View A Video on Heating Elements - A Quick Introduction
Heating elements are the heat generation equipment in all electric heaters. Electric heating elements can be found in electric heating equipment of all shapes and sizes. Elements are manufactured in a variety of materials and configurations, but their function remains the same: to convert electrical energy into heat energy, then to transfer that heat energy to or through air, liquid or solids by convection, conduction or radiation.
There are a wide range of industrial heating elements for various applications; just a few varieties include infrared heating elements, immersion heater elements, flexible heating elements, quartz heating elements and many more examples. Many of those heating element varieties are also applied in commercial and consumer products contexts. For example, tubular heating elements, one of the most easily recognizable heating elements, are used in consumer ovens and in dishwashers. Heating coils can be tubular, such as stovetop elements, or they may be wire, such as those that are used in toasters. Wire heating elements are among the most common industrial and commercial dryer heating elements; kilns, surface treatment heaters and many other kinds of dryers make use of wire elements. Ceramic heating elements, many of which are SiC heating elements, are used for convectional heating, such as in space heaters, furnaces and semiconductors. Heater elements are capable of producing temperatures of up to 1300° F.Most appliances that require heat to perform their processes use a heating element of one kind or another. Ovens, dryers, water heaters, electric furnaces and other appliances make use of heating elements. Countless industrial process heating applications in various types of industrial electric heaters require the use of electric heating elements. In packaging, plastic fabricating, foam fabricating, metal fabricating and food processing industries, cartridge heaters are inserted through a hole into the metal or material of equipment parts that require localized heat. Extruding channels and hoppers use coil heaters, band heaters or strip heaters wrapped around or bolted to the channel to maintain the plasticity of the material being extruded. Utilizing infrared heating elements, radiating types of heaters such as duct heaters, immersion heaters and tubular heaters are used to heat liquid or air in industrial ovens, storage tank heating, pressure vessel heating, steam generation, boilers, water treatment facilities and many other applications. For instance, immersion heater elements are required for materials such as mild acids, oils, water, air, salts, plating baths and chemical solutions. In addition, many applications require flexible heating elements, which allow the heaters to be bent to suit their environments.
Heating elements within electric heaters are mainly composed of three elements: an insulating core, a heat conductive coil wrapped around the insulation and an encasing sheath made from stainless steel, aluminum, nickel or iron. Insulating cores are necessary in most types of electric heaters to retain and absorb electrical energy so that it might be released as heat energy by surrounding coils or materials. Coiled wire heating elements, such as those used as household dryer heating elements, have no insulating core but transfer heat directly to the air through blown convection. In higher heat applications, cores are responsible for converting electrical energy into heat energy and are heating elements' major component. Heating element cores are generally made from either NiChrome, a high-resistance 80% nickel 20% chromium compound, or from a Positive Thermal Coefficient ceramic, a highly heat resistant barium titanate/lead titanate composite. Ceramic and NiChrome are by far the most common insulation materials, although heating elements can also use mineral insulation such as magnesium oxide, mica or fiberglass, depending on the heater's application requirements. Another common material is silicon carbide (SiC). SiC heating elements are capable of higher operating temperatures and watt loadings than metallic heating elements. Quartz can be used to transmit the heat from the core, making quartz heating elements very popular.Heating elements typically have a shorter lifespan than the item in which they are installed and therefore may need to be replaced from time to time. Replacement heating elements can be stock or custom-made to fit the application by most heating element manufacturers and service providers. Most industrial equipment types using heating elements for processing have made replacing heating elements part of regular equipment maintenance. These parts are often kept in stock by the equipment manufacturer or can easily be manufactured in a short time, assuming the product is not too specialized. When heating elements fail in consumer items such as hair dryers or toasters, it is typically easier and less expensive to replace the whole unit rather than replace the heating element. Manufacturers of industrial heaters fabricate standard replacement heating elements for easy equipment maintenance. Correctly pairing a heating element with its application is a very important consideration; the safe and effective operation of a heating element depends on it. Incorrectly choosing or improperly installing a heating element can cause fires, short circuiting, product damage, equipment loss and a host of other problems. Carefully selecting the right equipment combined with regular maintenance helps to ensure its safety and prolong its lifespan.
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Heating Element Terms
- A substance made of two or more metals or of
a metal and a non-metal that are fused together while molten.
- To heat and then cool a solid (usually steel or glass) for softening, cooling slowly in a furnace to result in a less brittle material.
- The joining of metals through the use of heat and a filler metal to form a strong joint, the filler metal is usually silver alloy.
- British Thermal Unit. The amount of heat required to raise or lower the temperature of one pound of water one degree Fahrenheit.
- To combine, often a metal, with carbon.
- The metric temperature scale in which water freezes at zero degrees and boils at 100 degrees, designated by the symbol "C".
- Any product made from a nonmetallic mineral (clay) by firing at a high temperature, examples: porcelain or brick.
- Any coiled element that serves as the source of heat.
- In a heat pump system, the coil absorbs heat from the outdoors.
- A pipe or conduit through which air is delivered. Ducts are typically made of metal, fiberboard or a flexible material.
- Direct expansion; a system in which heat is transferred by the direct expansion of refrigerant.
- The temperature scale on which water freezes at 32 degrees and boils at 212 degrees; it is designated by the letter F.
- A brick that can withstand high temperatures and is used specifically for lining furnaces or fireplaces .
- An element that has broken and is touching something metal, like the cage that is suppose to hold the element or the element metal housing.
- The component of the heater that is responsible for conducting the heat.
- Invisible waves, sensed as heat, which has lengths longer than red visible light and shorter than microwaves.
- Unit of measurement of energy 1000 watts.
- A mineral made of shiny, transparent, flat chemical crystals. It is often used as an electrical insulator.
- A space or ducting used to distribute the air evenly in the process of cooling, heating, or humidifying.
be determined by dividing the total bearing load by the bearing projected
area (inner diameter * width).
- A measurement of heat equal to 100,000 btu.
- Measures the difference in potential created at the junction of two different metal wires that feed from the measuring instrument.
- A device for controlling temperature.
-The meter-kilogram-second unit of power equal to the power produced by a current of one ampere across a potential difference of one volt, 1/746 horsepower.