4-79-8D Centrifugal Fan

This article's table of contents introduction:

1. Decoding the Model: "4-79 No. 8D"
2. Typical Specifications (Approximate)
3. Common Applications
4. Summary for the user:

Based on the string you provided, "4-79-8D Centrifugal Fan" , this is a specific model designation for a type of industrial fan. Here is the breakdown of what each part of the code means and the fan's typical characteristics.

Decoding the Model: "4-79 No. 8D"

In the Chinese industrial fan naming convention (GB/T standards), this code breaks down as follows:

• 4-79: This is the Series Designation.

  • It indicates the aerodynamic design of the fan blades. The "4-79" series is one of the most common types of backward-inclined (or backward-curved) centrifugal fans.
  • Key Performance: These fans are known for high efficiency, low noise, and a non-overloading power curve. This means the motor will not burn out if the duct system becomes less restrictive.

• 8: This is the Fan Size (Impeller Diameter) .

  • In the metric system used for this series, this number refers to the diameter of the impeller in decimeters (dm).
  • Calculation: No. 8 means the impeller diameter is 8 dm = 800 mm.

• D: This is the Drive Type.

  • D-type means the fan is directly coupled to the motor via a coupling. In this configuration:
    • The fan impeller is mounted on a shaft supported by its own bearing housing.
    • The motor shaft is connected to the fan shaft using a flexible coupling.
    • The fan speed (RPM) is exactly the same as the motor speed.

Typical Specifications (Approximate)

While exact performance depends on the specific manufacturer and motor, a "4-79 No. 8D" fan generally falls into this range:

• Impeller Diameter: 800 mm
• Airflow: Typically ranges from 8,000 to 25,000 m³/h (depending on motor speed and static pressure)
• Pressure: Typically ranges from 500 to 2,500 Pa (Pascals)
• Motor Speed: Typically coupled to a 4-pole (1450 RPM) or 6-pole (960 RPM) motor.
• Motor Power: Usually between 2 kW and 11 kW, depending on the specific operating point (flow vs. pressure).

Common Applications

Because of its high efficiency and stable performance, the "4-79" series is used for general ventilation and air handling in:

• HVAC Systems (Heating, Ventilation, and Air Conditioning)
• Factory and Warehouse Ventilation (exhausting fumes, dust, or hot air)
• Air Supply for Boilers or Dryers
• Tunnel or Underground Ventilation

Summary for the user:

If you are ordering a replacement, specifying to a technician, or configuring a system, you have identified a medium-pressure, high-efficiency, backward-inclined centrifugal fan with an 800mm impeller, direct-driven by the motor.

Note: If you need specific performance curves (RPM, kW, CFM, static pressure), you will need to consult the manufacturer's data sheet for that exact fan, as the "8D" is just the frame size.