What Is Induction Heating?




Induction heating is a process that utilises electromagnetic induction to heat an electrically conductive material. As voltage is induced, the losses from the resulting current flows are seen as heat. This type of induction heating method is highly efficient and precise, relying on the principles of electromagnetic fields and the electrical resistance of the material being heated. These are the principles of induction heating:

  • Electromagnetic Induction involves a high-frequency with alternating current that is passed through a coil, creating a rapidly changing magnetic field.
  • Eddy Currents is when an electrically conductive material is placed within a changing magnetic field, eddy currents are induced in the material due to electromagnetic induction.
  • Ohmic Heating or also known as Joule heating, occurs when a material’s resistance is induced with eddy currents to cause heat, achieving the desired temperature quickly and selectively.

Main Uses

Induction heating is a highly-versatile technology that is maximised in a wide array of applications across diverse industries. Its non-contact and energy-efficient method delivers precise and rapid heating contributing adaptability and advancements to several processes in fostering innovation and efficiency.

Applications of induction heating:


1. Metal Hardening

Induction heating is commonly used for hardening the surface of metal components. This is to enhance their durability and wear resistance.

2. Brazing and Soldering

The precise and localised heat that the induction heating method provides makes it ideal for joining metals through processes like brazing and soldering.

3. Annealing

Induction heating is employed in annealing processes to relieve stress, improve material properties, and enhance machinability.

4. Forging

Induction heating facilitates controlled and efficient forming of metals. This enables the process of shaping components with high precision.

5. Cooking Appliances

When cooking, using induction cooktops makes use of this technology to directly heat the cooking vessel. This offers rapid and precise temperature control for different cooking processes.

6. Medical Applications

Induction heating is utilised in medical devices for procedures like hyperthermia treatment, where having efficient and targeted heating of tissues is required.

7. Automotive Industry

Induction is employed for various automotive applications. Using an induction heating tool is common especially for necessary heat treatment for engine components and manufacturing precise suspension parts.

8. Plastic Welding

When used in plastic welding processes, an induction heating tool ensures fast and efficient bonding of plastic components.

9. Jewellery Manufacturing

The jewellery industry utilises induction heating equipment for tasks such as soldering and shaping precious metals with minimal thermal impact.

10. Research and Development

Because of its many applications, induction heating in laboratories is essential for processes such as material testing, research, and development activities due to its precise and controlled heating capabilities.

What are the advantages of the induction heating method?

Induction heating is a transformative technology that benefits a wide array of industries. It reduces processing time, energy consumption, as well as offers adaptability to selectively target heat while minimising waste. Here is a quick overview of the many advantages induction heating can offer you: 

Induction heating allows precise and controlled temperature management. This is crucial for customising heat to necessary temperatures and targeted areas when conducting laboratory experiments and material testing.

With induction heating equipment, rapid heating is achieved as these reduce waiting times and enable quick experimentation or processing of materials.

Because of its ability to target specific areas, induction heating tools minimise the risk of affecting surrounding materials. This is vital for experiments requiring localised temperature changes.

One of the visible advantages of induction heating is that it eliminates the need for open flames. This is a transformative benefit which helps reduce potential risks of accidents and ensures a much safer laboratory environment.

The induction heating method is energy-efficient, converting a high percentage of electrical power into heat, contributing to cost-effectiveness in laboratory operations.

Induction heating can be adapted for various materials, making it suitable for a wide range of laboratory applications such as metallography, material synthesis, and thermal analysis.

Heating in itself is identical cycle to cycle and part to part. Variations in incoming power are automatically compensated for. There is no warmup time required and cycles provide consistent results. 

When all costs are weighed, induction heating is often the best and most profitable heating alternative for the long term. Energy is targeted, and achieves much higher efficiency than fossil fuels or radiant heating systems. With no warm up time required, there is no need for changing tanks, or leaving the heat on when parts are not present while providing consistent results.

What is the difference between induction heating and electric heating?

While induction heating and electric heating may seem similar in processes, there are a few differences that can offer unique advantages depending on the material and required heating capabilities. Here’s a quick guide to differentiate the two:

Type of Heating

Induction Heating 

Electric Heating 

Mode of heating 

Relies on electromagnetic induction.

