This article's table of contents introduction:
- What is it? (Core Function)
- Primary Applications in Thermal Power Generation
- Key Technical Specifications
- Leading Global Manufacturers
- Key Selection Criteria for a Thermal Plant
- Summary for a Purchase Inquiry
This is a very specific and critical piece of equipment. An AC Electric High Pressure Blower for Thermal Power Generation typically refers to a specialized fan used to move air or flue gas against a high resistance (pressure).
Here is a detailed breakdown of what this is, its specific applications in a power plant, key specifications, and leading manufacturers.
What is it? (Core Function)
Unlike a standard ventilation fan, this is a centrifugal fan (or blower) designed to generate a high static pressure (e.g., 1000 mmWG to 3000+ mmWG) while moving a large volume of air. In thermal power plants, these are often called FD (Forced Draft) Fans, PA (Primary Air) Fans, or Exhausters depending on their location.
Primary Applications in Thermal Power Generation
- Forced Draft (FD) Fan: Sucks fresh air from the atmosphere and forces it through the Air Preheater (APH) and into the furnace (boiler). It must overcome the resistance of the air preheater, burners, and ductwork.
- Primary Air (PA) Fan: A high-pressure fan that supplies hot air to the coal mills (pulverizers). The high pressure is crucial to: (a) dry the coal, (b) carry the pulverized coal dust to the burners, and (c) provide initial combustion air.
- Induced Draft (ID) Fan: Located at the very end of the flue gas path (after the Electrostatic Precipitator or FGD). It pulls flue gas out of the boiler, overcoming the resistance of the economizer, APH, ESP, and scrubber. While typically larger volume, they are very high pressure to pull a vacuum on the furnace.
- Fluidizing Air Blowers (CFBC Boilers): In Circulating Fluidized Bed Combustion (CFBC) boilers, high-pressure blowers are used to fluidize the bed material (sand and limestone).
Key Technical Specifications
A buyer for a thermal power plant would look for these parameters in the datasheet:
- Type: Typically Centrifugal Double Suction (Double Inlet) for large FD/PA fans. For very high pressure, Single Suction or Multistage Centrifugal Blowers (Roots-type or Screw-type are rare for large coal plants but used for ash handling).
- Flow Rate (Volume): m³/hr or m³/s (e.g., 100,000 to 2,000,000 m³/hr for a 500MW unit).
- Total Pressure Rise (Head): mmWG (mm of Water Gauge), Pa, or kPa.
- PA Fan: Typically 1,200 - 2,500 mmWG.
- FD Fan: Typically 400 - 800 mmWG.
- Motor: AC Induction Motor (Squirrel Cage or Slip Ring).
- Voltage: 6.6 kV, 10 kV, or 11 kV (most common for large plants).
- VFD (Variable Frequency Drive): A modern, mandatory feature. VFDs allow precise control of air flow, drastically improving plant efficiency compared to old damper/guide vane control. (Newer plants use Synchronous Motors with VFDs for highest efficiency).
- Material of Construction: High-strength steel (EN10025 S355J2+N, ASTM A516 Grade 70). Impellers must be robust to handle high centrifugal forces. Inlet casings often have wear liners.
- Temperature Rating: Ambient air for FD, but pre-heated air (~250-350°C) for PA and flue gas (~140-180°C) for ID.
Leading Global Manufacturers
These are the top tier companies that supply DCS-controlled, high-reliability blowers for thermal power plants:
- Howden (UK/Global): An absolute leader in air and gas handling for power. Their FD, PA, and ID fans are found in the largest coal and biomass plants worldwide. (Now owned by Chart Industries).
- TLT-Turbo (Germany/China): A major competitor to Howden, known for highly efficient axial and centrifugal fans for power generation. (Part of the US-based SciGen-Sheng Technology Group).
- Siemens (Germany): Offers a complete range under their Process Industries division (often via their "Siemens Energy" or "Dresser-Rand" legacy). Known for high-pressure multistage blowers.
- Gardner Denver (USA/Global): A leading OEM for multistage centrifugal blowers (e.g., Lamson, Hoffman brands). These are excellent for lower-flow, very high-pressure applications like fluidizing air or pneumatic ash conveying.
- Atlas Copco (Sweden/Global): Their industrial range (Z series, high-pressure centrifugal compressors) is used for critical high-pressure applications, though more common in synthetic gas or large CFB plants.
- Shanghai Electric / Dongfang Electric (China): The dominant local manufacturers for China's massive power plant fleet. They produce high-quality copies of Siemens/Howden designs at a lower cost.
Key Selection Criteria for a Thermal Plant
- Reliability: The blower must run 24/7 for months (typically 8,000 hours/year). Downtime is extremely costly.
- Efficiency (Aerodynamic): A modern, high-efficiency impeller (like a backward-curved centrifugal type) can reduce electricity costs by 15-30% vs. an old radial design.
- Vibration Control: Must meet ISO 1940 G2.5 balance grade for high-speed rotating parts.
- Corrosion/Erosion Resistance: Depending on coal quality and process gases, the impeller may need hard facing (e.g., Stellite) or special coatings.
Summary for a Purchase Inquiry
If you are sourcing one, your query should look like:
RFQ: AC Electric High Pressure Centrifugal Blower Application: Primary Air Fan for 660MW Thermal Power Plant Flow: 180 Nm³/s (at operating conditions) Pressure Rise: 1,800 mmWG Motor: 6.6 kV, 50 Hz, 2,000 kW with High-Efficiency VFD Standards: ISO 1940 (Balance), AMCA (Performance), API 673 (if rotating assembly). Installation: Indoor / Outdoor, horizontal discharge.
If you have a specific flow or pressure requirement or a budget in mind, I can help you narrow down the exact model or manufacturer.
