49000 m³h Dust Collector Exhaust Fan

This article's table of contents introduction:

1. The Critical Missing Specification: Static Pressure (SP)
2. Estimated Motor Power (Assuming Typical Industrial Use)
3. Recommended Fan Type
4. Example Fan Size & Dimensions (Approximate)
5. Critical Application Considerations
6. Summary for a Quotation

To properly address a 49,000 m³/h Dust Collector Exhaust Fan, we need to translate that airflow into the specific requirements for selection (static pressure, motor power, and application context).

Here is the breakdown of what a 49,000 m³/h fan system typically entails.

The Critical Missing Specification: Static Pressure (SP)

The airflow (49,000 m³/h ≈ 28,800 CFM) tells us the volume, but Static Pressure (measured in Pa, mmH₂O, or inWG) tells us how hard the fan has to push.

For a dust collector, the SP depends on the system:

• Simple cyclones + short ducting: 1,500 – 2,500 Pa (6 – 10 inWG)
• Baghouse/Dust collector with filters (typical): 2,000 – 3,000 Pa (8 – 12 inWG)
• Dust collector with high-efficiency cartridges + long ducting: 3,000 – 4,500 Pa (12 – 18 inWG)

Without the SP, we cannot calculate the motor power.

Estimated Motor Power (Assuming Typical Industrial Use)

Assuming a medium-pressure dust collector system (e.g., a Baghouse) requiring 2,500 Pa (10 inWG) :

• Air Power (Hydraulic Power): $P_{air} = \frac{Q \times p}{3,600}$

  $P = \frac{49,000 \times 2,500}{3,600} = 34,028 \text{ Watts} \approx 34 \text{ kW}$

• Shaft Power (including fan efficiency ~75%):

  $P_{shaft} = \frac{34}{0.75} \approx 45 \text{ kW}$

• Motor Power (including drive losses, safety margin ~10-15%):

  • Result: 55 kW to 75 kW (73 HP to 100 HP)

Summary:

• 55 kW (75 HP) for a light system (low pressure drop).
• 75 kW (100 HP) for a heavy system (clogged filters, long duct runs).

Recommended Fan Type

For 49,000 m³/h (high flow), the most common and efficient types are:

1. Backward Inclined / Backward Curved (BI/BC) Fan (Best Choice):

   • Why: Very efficient (85%+ for non-stalling). Handles high static pressure. Non-overloading power curve (motor won't burn out if filter clogs). Ideal for Baghouses and Cartridge collectors.

2. Airfoil Fan:

   • Why: Highest efficiency (90%+). Quiet. Used for continuous operation. More expensive.

3. Radial / Paddle Wheel Fan (Cheap / Dirty Air):

   • Why: Handles heavy particulate and sticky dust (e.g., wood chips, textile lint) without clogging.
   • Downside: Low efficiency (60-70%), louder, requires larger motor (likely 75-110 kW for your flow).

Example Fan Size & Dimensions (Approximate)

For a Backward Inclined fan at 49,000 m³/h and 2,500 Pa:

• Impeller Diameter: Approx. 1,200 mm to 1,400 mm (47" to 55")
• Inlet Diameter: Approx. 700 mm to 800 mm (28" to 32")
• Outlet Size: Approx. 800 mm x 600 mm (32" x 24")
• RPM: Approx. 900 to 1,200 RPM (depends on drive arrangement)
• Sound Level: Likely > 85 dB(A) – a silencer (attenuator) is recommended.

Critical Application Considerations

For a Dust Collector Exhaust Fan, you must answer these 5 questions:

1. What is the Dust Type?

   • Wood dust: Standard BI fan.
   • Combustible dust (metal, grain, carbon): Explosion-proof motor, spark-resistant construction (aluminum or stainless steel impeller), and a blast gate/damper.
   • Sticky dust (resin, fibers): Radial fan (tends to self-clean better).

2. What is the Temperature?

   • Standard: 40°C (104°F).
   • Hot gas (from dryers/ovens): 100°C – 200°C (needs high-temp bearing and shaft cooling fins).

3. Drive Type:

   • Belt Drive (Recommended): Allows you to change RPM to adjust airflow/SP. Slower motor speeds.
   • Direct Drive: Fewer moving parts, cleaner installation, but harder to change performance.

4. VFD:

   • For 49,000 m³/h, a Variable Frequency Drive (VFD) is highly recommended. It allows soft start, energy savings (you can ramp down at night), and precise airflow control.

5. Silencer:

   • A 49k m³/h fan is very loud. An inlet silencer (duct silencer) is almost mandatory for workplace safety (compliance with < 85 dB(A) regulations).

Summary for a Quotation

If you are asking a supplier for a quote, you need to provide this:

Fan Requirement:

• Airflow: 49,000 m³/h
• Static Pressure: [Insert Value] Pa (e.g., 2,500 Pa)
• Application: Dust Collector Exhaust (Baghouse)
• Dust Type: [Wood / Metal / General]
• Temperature: [Ambient / Hot]
• Motor: [55 kW / 75 kW] | [Standard / Explosion-proof] | [Belt / Direct]
• Options: VFD / Silencer

Final Answer: A 49,000 m³/h dust collector fan typically requires a 55-75 kW motor driving a Backward Inclined impeller at 900-1,200 RPM. You must specify the Static Pressure to get an exact power rating.