Cartridge Heater are used mainly in immersion. However, due to their compact cylindrical shape, they can also be used in a variety of other applications. Important parameters to consider when specifying cartridge heaters are maximum operating or sheath temperature, AC voltage required, watts and watt density. Maximum operating temperature is the maximum temperature that the sheath covering the cartridge heater may reach. Note that the maximum sheath temperature is not the hottest temperature that a heated substance may reach. AC voltage is the minimum alternating current (AC) volts required to operate the cartridge heater. Watt density is the amount of wattage per square inch that a cartridge heater can deliver. Suppliers calculate watt density by dividing the available wattage by the heated area. High watt density heaters should not be used with extremely viscous materials, poorly-circulated materials, or explosive/volatile materials due to risk of fire. Important dimensions for cartridge heaters are the nominal diameter and cartridge length or heated length.
Sleeves, jackets or sheaths are used a protective outer covering for heating elements. Typically, cartridge heaters use sleeve materials made of aluminum, brass, copper, iron, nickel alloy, stainless steel, or steel. Heater insulation reduces heat loss to the environment. Some heaters have multiple insulation options. Choice for cartridge heater insulation includes no insulation, ceramic insulation, mica insulation, mineral insulation, and fiberglass. Uninsulated cartridge heaters have a lower profile and are useful in areas where space is at a premium; however, these products are not particularly energy efficient. A cartridge heater equipped with a layer of ceramic insulation can resist heat and chemicals. Ceramics are made of nonmetallic minerals, such as clay, that have been permanently hardened by firing at a high temperature. Mica is known for its high resistance to heat and acids, as well as for its electrical insulating properties.
- High quality
- Optimum strength
- Accurate functioning