Induction heating applications

Cooking

In induction cooking, induction coils inside the cooktop heat the iron base of the cookware through magnetic induction.Using an induction hob is safe, efficient (the hob itself does not heat) and speed.Non-ferrous metal pots such as copper bottom pots and aluminum pots are generally not suitable.Through heat conduction, the heat generated at the bottom is transferred to the food inside.

Brazing

Induction brazing is often used for higher production runs.It produces uniform results and is very repeatable.There are many types of industrial equipment that use induction brazing. For example, induction is used to braze carbide to shafts.

Seal

Induction heating is used for the closure of containers in the food and pharmaceutical industries.A layer of aluminum foil is placed over the opening of the bottle or jar and is fused to the container by induction heating.This provides a tamper-evident seal, since changing the contents requires breaking the foil.

Heating fit

Induction heating is often used to heat items to cause them to expand prior to installation or assembly.Bearings are usually heated in this way using mains frequency (50/60 Hz) and a laminated steel transformer core passing through the center of the bearing.

Heat treatment

Induction heating is commonly used in the heat treatment of metal objects.The most common applications are induction hardening of steel components, induction welding/brazing as a means of joining metal parts, and induction annealing to selectively soften an area of a steel component.Induction heating can generate high power densities,allowing short interaction times to reach the desired temperature.This allows tight control of the heating pattern, which closely approximates the applied magnetic field, and reduces thermal distortion and damage.This ability can be used for hardening to produce parts with different properties.The most common hardening process is to produce localized case hardening in areas where wear resistance is required, while retaining the toughness of the original structure as needed elsewhere.The depth of the induction hardening pattern can be controlled by selecting the induction frequency, power density and interaction time.Process flexibility is limited due to the need to produce specialized inductors for many applications.This is quite expensive and requires marshalling high current densities in small copper inductors, which may require specialized engineering and "copper fittings"."

Plastic processing

Induction heating is used in plastic injection molding machines.Induction heating increases the energy efficiency of injection and extrusion processes.Heat is generated directly in the barrel, reducing warm-up time and energy consumption.The induction coil can be placed outside for thermal insulation, so the working temperature is low and the service life is long.The frequencies used range from 30 kHz to 5 kHz, the thicker the barrel the lower the frequency.The reduction in cost of frequency conversion equipment has made induction heating more and more popular.Induction heating can also be applied to the mold, providing a more uniform mold temperature and improving product quality.

Pyrolysis

Induction heating is used to obtain biochar in biomass pyrolysis.Heat is generated directly into the vibrating reactor wall, enabling pyrolysis of biomass with good mixing and temperature control.

Core type furnace

The furnace consists of a circular hearth in which is held an annular charge to be melted.The metal rings have a large diameter and are magnetically interconnected with electrical windings powered by an AC power source.It is essentially a transformer in which the charge to be heated forms a single turn shorted secondary and is magnetically coupled to the primary through an iron core.