In our industry, many resources are available to find information on a variety of technologies. IHEA is one of those resources, and this induction article was graciously contributed by them.

Industrial processes use a wide range of heating technologies to accomplish various effects on manufactured products. IHEA has several technical divisions, and one of these focuses on induction.

Induction, as the name implies, induces a high-frequency electrical alternating current into a workpiece, causing it to heat up. The workpiece does not have to be magnetic, but it must be conductive. Induction can be used for both heating and melting.

The basic components of an induction heating system include a power supply, an induction coil, workpiece material handling and a cooling system. The basic components of an induction melting system include a power supply, a channel or coreless furnace, material-handling equipment and a cooling system.

 

IHEA

IHEA is all about industrial process heating. Whether it is a vacuum carburizing furnace or an infrared powder-coating curing oven, IHEA covers the spectrum of heating in manufacturing processes. IHEA members are oven and furnace equipment OEMs, electrical utilities, combustion burner manufacturers, various magazine publishers and even energy consultants. From 1929 to 2019, IHEA has been the leader

for the process heating industry. To learn more about IHEA, check out our website: www.ihea.org.

 

Why Use Induction?

There are several reasons to use induction heating technology.

  • Directed, precise heating: Only heats the portion of the workpiece that needs to be heated
  • Fast heating: Much faster than other techniques, with pinpoint temperature control
  • Energy-efficient: Instant on/instant off and precision minimize wasted energy
  • Clean: The coil does not touch the workpiece, no residue
  • Superior repeatability: Limited process variability, good quality
  • Flexible: Good for many different shapes and sizes, numerous applications

One of the key components for induction heating is the induction coil. The induction coil is the part that directs the induced electrical current into the workpiece. The coil will be geometrically similar to the workpiece (e.g., a circular coil for heating a round shaft).

Coil design and construction is almost as much an art as a science. Through testing and iteration, coils can be created to heat almost any geometry, which contributes to the great flexibility of induction heating technology. Additionally, there are many different ways to make induction coils, including:

  • Brazing
  • Machining
  • Casting
  • Additive-manufacturing (i.e., 3D printing) techniques using electron-beam melting (EBM) or laser-beam melting (LBM)

Coils are conductors of electricity for induction heating and, as such, are typically made of copper or other highly conductive material. At the same time, carrying the electricity generates heat, so induction coils are typically hollow to allow for cooling-water flow.

Coil life is a critical component of overall induction heating part production. Depending on the parts and the coil design, part production from one coil life cycle can be in the hundreds of thousands.

Similarly, induction melting also uses induction coils. These coils are typically much larger and surround a refractory-lined vessel where the metal is melted. Higher power and longer times are required to melt metal versus just heating metal.

 

The Wide World of Induction Applications

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Here are some of the many industrial induction applications: brazing, annealing, soldering, curing, shrink fitting, crystal growing, forging preheating, heat treating, hot forming, melting, bonding, cap sealing, carbide tipping, pipe seam welding, pipe bending (photo) staking, surface hardening, testing, toolmaking and many more.

 

Melting Furnaces

The two types of induction furnaces are channel and coreless. The channel induction furnace is typically used as a holding furnace and for metals that have lower melting points. The coreless furnace is best utilized for metals with higher melting points. Once materials like cast iron are melted by a coreless induction furnace, a channel induction furnace can then be used to maintain, or hold, the iron in its melted state.

 

Cooling

Finally, all induction heating and melting systems require some type of cooling for the power supplies, coils and conductors. This is typically accomplished with process cooling water, heat exchangers, chillers and/or cooling towers. Deionized water is nonconductive and must be used when cooling electrified components such as conductors. Maintenance of cooling water and deionized water systems is critical for the proper operation of an induction heating or melting process.

 

IHEA 2019 Fall Seminar Series

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The Industrial Heating Equipment Association (IHEA) heads to Cleveland, Ohio, for its 2019 Fall Seminars and Fall Business Conference. The event will be held at the Intercontinental Cleveland Sept. 24-25. The technical seminar series will be held on Tuesday and Wednesday, followed by the IHEA Fall Business Conference on Thursday.

“Cleveland has been the site of some of our most successful seminars and meetings,” said IHEA Executive Vice President Anne Goyer. “We’re excited to return to an area that draws attendees interested in learning ways to continuously improve their operations.”

In its 90th year, IHEA remains an industry leader by providing expert-led, unbiased training for those in the industrial thermal-processing industry. The 50th Combustion Seminar and the Safety Standards and Codes Seminar will take place concurrently over the first two days. There will also be a one-day Process Heating Seminar that includes infrared, induction and other process heating technologies. Attendees of all seminars will have access to IHEA’s Tabletop Exhibition and Reception on the afternoon of Sept. 24.

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The Combustion Seminar is presented by industry professionals from leading heat-processing companies. They will deliver relevant information on combustion technologies. The comprehensive Safety Standards and Codes Seminar covers critical safety information for those involved with a wide range of industrial thermal-processing applications as well as the 2019 updates to the NFPA 86 standard.

New this year, the Process Heating Seminar will be held at a nearby IHEA member company, Selas Heat Technology. The unique venue allows attendees to experience hands-on demonstrations of the different technologies described throughout the seminar. Selas will also offer a facility tour for those in attendance.

Mark your calendars for Sept. 24-25, and watch for more details on registration information at www.ihea.org/page/fall19.

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Conclusion

As you can see, induction heating and melting provide a wide range of process heating technology for manufacturing. Induction heating and melting processes can be found in many industries across many markets. Applications are nearly unlimited because induction systems can be tailored to match power requirements, geometry, overall workpiece size and required final material characteristics.

For more information: Contact IHEA, P.O. Box 679, Independence, KY 41051; tel: 859-356-1575; web: www.ihea.org (see Contact Us). You can learn more about induction at the upcoming IHEA Process Heating Seminar this fall (see sidebar). Please plan to join us.

References available online