The core of fire safety design for coal grinding and conveying equipment lies in establishing a fully enclosed, anti‑static, explosion‑resistant, and monitorable passive protection and active intervention system. The following are specific design requirements based on national standards and practical experience:

Intrinsic Safety of Materials and Structures
Non-combustible materials: The equipment body, piping, and supports must be constructed from non-combustible materials; the thermal insulation layer must also be made of non-combustible or flame-retardant materials to prevent fire hazards during maintenance.
Explosion‑proof design: Pressure‑bearing components (such as separators) must be able to withstand an internal explosion pressure of 0.35 MPa without disintegrating. Dust collectors must be equipped with explosion‑proof structures and pressure relief devices to prevent secondary damage.
Electrostatic Control and Fire Source Management
Anti-static measures: Dust collector filter bags used for conveying coal powder must be made of anti-static filter media to prevent the accumulation and discharge of static electricity. The equipment body and piping must be reliably grounded to eliminate static sparks.
Electrical Explosion Protection: Motors installed in production areas where combustible dust may be present must be explosion‑proof. For example, open-type motors can be converted to positive-pressure types, maintaining an internal pressure that is at least 50 Pa higher than the ambient pressure, and ensuring that the junction box meets an IP65 protection rating to prevent dust ingress.
Temperature and Medium Control
Hot Air Valve Interlock: Design an explosion-proof interlocking device. When the temperature exceeds the safe threshold, the hot air valve will automatically shut down and the cold air valve will open to rapidly cool the system, eliminating the heat source at its source.
Emergency Cooling: A fire-water suppression system shall be installed and kept in standby at all times. If the outlet temperature abnormally exceeds the set limit (e.g., >100°C) and cannot be reduced, fire-water can be immediately introduced to cool the equipment and extinguish any resulting fire.
Operational Monitoring and Proactive Intervention
Continuous monitoring: The outlet temperature of the conveying equipment (typically ≤70°C) and the CO concentration (a hallmark product of coal dust spontaneous combustion) must be monitored in real time, as these are critical indicators for determining the onset of spontaneous combustion.
Inerting Protection: Dust collectors and coal-powder silos shall be equipped with CO₂- or N₂-based fire suppression/inerting systems. These systems shall automatically discharge the inerting agent when temperature exceeds the set limit (e.g., >80°C) or when CO concentration is abnormal.
Operation and Maintenance Management
Drain and Purge Before Parking: For extended parking periods (e.g., more than 3 days), the coal powder in the equipment and piping must be completely drained, and all inlet and outlet valves must be closed to isolate the system from air.
Dust generation is strictly prohibited: the use of compressed air to blow off surface dust from equipment is forbidden to prevent the formation of explosive dust clouds.

Technical Information on Pulverized Coal Burners and Coal Pulverizing & Conveying Systems

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