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The importance of starting the exhaust and supply fans for ventilation before igniting the heating furnace: Before initiating the ignition process of the heating furnace, it is necessary to start the exhaust fan and the supply fan to ensure ventilation for 10 to 15 minutes; this is a crucial step to safeguard the safety of the equipment and personnel. Its primary purpose is to remove or dilute any combustible gases or coal dust that may accumulate in the furnace, thereby preventing explosions at the moment of ignition. After the last shutdown, unburned combustible gases or suspended coal dust may remain in the furnace. Furthermore, if there are leaks in the fuel system, such as pipe corrosion, loose connections, or damaged valves, combustible gases or coal dust may also penetrate into the furnace during shutdown. If proper ventilation is not carried out before ignition, when a torch is inserted into the furnace, if the concentration of the gas mixture within it falls within the explosive range, a violent explosion is highly likely to occur, resulting in damage to the furnace walls and even serious injuries or deaths. To prevent such leaks, fuel pipes and fittings should be inspected regularly to ensure the tightness of valves, and high-quality sealing materials should be used. By starting the intake and exhaust fans to provide forced ventilation at 10%–15% of the rated air volume, it is not possible to eliminate all combustible materials completely, but it is sufficient to dilute the concentration of combustible substances in the furnace below their lower explosive limit, thereby effectively eliminating the risk of ignition. This range of air volume is determined based on experience and safety standards, ensuring an adequate level of ventilation without causing unnecessary energy consumption or strain on the equipment due to excessive air volume. This process enables proactive control of potential hazards, and is an essential safety prerequisite for the ignition operation.