Duct electric heaters are explosion-proof electric heaters that can be used in hazardous locations where explosions may occur. The explosion-proof grade can reach dⅡB and C levels, and the pressure resistance can reach 20MPa.
Duct electric heaters have fast thermal response, high temperature control accuracy, and high overall thermal efficiency. The working temperature is high, the medium outlet temperature is uniform, the application range is wide, and the adaptability is strong. Duct electric heaters are made of special electric heating materials, designed with low surface power load, and adopt multiple protections, greatly increasing the safety and service life of the electric heater.
Explosion-proof electric heaters are generally used in hazardous locations where explosions may occur. Due to the presence of flammable and explosive oils, gases, dust, etc. in the surrounding environment, contact with electric sparks can cause explosions. Therefore, explosion-proof electric heaters are required for heating in such occasions. The internal control system of the electric heater automatically adjusts the output power of the electric heater based on the temperature sensor signal at the outlet, making the medium temperature at the outlet uniform.
If the heated material overheats, causing coking, deterioration, or carbonization, it can severely damage the heating element, effectively extending the service life of the electric heater. The main explosion-proof measure of explosion-proof electric heaters is an explosion-proof device installed in the junction box of the heater, eliminating the risk of electric spark ignition.
The resistance wire of duct electric heaters is made of nickel-chromium alloy, with temperatures reaching over 800°C. Since the power of electric heaters is relatively large, if users neglect safety, a fire can occur at any time.
What are the causes of fires in electric heaters? How can we prevent fire hazards?
The main causes of fire are as follows:
1. The electric heater is not equipped with a plug, and the wire end is directly inserted into the socket, which can easily cause a short circuit and lead to a fire.
2. Placing an energized electric heater on combustible materials or near flammable materials can cause a fire under prolonged high-temperature baking.
3. The user of the electric heater fails to unplug the heater when leaving, causing the heater to overheat over time and ignite nearby combustibles, resulting in a fire.
4. Repeatedly repairing and continuing to use the resistance wire can cause circuit overload and lead to a fire.
Measures to prevent fire hazards:
(1) When in use, do not place flammable or explosive items near the electric heater; maintain a certain safe distance.
(2) The safe current-carrying capacity of the electric heater's wires must meet the capacity requirements of the heater. Industrial electric heaters must be equipped with a separate circuit in all cases.
(3) The wires must be equipped with a plug; do not directly insert the wire end of the electric heater into the socket. The electric heater must be placed on a non-conductive, non-combustible material base.
(4) Duct electric heaters must be attended during use. Unplug the heater when leaving. In case of a power outage during use, promptly unplug the electric heater to avoid forgetting.
(5) For resistance wires that have been repaired multiple times, it is no longer recommended to use them; replace with new resistance wires.
(6) If the wires of the electric heater are aged or damaged, replace them promptly. Electric heaters without a fuse installed in the circuit must not be used.
(7) Flammable and explosive items are strictly prohibited from being dried using electric heaters.
(8) Electric ovens should have a temperature control device to prevent both excessive temperature and prolonged heating time.
(9) Although duct electric heaters have multiple protection devices, check all wiring terminals before use to ensure they are secure. Implement grounding measures to ensure safety.
(10) A filter screen should be installed at the air inlet, and the filter screen should be cleaned regularly to prevent various foreign objects from entering and damaging the heating tube or affecting its service life and heat dissipation performance.
