Cartridge heater often considered as component heater has a heating coil wound on a ceramic core and are cylindrical-shaped, heavy-duty Joule heating element. Electricity flows through coil when a two or three-phase voltage is applied. The electricity heats the coil and, subsequently, the cartridge sheath. The watt density (in Watt/inch2) depends on the number of spirals or turns per inch. The sheath comes in contact with the surface being heated. Insulation in the cartridge heater ensures that the heating wire never comes in contact with the sheath and protects the sheath from melting in case of any mishap. The leads that come out of the heater terminal have metal conduit, or silicon sleeves to protect from high temperature. Lead wires are often fiberglass or silicon rubber.
These heaters provide a suitable, reliable and competent method of applying concentrated heat to solid metal components to high temperatures, particularly where compact, insert type heating is desirable. Swaged construction provides minimal air gaps, which lead to high efficiency and improved heat transfer. Distinguished for long trouble free service, cartridge heaters have precise dimensions and tolerances. Heating elements are kept close to the material being heated for maximum heat transfer, minimum core temperature, and faster heating. Use of stainless steel sheaths provides non oxiding surfaces. The surface watts density and operating temperature of a cartridge is dependent on hole clearance. The larger the hole clearance the lower the recommended watt density. For temperature sensing, a thermocouple should be positioned in the heater but its life is reduced by slow “on/off” cycling of power controllers. So PID auto tuning controllers with solid state relay or thyristor output are suggested
|Sheath Material||Stainless steel, INCOLOY|
|Watt Density||Up to 400 W/in2|
|Design temperatures||Up to 760°C (1400° F).|
|Voltage||Up to 480V AC|
|Length||Up to 72 inches|
|Leads||Stranded/ Swaged in/ Pin leads/ Crimpedon/ Customised|
Note- For custom design requirements please contact thre factory.
Lead wire options
|Wire Type||Temperature Rating||Maximum Recommended Temperature||Comments|
|Ultralead||250°C||450°C||Excellent, durable wire, good for high-temperature application|
|Teflon||250°C||250°C||Good dielectric strength|
|Silicon Rubber||200°C||200°C||Good moisture resistance|
|Braided Silicon rubber||200°C||200°C||Inexpensive wire, good for non-abrasive applications.|
|MGT||450°C||450°C||Superior high-temperature resistance|
|SJO cord||90°C||90°C||Rubber Jacket, resistance to oil and moisture. For use on 3/8” diameter and larger.|
- Swaged in Leads
- Swaged in Leads are ideal for application where there is excessive movement or leads are required to bent sharply upon exiting the heater.
- In heaters under 3” long, leads wire goes dirently into the core whereas in heaters over 3” long, leads are connected to power pins in unheated section.
- Also remember, if the leads are required to be inserted completely into the hole, they are exposed to the block temperature ( maximum temperature for standard leads is 550°C )
- Unless otherwise specified, all heaters will be supplied with Swaged in Leads.
- Crimped on Leads
- The connection between the leads and the power pins are made outside the heater using connectors. Crimp-on leads are generally used where the temperature at the end of the heater exceeds the maximum allowable temperature of the lead wire.
- Not recommended for the applications where the leads must be bent sharply at the heater exit.
Connectors are covered by high volt silicon rubber-coated fibre glass sleeve.
3.Right angle Leads
Right angle leads are ideal for application with tight spaces. Leads are covered with a silicon impregnated fibreglass sleeve where they exit the heater.
|Molds, Metal dies, Patens, hot plates, sealing tools, fluid heating, aerospace, semiconductor industry||Stainless Steel, INCOLOY|
|Food service and medical equipment, Deionized water||Stainless Steel|
|Highly corrosive applications||Titanium|
- Cartridge heaters can also accommodate internal thermocouple which helps in controlling temperature of heater more accurately. Thermocouples can be type “J” or type type “K”, grounded or ungrounded, and can be attached at the disc end or middle of the heater.
Maximum Operating Temperatures
Maximum Watt Density