Axial fans are one of the common types of industrial fans used today. These fans are used for applications that demand a larger flow rate at small pressure gain. Over the years, various types of axial fans or axial flow fans have gained popularity. Tube axial fans are one of them. These fans are nowadays used in a wide range of applications from drying to cooling to ventilation and air supply for any machine or industrial process. Owing to the distinct advantages gained from their typical construction, these fans have gained immense traction. This post discusses everything you may want to know about these fans.
What is Tube Axial Fan?
A tube axial fan is a type of industrial fan comprising a disk type of wheel or a propeller, which is contained within a cylindrical tube-like structure. This fan is much similar to a vane axial fan, another popular axial flow fan variant, with the only difference that it has no straightening guide vanes. The propellers or wheels are organized such that there is a small gap between the housing and blade, which helps improves the fan efficiency.
Components of Tube Axial Fan
Here is a detailed explanation of a few important components of tube axial fans:
These fans are fitted with propellers made of cast aluminum or heavy-duty steel. Sometimes propellers are also made of stainless steel. All these materials can withstand high temperatures, which makes them a suitable choice for a propeller. The propeller features a hub to which the blades are welded. These blades are welded precisely at angles ranging from 30° to 50°. Some manufacturers also provide customization choices when it comes to angles. Usually, propellers are balanced statically to ensure their smooth operation.
The housing is the structure that hosts the impeller. It also serves as the welded base of the engine, which supports the axial airflow. Among various factors, the performance of the tube fans depends on the design of the impeller and the shape of the housing.
These fans may be equipped with ball bearings or roller type bearings.
A variety of single to three-phase motors are used in these axial fans.
As the name suggests, this is a small door present on the case; it is useful for inspections, and is mainly used during maintenance operations.
Belt or Pulleys:
They play a key role in the function of belt-driven fans. The belts are usually chosen based on factors such as the desired performance of the fan or number of engine revolutions.
Direct or Belt Driven:
Generally, the tube axial fans are belt driven or directly connected to the motor. When belt driven, the propeller is positioned on a separate fan shaft and connected to the motor, which runs it through sheaves and belts. If motor driven, you will see the impeller placed on the shaft of the motor. Axial flow fans of this type are ideal for applications that demand large air flow at low pressures.
Many manufacturers offer these fans in all steel or aluminum construction.
Types of Tube Axial Fans
As said before, there are two types of tube axial fans – direct drive tube axial fan and belt driven tube axial fan.
Direct Drive Tube Axial Fans:
Direct drive tube axial fans are ideal for applications where efficiency and quietness are required. These fans are equipped with precision designed and accurately balanced aluminum, spark propellers, which can easily move air laden with pigments and condensable fumes. Direct drive tube axial fans are used for heat control process, smoke or heat removal, general ventilation as well as process ventilation purposes. The tube axial fans of this type require less maintenance than belt driven ones.
Belt Driven Tube Axial Fans:
As the name suggests, these industrial tube axial fans feature belt drive, which ventilates the propeller from outside the fan. These fans are regularly used for general and industrial ventilation applications where they are used to remove contaminated air streams or moisture-laden air streams.
Performance Characteristics of Tube Axial Fans
Tube axial fans have typical performance characteristics due to their propellers and fan designs.
- The fans exhibit high airflow efficiency up to 65%.
- Owing to their durable construction, these fans can withstand 4" water pressure gauge.
- Generally made of durable materials, these fans can easily withstand up to 600 degrees Fahrenheit.
Advantages of Using Tube Axial Fans
Tube fans are preferred over the other axial flow fans owing to the following advantages that they offer:
- These industrial fans are often made of materials that can withstand abrasion, high temperatures, corrosion, explosive vapors, and so on.
- Most tube axial fans have spark resistant construction.
- Their strong construction allows them process high horsepower and speeds compared to centrifugal fans and regular panel fans.
- Tube axial fans are known for their better pressure characteristics than regular panel fans.
- They are designed for ducted applications, so are also known as duct fans.
- Belt driven tube axial fans or direct drive tube axial fans offer the flexibility of positioning.
- You can easily alter their pressure and airflow characteristics by taking advantage of positioning flexibility. Parallel positioning enables better airflow and series positioning helps optimize their pressure characteristics.
- Using propellers with large hub-to-tip ratio help alter its speed to pressure characteristics. For instance, using the fan with a large hub-to-tip ration can be made to work at a particular speed against a specific pressure. Also, it can be made to work at low speed against a specific pressure.
Applications of Tube Axial Fans
Tube axial fans are used across industries and the following are a few common ones:
- Air makeup
- Paint spray booth exhaust
- Fume exhaust
- Cooling electric equipment or sensitive components
- Engine room, process, and general ventilation
- Steam exhaust
- Glass drying and glass tempering
- Drying parts
- Drying grains
- Sucking air from contaminated air streams
- Marine services
Like any other industrial cooling fans, it is important to source these tube axial fans from trusted manufacturers. Owing to their widespread use, these fans are sold by several brands and Sofasco stands tall among them. The company is one of the leading manufacturers of a variety of industrial fans in the US. They provide the fans in custom configurations to suit your application requirements.