When Bemidji Steel expanded their laser cutting operations, they built a new building to support the additional machinery. They turned to Fluid-Aire Dynamics (FAD) for expert compressed air system design and installation. FAD’s solution gives them the clean, dry air they need for nitrogen generation and air tools and provides flexibility to support future growth.
Challenge: Clean, Dry Compressed Air for Nitrogen Generation
Bemidji Steel, founded in 1983, is a national distributor of steel and aluminum products, including sheet, plate, tubing, beams, rods and structural steel. In 2017, they started offering value-added services, including precision laser cutting and forming. To keep up with growing demand, they built a new fabrication facility to house their equipment and production lines.
The new facility currently runs four lasers (flat and tube). They also have metal-forming equipment and various pneumatic tools, such as air hammers. The laser equipment relies on high-purity, high-pressure nitrogen (N2) to prevent oxidation and maintain cut quality. Bemidji Steel uses a NitroCube5 membrane nitrogen generator capable of producing up to 1200 m3 of high-purity nitrogen per day. To meet nitrogen purity requirements, they need a consistent supply of clean, dry compressed air going into the nitrogen generator. Bemidji Steel wanted a compressed air system that would ensure air quality and have enough redundancy to prevent unplanned downtime and support future growth.
The Fluid-Aire Dynamics Solution
Bemidji Steel brought Fluid-Aire in at the beginning of the new build, while the facility was still a blank slate. FAD designed the new system from the ground up for optimal efficiency and performance, including compressor selection, storage, air treatment and distribution system.
The system relies on two 60HP PneuTech rotary screw air compressors (RK-60). This provides complete redundancy; the company can run all their air-using processes, including nitrogen generation, off one of the compressors. They cycle between the two compressors to extend the service life of both. This ensures that they always have plenty of air to run operations, even while one machine is offline for maintenance.
"Fluid-Aire is in the long-term planning process with us. It's not just a one-time sale. They're looking to grow with us and spec out the system to be able to support that growth."
Tobias Glen, Director of Manufacturing, Bemidji Steel
Air treatment is an important consideration for N2 generation. Air coming out of the compressor goes first into an oil/water separator and then into a desiccant air dryer (Great Lakes GPS-500-116), which is capable of achieving dewpoints as low as -40°F. Inline filtration before and after the air dryer removes particulates and oil carryover for optimal air purity. A dry air receiver tank installed after the desiccant dryers ensures consistent supply and pressure for nitrogen generation and air tools. The compressors are housed in a dedicated compressor room; waste heat is captured to offset facility heating costs in the winter. An efficient aluminum loop-style distribution system from Unipipe carries air where it is needed. Unipipe piping also delivers nitrogen from the membrane generator to the laser cutters.
Results: An Efficient and Scalable Compressed Air System
The new system provides the reliability and performance they need to power operations today while giving them room to grow in the future. With two 60HP compressors, they have the ability to add more lasers or a more powerful nitrogen generator without adding compressed air capacity immediately. The system is modular, and there is enough room in the compressor room to eventually add a third compressor if needed. The Unipipe distribution system also makes it easy to change configurations or add air drops if they expand their production lines.
Bemidji Steel appreciates the partnership they have developed with Fluid-Aire over the course of the project. FAD even helped them resell their used compressor (a 40HP) to offset the costs of their new system. Alex Grasdalen, Chief Operating Officer for Bemidji Steel, says, “[This project] shows the extremely high level of partnership and mutual respect we have with Fluid-Aire. We don’t really have that with any other vendors.”
As Bemidji Steel continues to evolve their business, Fluid-Aire Dynamics will be there with them to help them grow. FAD provided a scalable, energy-efficient solution that addressed their immediate needs and laid a strong foundation for future expansion.
