Explosion Proof Heaters Information
Explosion proof heaters are constructed with housings that can withstand explosions, sparking, and flames during the heating of materials. Most devices include a protective sheath that covers the heating element.
Cartridge heaters are cylindrical devices that are generally inserted into a heated substance.
Circulation heaters are used to heat moving or circulating fluids.
Duct heaters are used to heat moving gas streams.
Immersion heaters are used in applications that require the heater to be immersed in the substance being heated. For example, over-the-side heaters are immersion heaters that hang over the side of a tank of heated material.
Both radiant and infrared heaters use a reflective shield to direct radiant heat onto a heated surface. Common types of infrared heaters include:
Metal-sheathed tubular heaters
Quartz tubes and lamps
Gas-fired catalytic heaters
Flat faced panels
Maximum sheath temperature
Maximum AC voltage
Maximum watt density
Watt density, a measure of how quickly heat is transferred, is calculated by dividing the available wattage by the area of the heated surface.
Sleeve / Sheath Material
Aluminum, a metallic element with good electrical and thermal conductivity, is resistant to oxidation.
Brass provides good strength and conductivity, excellent corrosion resistance and high temperature ductility, and low magnetic permeability.
Steel, a commercial iron that contains carbon, is malleable under suitable conditions.
Stainless steel is chemical and corrosion resistant and can have relatively high temperature ratings.
Rubber heater sheaths are made of natural compounds such as gum rubber (polyisoprene), styrene butadiene (SBR), or synthetic rubber materials.
Other heater sleeve materials for explosion proof heaters include copper, iron, nickel alloy, and proprietary materials.
Rated for cryogenic use
Internal temperature detector
Some are equipped with thermowells facilitate the use of thermocouples or other temperature sensors.
Custom heater designs are sometimes available.
Explosion proof heaters that bear the UL mark have been approved by Underwriters Laboratories (UL), a product testing organization.
IECEX Bulletin - IEC system certification for standards relating to equipment for use in explosive atmospheres
GOST 22782.0 - General requirements and methods of testing explosion proof apparatus