Electrically powered fans and blowers create airflow by utilizing the principles of aerodynamics and fluid mechanics. They generate a flow of air by using an electric motor to rotate a set of blades or impellers. The blades are designed to push or pull air in a specific direction, creating a pressure difference that results in the movement of air.
Here's a step-by-step explanation of how electrically powered fans and blowers create airflow:
Electric Motor: The fan or blower is equipped with an electric motor that converts electrical energy into mechanical energy. When the motor is turned on, it starts rotating the blades or impellers.
Blades or Impellers: The blades or impellers are specifically shaped to efficiently move air. They can be flat, curved, or even twisted to optimize the airflow. The design of the blades influences the performance of the fan or blower.
Air Intake: The fan or blower has an inlet or air intake where it draws in the surrounding air. As the blades rotate, they create a low-pressure area at the inlet, which causes air to be pulled into the system.
Centrifugal or Axial Flow: There are two main types of airflow generated by fans and blowers: centrifugal and axial flow.
Centrifugal Flow: In centrifugal fans, the air is drawn in radially and then directed outward perpendicular to the axis of rotation. The impeller blades in centrifugal fans accelerate the air outward, creating a high-pressure region. This high-pressure air is then forced out of the fan through a duct or opening.
Axial Flow: Axial fans have blades that are shaped like an airplane propeller. As the blades rotate, they draw in air axially (parallel to the axis of rotation) and then push it out in the same direction. Axial fans are often used when a high airflow rate is required.
Air Discharge: The high-pressure air generated by the blades is discharged into the environment through an outlet or discharge opening. This creates a flow of air in the desired direction, whether it's for ventilation, cooling, circulation, or other purposes.
Airflow Control: Some fans and blowers have features to control the speed of the motor, which in turn adjusts the airflow rate. This can be done using switches, speed controllers, or electronic control systems.
Overall, the rotation of the blades or impellers creates a pressure difference between the inlet and outlet of the fan or blower. This pressure difference, also known as the pressure gradient, propels the air to move from an area of higher pressure to an area of lower pressure, generating the desired airflow. The design of the fan, the shape of the blades, and the speed of the motor all contribute to the efficiency and effectiveness of the airflow generation process.