When we took up this project at a steel plant, the main concern was that the furnace fumes and heat were not being captured effectively.
The area around the furnace was heavily exposed to hot fumes, and the existing exhaust arrangement could not maintain the required airflow consistently.
The challenge was that this was not a normal ventilation application. We were dealing with high temperatures, continuous furnace operation, and particulate-laden fumes. So, selecting a fan based only on CFM would not have worked.
The first thing we looked at was the furnace’s actual operating conditions.
We studied the furnace temperature, required airflow, duct layout, pressure losses, and the nature of the fumes. We also looked at how close we could bring the fume capture points to the source without interfering with furnace operations.
From there, we worked backwards to select the fan and design the exhaust arrangement.
For this application, we selected a high-temperature centrifugal fan suitable for the required airflow and static pressure. We selected fan construction and supporting keeping the operating temperature in mind.
One mistake we wanted to avoid was allowing excessive furnace heat to reach the fan and downstream equipment.
We therefore considered the temperature at different points in the system and incorporated the necessary provisions to keep the equipment within its safe operating range.
We paid particular attention to:
Fan construction and material selection
Heat-resistant components
Cooling or dilution requirements
Duct expansion due to temperature
Bearing and drive arrangement
Maintenance access
Our objective was not simply to install a powerful exhaust fan. The entire system had to work reliably under actual furnace conditions.
After commissioning, furnace fumes were captured more effectively, and the working area around the furnace had noticeably better ventilation.
What stood out to us from this project was that high-temperature fume extraction cannot be treated as a standard exhaust application. The fan, ductwork, capture arrangement, temperature, and downstream equipment must be considered together.
A fan with the right CFM but the wrong temperature rating or pressure selection can create problems later. We prefer to address those issues during the engineering stage rather than after installation.
