Structural characteristics and features of duct heaters

Duct heaters are primarily used to heat air in ducts. They come in three different construction types: low-temperature, medium-temperature, and high-temperature. All three types share a common feature: a steel plate supporting the heating element, which reduces vibration when the fan is stopped. All are equipped with an over-temperature control device in the junction box. The low-temperature model can be installed directly in the duct. Due to the structural differences between the medium-temperature and high-temperature models, a 100mm-thick insulation material is sandwiched between the duct wall and the heater junction box. This reduces heat dissipation throughout the duct and lowers the temperature within the wiring compartment.

Duct heaters are primarily used to heat the airflow from its initial temperature to the desired air temperature, reaching up to 850°C. They are particularly suitable for testing automatic temperature control and high-flow, high-temperature combination systems and accessories. The duct heater consists of a main unit and a control system. The heating element is constructed from stainless steel tubing, high-temperature-resistant alloy wire, and crystallized magnesium oxide powder, formed through a compression process. The control system utilizes advanced digital circuitry, integrated circuit triggers, high-back-voltage thyristors, and other components for adjustable temperature measurement and constant temperature, ensuring the heater's proper operation. Duct heater structure and features:

The duct heater utilizes a modular connection system;
It utilizes a stainless steel heating tube as the heating element;
It utilizes a carbon steel or stainless steel bracket.

The duct heater features dual protection for superior safety. A thermostat and fuse are also included to control duct air temperature, ensuring operation in both overheated and windless conditions, ensuring a foolproof operation. The design is also highly rational, with minimal air resistance and uniform heating, eliminating hot and cold spots. The use of an externally wound corrugated stainless steel belt increases the heat dissipation area and significantly improves heat exchange efficiency.