Utilises direct application of electrical resistance to generate heat.

How It Works

Involves a coil through which a high-frequency alternating current passes, creating a changing magnetic field.


Involves a resistive element (e.g. heating coils or wires) that converts electrical energy into heat.

Advantages

Heating is rapid and selective, focusing on the material itself.


Provides precise temperature control and uniform heating.


Well-suited for localised applications, such as induction cooktops and industrial processes.


Energy-efficient with minimal heat loss.

Common in electric stoves, ovens, and space heaters.


Applicable to a wide range of materials, both conductive and non-conductive.


Disadvantages

Equipment can be complex depending on the design and quality.

Heat distribution may be less uniform compared to induction heating.


May take longer to reach desired temperatures.


Can be less energy-efficient due to potential heat dissipation.

In summary, while both heating methods involve the application of electrical energy for heating, induction heating uses electromagnetic induction for efficient and selective heating, while electric heating relies on direct resistance for a broader range of applications.

What is an induction system?

An induction heating system refers to the integrated setup required for applications using induction heating technology. This usually comprises several key components working in tandem to generate and control electromagnetic induction for heating purposes. The core elements include:

1. Induction Coil

This is a crucial component that generates the alternating magnetic field when connected to a high-frequency power source.

2. Power Supply

Power supply provides the high-frequency alternating current necessary to drive the induction coil and create the magnetic field.

3. Control System 

A control system is required to manage and regulate the power supplied to the induction coil, allowing precise control over the heating process.

4. Workpiece 

Induction heating requires an electrically conductive material that responds to the induced electromagnetic field.

Together, these components form a cohesive induction heating system capable of efficiently and selectively heating materials for various industrial, laboratory, or commercial applications. When the system's design and configuration are tailored to specific heating requirements, this ensures optimal and efficient performance with minimal energy waste.

Define induction heating frequency  and how it works.

The induction heating frequency refers to the rate of alternating current cycles within the induction coil during the induction heating process. This induction heating frequency is typically measured in kilohertz (kHz) and plays a crucial role in determining the system's efficiency and heating characteristics.

Choosing an optimal induction heating frequency will depend on several factors such as the material properties, the desired heating depth, and the application requirements. 

Higher frequencies are often used for shallow induction heating, whereas lower frequencies could penetrate deeper into the material. The selection of the optimal frequency is crucial for achieving efficient and controlled induction heating.

How do I choose the right induction heater for my needs?

Model

High Frequency

Medium Frequency

Low Frequency 

Temperature / Frequency

30 kHz to 1100 kHz

30 kHz to 80 kHz

1 kHz to 20 kHz

Workpiece

SMALL

MIDSIZE

LARGE

Applications

Ideal for fine steel wires (such as those used in dentistry) annealing, small precision shaft quenching, hard alloy saw blade brazing and metal powders melting.

Can be used for small parts heating, cutting, diamond tool brazing, soldering copper plumbing fittings, auto parts heat-treating, annealing of stainless steel containers and more.

Used for deep heat penetration for full hardening processes, steel rod forging, tempering of pressing dies, preheating for welding, and melting of metal batches over 4 lbs. 


They are not limited to ferromagnetic materials, so nonferrous metals can also be used effectively.

Cost

5,211 AUD - 24, 291 AUD

3,321 AUD - 17, 991 AUD

8,091 AUD - 18, 891 AUD

To summarise the types of induction heaters: 

  1. High frequency induction heaters are good for powder, small parts, surface heating, as well as heating from a distance with high efficiency.
  2. Mid-frequency induction heaters are good for midsize parts heating or melting and surface heating. 
  3. Low-frequency induction heaters are designed for large-sized parts heating that requires deep heat penetration; they are also great for large amounts of gold, silver, copper or ore melting.

Where to buy an induction heater - how can we help?

At Across International, we offer a complete line of all solid state energy-saving induction heaters for various purposes. We are also a manufacturer of induction melting furnaces and a go-to place for high-quality. Whether you’re looking for an induction melting furnace, a gold melting furnace, or accessories as well as spare parts for your induction heating equipment, Across International has what you need. For more information you can, contact us today at 1300 118 228 or leave your enquiry here.