Wastewater Case Studies

A Midwest facility replaced their multistage blowers with Inovair IM-20 Geared Centrifugal blowers and reduced power consumption by more than 45%


Challenge

The Kill Creek Water Resource Recovery Facility was looking for a way to reduce their power consumption at their plant, and investigated replacing their existing 125 HP multistage blowers with a more efficient option. The new blowers would need to operate on a constant pressure control loop as the plant also uses the blower air to run an air lift. Additionally, the plant was hoping the new blowers would reduce the heat dissipation into the blower room since during the summer months, as the blower room was very uncomfortable due to the heat from the existing blowers and small room size. The plant needed to meet all of these requirements on a limited budget.

Solution

Inovair was able to deliver on all of the requirements. The Inovair IM-20 was the perfect solution as it was designed to directly replace multi-stage blowers thus ensuring a low installation cost. The top discharge and small footprint allowed the Inovair IM-20 to be installed on the same pads as the existing multi-stage blowers and required minimal piping modifications. The direct drive high-efficiency IM-20 only needed 75 HP to meet the design flow 1350 SCFM @ 7.5 PSIG, which together with a compact footprint allowed the existing electrical to be reused. The increased blower efficiency delivered a 40% reduction in energy consumption vs the existing 125 HP blowers. Additionally, using the Inovair in-house designed control system, the plant was able to optimize its operation and reduce the power consumption by another 7% for a total savings of 47%. According to Scott Millholland - Kill Creek WRFF Superintendent “With over 45% energy savings compared to our previous multi-stage blowers, this project pays for itself very quickly”. A further benefit of the high efficiency of the Inovair IM-20 blower was a reduction in the blower room temperature by at least 15 Degree F.

Results

The Inovair IM-20 is the perfect solution for any blower replacement project, and in many instances can reuse the existing pads and electrical. For multistage centrifugal replacement, the small footprint and top discharge of the IM-20 ensures an easy trouble-free installation maintaining low installation costs. The high efficiency achieved with Inovair IM blowers will make any multi-stage replacement project pay for itself very quickly, many times within 2 years.

Inovair Delivers Substantial Turndown with Robust and Flexible, High Efficiency Solution

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 11:1 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 – 5500 SCFM) and two 100 HP in the other footprint (800 SCFM – 1750 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 500SCFM – 5500 SCFM or a 11:1 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.


Inovair Operating Trouble-Free in High-Pressure 24/7 Waste Treatment Application

A waste treatment plant in Arkansas was having issues with their screw PD blower reliably operating on their equalization tank. The blower had failed several times forcing the plant to operate with a spare blower. When the spare blower also started having issues, the plant reached out to Inovair to see if they could provide a more reliable option. The new blower would have to provide 1,750 ICFM @ 15.6 PSIG and also be able to operate at 19.0 PSIG with reduced flow. Because of the plant’s limited budget, they would need to be able to install the new blower themselves, re-use any electronics as well as any piping and appurtences. Also, as the spare blower was limping by, the plant would need delivery and installation of the new blower within six weeks. Because Inovair geared centrifugal blowers are designed for applications just like this, with the ability to operate up to 22 psig, Inovair was confident their proven reliable geared centrifugal blower would operate trouble-free in this application.

With the failed screw PD blower only a couple of years old, the plant asked if Inovair would be able to use the existing 150 HP VFD. The problems associated with the failures of the screw blower were due to the blower itself and the VFD was in good operational shape, and Inovair was able to re-use the existing VFD. The ability to re-use VFD's is a standard feature of the Inovair blower line and allows a plant to not only reduce capital costs but to reduce installation costs as well.

With the VFD already in place, all the plant had to do was remove the non-functioning screw blower and install the new Inovair IM-30 geared centrifugal blower. The Inovair IM-30 is shipped pre-wired and the low vibration characteristics of the blower mean that no special pads or mounting structure was necessary. The new Inovair blower package was shipped within four weeks of the purchase order, a full two weeks before the deadline. After a short 4-hour trip from Inovair’s manufacturing and testing campus, the new blower was installed in a few hours by plant personnel. Inovair field service technicians finalized the start-up process on the same day and the blower started as expected. The Inovair IM-30 has been operating trouble-free in this high-pressure application 24/7 ever since.


Mountain Community WRF improves performance and reliability of the blower systems

Due to increasing ammonia discharge requirements and aging equipment, a Montana Water Reclamation Facility (WRF) had to upgrade their waste treatment plant. The upgrade would include new blowers for their Sequential Batch Reactor (SBR), Waste Activated Sludge (WAS) holding tank, and the aerobic digester tank. The original specification called for hybrid/screw positive displacement blowers for all three processes, but after the plant engineer’s prior success using Inovair blowers at another plant, he changed the design of the new plant to include the Inovair IM-30 stack, which was a better solution because of the reliability, design flexibility, and ease of maintenance experienced by that plant.

