Fans with metal impeller

Types of Metal Impeller Fans

Fans with metal impellers are preferred over other types for a variety of reasons. These fans come in a variety of shapes and sizes.

• Centrifugal Metal Impeller Fan:

This fan creates static pressure and propels air in a radial direction. It is one of the most common types of fans with metal impellers. The exact design may differ from one model to the other, but generally, it consists of a housing, rotor, and outlet. The housing surrounds the rotor and also contains the air passage. The air comes out from the outlet. The support system in a centrifugal impeller is called the snail or trumpet. Its housing consists of a spiral-shaped section that gradually widens as the air exits the housing. The design and shape of the housing affects the airflow and pressure.

• Axial Metal Impeller Fan:

  An axial metal impeller fan is quite similar to a centrifugal metal impeller fan. The main difference lies in the direction of the airflow. While a centrifugal fan pushes air in a radial direction, an axial fan propels air parallel to the axis of the rotor. This fan consists of a rotor and a stator. The stator surrounds the rotor and contains coils of wire connected to an electric motor. An axial fan does not create pressure but moves air efficiently.

• Belt Driven Metal Impeller Fan:

  A belt-driven metal impeller fan transmits power through a belt and pulley system. One of the pulleys is fixed to the motor, and the other is attached to the fan. The fan can be installed easily in a system where it will be used at a fixed location. It cannot be used in an application where adjustability is needed.

• Direct Drive Metal Impeller Fan:

  A direct-driven fan is attached directly to the motor shaft. This results in a lightweight assembly with less operational noise. The drawback is that this type of fan will have a limited capacity for pressure generation.

Specification and maintenance of fans with metal impeller

Specifications

• Material: The impeller is mainly made of metal materials such as cast iron, stainless steel, aluminum alloy, and other materials, which can bear heavy loads and high-pressure environments.
• Diameter: Its diameter ranges from small to large according to the application fields. A bigger diameter usually results in a higher airflow volume.
• Blade Design: Metal impeller fans have more blades, ie. blade pitch, which may affect their overall efficiency. The efficiency of the fans with metal impellers increases with the increase of blade pitch until they reach the saturation point.
• Hub Size: The size of the hub is often changed to improve fluid dispersion, variable transmission ratios and noise reduction.
• Shrouded or Unshrouded: Shrouded impellers contain a shroud around the blades that wraps around the tip gap of the blades. This configuration improves performance and efficiency by reducing tip vortices. Unshrouded impellers lack the shroud and are usually used in applications that do not require high performance.
• Speed: The working speed of impeller fans with metals is expressed in RPM (Revolutions Per Minute). Factors such as the application field, required airflow, and pressure can determine it.
• Airflow Volume: Airflow volume fans with metal impellers produce is usually represented in Cubic Feet Per Minute (CFM). The value is determined according to the fan speed, blade design, diameter, and pressure. Higher airflow volumes can be produced by higher RPM, larger diameters, and blades.
• Pressure: Pressure is the driving force that fans with metal impellers produce air. Metal impeller fans usually have high pressures, which allows them to overcome resistance and move a large volume of air in high-pressure environments.

Maintenance

• Surface cleaning: Use a clean wet cloth to wipe the surfaces of metal impeller fans, and keep them clean. Avoid using abrasive products to prevent damage to their surfaces.
• Regular inspection: Check the fans with metal impellers regularly to ensure that they work well. Check whether the blades are damaged, deformed, or have foreign bodies, and ensure that the bearings and motors are working well, too.
• Lubrication: Lubrication is vital to ensuring the normal operation of metal impeller fan bearings. Users can add lubricating oils or grease specified for bearings according to instructions. Make sure to clean the dirt on the bearings before lubricating them.
• Prevent rust: Metal impellers are usually easily rusted. To avoid this, users can regularly apply anti-rust oil or anti-rust coating to the impeller's surfaces. Besides, users must avoid long-term exposure to humid environments.
• Pay attention to the operating environment: Users must avoid placing fans with metal impellers in high temperatures, high humidity and other harsh environments. If they have to, they should adopt appropriate protection measures, for example, installing ventilators to ensure good heat dissipation and ventilation effects.

Scenarios

Below are some scenarios in which industrial impeller fans may be used in industries.

• Factory ventilation:

  The metal impeller fan serves a major purpose in factories by providing ventilation. This is very important in industries such as welding, foundry, and chemical factories, where a large number of fumes are generated. The fans with metal impellers are usually mounted on the ceiling or upper part of the walls. They are used for the dilution of welding fumes and removal of chemical fumes from the ventilation channels. As a result, there is a constant supply of fresh air to the workers, which promotes their health and productivity.

• Material handling:

  In industries such as the cement, coal, and grain processing ones, there are bulk solid materials that need to be transported. Metal impeller fans are applied in those industries to pneumatically convey those materials. With the help of the fans, the bulk solid materials are swiftly moved through the pipelines. As a result, efficiency is improved, and the process becomes seamless.

• Combustion air supply:

  In industries with combustion processes, such as power generation and petrochemical ones, the propeller metal fans help to ensure that there is adequate air supply for the burning process. This is important because the efficiency of the equipment is boosted, and emission control is enhanced.

• Cooling and freezing:\strong>

  In the metallurgical industry and refrigeration ones, impeller fans can be used to provide cooling or freezing for equipment. Also, the fans can be used for product cooling. The fans do this by facilitating heat exchange. For example, in a refrigeration machine, the passing of refrigerant through the fins of the fan makes the air to be cooled. In the same vein, if there is a hot product in the industry, cooling it with the fan will promote rapid cooling.