniform drying of the layer of the fresh paint without wastage of the energy. Infra red heating is also used as painkiller in medical therapy.

3. Very high frequency radiation heating :

It is similar to infra-red heating. With frequency 3 GHz we can obtain heating process.
It is used in the applications such as deep heat therapy and for fast cooking of the foods. e.g. Micro wave ovens.

4. Bombardment heating :

In this method heating of an object is achieved by bombarding the object with high speed electrons or ions.
It is used for heating of anodes and grids of high vacuum tubes during the process of evacuation. It has operations in high vacuum. So could not found commercial applications.

5. Dielectric heating :

It is popularly used in the industries. In this method the dielectric losses taking place in the materials when kept in alternating electrostatic field are used for heating process.
Dielectric losses increase with increase in the frequency of operation. It is used for heating nonconductive materials.

6. Induction heating :

In induction heating eddy current loss is effectively utilized for heating of metals e.g. forging process.