Industrial fan impellers

Types of industrial fan impellers

Industrial fan impellers are the moving parts inside a fan that accelerate air from the inlet of the fan to the outlet.

• Centrifugal fan impeller

  Centrifugal fan impellers give direction to the airflow by using centrifugal force. Common types of centrifugal impeller fans include closed impeller, volute (scroll) casing, open impeller, rear shroud, and semi-open impeller.

  During the revolution of the impeller, the air enters the impeller center from the inlet. Then, the air is pushed out to the periphery due to the centrifugal force. Finally, the direction of the air is changed through the volute (scroll) casing which results in an increase in pressure. The outer wall of closed impeller blades encapsulates the blades. This type of impeller mainly encloses the liquid between the blades and is applicable to situations with high pressure and low turbulence. Open impellers lack outer casing and are more prone to clogging less, which makes them more applicable to liquids with a tendency to aggregate. Open impellers are also easier to maintain. As for semi-open impellers, they are more applicable to situations with aggregates and liquids that are hard to maintain. Closed impellers use rear shrouds that cover the back of the blades. The shroud provides support for the blades and improves efficiency by reducing vortex leakage.

• Axial fan impeller

  Axial fan impellers accelerate the flow of air or liquid perpendicular to the rotation axis. Usually, an axial fan consists of a rotor, stator, and housing. The rotor is the core component of the fan, which is responsible for air compression. The housing of an axial fan is a cylinder that encloses the impeller and provides a pathway for compressed air. The stator straightens the turbulent air and increases the efficiency of the fan. An axial flow fan offers a lot of air compression by utilizing relatively little power. Meanwhile space is also saved greatly.

Specifications and maintenance of industrial fan impellers

Specifications for an industrial fan impeller will vary depending on the specific type, make, and model. However, some typical specifications that may be available for the impeller include the following:

• Diameter: The overall width of the impeller from one outer edge to the other. This size could come in small diameters of 100-300 mm or larger diameters of 400-700 mm.
• Materials: Industrial fan impellers are often made from materials such as plastic, aluminum, stainless steel, carbon steel, etc. The material chosen will affect the durability, noise, airflow, etc.
• Design: The design will include the number of blades, angle, width, etc. For example, a backward-inclined blade design with less width will provide better energy efficiency for heavy-duty fans as opposed to forward-curved blades that are more suitable for high-pressure applications.
• Airflow: The volume of air the impeller pushes or pulls through the fan.
• Speed: The rotational speed is usually measured in revolutions per minute (RPM).
• Static Pressure: This is the pressure generated by the impeller when air moves through a system. It is usually expressed in inches of water column (in WC).
• Noise Level: This is expressed in decibels (dB).

Maintenance:

In general, industrial fan impellers need to be maintained rather than replaced, as they are usually an integral part of the equipment. Regular inspection of the fan will help catch minor issues before they turn into major problems.

• Regular inspection: This will include a visual inspection of the impeller's condition. Users should look out for signs of damage, excessive wear, or imbalance.
• Clean regularly: Fans need to be cleaned regularly to remove dust and debris that settle on the impeller blades. This, too, will promote efficient airflow.
• Lubricate: If the industrial fan has moving parts, those parts will need to be regularly lubricated with the appropriate lubricant to maintain efficient performance.
• Watch for unusual noises: If the impeller becomes noisy, this could be an early sign of wear or damage. Investigate the noise and determine the cause before it becomes a major problem that requires replacement.

Applications of industrial fan impellers

Industrial blower impellers have many applications in various industries due to their ability to move air, gases, and other materials efficiently. Below are a few main application areas where industrial fan impellers are used.

Impellers are used in cooling towers to circulate air for the cooling process. The circulation of air ensures that heat transfers effectively. Because there are different types of cooling towers, fan impeller manufacturers produce different designs of cooling tower impellers. The choice of impeller design depends on the specifications of the cooling tower.

In waste treatment facilities, air circulation is important to keep waste flowing. This prevents clogging and the buildup of waste material. The constant flow of waste helps to accelerate the breakdown of waste material, particularly organic waste. Industrial fan impellers are used in water treatment facilities to filter, purify, and treat water to make it fit for consumption.

Industrial fan impellers are commonly used in HVAC systems to move air around buildings. They are used in ducts to push conditioned air into rooms. The blowers are also used to extract waste air from rooms. The exchange of air ensures that the right number of air exchanges is achieved within a building. Users can enjoy indoor air that is fresh and free of contaminants.

Impeller fans are commonly used in industrial dust collection systems. The fans suck in dust-laden air from the process generating the dust. Following the air filtration process, clean air is released back into the system or the environment through the exhauster fitted with an impeller.

Impellers drive centrifugal compressors, which are commonly used to compress refrigerant gases in the refrigeration industry. Refrigerant gases have to be compressed to ensure the proper functioning of refrigeration and cooling equipment.

Industrial impeller fans are used in power generation facilities to facilitate air exchange and cooling. Power plants require a constant flow of air to ensure processes are done efficiently. The plants also need to be well-ventilated to prevent overheating of equipment and machines.

How to choose industrial fan impellers

Let the following parameters help when choosing industrial fan impellers:

• Application requirements:

  Determine the application requirements, check the working environment, the nature of the transmitted media, and the specific purpose. Select the suitable type and material of the impeller based on the application needs.

• Compatibility with the fan:

  Ensure that the chosen industrial fan impeller is compatible with the fan used. Check the mounting dimensions, speed regulation range, etc., to ensure a proper fit and working together.

• Performance parameters:

  Choose an industrial fan impeller with suitable performance parameters, such as air volume, wind pressure, speed, etc. These parameters should meet the requirements of the application to ensure the intended effects.

• Noise control:

  If noise control is a concern, select industrial fan impellers with design features for noise reduction, such as impellers with a slipstream design or those allowing for lower rotational speeds. Additionally, consider using sound-absorbing materials or dampers to reduce noise transmission.

• Installation and maintenance:

  Consider the ease of installation and maintenance of the chosen industrial fan impeller. Select impellers that offer good maintenance accessibility and installation convenience, which will facilitate subsequent equipment maintenance and repair.

• Cost considerations:

  Comprehensively consider cost factors such as the initial purchase cost, operating expenses, and maintenance costs. Choose an industrial fan impeller that offers a good balance between performance and cost based on budget constraints and needs.

Industrial fan impeller Q&A

Q1: What are industrial fan impellers made of?

A1: The material used for an impeller will depend upon the specific application of the fan as well as where in the machine the impeller is located. Generally speaking, if an impeller is being used in an environment where there is high humidity or possible corrosion, the material will likely be something like stainless steel. Plastic impellers are sometimes used in smaller fans to reduce noise levels.

Q2: Are all industrial fan impellers the same size?

A2: No, impellers come in different sizes and are often made to order to suit the specific application of a fan within an industry.

Q3: Do industrial fan impellers make noise?

A3: Some noise is to be expected, but if the noise is really loud, it could be a sign that the impeller is damaged or has debris lodged in it.

Q4: What are some signs of damaged industrial impeller fans?

A4: Some signs could include a change in air pressure, unusual noises, excessive power consumption, or even visible damage if the fan is inspected closely with proper equipment.