Handling Extreme Boiler Exhaust
In thermal power generation, the Induced Draft (ID) blower is the most highly stressed rotating equipment on site. Positioned downstream of the boiler and electrostatic precipitator, the ID fan pulls combustion exhaust (flue gas) out of the furnace and pushes it through the desulfurization scrubber. This gas is heavily laden with abrasive fly ash and corrosive sulfur dioxide, often entering the fan at temperatures exceeding 150°C.
Radial Tipped Impellers and Thermal Expansion
To survive these brutal conditions, ID fans utilize radial-tipped or forward-curved backward-inclined (FCBI) heavy-duty impellers. Because the massive steel casing and impeller expand significantly at operating temperatures, the fan is engineered with expansion joints and water-cooled journal bearings. Any imbalance caused by ash buildup can cause catastrophic vibration, making continuous vibration monitoring mandatory.