Over the years, various types of industrial fans have gained immense torque across industries. Radial fans are one of the important types of industrial fans to have received wide acceptance. These fans are used in factories, mines, and commercial buildings. Widely known as centrifugal fans, the radial fans are also used to move gases, moisture, and dust in the direction of incoming fluid. These fans are also known as paddle wheel fans or radial plate fans, air blower fans, squirrel cage fans, and squirrel fans depending on their construction and operation. Owing to their distinct advantages, today, it is easy to find these fans in different designs. Are you intrigued to know what makes these fans popular? If so, this post answers everything you want to know about these fans.
What is Radial Fan?
A radial fan is a mechanical device that features an impeller, which is powered by an electrical motor. The impeller rotates on its own and provides direction to the air. This air that it lends works upon is usually sucked from the sides of the fan and it is blown through the outlet of the fan.
What are the components of Radial Fan?
A radial fan mainly comprises the following:
- Impellers
- Fan Housing
- Inlet and Outlet Duct
- Drive Mechanism
- Drive Shaft
How does a Radial Fan Work?
In a radial fan, the fan wheel gets a gush of air, gets into a right angled position, and is accelerated by flat radial blades on the impeller. The accelerated air is discharged radially, thus, the name. The airflow is induced by the centrifugal force, produced in a rotating column. These fans may be belt-driven or motor-driven.
Radial fans are also used in car radiators, which is why these fans are also referred to as radiator fans. These fans blow cooler air through the radiator, help remove heat from the engine and lower the temperature of the coolant. There are two types of radiator fans – mechanical and electric radiator fans. The next section discusses these fans at length.
Radiator Fan Types and Their Working Discussed
The radiator fans are categorized into two parts, which are described below.
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Electrical Radiator Fans:
Electric radiator fans provide a reliable and efficient cooling solution for automobiles, using a small electric motor and a wiring system that comprises connectors, fuse, relay(s), sensors, wires, and a control module. Their compact size makes them ideal for tight installation spaces, while their ability to be controlled by sensors and ECUs ensures that they only come on when necessary and at the correct speed for optimal efficiency. -
Mechanical Radiator Fans:
This engine cooling fan is generally found in old vehicles and is driven off the crankshaft, and connected to the water pump pulley. It only runs when the engine is running, but to ensure it only comes on when necessary, a special type of clutch is used which engages and disengages the fan based on the engine's cooling needs. This type of fan has the advantage of being less prone to failure and is easy to service. It also packs a great deal of power and is able to cool engines with advanced designs.
Working of Electric Radiator Fans Explained
A radiator fan is a mechanical component in an internal combustion engine's cooling system. It helps dissipate heat generated by the engine by blowing air over the radiator, which transfers the heat from the coolant to the outside air. The fan operates by pulling air into the radiator through the front grille and blowing it over the finned tubes of the radiator. As the air flows through the radiator, it carries heat away from the coolant, which has been heated by the engine, and dissipates it into the surrounding air. The fan is controlled by a thermostatic switch, which turns the fan on and off depending on the temperature of the coolant. When the coolant temperature reaches a certain level, the thermostatic switch turns the fan on, and it continues to run until the coolant temperature drops to a safe level. This helps regulate the temperature of the coolant, ensuring that the engine operates within its optimal temperature range. In some vehicles, the radiator fan is reversible, which can blow air in either direction. This allows it to be used for both cooling and heating the engine. In the cooling mode, the fan pulls air through the radiator and over the engine, dissipating heat. In the heating mode, the fan pushes hot air from the engine into the cabin, providing heat for the passengers.
Radial Fans and other Centrifugal Fans
There are several types of centrifugal fans, which are distinguished based on their designs. Of these, the forward curve, backward curve, airfoil fans, and radial fans are the most popular ones. Let’s see the other three fans, in brief, to understand how they differ from radial fans.
Airfoil Fans:
Centrifugal fans are named so owing to their airfoil-profiled blades. Airfoil fans are used in applications where ambient or elevated temperatures are involved such as chemical, power generation, metals, resource recovery industries, and so on. These fans assure high efficiency as well as quiet operations. Dust buildup is one of the drawbacks of this fan. Thus, they are more appropriate for clean air applications.
Forward Curve Fans:
These fans have squirrel cage impellers, which generate the highest airflow volume. Forward curve fans are most commonly used in high-temperature furnace applications, and ventilation applications where there is a low chance of dust loading. This fan requires a large number of blades to drive forward curve wheels. This is why they cannot be used in applications where there is a chance for high dust loading. If dust settles on blades, then the volume of air supply will be impacted.
