Electric Stoves, Calrods and Cooking with Electricity

Electric Stoves, Calrods and Cooking with Electricity

Engineers have improved the quality of life of humankind through development of electrical household appliances. One of the most widespread uses of electricity is in cooking. There are several ways to heat food using electricity:

1.) Resistive heating
2.) Induction heating
3.) Microwave heating
4.) Electric Arc

1.) Resistive Heating Elements:

Above: hand-held Calrod heater. Dip the hot end into a pot and you can bring the water boiling faster than other methods by using direct conductive heat transfer. This calrod is now a historical artifact as they are no longer sold for safety reasons.

There are several ways to cook food using resistive heating elements. Toasters and hair dryers use Kanthal, Nichrome or Cupronickel wires.  Heat lamps use incandescent lamps to keep food warm after it has been cooked. Calrods are the dark grey tubing you see on ovens and in dishwashers.

“Calrod” is a GE trademarked name for the main type of heater used in all sorts of devices. They use nickel chromium wire (Nichrome) encased in a steel tube.  Vitrified magnesite is packed in the steel tube to provide electrical insulation, yet at the same time this material conducts heat very well.  This is why if you touch a calrod heating element you don’t get an electrical shock (in addition to the burns!). Calrod technology is used in irons, ovens, stovetops, toaster ovens, dishwashers,electric heaters and other industrial ovens.

See this old film which shows how Calrods are made >

Calrods are bent into any shape and are used in ovens and on the cooktop

Above: possibly Nichrome wire heating element used in an early space heater. This shows the same kind of coiled wire that is found inside the Calrod.

Left: heat lamps are used to keep food warm. Incandescent lamps are used as they release 90% of energy through heat (the other 10% is light).

2.) Induction Cooking:

See our page here on induction cooktops >

3.) Microwave Ovens:

See our page on Microwave ovens here >

4.) Electric Arcs:

Electric Arcs are not really used to heat food, but you can see our video below where a hotdog and apple are subject to a high voltage arc:

Related Topics:

Dishwashers

The Microwave Oven

Induction Cooktops

12 Major Forms of Electric Light

The Fan

More Stuff

Article by M.W. and W.Kornrumpf
Sources:
GE Appliances
Calrod by Hotpoint. 1928
High Voltage Demonstration, Nucla, CO. Edison Tech Center. 2014

Photos:
Edison Tech Center