Defect Analysis of Industrial Large Ceiling Fan Blades

The blade structure of industrial ceiling fans varies greatly and is often affected by random factors such as the manufacturing process, welding process, and fastening process. Defects are commonly found in the interior of the blades and at the leading and trailing edges, with common types including inclusions, pores, cracks, and delamination. These defects can be a single type or several types of defects coexisting due to the presence of hidden defects during use.

Inclusions are non-structural materials introduced during the production process of the blades, often caused by subjective factors such as foreign objects accidentally falling into the raw materials during formation.

Pores refer to holes formed during the molding process of the blades, caused by factors such as the introduction of bubbles during the infusion process or incomplete removal of bubbles during the shaping process, as well as the presence of bubbles in the aluminum alloy raw materials themselves.

Cracks in the blades mainly occur in welding and bolt fastening areas and are caused by external impacts and fatigue effects after the blades have been operating for a certain period of time.

Delamination is a phenomenon that occurs due to various interfering factors in the complex aluminum alloy plate structure of the blade, mainly referring to the delamination between the double-layered boards. Reasons for delamination may include inadequate spot welding, substandard bending processes, and secondary shaping.

As for blade aging, there are several types, such as humid heat aging, chemical medium aging, physical abrasion aging, and salt spray corrosion aging. Humid heat aging includes matrix aging, fiber aging, and interface aging, caused by long-term exposure to air in harsh working environments. Physical abrasion aging comes from solid particles such as salt and sand in the air, which can cause varying degrees of wear and even form pits that can penetrate the blade over time. Salt spray corrosion aging refers to the formation of a covering layer on the surface of the blade due to the electrostatic effect of the blade with other particles in the air in a salt spray environment, seriously affecting the performance of the blades and causing noise pollution and aesthetic issues.

The blade is the power and air delivery component of the industrial ceiling fan, and its condition directly affects the effectiveness of the fan. Understanding the common defects of blades and regularly monitoring and repairing minor defects and potential hazards is an effective way to eliminate blade damage accidents at the initial stage, reduce incidents, improve safety systems, and stabilize the wind power industry.