WWS Hvac Private Limited

An ID fan (short for Induced Draft fan) is a large industrial fan used in systems like boilers, furnaces, kilns, power plants, and pollution control equipment to draw flue gases or hot air out of a process and discharge them into the atmosphere through a chimney or stack.

• Maintains negative pressure inside the combustion chamber or furnace so that air and flue gases flow steadily through the system.

• Ensures complete combustion by controlling the flow of combustion air and exhaust gases.

• Improves efficiency of heat transfer and keeps the process safe by preventing leakage of hot gases into surrounding areas.

1. Suction of Flue Gas: The ID fan is placed after heat recovery equipment such as economizers, air preheaters, or dust collectors (e.g., electrostatic precipitators or bag filters).

2. Creates Negative Pressure: By pulling the gases, it creates a slight vacuum in the furnace or boiler, which induces draft and ensures the hot gases move toward the chimney.

3. Discharge to Stack: Finally, the fan discharges the cleaned gases into the chimney for safe release to the atmosphere.

• Impeller/rotor: Large blades (backward-curved, forward-curved, or radial) to handle high volumes of hot gases.

• Housing/Casing: Heavy-duty steel casing designed to withstand high temperatures and corrosive flue gases.

• Drive system: Usually driven by an electric motor through direct coupling or belt drive.

• Bearings & Shaft: Designed for high-temperature operation with appropriate lubrication and cooling.

• Centrifugal ID Fan (most common): Uses centrifugal force to move gases radially outward.

• Axial ID Fan: Less common; used where space is limited and lower pressure is acceptable.

• Thermal power plants

• Industrial boilers and furnaces

An Induced Draft Fan is a mechanical fan used to pull air or flue gases through a system, commonly found in boilers, furnaces, cooling towers, and industrial ventilation systems.