Definition and general information
Electric cartridge heaters are single-tube cylindrical resistors, characterized by a connection outlet at one end only. They are designed to be inserted into blind (non-through) bores, to heat metal parts such as trays, dies or molds, up to temperatures of 700°C.
They can also be used to heat liquids, either statically or in circulation, either directly or via a sealed sheath known as a thermowell.
Heating cartridges are widely used in many industrial sectors, such as food processing, industrial processes, and pharmaceuticals. They are used in particular for heating molds for plastic injection, dies for marking food products (such as cakes or fish), or in Screw plug immersion heater flangeScrew plug immersion heater for heating liquids.
Mounted in metal parts, cartridge heaters transmit heat mainly by conduction. A good fit between the cartridge and the bore ensures optimum heat transfer. When immersed in a liquid, heat is transmitted mainly by convection, either natural or forced, depending on fluid flow conditions.
They consist of a resistive nickel-chromium alloy wire, a protective metal sheath (usually stainless steel or brass) and two power cables for electrical connection.
As an option, they can incorporate a thermocouple to measure the temperature at the core of the cartridge, as well as a fastening device (insert, threaded plug, etc.) for direct mounting on a part or container.
- Single-phase or three-phase voltage.
- Cartridge diameters from 6.35 mm to 31.8 mm
- Lengths from 25 mm to several metres depending on model
- Sheath material: Brass, stainless steel 321, stainless steel 316L, stainless steel 904L, Incoloy®800 or Incoloy®825
Applications
Cartridge heaters are used in a wide range of applications. Here are just a few examples:
Food industry
Cartridge heaters are used to heat metal dies or cavities for hot stamping the surface of products such as cakes, cookies or fish fillets.
Chemistry and pharmaceuticals
Mounted on our Clamp flange immersion heaters, cartridge heaters feature a surface finish (Ra ≤ 0.6) in line with pharmaceutical industry requirements, making them suitable for heating purified water as well as cleaning-in-place (CIP) solutions.
Energy sector
In the power generation sector, cartridge heaters are used to preheat mechanical components such as pumps, gearboxes or reducers, in order to fluidize lubricants prior to commissioning.
Industrial processes
In plastics processing, they are used for precise, localized heating of the tools involved in thermoforming and extrusion processes. They are integrated into molds, dies or heating zones to maintain thermoplastic materials at optimum forming temperature.
Technical data
The cartridge heaters consist of :
- Nickel-chromium alloy resistance wire
- An outer protective sheath (or shield) for mechanical protection and corrosion resistance.
- 2 Electrical connection cables. Cable material is adapted to the maximum temperature at the connectors. Mechanical protection with corrugated metal sheath is available as an option.
- Optional safety thermocouple J or K inserted in the cartridge
- Optional fixing device (plate or threaded plug) for mounting the cartridge on the workpiece to be heated or on a container.
Further information
- Cartridges used alone are not suitable for ATEX environments.
- In addition to the wide range of finished products available in our online catalog, Vulcanic can design custom-made equipment to meet your specific requirements (power, voltage, length, connectors, etc.).
Recommendations
Precautions for use
The heating part of the cartridge must be in full contact with the medium to be heated.
Installation and connection
When heating a metal part, the bore must be precisely adjusted to reduce the air gap between the cartridge and the wall, thus promoting heat conduction and optimizing heat transmission.
Please refer to the instruction manual for all recommendations relating to the equipment.
