the ventilation fans direction of air movement

According to the direction of air movement, ventilation fans can be divided into the centrifugal fan: air into the rotating blade channel, the gas is compressed and flows along the radial direction under the centrifugal force. Axial fan: the fan air flow axial fan impeller, the flow along the axial direction in the flow channel of the rotating blades. Relative to the centrifugal fan, axial fan flow, small volume, low pressure head should pay attention to dust and corrosive gas. Diagonal flow fan (Francis fans): in the ventilation fans  impeller, airflow direction in the axial flow, similar to the flow along the cone, it can be called a diagonal flow fan of (Francis fans). Pressure coefficient of this fan, axial fan, the flow coefficient is higher than the centrifugal fan.