The Inovair IM-30 stack blower was a perfect fit for these processes with Inovair’s ability to operate in varying pressure applications while having a small design footprint. This was extremely important since the new blowers would be in a small blower room and would need the flexibility to supply 820 SCFM to the aerobic digester tank and 970 SCFM to the WAS tank, while pressures would fluctuate between 5.5 – 9.6 psig. Additionally, each process blower stack would have to have the ability to be the redundant blower for the other process. The ability to stack the IM-30 modules made installation a breeze and the Inovair IM 2200 gearbox’s high damping, unlimited-life oil-film bearings ensured the blowers are operating seamlessly in either application independently or at the same time if the need arises.

After being in operation for over two years and with no down time, the plant is extremely happy with the performance and reliability of the Inovair Geared Centrifugal Blowers. Plant superintendent Russ S. said he loves the Inovair blower’s quietness, reliability, and ease to maintain compared other blower technologies. He should know, as he has two Screw PD blowers in the same blower room and has not had the same reliable and quiet operation as the Inovair IM-30 stack.

Inovair Reduces Annual Energy Costs By More than 25% and Improves Process Control

An Ohio WWTP replaced its multi-stage centrifugal blowers with Inovair direct drive Modular (IM) model integrally-geared turbo blowers. The high efficiency blowers and improved dynamic control reduced the plant’s annual energy costs.

Project Background

In 2016, the wastewater aeration system was consuming approximately 50% of the total electricity at the Pickerington, OH plant. Knowing Inovair’s direct drive Modular (IM) model integrally-geared turbo blower provided the lowest total cost of ownership over other High-Speed Turbo Blowers Pickerington reached out to Inovair to apply their solution to lower the existing power costs and improve DO control. The existing blowers operated at a constant speed and used an inlet throttling valve to regulate flow. The existing blowers had been moved into the new blower building in 2010. However, the three (3) 100 HP existing blowers were difficult to control, very inefficient, and had limited turndown. Because of the compact footprint, self-contained motor, and ability to use the existing electrical and discharge piping/components the City of Pickerington chose to act as their own General Contractor to install the more efficient and dynamically controlled Inovair Blowers.

Challenge

The goal was to reduce the annual energy costs of the blowers as well as improve DO control which would additionally help lower energy use. The plant had three (3) constant speed 100 HP multi-stage centrifugal blowers two (2) multistage blowers ran 24/7during the summer and one (1) ran during the winter, delivering a maximum of 2750 SCFM throughout the year. The existing multistage centrifugal blowers had a design flow of 1375 SCFM each at a discharge pressure of 8.50 PSIG. These blowers were constant speed and utilized an inlet throttling valve to control the output flow. This limited control of the blowers allowed the DO levels to fluctuate as ambient conditions changed.

Solution

Utilizing Inovair’s selection software it was determined the Inovair IM integrally-geared high speed turbo blower could meet the same design conditions with 75 HP blowers and upon installation the plant could immediately reduce their blower’s power consumption by over 25%. The Inovair direct drive Modular (IM) model integrally-geared turbo blower turndown range gave the plant operational flexibility that was not previously possible; additionally, the onboard PLC which automatically controls the blowers’ airflow based on ambient conditions was able to tighten up the fluctuating DO levels in the aeration basins. This control ability resulted in less airflow with limited operator input thus contributing to the overall blower system efficiency and cost savings. Thanks to Inovair’s blowers’ energy efficiency and a dynamic control of airflow the energy consumption went down by almost 350,000 kWh, reducing energy bills by over $26,000. Combining the low initial capital cost, installation costs, and energy savings the payback was substantially faster than would be possible with other blower technologies.

The Inovair IM-30 Stacked Blower Operates Efficiently and Reliability in a Digester Application with Pressures as High as 18.0 PSIG


In 2018, an Idaho treatment plant installed a new digester tank and because of limited space had to utilize a deeper than normal tank. For proper operation of this new digester process the new blowers would need to operate at flows between 400 SCFM and 1,200 SCFM and a pressure range of 7.0 PSIG -18.0 PSIG.

With our proven-reliable gear drive and unlimited-life oil-film bearings, Inovair blowers were ideal for this type of application—Inovair blowers are designed to operate in pressures as high as 22.0 psig. The robust design of the gear drive and stability of the oil-film bearings has allowed the Inovair blower to operate in this type of application where PD and centrifugal blowers (including multi-stage and gearless turbos) cannot efficiently operate. Over the last two years the Inovair IM-30 geared centrifugal blower has performed as designed for this difficult application. The Inovair IM-30 blower has operated with flows as low as 400 SCFM at a pressure of 7.0 PSIG pressures and flows as high as 1,200 SCFM with at a pressure of 18.0 PSIG.

The digester tank wasn’t the only place where space was limited—the blower room also had space constraints. Because of the limited space, the plant opted to use the stacked version of the IM-30 geared centrifugal blower. Having the flexibility to stack two blower modules together reduced the installed footprint by over 50% and since each module can operate independently, the plant was able to stack the stand-by blower with another process blower. The plant therefore was able to install 4 125HP blowers in the space of two blowers.

