Ditch the oven!

Are you tired of wasting energy in your current heating process?

Direct Resistance Heating equipment is typically above 90% efficient!

What is Direct Resistance Heating?

  • Resistance Heating is heat produced by passing current through a part and the resistance of the part generates the heat.

  • It is exactly the same phenomena as the heat generated to light an incandescent lamp – in the industrial heating case, the work is the heating element.

  • The complete part is heated throughout simultaneously.  This differs from induction heating where the part is heated from the outside in, through conduction.

  • Therefore – this process is used only where it is desired to heat the part completely through its cross-section.  It is not used to provide localized heating – for example, just the outer case of a round bar.

Resistance Heating Benefits?

  • No warm-up period

  • Power is on only when required

  • No pollution

  • No gas or oil

  • Uniform heating throughout the part

  • Reduces carburization

  • Low ambient temperature around the work area

  • Faster heating time reduces cracking of the material and improves metallurgical characteristics, such as in machining of certain types of steel

  • The part can be heated above the Curie point in which the part no longer is magnetic

  • The machine can easily be automated

  • Temperature can be controlled to within ± 25° typically

  • The part can be easily held at a holding temperature

  • The controls are simple and therefore reduce maintenance

  • The equipment is safe because we are not using high voltage or high frequency. In addition, gasses are eliminated and therefore eliminate any chance of explosions or fires.

  • The work piece is the only item that becomes hot. All of the tooling, clamps and machine components remain cool.

  • Short Heating Times lead to very high production rates

Efficiency

  • All power is put into the part and losses are eliminated into the air, and tooling surrounding the part

  • Direct Resistance Heating Will Require 60% Less Energy Then Comparable Processes Such As Furnaces And Induction Heating.

  • Efficiencies of 90% and above are common (Induction heating is around 50%)

  • Installed power requirements will be greatly reduced

Purpose

  • Stress Relieving

  • Normalizing

  • Annealing

  • Forging

  • Warm forming

  • Brazing

  • Austenitizing

  • Tempering

  • Hot Upsetting

Requirements

  • Electrically Conductive

  • Good Contact

  • Uniform Cross-Section*
    It can be irregular; Under special conditions

As an example of power savings, if an induction heating unit took 600 KW, the power savings with resistance heating would be 240 KW. Based on a 5/kilowatt hour, which is typical, that would add-up to a total savings of $24,000/year on power alone. In addition, the savings in water to take care of the losses generated by the induction heating unit would add-up to 170 gallons/minute to cover the losses generated by the inefficiencies. As you can see, there is a great savings with resistance heating and not only is there money saved in power but also in water consumption

No warm-up – Since all fo the power is going into the part and is only on while part is being heated.

This process does not use any gas or oil, No dangerous chemicals / fumes / or ambient heat.  This means there is no heat loss when the equipment is idle or between parts.  This also reduces worker fatigue

The part is heating uniformly.  This allows much faster heating, reduce cracking and improves certain metallurgical and machinability characteristics. Therefore much less decarburization, scaling and loss of material due to scaling. This also means less scaling contamination in forging dies.

Not necessary to change heating frequency above Curie point temperature to obtain good efficiency.

Process lends itself well to automation – this, coupled with short heating time, provides very high production rates.

Good temperature control – Temperature is controlled and can be help typically within ± 25°

The equipment and controls are relatively simple and easy to understand, therefore machines have a high degree of up time.

Equipment is very safe – no unusually high voltages, no explosive gases, nothing hot except the work piece itself.

Versatility – For example, with quick changes in tooling and clamp position, the same machine could be used to heat 3/8″ diameter up to 2″ diameter bars, varying from 5′ to 30′ in length.