During inspections in chemical workshops, delayed temperature rise and temperature fluctuations beyond the process window of thermal oil furnaces are often related to surface coking or degraded insulation performance of explosion-proof electric heaters. After coking on the heating tube surface, heat transfer efficiency decreases, and the oil temperature response becomes slower; degraded insulation performance may cause leakage or short-circuit risks, affecting continuous production.
Long-term high-temperature operation of thermal oil produces carbon deposits, which adhere to the heating tube surface and form a heat-insulating layer. At the same time, under alternating hot and cold conditions, the insulation material of the electric heating element may age, resulting in reduced insulation resistance. In addition, insufficient design pressure or seal failure of the explosion-proof structure can also aggravate operational hazards. In response to these phenomena, the FBD-480 explosion-proof electric heater has been specifically addressed in its structural design.
The FBD-480 explosion-proof electric heater has a design pressure of 1.6MPa and an explosion-proof grade of dⅡCT4, making it suitable for chemical sites where flammable and explosive gases exist. The heating tubes are directly inserted into the liquid medium, reducing intermediate heat transfer links. Electrical interfaces are distinguished by voltage: 220V uses M20×1.5 steel conduit wiring, and 380V uses M24×1.5 steel conduit wiring, facilitating on-site wiring and sealing. The tube body material balances thermal conductivity and corrosion resistance, reducing the tendency to coke.
Regularly test insulation resistance, clean the coking layer on the heating tube surface, and inspect the condition of explosion-proof seals. If process temperature fluctuations continue to exceed the allowable range, it is recommended to shut down and troubleshoot the compatibility between the heater and the control system.
