In industrial settings, ID (Induced Draft) fans and FD (Forced Draft) fans are commonly used to control the flow of air or gas in various systems. The main difference between these two types of fans lies in their function and the direction of airflow.
ID Fan (Induced Draft Fan): An ID fan is typically installed at the outlet of a system or equipment. Its primary purpose is to create negative pressure or suction, which induces airflow in the system. The ID fan draws the air or gas from the system and exhausts it to the atmosphere. This type of fan is commonly used in applications such as industrial boilers, thermal power plants, and process systems where a suction force is needed to remove combustion gases, fumes, or exhaust from the system.
FD Fan (Forced Draft Fan): An FD fan is generally positioned at the inlet of a system or equipment. It functions by providing positive pressure to force air or gas into the system. The FD fan pushes or supplies air or gas into the system against the resistance offered by the system's ducts, filters, and other components. It helps in maintaining the desired airflow and pressure within the system. FD fans are commonly used in applications like industrial furnaces, HVAC systems, and air pollution control systems.
To summarize:
- ID fans create negative pressure and draw air or gas out of the system.
- FD fans provide positive pressure and force air or gas into the system.
Both ID fans and FD fans play crucial roles in maintaining proper airflow, pressure, and overall system performance in various industrial processes. Their specific placement and functions depend on the requirements and design of the system they are installed in.