This article's table of contents introduction:
- The Material: HG785 Alloyed Steel
- The Application: High Pressure Sintering Machine
- The Equipment: Heavy Duty Centrifugal Fan
- Key Performance Parameters (Typical Specifications)
- Why "HG785 High Pressure" is specified together
- Summary: What this fan IS
- Where to buy / specifications needed
Here is a technical breakdown of the HG785 Alloyed Steel High Pressure Sintering Machine Heavy Duty Centrifugal Fan.
This is not a standard "off-the-shelf" fan model, but rather a description of a custom-engineered industrial fan built for extreme environments. The name combines the material specification (HG785), the application (Sintering Machine), and the function (High Pressure Centrifugal Fan).
The Material: HG785 Alloyed Steel
This is the critical differentiator. HG785 is a high-strength, low-alloy (HSLA) structural steel, often used in Chinese heavy machinery standards (similar to ASTM A514 or EN 10025-6 S690QL).
- Tensile Strength: 785 MPa (114,000 psi) minimum.
- Yield Strength: 690 MPa (100,000 psi) minimum.
- Why it's used for this fan:
- Extreme Pressure: High-pressure fans generate massive hoop stress on the fan housing and impeller. HG785 allows for a thinner, lighter shell without sacrificing strength vs. standard Q235 steel.
- Durability: Resists fatigue cracking from constant vibration and dynamic loading.
- Heat Resistance: Better performance at the elevated temperatures common in sintering processes than standard carbon steel.
The Application: High Pressure Sintering Machine
In a sintering plant (iron/steel, powder metallurgy, ceramics), the fan is a critical process component.
- Function: It pulls hot, corrosive, and abrasive gases through the sinter bed to provide combustion air and pull the flame front down.
- Operating Conditions:
- Temperature: 120°C to 350°C (250°F to 660°F) – often requiring cooling or insulation features.
- Gas Composition: Contains SO2, NOx, HF, HCl, and fine dust particles.
- Pressure: High static pressure (e.g., 8,000 Pa to 15,000 Pa) to overcome the resistance of the sinter bed, ductwork, and baghouse filters.
The Equipment: Heavy Duty Centrifugal Fan
This refers to the fan type and construction class (typically AMCA Class III or IV / API 610 modified).
- Fan Type: Usually Backward-Curved (BC) or Airfoil (AF) blades.
- Why: High efficiency, non-overloading power curve, and self-cleaning properties (especially BC blades for dirty gases).
- Construction Features:
- Heavy-Duty Bearings: Spherical roller bearings with high-temperature grease or oil-lubricated, often with vibration sensors.
- Shaft: Large diameter, machined from forged steel (e.g., 40Cr or 42CrMo) to handle high torque.
- Housing: Volute casing made from HG785 plate, flange reinforced, with replaceable wear liners on the cut-off and side plates.
- Wheel/Impeller: Welded structure (HG785), stress-relieved, dynamically balanced to ISO 1940 G6.3 or better.
- Drive System: Coupling (fluid coupling or torque-limiting coupling) connected to a high-voltage motor (e.g., 6kV or 10kV).
- Seal: High-temperature shaft seals (labyrinth or carbon ring) to prevent gas leakage.
Key Performance Parameters (Typical Specifications)
| Parameter | Typical Value / Range | Notes |
|---|---|---|
| Flow Rate (Q) | 200,000 – 800,000 m³/h | Depends on sinter machine size |
| Static Pressure (P) | 8,000 – 16,000 Pa | High pressure for bed resistance |
| Operating Temp | 120°C – 250°C | Continuous; peak 350°C (with cooling) |
| Speed | 750 – 1,500 RPM | Often driven by variable speed drive |
| Impeller Diameter | 5 – 4.5 meters | Large for high flow |
| Power | 800 kW – 3,500 kW | High energy consumption |
| Weight | 15 – 60 tons | Including housing, shaft, bearings |
Why "HG785 High Pressure" is specified together
Most standard sinter fans use Q345B (S355) steel. An HG785 fan is a high-spec upgrade, typically chosen when:
- Pressure is very high ( >12,000 Pa). Standard steel would require a housing too thick to weld reliably.
- Weight is a concern (e.g., for roof-mounted installation).
- Extreme wear is expected – HG785 provides better abrasion resistance.
- Cyclic fatigue is an issue – High-strength steel has better fatigue limits.
Summary: What this fan IS
It is not a consumer product. It is a massive, custom-engineered industrial fan built to withstand the most punishing conditions in a steel mill. The HG785 steel allows it to be:
- Stronger (handles higher pressure)
- Lighter (compared to Q345 of equivalent strength)
- More durable (wear and fatigue resistant)
Where to buy / specifications needed
If you are sourcing this fan, you cannot buy it "off the shelf." You need to provide a detailed specification sheet to a manufacturer like Howden, TLT-Turbo, Zibo Boji, or Changsha Shenxiang. You must specify:
- Gas conditions: Temperature, density, dust concentration, chemical composition (H2O, SO2, Cl-).
- Performance: Required flow (m³/h) and total pressure (Pa) at operating temperature.
- Drive: Motor power, voltage, speed control method (VFD? Fluid coupling?).
- Material upgrade: Explicitly demand HG785 for housing and impeller.
- Special features: Wear liners, expansion joints, inlet vanes, high-temperature seals.
