What Is Electric Heating

 

19 Feb, 2023.

In this post, we will see the concept of electric heating.

In many domestic and industrial applications, heating is required for a certain process. It is the most general used process because heat is required in many uses. Take a simple example of a water geyser installed in your washroom. It will provide you with hot water in cold weather, when most necessary. So, heating is required in many areas. Heating is generally achieved by two ways – natural and man-made. Natural means by burning something like wood, coal which creates combustion and generates heat, or even solar energy; and man-made means by electric heating. Electric heating is the mostly widely used method nowadays to produce heat wherever required. In this post, we will see all the basic concepts related to electric heating.

Electrical Heating:  

So, what is electric heating? As the name implies, it is a process where heating is achieved by means of electricity. Means, the electrical energy is converted to thermal energy to generate heating. Here, the heat is produced due to circulation of electric current through a resistance. The resistance is the main reason for generating heat. Electric heating process is also dependent on other factors like current flow, and time duration. Let us first understand each concept properly step by step.

Heating Effect Of Electric Current:  

As you know, electricity flows through a conductor. A conductor is a component which allows electrons to pass through it. An insulator, on the opposite side, is a component which blocks the flow of electrons through it. A conductor can be any material like copper, aluminium, nickel, chromium etc. Every material has it’s own resistance to electricity. When electricity is provided to the conductor and if it is resisting, it means it is indirectly resisting the flow of electrons. These electrons will then collide with other atomic particles in a conductor. This collision basically produces heat. In the other way, it can also be seen that the electrons have not travelled all the way to their destination due to the resistance prevalent. So, this conserved energy can also be a cause of the heat generation. Majorly, due to the resistance provided for the flow of electrons, heat is produced in the conductor and this is the reason how electrical energy is converted into thermal energy.

Now, as discussed earlier, every material offers different type of resistance depending on it’s substance construction and component properties. The most widely used components for electric heating are alloys (mixture of some metals). The generally used one in electric heating is nichrome (nickel and chromium). This alloy makes up a heating element, which you normally must have seen in heating coils used to heat water. This heating element is the main component of electric heating.

Let us see how this heating principle works now. As you can see in the below image, a heating element is connected to a single phase power supply. When electricity is supplied to the coil material, it starts heating up to the desired temperature. After a certain period of time, it will reach it’s maximum temperature and maintain it. And, when the power supply goes off, then due to non-movement of electrons, there is no collision and thus, no resistance offered. This starts to bring down the temperature.

Generally, the heating element is covered inside some insulator material. This is done to avoid short-circuit, accidental touch and any physical damage to the environment.

Methods Of Electric Heating:  

1.       Power Frequency Heating

a.       Resistance Heating – Direct, Indirect and Infrared.

b.       Arc Heating – Direct and Indirect.

c.       Election Bombardment Heating.

2.       High Frequency Heating

a.       Induction Heating – Direct and Indirect.

b.       Dielectric Heating.

Advantages Of Electric Heating:

If you compare it with natural heating method, then one main advantage is that you have total control over it. Burning of elements, solar energy is not in our hand. But, you manage this type easily as electricity is in our hands. Also, as there is no combustion, it is totally environmental friendly. You can also easily set the temperature and use a sensor inside the assembly to give accurate temperature output as per control. Also, this method is cheaper than conventional heating methods. Due to all these factors, the efficiency of electric heating is very high.

I have covered the general principle of electric heating step by step. I have also not attempted to cover every theory of these types deeply; you can learn it easily once you get familiar with them. I have just given you an insight of these types of designs. Once you are done with these, I am hopeful you will be easily able to understand electric heating properly. Learn the basics and explore a new type of study in this type of engineering.

Thank you guys; I hope you enjoyed reading the practices normally used for this type of study in industrial automation.