A municipal wastewater treatment plant in the Southeast needed to upgrade its aerobic digesters to better process the wastewater demands of the city. It was important the upgrades be efficient, low cost, and reliable for their 8.25 MGD plant. Since the city was also growing rapidly, the design also had to be flexible to meet likely future demands.
All current blower technologies were reviewed and Inovair was determined to be the best solution for the plant’s requirements. The Inovair IM-30 stacked blower, designed and built in Kansas City, checked all of the boxes when it came to being competitively priced, efficient, reliable, and flexible. Additionally, because of Inovair’s weather-resistant design, the geared centrifugal blower could be installed outdoors adjacent to the digesters eliminating the need for a separate blower room required by some other technologies, resulting in considerable construction-cost savings.
At this plant, the blowers would need to be able to operate over a range of discharge pressures to accommodate digesters’ varying water levels. The Inovair 2200 gearbox with non-contact oil film bearings is ideal for this application. Because of the superior damping ability of these bearings compared to air bearings or traditional bearings the Inovair IM-30 could easily handle the 3 psi pressure swing seen in the digester application. In fact, the IM-30 can reliably operate in single applications encompassing a pressure range as low as 2 psi or as high as 22 psi.
The most decisive factor in selecting Inovair for the this digester upgrade was the operational flexibility of the Inovair IM-30. The industry-exclusive stacked option allowed Inovair to efficiently provide an 8.8:1 turndown within two footprints. This modular design allowed Inovair to supply a 50 HP blower and a 100 HP in the one footprint (500 SCFM – 2,650 SCFM) and two 100 HP in the other footprint (800 SCFM – 1,750 SCFM, in which one of the units was the required stand-by blower). This means in two footprints the Inovair IM-30 was able to provide 500 SCFM – 4,400 SCFM or a 8.8:1 flow ratio. This industry-leading design offered operational optimization not typically seen in so few footprints. Having the ability to turn off a blower when not needed is the ultimate in energy savings. Without the ability to stack lower HP blowers, the utility would have had to install two (2) 200 HP blowers with at best 3:1 turndown which would mean during some operational conditions air (and the power used to create it) would be wasted, costing the utility with no benefit. With the Inovair stacked IM-30, the utility can optimize blower performance to provide the exact amount of air needed to the process and avoid unnecessary costs.
An additional positive factor was that Inovair is a vertically integrated manufacturer. This means Inovair controls the entire process, in house - the design, manufacture, assembly and service of its geared centrifugal blowers. Being a vertically integrated manufacturer, along with being the sister company of ProCharger (the world’s leading automotive aftermarket supercharger manufacturer), allows Inovair to utilize economies of scale. Inovair’s cutting-edge efficiency and flexibility, along with the low acquisition and construction costs, have allowed this plant to reliably and efficiently run its upgraded digester process.