Overview:
A Midwest steel plant needed a ventilation solution for their hot strip mill building where slabs of steel are rolled into steel coils. The plant produces carbon, stainless, and electrical steels; hot and cold-rolled steel; as well as aluminum-coated stainless steel. The hot strip mill building had been ventilated with upblast roof exhaust fans, which were difficult to access for maintenance. As a result, the roof exhaust fan bearing began to fail, necessitating a prompt solution.
The obvious solution seemed to be replacing the roof ventilators with newer units, but this fix would mean the same accessibility issues, and likely lead to further failures. Alternatively, the steel plant opted to place fans through the side of the building, allowing for maintenance accessibility from the outside of the structure.
The plant planned to install one fan to prove the concept and purchase more if the fan met their requirements. Aerovent was selected for the project.
Problem:
The ventilation fan needed to remove fumes, heat, and moisture from the building. Constant exposure to heat and moisture in the tough steel mill environment meant that the fan selected would have to perform reliability in these challenging conditions.
After discussing the ventilation, installation and fan requirements, the Aerovent representative determined that the plant would require a custom-designed swing-out panel fan with a wall box, inlet screen, and outlet damper. The damper would need to be mounted outside of the mounting adapter, and would have to be split into two pieces and hinged to permit access.
The damper would be located on the outside of the assembly and the fan was to be designed to mount rigidly inside the wall mounted section of the hinged mounting adapter. The finished assembly would be installed about 50 feet high through the side of the building.
An additional fan requirement was that it would have parts that were removable from the outside of the building so the main fan components could be accessed by maintenance tech using a lift bucket. Other fan requirements included a direct drive motor, heavy duty construction, corrosion resistance, and easy installation.
Solution:
An Aerovent DDPRC direct-drive, reverse-construction panel fan was selected for the project to meet the access requirements. The fans could be serviced from outside the building, a huge improvement over the previous fans which had to be removed for service by helicopter in a highly expensive process.
The 48-inch 5HP fan exhausts 35,000 CFM of air at 0.125-inch static pressure, which allows for the mounting adapter and louvers. The heavy duty fan has a solid cast aluminum propeller, and a corrosion resistant epoxy coating to withstand the harsh conditions.
Result:
Aerovent developed a custom-designed swing-out panel fan to provide ventilation for the hot strip mill building. The Aerovent solution satisfied the ventilation requirements while also meeting the accessibility needs.
In addition to reliability, easy access, and ease of installation, the steel plant’s new fan is
easy to maintain. Per the plant’s request, the fan has a direct drive configuration with no belt, sheaves, or extra bearings to maintain. It’s all-welded solid construction and solid cast aluminum propeller made it the ideal fan for the application.
The plant has been very happy with the Aerovent fan, and has since ordered several more. The ultimate plan is to install nearly 40 fans like this one to accomplish the required amount of ventilation needed for building.