5 impeller types and how centrifugal fans work

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5 impeller types and operating principles of centrifugal fans ( CENTRIFUGAL FANS)

Welcome back to another informative article from Today we discuss fan selection, especially impeller types, which are particularly important. You need to understand their types and operating characteristics. They are classified by different applications, using the source's earth, water, air and fire framework.

This article discusses impeller types and the operating principles of   scroll or centrifugal fans ( Centrifugal or Radial fan)
Their operating principle is   to draw air in from the side and throw it radially outward, increasing its velocity. The air then passes through an expanding scroll-shaped cross-section. These fans are relatively quiet and come in several types, described below.

Centrifugal fans ( Centrifugal Fans)
draw air in from the side and throw it radially outward, increasing its velocity, then guide it through an expanding scroll-shaped cross-section. They are divided into the following types.

1. Forward Curved 
Forward-curved fan blades curve in the direction of impeller rotation and resemble a squirrel cage.

Advantages
- Quiet operation

Disadvantages
- The motor can become overloaded
- Low pressure , For clean air only; suitable for
- ventilation , cooling systems

2. Backward Curved
Backward-curved fan blades curve in the direction opposite to impeller rotation.

Advantages
- Good pressure generation; suitable for long duct runs
- Suitable for moderate dust loads
- Good efficiency

Disadvantages
- Unsuitable for heavy dust or large quantities of dust; suitable for
- filtered dust extraction systems , Blower
3. Backward Inclined
Backward-inclined flat fan blades incline against the direction of impeller rotation.

Advantages
- Good pressure generation; suitable for long duct runs
- Suitable for heavy dust or large quantities of dust
- Dust does not accumulate on the blades

Disadvantages
- Lower efficiency than Backward Curved Suitable for
- filtered dust extraction systems , IDF Boiler

4. Radial Tipped
Forward-inclined fan blades incline in the direction of impeller rotation.

Advantages
- Higher pressure than Backward

Disadvantages
- Lower efficiency than Backward
- Suitable for small quantities of dust
- May overload the motor; suitable for
-  high-pressure air extraction or delivery ,   air compression

5. Radial
Radial flat-blade fans

Advantages
- Suitable for large quantities of coarse dust

Disadvantages
- Low efficiency; suitable for
-  conveying material through the impeller ,   wood, rice husks and bagasse