This article's table of contents introduction:
- Breaking Down the Search Query
- Key Engineering Specifications for this Fan Type
- Common Fan Models for this Application (Chinese Naming)
- Critical Performance Parameters (You must verify)
- Suggestion for Sourcing
- Summary
It appears you are referencing a specific type of industrial centrifugal fan designed for a high-temperature, high-volume application, likely in a steel plant or cement plant.
Here is a breakdown of what this specification typically means, the engineering challenges involved, and common configurations.
Breaking Down the Search Query
- Q345 (Material): This is a Chinese standard low-alloy high-strength structural steel (similar to ASTM A572 Grade 50 or S355JR). It is not typically used for the impeller (wheel) of a high-temperature fan due to creep and thermal stress issues. However, Q345 is commonly used for the housings (scrolls), inlet boxes, and base plates because it offers good strength and weldability at ambient to moderate temperatures.
- Thermal Warning: For the rotating assembly (impeller) exposed to 300°C+ (572°F+), Q345 loses strength rapidly. Impellers in high-heat applications usually require Q345R (boiler plate), Q245R, 16MnCr5, or stainless steel (e.g., 310S, 253MA).
- High Volume: This implies a very large Air Flow Rate, typically measured in m³/h or CFM. Look for fans with large inlet diameters (e.g., 1500-3000 mm) and wide impellers.
- Backward Kilns Cooling: This is the key application.
- Backward (BKWDR or BDH): Refers to a Backward-Curved / Backward-Inclined blade design (non-stalling).
- Kilns Cooling: The fan is pulling hot (150°C – 400°C) air from a rotary kiln or clinker cooler to cool the product. This air is often dusty and abrasive.
- Industrial Centrifugal Fans: High-pressure, high-torque machines.
Key Engineering Specifications for this Fan Type
If you are sourcing this fan, the manufacturer will need to design around these specific parameters:
| Feature | Standard Design | High-Temp / Abrasive Design |
|---|---|---|
| Impeller Material | Q345 or Q235 | 16Mn (Q345D) or Wear-resistant steel (NM400) |
| Blade Type | Backward Curved | Backward Aerofoil (high efficiency) or Sword Blade (abrasion resistance) |
| Shaft Material | 45# Carbon Steel | 40Cr or 35CrMo (alloy steel for thermal stability) |
| Bearing | Standard roller bearings | Water-cooled bearing housings or High-temp grease (SKF/FAG) |
| Cooling | None | Shaft cooling fan or Water cooling on pedestal |
| Seals | Standard labyrinth | Double labyrinth or Graphite packing to prevent hot gas leaks |
Common Fan Models for this Application (Chinese Naming)
- W9-26 Series: High pressure, for pulverized coal or waste gas.
- Y4-73 / Y5-47 Series: Induced draft (ID) fans for boilers/kilns (backward blades).
- W4-73 Series: High temperature centrifugal fans (200°C - 350°C).
Critical Performance Parameters (You must verify)
For a "Backward Kilns Cooling" fan, the buyer or engineer needs to confirm:
- Temperature: What is the inlet temperature?
- < 80°C: Standard Q345 housing, Carbon Steel impeller.
- 250°C - 350°C: Q345 housing, alloy steel impeller (16Mn or 15CrMo), water-cooled bearings.
- > 400°C: Stainless steel (304/310S) impeller.
- Dust Load: If the air from the kiln cooler has heavy clinker dust, you need wear liners (Wear-resistant ceramic tiles or Hardox plates) on the leading edge of the blades and the cut-off (volute tongue).
- Vibration & Balance: High volume fans require a balanced rotor (ISO 1940 G6.3 or better). High temperature causes thermal expansion; the rotor must be dynamically balanced at operating temperature (or a cold balance correction must be applied).
Suggestion for Sourcing
When contacting a supplier (e.g., for a Q345 High Volume Backward Kilns Cooling Industrial Centrifugal Fan), provide this minimum data:
- Flow Rate: m³/h (or CFM)
- Total Pressure: Pa (or mmH₂O)
- Inlet Temperature: °C
- Dust Content: g/Nm³ (high, medium, low)
- Motor Speed: Fixed or VFD (Variable Frequency Drive)? High volume usually demands VFD for soft start and efficiency.
- Model Preference: W9-26, Y4-73, or custom design?
Summary
- Q345 is acceptable for the housing (scroll) at high temps, but not for the impeller if the temperature exceeds ~300°C.
- A Backward Kilns Cooling fan requires robust design against thermal expansion (shaft cooling) and abrasion (wear plates).
- Ensure the fan has a suitable high-temperature seal to prevent hot gas from destroying the bearings.
Would you like a technical drawing specification, a calculation for a specific volume, or a supplier sourcing checklist?
