A fan is a primary mechanical unit in the industrial ventilation system. It creates a flow of air and directs the air supply or exhaust from the building. The industrial fan consists of a rotating arrangement of blades and hub which is known as impeller or runner. The rotating assembly is to be powered and rotated by the motor to create airflow. Most of the fan is powered by the electric motor, but other power sources such as hydraulic motor, internal combustion engine, or handcranks can be used to power the fan system. Industrial fan systems also provide other solutions to us such as cooling and exhausting heat for material handling or dust collection. Many types of industrial fans are available in unique designs and made for different applications across a wide range of industries. To determine which type of fan should be installed for your application, we need to know the amount of air required, its efficiency, pressure level, operation temperature, and the drive arrangement. A wrong fan system installed will result in higher costs and lower overall functionality. Generally, there are two types of industrial fans which are the axial fan and centrifugal fan. Each type has its own functionality, design, and direction of airflow.
Axial Fan
The axial fan is also called an ‘in-line’ fan that creates the flow of air in a linear direction which means that it extracts air and then forced it in a parallel direction to the shaft and then rotates the blades. In this case, the direction of the airflow will not be altered. An axial fan consists of a propeller that rotates in the round section of the duct, it also equipped with guided vanes to remove the air twist and direct the airflow in a linear direction. The axial fan can create a large volume and low-pressure airflow. It is suitable for general applications such as moving the air from one space to another, cooling a large space like an office, or cooling a confined space like a computer. It is best for use in automotive products, compact electronics, medical appliances, or devices as well.
There are various sizes and dimensions of axial fans available for different operating environments and installation places. The shape of the blade is also designed in multiple shapes to fit multiple requirements. For instance, the aerofoil blade shape is highly efficient, low noise, and considered the most effective standard fan design. Other blade shapes such as paddle, or variable pitch are available.
There are three types of axial fans: Propeller fans, Tubeaxial fans/duct fans, and Vaneaxial fans.
- Propeller Fan is normally used in an indoor ventilation system as an exhaust fan, it runs at a lower speed with moderate temperature.
- Tubeaxial Fan has a fan wheel inside the cylindrical housing to improve the efficiency of airflow. The wheel makes it run faster and able to operate under high pressure of up to 400mm WC.
- Vaneaxial Fan is similar to the tubeaxial fan but it has guide vanes that direct and straighten the flow of air. As a result, it has a higher static pressure and capable to handle higher pressure. Vaneaxial fan is considered as the most energy-efficient fan that can be used for general ventilation, heat/smoke removal, process drying/cooling, etc.
Centrifugal Fan
A centrifugal fan creates the airflow in a radial direction. The air enters the impeller in an axial direction, but the centrifugal force changes the air direction by 90 degrees to spin the air outward radially. It can provide a strong & stable airflow than the axial fan and able to operate effectively in an extreme temperature and high-pressure environment. We can easily find that centrifugal fan is widely used in process plants like steel, cement, chemical or where the air movement is critical, or used for a larger system such as air handling unit, dust collection, boiler application, air re-circulation, ventilation, drying, cooling system, material handling, etc. And depending on the pressure, volume flow rate, or other operating conditions, it can be customized to provide solutions for extremely high or low temperature, corrosive elements, acidic fumes, abrasive material, etc. The required airflow rate can also be reached by combining multiple fan systems in a parallel arrangement.
We classify the types of centrifugal fans by their configuration of the blade. They are backward curved, forward curved, airfoil, etc. The main difference between the backward curved fan and forward curved fan is the direction that the air exits. The air exits in a radial direction from a backward curved centrifugal fan, whereas the air exits in a tangential direction from a forward curved centrifugal fan.
Forward Curved Centrifugal Fan is designed in a cylindrical shape and has many small/shallow blades that facing the rotating direction. It can generate the same pressure as per backward curved impeller at a lower speed for any given flow rate, the forward curved impeller is therefore produced less noise than backward curved blades. However, it provides lower efficiency, more vibrates, and not as strong structurally when compare with the backward curved centrifugal fan. Forward curved is suitable for application that requires constant pressure delivery and airflow. It is widely used in refrigeration, warm air heater, domestic boilers, and many more. Additionally, medical industries also prefer to use this type of centrifugal fan as the chemicals or debris are less likely to accumulate on the blades.
Backward Curved Centrifugal Fan has a less number of longer blades and it is facing away from the rotating direction. Backward curved blades have high air overload capability and able to save up to 20% energy. It is stronger, more energy-efficient, and heavier than the forward curved centrifugal fan. It can be used for somewhere requires high efficiency and high-pressure applications such as gas burner system, condensing boilers, heat recovery system, extract ventilation system, and many more.
When selecting the right fan for your industrial application, we have to consider several important factors which including the capacity (required pressure and flow rate), airstream, flow control, level of noise, space limitation, power source, the materials handled by the fan, accessories, as well as the safety requirements. A right industrial fan system can improve the overall efficiency and performance. MecHero Malaysia supplies different types of industrial fans (Axial Fan / Centrifugal Fan) and its accessories for meeting your project requirements. You can always contact us at +6011-7000 7687 or email us at my.mechero@gmail.com for an inquiry about the supply and installation of industrial fans in Malaysia for industrial usage. As a steel and online hardware store Malaysia, we also supply a wide range of steel material, general hardware, or mechanical components. Tell us your requirements now and we can advise you accordingly.
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