The centrifugal fans with forward curved blades 2l 90 o are designed due to the small dimensions and good static pressure characteristics of fans and such a recommendation refers to the fans.
Forward curved vs backward curved centrifugal fan.
The forward curved type is generally are blowers and the backward curved type are induced draft fans.
Do not rate fan in the pressure curve dip to the left of peak pressure.
Another important design feature is the position of the motor.
Forward curved centrifugal fans are more cost effective than backward curved centrifugal fans though and have become popular in industries like the medicinal industries since they don t accumulate chemicals and other debris on their blades.
In most cases these fans are designed with external motors.
How does backward curved centrifugal fan work.
A backward curved centrifugal fan is characterised by its cylindrical shape several large curved blades and a conical inlet nozzle.
The difference is the length of impeller rail and the edge.
Backward curved these wheels are extremely efficient more robustly built and very quiet.
1 forward curved blades curve in the direction of the fan wheel s rotation on the other hand backward curved blades curve against the direction of the fan wheel s rotation.
The forward and backward curved centrifugal fan mainly refers to the different blades of their assembled.
Pressure curve less steep than that of backward curved fans.
With a backward curved impeller the air exits in a radial direction whereas with a forward curved the air exits tangentially from the circumference of the fan.
The difference in flow direction between a forward and backward curved centrifugal fan is the direction that the air exits the impeller circumference.
This reduces the level of noise.
Backward curved centrifugal fans.
The forward curved is parallel to the edge.
On the other hand those with backward curved blades are basically free wheeling fans.
The modern forward curved blades are designed with a scroll housing.
Flatter pressure curve and lower efficiency than the airfoil fan backward curved fan and backward inclined fan.
Motor selection must take this into account.
2 forward curved blades provide a low noise level comparitive to backward curved blades because backward curved blades have high speed relatively to forward curved blades for same capacity range.