![](https://www.aiche.org/sites/default/files/images/conference/logo/2022_spring_gcps_logo_cmyk.png)
![](https://www.aiche.org/sites/default/files/images/conference/logo/2022_spring_gcps_logo_cmyk.png)
METHOD OF FAN CONTROLS
Brad Smith
Senior Sales Manager
Twin City Clarage, LLP
Mike Lowe
Senior Sales Application Engineer
Twin City Clarage, LLP
Prepared for Presentation at the 2022 Spring Meeting
San Antonio, Texas, April 14-14, 2022
AIChE and the EPC shall not be responsible for statements or opinions contained papers or printed in its publications.
METHODS OF FAN CONTROLS
Brad Smith, P.Eng.
Senior Sales Manager
Twin City Clarage, LLP
Mike Lowe
Senior Sales Application Engineer
Twin City Clarage, LLP
Abstract:
With the increase in environmental emission regulations, the designs of the Ethylene plant auxiliary equipment (such as fired heaters, furnaces, and fired boilers) has put more strain on the turn down requirements of the centrifugal fans. The low NOx emission regulations sometimes require low turn to start up the auxiliary equipment. This paper will explain the various methods to control the centrifugal fan; including pre-spin and resistance dampers, speed control, and airflow recirculation:
- Inlet louver damper (ILD)
- Variable inlet vane damper (VIV)
- Outlet louver damper (OLD)
- Variable speed drive (VFD)
- By-pass recirculation duct and FGR dampers
Along with providing a complete description of each method of control, this paper will also use of a combination of two methods, such as:
- Inlet louver damper (ILD) or variable inlet vane damper (VIV) and variable speed drive (VFD)
- Inlet louver damper (ILD) and by-pass recirculation duct
- Inlet louver damper (ILD) or variable inlet vane damper (VIV) and outlet louver damper (OLD)
Finally, we will present a case study where combustion air (FD) fan on an industrial boiler is designed with using an ILD, OLD, and by-pass recirculation duct installed to reach low-fire startup condition.