Main ventilation fan impeller section
1) Personalized Design: Optimize the selection and perform personalized design based on parameters provided by the user. The fan’s performance is matched to the mine’s resistance characteristics, ensuring that the fan operates with high efficiency both at minimum and maximum negative pressures and stays well away from the surge region.

2) Design and Inspection Procedures: The blades were designed based on low-speed blade test data from the U.S. NACA. To ensure blade strength, a structural design concept featuring a three-dimensional twisted airfoil with a large cross-section was adopted. Both the blade and the blade hub have safety factors exceeding 10 to 13 times the expected loads. To verify the rationality of the blade design, vibration frequency tests and modal analyses will be conducted to ensure that the blade’s natural frequencies are sufficiently away from the excitation frequencies of the first- and second-stage impellers, thereby avoiding resonance. For each batch of blades, we provide material inspection reports and mechanical performance test reports. Additionally, every blade undergoes non-destructive testing—including X-ray inspection and magnetic particle inspection—in a dedicated flaw detection room.
3) The blade material is made of high-strength, premium-grade ZL104 alloy and is produced via die-casting with metal molds, ensuring superior blade strength and surface quality. It exhibits excellent corrosion resistance and wear resistance in oxidizing environments, remaining rust-free, wear-resistant, and corrosion-resistant. The critical cross-sections of both the blades and their stems are designed with a safety factor exceeding 13 times the expected load, and the blades undergo age-hardening treatment.

4) Blade Installation and Adjustment: The blades are securely and reliably fixed to the hub. The hub is engraved with clear markings indicating blade installation angles—-9°, -6°, -3°, 0°, +3°, and +6°—allowing the blade angle to be adjusted freely on the spherical hub surface according to operational requirements. The blade adjustment method involves stopping the machine and performing individual blade adjustments externally using specialized tools. By loosening the wedge-shaped pressure blocks via dedicated adjusting bolts, the blade angles can be adjusted remotely, thereby meeting varying air supply demands at different stages.
5) Hub Manufacturing: The hub is one of the core components of a wind turbine. This part features a large diameter and significant weight, with stringent requirements for dimensional accuracy and geometric tolerances. It represents a major challenge in the machining process and is a critical step in wind turbine assembly. The hub is made from Q355 steel, and its weld seams are inspected using magnetic particle testing; a magnetic particle inspection report is provided. To ensure the coaxiality between the spindle connection hole and the outer diameter of the hub, as well as the spherical dimensions of the hub face and the dimensional accuracy of the holes, our company specifically employs a large-scale CNC falling-axis lathe. During hub machining, a single clamping operation controlled by a computer program enables one-step forming. This approach not only guarantees the dimensional and geometric accuracy of the workpiece but also ensures that the surface quality fully meets the requirements specified in the product drawings. The motor shaft extension is designed with a tapered structure, allowing direct connection between the motor and the impeller and achieving precise alignment through a tapered fit, thereby optimizing the convenience of impeller installation, removal, and maintenance. The impeller is secured onto the motor shaft using a dual-locking mechanism consisting of two nuts paired with double stop washers.

6) Impeller Balancing: Our company has purchased an YYW-6000 dynamic balancing machine. First, the hub undergoes both dynamic and static balance tests; then, the impeller itself is subjected to dynamic and static balance testing until it meets the required standards, ensuring that the impeller’s balance quality grade reaches G4—exceeding the national standard requirement of G5.6. This guarantees excellent static and dynamic characteristics of the fan, ensuring reliable operation and compliance with relevant national and industry standards, including JB/T8689-2014 “Vibration Testing and Limits for Fans,” which stipulates a maximum root-mean-square (RMS) vibration velocity of ≤4.6 mm/s.