Working principle of centrifugal fan

The working principle of a centrifugal fan is to use a high-speed rotating impeller to accelerate the gas, then decelerate and change the flow direction, so that the kinetic energy is converted into potential energy (pressure). Specifically, when the gas enters the impeller from the axial direction, under the drive of the impeller, the gas rotates with the impeller on the one hand, and increases its energy under the action of inertia on the other hand, leaving the impeller in the radial direction. This process relies on the centrifugal force to make the gas gain kinetic energy (dynamic pressure head), and then the gas flows to the fan outlet through the guidance of the casing, and at the same time forms a negative pressure in the center of the impeller, so that the external gas continues to flow in and replenish, thereby continuously transporting the gas to the required place. ‌12

The structure of a centrifugal fan includes an impeller, casing, air inlet, air outlet, bearing, and other parts. The impeller is the core part of the centrifugal fan, which is driven to rotate by a motor and usually consists of a central shaft and multiple blades. The design and structure of the impeller have an important impact on the performance and efficiency of the fan, including the number and shape of the blades. The role of the casing is to introduce and discharge the gas, and at the same time convert part of the kinetic energy of the gas into pressure energy. The design of the air inlet and outlet also affects the performance of the fan. The size and shape of the air inlet affect the air volume and speed, while the design of the air outlet affects the exhaust speed and direction.

Centrifugal fans are widely used in ventilation, dust removal, and cooling of factories, mines, tunnels, cooling towers, vehicles, ships, and buildings; ventilation and air induction of boilers and industrial furnaces; cooling and ventilation in air conditioning equipment and household appliances; drying and selection of grains; wind tunnel wind sources and inflation and propulsion of hovercraft.

The centrifugal fan plays a crucial role in various industries, providing efficient airflow and pressure conversion for a wide range of applications. When selecting a centrifugal blower with motor, it is important to consider the specific requirements of the system, such as airflow rate, pressure, power consumption, and noise levels. Proper design and maintenance of centrifugal fans are key factors that affect their performance and lifespan.

One of the main advantages of centrifugal fans is their ability to handle large volumes of air at relatively low speeds, making them suitable for applications where air volume control is essential. These fans are commonly used in HVAC systems to ensure consistent airflow throughout buildings, helping to maintain comfortable temperatures and air quality. In industrial settings, centrifugal fans are employed for ventilation purposes, ensuring that hazardous fumes or dust particles are efficiently removed from the workspace.

Centrifugal blowers with motors are commonly found in cooling systems, particularly in industrial refrigeration units and cooling towers. The motor drives the impeller, creating a pressure difference that allows the fan to move air through the system. By accelerating air through the impeller and converting kinetic energy into pressure, the centrifugal blower helps to improve the efficiency of the cooling process, preventing equipment from overheating and enhancing the overall performance of the system.

In applications such as air filtration systems, centrifugal fans are essential in creating the necessary air movement to pass through filters and remove contaminants from the air. The design of the fan's impeller and casing is tailored to accommodate the needs of the filtration process, ensuring that the airflow is directed in a controlled manner. This helps to extend the life of the filters and improve the quality of the air being circulated.

Another critical application of centrifugal fans is in the drying and processing of materials in industries such as food production, pharmaceuticals, and textiles. In these sectors, consistent airflow is necessary to facilitate the removal of moisture from products, ensuring their quality and safety. Centrifugal fans are used to create a uniform flow of air across drying surfaces, improving efficiency and reducing processing times.

When integrating a centrifugal fan into a system, careful attention must be paid to the fan's motor power and speed settings. The motor must be capable of driving the fan at the required RPM to achieve the desired airflow and pressure. Overloading the motor or running the fan at incorrect speeds can advance to reduced efficiency, increased energy consumption, and premature wear. It is essential to select a motor that matches the fan's specifications and to regularly maintain both the motor and the fan components to prevent breakdowns.

In conclusion, centrifugal fans and centrifugal blowers with motors are versatile components used in various industries to achieve efficient air movement and pressure control. Their design allows them to handle a broad range of applications, from ventilation and dust removal to cooling and drying processes. Proper selection, installation, and maintenance of these fans are essential to ensure reliable performance, energy efficiency, and prolonged service life. As technology continues to advance, centrifugal fans are likely to evolve, incorporating smarter controls and materials to meet the ever-increasing demands of modern industrial systems.