FBCDZ-6-No32 Coal Mine Exhaust Explosion-Proof Counter-Rotating Axial Flow Fan

This article's table of contents introduction:

1. Model Nomenclature Breakdown
2. Key Technical Specifications (Typical for No32)
3. Design & Operational Characteristics
4. Typical Blade Adjustment
5. Common Application
6. Potential Issues & Considerations (for maintenance/operation)

Based on the model number you provided, FBCDZ-6-No32, here is the breakdown of this specific type of coal mine ventilation equipment:

FBCDZ-6-No32 is a Coal Mine Explosion-Proof, Counter-Rotating Axial Flow Fan used primarily for main mine ventilation (exhaust). Here is the technical breakdown of the model name:

Model Nomenclature Breakdown

• F: Fan
• B: Explosion-proof (防爆)
• C: Counter-rotating (对旋)
• D: Electric motor (电机 driven, typically direct drive)
• Z: Main fan for mine ventilation (主扇) – Note: Some catalogs use "Z" for "axial flow" or "main," but in coal mine standards, it denotes a main fan for the mine ventilation system.
• 6: Impeller Stage (Pole) Designation.
  • In counter-rotating fans, this number often refers to the number of poles in the motor (e.g., 6-pole motor) or a design iteration. For a 6-pole motor, the synchronous speed is approximately 980 RPM at 50 Hz.
• No32: Impeller Diameter. This is critical.
  • No32 means the impeller diameter is 32 dm (decimeters), which equals 2 meters (approx 126 inches).

Key Technical Specifications (Typical for No32)

Given the large diameter (3.2m) and 6-pole motor speed (~990 RPM), this is a high-volume, medium-pressure main ventilation fan.

• Air Volume (Q): Approximately 3,000 to 12,000 m³/min (50 to 200 m³/s) depending on blade angle and configuration.
• Static Pressure (P): Typically 800 Pa to 4,500 Pa (depending on the specific fan curve and blade setting).
• Motor Power: For a No32 fan:
  • Usually paired with motors ranging from 2 x 250 kW to 2 x 500 kW (two motors, one for each rotor).
  • Common configurations: 2×315 kW, 2×355 kW, 2×400 kW.
• Speed: ~ 980 RPM (Synchronous) / ~ 990 RPM (Actual, depending on slip).
• Efficiency: Modern designs aim for ≥ 80% (Static efficiency) at the design point.

Design & Operational Characteristics

• Counter-Rotating (C): This fan has two impellers rotating in opposite directions on the same axis.
  • Advantage: No guide vanes are needed (reducing size and weight).
  • High Pressure: Achieves high static pressure in a compact axial length.
  • Instability Region: These fans have a characteristic "saddle" or instability zone at lower volumes. They must be operated either above the minimum stable volume or controlled via blade adjustment.
• Explosion-Proof (B): The motor casings, wiring, and fan housing are designed to be explosion-proof to meet China’s coal mine safety standards (GB3836). This prevents the fan from igniting methane gas (CH₄) in the mine air.
• Direct Drive (D): The impellers are mounted directly on the motor shaft. There are no belts, couplings, or gearboxes, which reduces maintenance and ignition sources.
• Exhaust (E): This specific model is designed to be installed on the return air side (exhausting air from the mine to the atmosphere).

Typical Blade Adjustment

Most FBCDZ fans (especially the larger sizes like No32) use hydraulic or manual blade angle adjustment while the fan is running (or stopped).

• Running Adjustment: Hydraulic system allows changing the blade angle on both rotors to match mine demand without stopping the fan.
• Stopped Adjustment: Manual adjustment of blade angles.

Common Application

This specific model is used in large, underground coal mines where the primary ventilation system must move massive volumes of air (often exceeding 100 m³/s) against significant mine resistance (typically 2,000 to 4,000 Pa). The "Z" designation confirms it is a main fan (not a local or auxiliary fan).

Potential Issues & Considerations (for maintenance/operation)

• Motor Cooling: The motors are mounted inside the airway. They rely on the air stream for cooling. If the fan operates at very low volumes (near the stall region), the motors can overheat.
• Bearing Temperature Monitoring: Must be wired into the mine SCADA system. High temperatures indicate bearing failure or misalignment.
• Vibration Monitoring: Due to the large diameter (3.2m) and high tip speeds, blade passing frequency and imbalance are critical.
• Blade Tip Clearance: For optimal efficiency, the gap between the blade tip and the casing must be tight (typically ≤ 1.5% of the blade chord length). Wear or corrosion increases clearance, reducing efficiency.

Summary: The FBCDZ-6-No32 is a large, explosion-proof, counter-rotating axial fan specifically designed as a main exhaust fan for high-capacity coal mine ventilation systems. It operates at ~990 RPM with motors typically in the 2×315 kW to 2×400 kW range, moving up to 10,000+ m³/min against significant mine resistance.

If you need specific performance curves, motor specifications (voltage, insulation class), or installation drawings, you would need to refer to the manufacturer's data sheet (e.g., from Shanxi Fenglei, Nanning Guangfa, or similar Chinese manufacturers).