This article's table of contents introduction:
- Model Number Breakdown (9-26-12.5D)
- Key Characteristics (9-26 Series)
- Specific Specifications for the "12.5D" Size
- Applications
- Important Technical Considerations
- Summary for Maintenance
Based on the model number you provided, "9-26-12.5D" , this is a specific, large industrial High-Pressure Centrifugal Fan designed for heavy-duty air or gas handling systems.
Here is the breakdown of the model number, its technical specifications, and typical applications.
Model Number Breakdown (9-26-12.5D)
This is a Chinese standard fan designation. Each segment carries specific meaning:
- 9: The Impeller Diameter code (specifically, the diameter is 9 100mm = 900mm, or 0.9 meters). Note: For the "12.5" size, the actual diameter is 1250mm, but the "9" series prefix sometimes refers to the specific blade profile family.*
- 26: The Specific Speed (ns) of the fan, which is very low (high pressure, lower flow). This is a defining feature.
- 5: The Impeller Diameter in decimeters (dm). 12.5 dm = 25 meters (1250 mm) .
- D: The Drive Type. "D" means Direct Drive (the fan impeller is mounted directly on the motor shaft). This is for high RPM and high efficiency.
Key Characteristics (9-26 Series)
- Type: High Pressure, Single Inlet, Forward-Curved Blades (or high-pressure backward-curved depending on the exact sub-variant, but 9-26 is specifically a high-pressure series known for robust construction).
- Pressure: High static pressure (typically up to 20,000-30,000 Pa depending on RPM and size).
- Flow: Comparatively lower airflow than a similar-sized "4-72" or "9-19" series fan, but optimized for overcoming resistance.
- Impeller: Heavy-duty, rigid design to handle the stresses of high-speed rotation.
Specific Specifications for the "12.5D" Size
| Parameter | Typical Value / Range | Notes |
|---|---|---|
| Impeller Diameter | 1250 mm | Physical diameter of the fan wheel. |
| Flow Rate (Air Volume) | ~30,000 – 70,000 m³/h | Varies significantly by RPM and system resistance. |
| Total Pressure | ~10,000 – 25,000 Pa | (1,000 – 2,500 mmH₂O). Very high pressure. |
| Rotation Speed | ~1,450 – 2,900 RPM | Direct drive means it runs at motor speed (e.g., 2970 RPM for a 2-pole motor, or 1460 RPM for a 4-pole motor). |
| Motor Power | ~75 kW – 200 kW | Exact size depends on the operating point (flow and pressure required). |
| Temperature Range | Typically up to 80°C (standard) | High-temperature versions can be made for up to 250°C or more. |
Applications
Because of its high pressure, this fan is used specifically in systems that require moving air through significant resistance or over long distances.
- Pneumatic Conveying: Transporting materials like sawdust, cement, grain, plastic pellets, or chemicals through pipelines.
- Forced Draft in Boilers: Supplying combustion air to large industrial boilers, thermal oil heaters, or power plant burners.
- High-Pressure Dust Collection: In facilities with long duct runs and many collection points (e.g., woodworking factories, steel mills, and cement plants).
- Induced Draft (ID Fans): Sucking flue gasses out of furnaces or kilns.
- Ventilation in Mines & Tunnels: Overcoming high pressure drops in long ventilation shafts.
Important Technical Considerations
- Motor Size & Speed: Because this is a "D" drive (direct), the fan speed is fixed to the motor speed. To change performance, you must use a VFD (Variable Frequency Drive), which requires a VFD-rated (inverter-duty) motor. You cannot change the speed via pulleys/belts.
- Noise Level: High-pressure fans are very loud. You will likely need an industrial silencer (muffler) on the inlet and/or outlet.
- Balancing: The impeller must be dynamically balanced (typically G6.3 or G2.5 grade) to prevent destructive vibration.
- Material: Standard is Q235 steel. For corrosive gases, it should be stainless steel (304 or 316). For explosive environments (e.g., handling coal dust, wood dust), an aluminum impeller is required.
- Power Consumption: A fan this size will draw a significant electrical load. Ensure your motor starter, cables, and power supply (transformer ratings) are adequate.
- Damper Control: You may need an inlet damper or variable speed drive to control airflow, as overspeeding or running at full speed without proper duct resistance (damper fully closed) can overload the motor.
Summary for Maintenance
- Bearings: Use high-quality high-temperature grease (check the lubrication schedule).
- Vibration: Monitor regularly. Vibration is a leading indicator of bearing failure or imbalance (e.g., dust buildup on the impeller blades).
- Ductwork: Inspect the impeller periodically for wear (erosion by dust) or buildup.
Would you like a recommendation for the correct motor power or VFD for this fan based on your specific pressure or flow requirement?
