Q345 40940m3/H Explosion Proof Blower Fan Industrial Building Ventilation

This article's table of contents introduction:

1. Material Specification: Q345
2. Explosion Proof Rating
3. Airflow: 40,940 m³/h (~24,100 CFM)
4. Recommended Fan Configuration
5. Technical Specification Table (Example)
6. Critical Considerations & Warning
7. Manufacturer Selection (Typical for this spec)
8. Final Recommendation

Based on the parameters you provided (Q345 material, 40,940 m³/h airflow, Explosion Proof), you are specifying a heavy-duty, industrial-grade centrifugal or axial fan for a hazardous environment.

Here is the technical breakdown and specification recommendation for this fan.

Material Specification: Q345

Q345 (now often replaced by Q355 in newer GB/T standards) is a high-strength low-alloy steel.

• Why use Q345? It offers 1.5x the yield strength of standard Q235 carbon steel. This is critical for:
  • High-pressure applications.
  • Large impellers (to resist centrifugal stress).
  • Spark-resistant environments (Q345 sparks less readily than standard steel when struck).
• Implication: The fan likely features a heavy-gauge spiral housing and a reinforced impeller.

Explosion Proof Rating

For a fan moving 40,940 m³/h, the motor alone is not enough. You need a full Ex-certified assembly:

• Ex d (Flameproof Enclosure): Standard for Zone 1/2.
• IIB T4 or IIC T4: Depending on the specific gas group (likely handling solvents, methane, or dust).
• ATEX / IECEx Certified (Required for most international industrial plants).
• Critical Components:
  • Motor: Ex d IIB T4 (IP55/IP56).
  • Shaft Seal: To prevent gas leakage into the motor.
  • Impeller: Non-sparking material or Q345 with a soft steel/bronze nose cone. Note: Q345 on Q345 casing can still spark; you should verify if the specification requires Copper/Aluminum inlay on the impeller tip.

Airflow: 40,940 m³/h (~24,100 CFM)

This is a high-volume, medium-to-high pressure fan. This flow rate typically corresponds to:

• Industrial Warehouse Exhaust: (e.g., 10,000 sq. ft. warehouse with 15 air changes per hour).
• Fume Extraction (Welding/Chemical): Multi-station systems.
• Sewage Treatment Aeration: Providing oxygen to biobeds.

Recommended Fan Configuration

Given the flow rate and explosion-proof requirements, the most likely configuration is:

Option A: Centrifugal (Backward Inclined / Airfoil) - Most Likely

• Type: SWSI (Single Width, Single Inlet) or DWDI (Double Width, Double Inlet).
• Pressure: Typically 1,500 – 3,000 Pa (6 - 12 in w.g.).
• Duct Connection: 600mm to 800mm (24" to 32") diameter inlet/outlet.
• Drive: Belt-driven (allows for speed adjustment) or Direct Drive (for low maintenance in clean gas).
• Setup: Arrangement 1, 3, 4, or 9 (Belt drive is standard for explosion-proof to isolate motor from gas).

Option B: High-Temp / Smoke Spill Variant

• If used for fire evacuation, the fan must be certified F300 (300°C for 2 hours) or F400.

Technical Specification Table (Example)

Critical Considerations & Warning

Power Calculation (Rough Estimate):

• Formula: $P (kW) = \frac{Q (m^3/h) \times P (Pa)}{3,600 \times \eta{fan} \times \eta{motor}}$
• Assuming 2,500 Pa and 75% efficiency: $P \approx \frac{40,940 \times 2,500}{3,600 \times 0.75 \times 0.95} \approx 39,750W \approx \mathbf{40\ kW}$.
• Recommendation: Specify a 45 kW to 55 kW motor to handle starts and potential duct blockages.

Spark-Resistant Construction (Critical for Q345):

• The specification "Q345" is not inherently explosion-proof. Q345 is steel. Steel on steel can spark.
• You must specify:
  • "AMCA Type A" (all metallic, no rubbing).
  • "AMCA Type B" (non-ferrous impeller tip). Preferred: A copper alloy or aluminum strip on the leading edge of the Q345 impeller.
  • Shaft Grounding Ring: Prevents static buildup.

Installation:

• The fan must be located outside the building or in a dedicated fan room with pressurized switchgear.
• Ductwork: Must be grounded and made of non-combustible material.

Manufacturer Selection (Typical for this spec)

• China: Sanyuan, Yilida, Huada, or Wanneng (ensure they provide Ex d certification for the whole unit, not just the motor).
• International: Greenheck (Model Vektor-H or SWB), Systemair, Soler & Palau, FläktGroup.

Final Recommendation

Do not order a "Q345 40940 m³/h Explosion Proof Fan" without the following clarifications:

1. Add "ATEX/IECEx Certified Assembly" to the PO (Purchase Order).
2. Define the Gas/Group: (e.g., "Ex d IIB T4 – suitable for Ethylene/Methane").
3. Define the Static Pressure: (e.g., "at 2,000 Pa").
4. Request a "Spark Resistant Construction Certificate" (AMCA Type B preferred).

If you send these specifications to a reputable fan manufacturer, they will provide a centrifugal fan with a Q345 housing, a reinforced impeller, and an Ex-rated motor appropriate for your 40,940 m³/h requirement.