In any boiler system or thermal power plant, industrial application fans play an important role in maintaining proper combustion and airflow. Two of the most important types are the FD Fan (Forced Draft Fan) and the ID Fan (Induced Draft Fan). Though both are used for air circulation in boilers, they have different purposes and functions. Understanding the difference between FD Fan and ID Fan is crucial for engineers, operators, and even students of mechanical or thermal engineering. In this blog we will briefly explain FD Fan VS ID Fan, ID Fan FD Fan Full Form, their applications, benefits, features or other information.
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What is an FD Fan – FD Fan Full Form
FD Fan stands for Forced Draft Fan, which is an industrial fan used to supply fresh air into the furnace or boiler for combustion. Unlike an ID Fan, which pulls flue gases out, the FD Fan pushes air into the system under positive pressure, ensuring a steady supply of oxygen for burning fuel.
Fd fan in boiler
Forced Draft (FD) Fan is installed at the inlet of the boiler to supply fresh atmospheric air into the furnace. This air provides the necessary oxygen for burning fuel (coal, oil, gas, or biomass). By maintaining positive pressure, the FD fan ensures that enough air enters the combustion chamber for efficient and complete combustion
Key Points About FD Fan:
- Purpose: To provide fresh air for combustion in the furnace.
- Airflow Direction: Pushes air into the furnace, creating positive pressure.
- Location: Installed at the inlet side of the boiler or furnace.
- Function: Helps maintain proper furnace temperature and improves fuel efficiency.
- Applications: Used in thermal power plants, industrial boilers, and other combustion systems.
How FD Fan Works:
- The fan draws atmospheric air from outside.
- The air is passed through an air preheater, where it gets heated.
- Then the fan forces this hot air into the furnace to support the burning of fuel.
Features of FD Fan
- Positive Pressure Creation – FD Fan forces air into the furnace, maintaining a positive pressure for proper combustion.
- High Airflow Capacity – Designed to supply a large volume of air to meet the fuel’s combustion requirements.
- Adjustable Air Supply – Air volume can be regulated according to load conditions of the boiler.
- Versatile Application – Suitable for thermal power plants, industrial boilers, and other combustion systems.
- Noise Reduction Features – Many FD fans are designed to operate with minimal vibration and noise.
- Compatibility with Air Preheater – Works efficiently with air preheaters to supply preheated air into the furnace.
What is an ID Fan – ID Fan Full Form
ID Fan stands for Induced Draft Fan, which is a type of industrial fan used in boilers, furnaces, and thermal power plants to draw out flue gases (exhaust gases) from the combustion chamber and discharge them into the atmosphere through the chimney. It works by creating a negative pressure inside the system, which helps maintain a smooth flow of air and fuel for efficient combustion.
Boiler ID Fan
In a boiler system, the Induced Draft (ID) Fan is used to extract the flue gases (hot exhaust gases) from the furnace/boiler and discharge them into the atmosphere through the chimney. It works by creating a negative pressure (vacuum effect) inside the boiler, which ensures a smooth flow of flue gases and helps maintain proper combustion.
Key Points About ID Fan:
- Purpose: To remove flue gases from the furnace after combustion.
- Airflow Direction: Pulls gases out of the furnace, creating negative pressure.
- Location: Installed at the outlet side of the boiler, usually before the chimney.
- Function: Maintains safe furnace pressure, supports proper combustion, and protects the boiler structure.
- Applications: Used in thermal power plants, industrial boilers, and other systems requiring exhaust gas management.
How ID Fan Works:
- Flue gases from combustion rise in the furnace.
- The ID Fan sucks out these gases, reducing pressure inside the furnace.
- The gases are then passed through dust collectors or electrostatic precipitators before being released through the chimney.
Features of ID Fan
- Negative Pressure Creation – Maintains negative pressure in the furnace for safe operation.
- High Exhaust Capacity – Efficiently removes large volumes of flue gases.
- Vibration and Noise Control – Designed to minimize vibration and operational noise.
- Supports Dust Control Systems – Works with ESPs or bag filters to control emissions.
- Load Flexibility – Can handle varying flue gas volume according to boiler load.
- Automatic or Manual Operation – Can be integrated into automatic boiler control systems.
- Enhances Combustion Efficiency – By maintaining proper negative pressure, it ensures complete combustion of fuel.
Key Differences Between FD Fan and ID Fan
| Feature | FD Fan | ID Fan |
|---|---|---|
| Purpose | To supply fresh air for combustion | To remove flue gases from the boiler furnace |
| Direction of Flow | Pushes air into the furnace | Pulls gases out of the furnace |
| Pressure | Creates positive pressure | Creates negative pressure |
| Position | At the inlet (before furnace) | At the outlet (after furnace) |
| Effect | Helps in fuel burning efficiency | Maintains safe and clean operation |
Importance of FD Fan and ID Fan in Industrial Applications
- Both fans are important for industrial operation to ensure safe, efficient and environmentally-friendly operations across industries.
- FD Fan (Forced Draft Fan): Sends air with pressure into the furnace, so that the fuel can burn completely.
- ID Fan (Induced Draft Fan): Removes flue gases and maintains negative pressure in the furnace.
Main importance:
- Increasing combustion efficiency
- Ensuring safe operation
- Improving production capacity
- Energy savings and cost control
- Reducing environmental pollution
Perfect Choice for FD Fan VS ID Fan
As a leading FD fan or ID fan manufacturer, we focus on its quality. We provide the best quality products and ensure reliable performance in their use. We always give priority to customer satisfaction, so we do not compromise on the quality and durability of our products. We well understand the difference between FD Fan and ID Fan and their features, functions, and applications needed in industrial operations. We committed toward the quality, reliability and durability of our machines.
Conclusion
Both FD Fans (Forced Draft Fans) and ID Fans (Induced Draft Fans) are essential components of industrial boiler and furnace systems. While FD Fans supply the required air for efficient fuel combustion, ID Fans remove flue gases and maintain negative pressure to ensure safe and smooth operation. Together, they improve combustion efficiency, energy savings, operational safety, and environmental performance. Understanding their differences, functions, and features is crucial for selecting the right fan system and optimizing industrial operations.