Backward Curve Fans:
These fans possess the same efficiencies as airfoil fans. They have curved plate blades, which can help avoid the possibility of dust buildup. This specific design makes them suitable for high-pressure applications.
Design Characteristics of Radial fans
The following design characteristics make them superior to the above-discussed fans.
- The impeller of this fan possesses a simple design that comprises six to twelve flat blades which extend radially from the center of the fan hub.
- The blades are narrower, heavier, and deeper than backward inclined and forward curve type centrifugal fans.
- Simple, yet rugged impeller design helps avoid accumulation of sticky materials or dust on its blades, which makes it suitable for high-pressure, yet, dust-loading applications.
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Impellers of these fans can be availed in various designs. You will find more variations in impellers than airfoil, forward curve, and backward curve fans. Some popular types include:
- Paddle Wheel
- Open Wheel (OW)
- Backplate Wheel (BW)
- Steel Plate
When compared to the airfoil, backward curve, and forward curve centrifugal fans, the radial fans are medium airflow fans. Owing to their high-pressure and non-dust build up designs, these fans are widely used in challenging industrial applications like mining facilities to move air at high pressure.
The Difference Between Radial Fan and an Axial Fan
The primary distinction between a radial fan and an axial fan lies in their airflow patterns and design. Radial fans, also known as centrifugal or blower fans, generate airflow by directing air perpendicular to the fan's axis. This results in a spiraling, radial flow pattern. These fans are well-suited for applications requiring higher pressure, such as air conditioning systems and industrial processes. On the other hand, axial fans propel air parallel to the fan's axis, creating a more linear flow. Axial fans are effective for applications where a higher airflow rate at lower pressure is essential, such as cooling electronic equipment or ventilating enclosed spaces. While both fans serve the purpose of moving air, their distinct designs make them better suited for different scenarios based on the required pressure and flow characteristics.
Benefits of Using Radial Blade Fans
Radial fans or radial blade fans possess one of the most robust structural designs in the field. This makes them an ideal choice for various industrial applications. The following features of these fans have helped increase their demand in recent years.
- Fitted with flat radial blades, these fans are suited for heavy-duty and challenging applications.
- Unlike several other centrifugal fans discussed here, radial fans possess a simple design and self-cleaning characteristics that contribute to easy maintenance. This is particularly beneficial for facilities that are concerned with high maintenance costs.
- Self-cleaning characteristics not only help in reducing maintenance costs but also help in improving operational efficiency.
- Rugged construction of these fans makes them an ideal choice for high-temperature, high static pressure, as well as corrosive and abusive environments.
- Rugged construction combined with durability also makes them a perfect choice for handling air streams containing dust and a large number of particulates.
- Radial fans are available at more affordable costs than other centrifugal fans, which make them a choice for various industry segments where the budget can be a main concern.
In short, radial blade fans are used in applications where a high degree of reliability and wear resistance is required. A blower is one of the brilliant examples of radial fans or centrifugal fans that are used to dry damp areas of buildings.
What are the Industrial Applications of Radial Fans?
Radial fans are used in various process plants to drive away acidic fumes and corrosive gases. The following pointers will help you understand various industrial applications of radial fans.
- These fans are employed in cement plants during various phases of production. For instance, they are used in raw material preparation, material grinding, storage, and blending, as well as the removal of waste gases from filter systems.
- Radial fans have been one of the integral features of steel plants, where they are used during applications such as de-dusting, sintering, and so on. These fans can withstand dusty conditions, high temperatures, and abusive environments in steel plants.
- Power station boilers use one of the various types of centrifugal fans or radial fans. These fans assure smooth functioning and consistent operation of boilers and can withstand high temperatures released by these boilers. Radial fans are commonly used by power plants below 500 MW.
- Heavy duty radial fans or centrifugal fans are used in chemical industries because they can meet the stringent safety requirements in the industry. These fans are usually used to exhaust hazardous gases from the facility.
- Radial fans and other types of centrifugal fans are used in the textile industry for low-pressure drying.
- Temperature management is one of the important requirements and concerns in the glass industry. Radial fans are used at various stages of glass preparation. They are used for cooling ovens at the beginning of the process. Also, they are used for driving hot gases within the oven.
Are you looking for a radial blade fan for your industrial facility? You must focus on their quality and operational characteristics before investing. Owing to their high demand, today, it is easy to find several cheap variants of branded radial blade fans, but that is not enough. Thus, you must partner with a trusted brand like Sofasco which not only produces an industry-leading brand of DC radial centrifugal fans but also provides them in custom configurations to meet client requirements. You can get in touch with their team of experts today to discuss your requirements.
