Although quality and safety management are conducted during the production and factory of large industrial ceiling fans, malfunctions can still occur due to improper operation and insufficient maintenance. The following are common malfunctions and corresponding countermeasures.
Wear Wear is a basic type of component failure. (1) Abrasive wear: the surface material of the equipment is lost due to friction with hard particles or protrusions (including hard metals). (2) Fatigue wear: the material surface loses substance due to alternating contact pressure stress between two contact surfaces.
Corrosion refers to the phenomenon that the metal structure of an industrial ceiling fan is damaged due to the effect of surrounding substances. This kind of damage is the result of chemical and electrochemical reactions occurring on metal parts under certain specific environments. (1) Electrochemical corrosion: impure metal components react with environmental gases or vapors. More active metals lose electrons and are oxidized, which is called electrochemical corrosion. The corrosion of steel in humid air is the most conspicuous example of electrochemical corrosion. (2) Chemical corrosion: metal components directly react with contact substances and undergo an oxidation process. For example, chlorine gas in a chemical plant reacts with iron components to produce ferrous chloride.
Fracture Fracture mainly refers to the fracture of the blades of large industrial ceiling fans. It is a failure phenomenon where the continuity of the material itself is destroyed under external factors such as mechanical force, temperature, and corrosion and partial cracking or separation occurs. There are three forms of fractures: (1) Plastic fracture: the blade has shown a certain degree of plastic deformation before fracture. If the stress further increases and exceeds the yield strength of the material, this type of fracture will occur. (2) Brittle fracture: the blade shows no obvious plastic deformation before fracture. This rapid fracture, which occurs suddenly, is called a brittle fracture and is a very dangerous form of fracture damage. (3) Fatigue fracture: the fracture phenomenon caused by a certain number of cyclic loads or alternating stress on the blade is called a fatigue fracture.
Fault countermeasures Wear countermeasures: (1) Reasonable selection of friction pairs. (2) Provide sufficient and clean lubricants for industrial ceiling fans to reduce friction and wear of mechanical equipment. (3) The structure of the ceiling fan should minimize the surface contact force and enlarge the contact area to reduce surface stress concentration. Corrosion countermeasures: (1) Cathodic protection. This method mainly applies cathodic DC to the metal surface of the protected ceiling fan structure to eliminate or reduce the corrosion cell effect on the metal surface. (2) Anodic protection. This method mainly applies anodic DC to the metal surface of the protected ceiling fan structure to form a passivation film on the metal surface, thereby increasing the resistance to corrosion. In addition, a more active metal can be riveted to the part to form a corrosion cell. The part is the negative electrode and will not corrode. This method based on the electrochemical principle is commonly known as the sacrificial anode method. (3) Adding corrosion inhibitors. When producing industrial ceiling fans, substances that can reduce corrosion rate, namely corrosion inhibitors, can be added in small amounts to corrosive media. According to their chemical properties, corrosion inhibitors can be divided into two types: inorganic and organic compounds. Inorganic compounds like potassium permanganate, sodium nitrate, and sodium sulfite can form a protective layer on the metal surface to separate the metal from the medium. Organic compounds like amine salts, gelatin, animal glue, and alkaloids can adsorb on the metal surface to inhibit both dissolution and reduction reactions of the metal, thereby reducing metal corrosion. (4) Changing environmental conditions. That is, removing the corrosion medium in the environment to reduce its corrosion effect. For example, using ventilation, dehumidification, and removal of sulfur dioxide gas. For commonly used metal materials, controlling the relative humidity below the critical humidity (50%-70%) can significantly slow down atmospheric corrosion. Fracture countermeasures: (1) Optimize the design of the fan blade shape and structure and choose suitable fan blade materials. In the fan blade structure design, stress concentration areas should be reduced. The impact of the working environment such as medium, temperature, and load characteristics of the fan blade should be considered comprehensively to select suitable part materials to reduce fatigue fracture. (2) Reasonably select fan blade processing methods. When processing fan blades, process methods that can generate residual compressive stress such as carburizing, nitriding, shot peening, and surface rolling should be used as much as possible. By inducing residual stress on the part surface, a portion of the tensile stress caused by external loads can be canceled out. (3) Installation aspect: a. Install correctly to prevent additional stress and vibration. During installation, prevent the fan blade from being bumped or stretched because every scratch can become a source of fracture. b. Protect the operating environment of the equipment and prevent corrosion media from corroding the fan blade and excessive temperature differences between various parts of the fan blade. In summary, the common faults of large industrial ceiling fans are wear, corrosion, and fracture. Although faults are inevitable, they can be detected and solved early by taking corresponding measures. It is hoped that large industrial ceiling fan manufacturers will fully consider the potential failure points during production, and customers should follow the operating instructions to operate, maintain, and service properly to reduce faults.