Coil Heaters

Ceramic-coated heat coils may be found in both consumer and commercial ovens; the ceramic layer protects the coils from leaking grease and other contaminants. Heat coils are used as the heat-generating mechanism in clothing dryers, hair dryers, industrial dryers, and many different types of heat generation and moisture removal equipment. Water heaters can utilize heat coils, and furnaces can mix heat coils and air blowers to warm air and then distribute it through ductwork.

Coil heaters come in flat, round, and micro, the smallest possible size. Maxi is the largest size and the most robust. Some of the forms and sizes offered are low-profile, meaning flat. Some have a lock positioning ring to make installation more accessible, while others are cast in brass for nozzle-to-nozzle applications.

Materials Used in Coil Heaters

• Layered heating elements are used in coil heaters and cable heaters. Heat is generated by resistance wire elements, such as a nickel-chromium alloy.
• They have an annealed exterior with ceramic, mica, or fiberglass insulation and are manufactured of brass, aluminum, nickel, copper, iron, or steel.
• Magnesium oxide, a unique substance that is an excellent heat conductor but a poor electrical conductor, insulates the sheath from the heating element, allowing heat but not electricity to flow from the nichrome. Ceramics, mica, and fiberglass are among other insulation possibilities.

Types of Coil Heaters

Straight or pre-formed electrical heating components with a metallic sheath are known as coil heaters. They come in various forms and sizes and have a round, square, or rectangular cross-section. Straight, tightly coiled, spiral wound, and star wound cables are examples of coil heater configurations.

• Straight Cables

  These are utilized to snake through or around various pieces of equipment. The end-user can also shape them for OEM purposes.

• Tightly Coiled Cables

  These provide the best heat distribution and can contain dispersed watts to focus heat transmission at specific spots.

• Spiral Wound

  These low-profile heaters create high temperatures in confined spaces.

• Star Wound Cables

  These are offset coils installed into pipes or ducts to generate a turbulent flow in air or fluid, improving heat transmission.

Construction of Coil Heaters

1. Most coil and cable heaters work with AC voltages; the required heat voltage is determined first.
2. The nickel-chromium wire is then coiled into the chosen shape.
3. The heating coil's end is cut as necessary.
4. The heat source is connected to the nickel-chromium wire.
5. Lastly, the heat source is checked, and the heating coil is secured.

Working of Coil Heaters

1. The metal alloy of the wire that goes through the heating coil's core is engineered to have a specified resistance.
2. Heat is produced when electricity is transmitted across the wire.
3. A high-temperature electrical insulator surrounds the wire, which is then surrounded by a high-temperature metal coating.
4. The wire is electrically isolated from the cladding, which is usually grounded. Thus, contacting it will not result in an electric shock.

Benefits of Coil Heaters

• Heat Pattern: Coil heaters operate on AC voltages and give a consistent heat pattern over a large area up to 1200 °F (648.9 °C).

• Flexible Shapes: Electric coil heaters' excellent flexibility allows them to be formed into practically any shape. As a result, they can be tailored to the application.

• Quick Temperature Change: The coil's low bulk facilitates heat transmission during heating and cooling.

• Long-lasting: These heaters are simple to maintain. They tend to be exceptionally long-lasting, even with minimum upkeep.

• Versatile Use: Electric coil heaters may be utilized in various applications, including liquid immersion, gas heating, and sub-freezing.

Applications of Coil Heaters

• Coil heaters are employed in various sectors, including heating, plastic manufacture, food, textile, and paper.
• Coil heaters, which come in various shapes and sizes, including round, spiral, and spiral-wrapped, may be bent to a particular size or form and are utilized when high temperatures are required in restricted spaces.
• Star coiled coils are put in pipelines and ducts to generate a turbulent flow in air or liquid.
• Coil warmers are used in holding tanks, blow molding machines, extruders, bag sealing, and hot metal forming punches.
• Some coil heaters are corrosion-resistant and can be submerged in hot substances or utilized in cryogenic applications, depending on the metal.
• These heaters have been effectively employed as vital heating cells in hot-runner nozzles for plastic injection molding.