Duct heaters are heat transferring devices which are an assembly of heating elements mounted in a frame or duct. Preferably used for non-pressurized air-heating systems, there are three types of duct heaters available: open coil, tubular or finned tubular heating elements that are either flanged or inserted in the duct. The individual elements are removable through the housing of the assembly, which eliminates the need to pull the complete heater from the ductwork. This reduces downtime costs because the heating elements can be replaced individually. Being the most easily adaptable heating solution, they are easily installed in applications requiring a wide range of temperature versus air flow combinations and offer greater reliability, energy efficiency, quicker response time and reduced infiltration from the air steam. Duct heaters can be equipped with a temperature control system and wired in various power configurations.
Terminal Enclosures :
In addition to the standard, general purpose terminal enclosure, the following optional terminal enclosures are available to meet specific application requirements:
High-temperature stand-off enclosures
Type J or K thermocouples, inserted in the thermowell, accurately sense element sheath temperature for overtemperature conditions. Using a thermocouple requires an appropriate temperature and power controller.
Field replaceable heating elements
Permits easy service and reduces downtime. Element change out is made simple by a single screw clamp. Prevents element sagging or deformation in various
Favorable Features :
Provide great mechanical strength
Not prone to moisture and dust
Quite easy to mount
Durable and easy maintenance
Rugged construction eliminates hazard of electricshock
Reinforced frame allows for minimum vibration and elevated temperatures
Typically used for outdoor applications or in environments that are too harsh for open coil elements
Heating of platens and molds
Load Banks – Resistive
Tubular duct heaters offer a number of options
Digital controls, Contactors, Relays, SCRs available for the most accurate temperature readings
Disconnecting switches, airflow switches to help control unexpected pressure drops
Fuse blocks and optional fuses available for low resistance and cool operations.
Manual reset limit thermal cutout is used to prevent excessive temperatures with this the terminal housing