This question precisely captures the core of explosion-proof fan blade design. While conventional fan blades prioritize heat dissipation efficiency, all design differences in explosion-proof fan blades revolve around eliminating ignition sources. This can be specifically analyzed from two perspectives: material selection and structural design.

1. Material Selection: From "Low Cost and Lightweight" to "Intrinsically Safety"

The materials used in conventional fan blades merely meet basic functional requirements, while those used in explosion-proof fan blades must eliminate spark generation from the source. Three key differences exist:

Core material type: Conventional fan blades are often made of standard PP plastic, ABS resin, or mild steel, which are prone to sparking and static electricity accumulation due to friction. Explosion-proof fan blades, on the other hand, utilize copper alloys (brass, bronze), modified aluminum alloys (6061-T6), or carbon fiber composites (with conductive media). These materials do not generate sparks due to friction and can conduct static electricity.

Different material performance requirements: Ordinary fan blades only need to meet basic performance requirements such as impact resistance and room temperature resistance; explosion-proof fan blades must pass anti-static testing (surface resistance ≤ 10⁹Ω), impact resistance testing (no sparking after a 1.5J impact), and high-temperature resistance testing (long-term resistance to 120-200°C) to ensure resistance to failure under extreme operating conditions.

Different risk-avoidance designs: Ordinary fan blades lack targeted treatment, and plastics are prone to static electricity accumulation, while mild steel is prone to sparking. Explosion-proof fan blades incorporate metal powder into the composite material to enhance conductivity, or are sprayed with an anti-static ceramic coating, eliminating potential risks from the very nature of the material. II. Structural Design: From "Efficient Heat Dissipation" to "Safety Redundancy"
The structure of ordinary fan blades serves only to ensure air volume and pressure, while the structure of explosion-proof fan blades is designed to control the spread of ignition sources. There are three key differences:
Different anti-collision and friction design: Ordinary fan blades, to maximize air volume, often have sharp edges and thin edges. Explosion-proof fan blades have rounded edges (radius ≥ 3mm), a curved transition between the hub and blade, and a thickened blade root to reduce the energy of impact with foreign objects and prevent friction-induced ignition.
Different electrostatic discharge paths: Ordinary fan blades have no dedicated electrostatic discharge treatment, and plastic blades may even lack a discharge path. Explosion-proof fan blades use nickel-plated conductive bolts to connect the blades to the hub. A copper conductive gasket is placed between the hub and the motor shaft. The motor shaft is then grounded (resistance ≤ 4Ω), forming a complete electrostatic discharge loop. Different fault protection designs: Ordinary fan blades lack redundancy, and fragments are easily scattered when they break. Explosion-proof fan blades feature a flameproof casing (joint width ≥ 15mm, gap ≤ 0.1mm), preventing internal flames from escaping. They also include an overspeed protector that automatically shuts off power when the speed is abnormal, preventing further malfunctions.

Would you like me to compile a comparison table comparing the material and structural differences between ordinary and explosion-proof fan blades? This will allow you to more clearly see the specific parameters and safety objectives of each difference.