The design flexibility of the IM-30 stack and proven reliability in varying pressure applications makes the Inovair geared centrifugal blower the right choice for most waste water treatment applications.

37% Energy Savings and Improved Reliability

A wastewater treatment plant in the Midwest replaced 2 of their 4 PD blowers with integrally geared turbo blowers in a nitrification-denitrification process. This resulted in over 35% less energy used by the integrally geared centrifugal blowers along with improved process control. Phase 2 replaced the 2 remaining active rotary lobe blowers with an additional pair of integrally geared turbo blowers, this pair having about 7% higher flow capacity relative to the first pair, and resulted in over 40% energy savings relative to the rotary lobe blowers. This total energy savings can be broken into 2 components: energy saved due to increased wire to air efficiency of the blower package and energy saved due to process improvements. It is estimated that wire to air efficiency accounts for approximately three-quarters of the savings while process improvement accounts for one-quarter of the total savings. This blower replacement was partially funded through an Energy Conservation Grant and the energy savings were independently verified by a third-party.

Reliable and Efficient Digester Application

The Valley Center WWTP in Escondido, CA replaced the PD blowers on their digester with more reliable and energy efficient Inovair (IO) Integrally Geared Turbo blowers. The Integrally Geared Turbo Blowers drastically improved the reliability of the process while substantially reducing the power consumption.

Project Background

In 2013 Valley Center started an evaluation process to replace their existing 75 HP PD Blowers. The existing blowers were only a few years old but were experiencing frequent down time and becoming a drain on the maintenance budget. In order to replace the existing blowers with more reliable blowers the utility decided to evaluate different blower technologies including PD blowers, gearless turbo blowers, and integrally-geared blowers, for the best solution. The utility would buy one unit at first and if their evaluation proved true would by a second unit within one year. The evaluation process would compare capital cost, power consumption, reliability, and design flexibility. Additionally, the digester process would require blowers which could reliably operate with varying water depths, from 8’ to 24’, as well as daily starts and stops. After thoroughly reviewing all five (5) proposals and even conducting a plant trial with one of the competitors Valley Center chose Inovair as their blower supplier.

Solution

The Inovair (IO) blower’s competitive price, compact size, high efficiency, reliability, and flexibility were all deciding factors in the in the selection of Inovair. The Inovair (IO) Integrally Geared Turbo blower’s compact size, W34" x L40" x H71", was a perfect fit for the eighty-six square foot blower room and could be easily installed through the 36” man door without any disassembly. The high adiabatic efficiency of the Inovair (IO) ensured a quick return on investment. Inovair being the only high-speed turbo blower which uses industry standard Variable Frequency Drives (VFD) and motors, allowed Valley Center to procure and use their preferred VFD. According to the plant operator “The ability to locally source the VFD and motor gives you piece of mind.” Additionally, the Inovair Blower was able to meet the required flows with a 60 HP motor. This was a 20% reduction in installed HP from the existing blowers as well the custom-built motors of the PD blowers. This product flexibility coupled with the reliability of the non-contact oil-film bearing and proved to be the best choice for Valley Center.

With the large operational discharge pressures required, 3.5 PSIG to 10.4 PSIG, and daily starts/stops the Inovair (IO) Blower was well suited for this application. Historically this type of application had been a concern for gearless high-speed turbo blowers. However, the robust integrally geared design of the Inovair Blower, which provides shaft stability throughout the operational range and the continuous oil film ensures there is no contact between the high-speed shaft and bearings during the start/stop process, eliminated this concern. This ability to operate reliably within these parameters was crucial in the selection. The plant is very happy with their selection “We are very happy with Inovair and their product, the blowers have eliminated our downtime and are running as advertised.”

Results

After six months in operation Valley Center purchased a second Inovair IO blower package, and after 5 years in operation and over 2000 starts/stops the Inovair (IO) Integrally Geared Turbo Blowers have operated flawlessly in this tough application. The Inovair (IO) Integrally Geared Turbo blower is not only robust but also efficient, reducing both maintenance and operational costs.

Inovair Installation from early 2013 Reduces Energy Consumption and Noise in an Outdoor Digester Project

In 2013 Nixa, MO WWTP replaced its positive displacement (PD) blowers with more efficient Inovair (IE) model integrally-geared turbo blowers. The high efficiency blowers reduced the installed horsepower required by the existing blowers while reducing the noise level. The Nixa facility was also able to maintain low installation costs by reusing the existing MCC and installing the Inovair blowers outdoors in the same location of the old blowers without any additional expensive canopy or blower building.

Project Background

In 2013, Nixa’s wastewater digester system was overtaxed due to the rapid population growth of the area. To treat the increased capacity, additional diffusers and additional blowers were needed. Because the existing PD blowers were noisy and inefficient, Nixa wanted a more efficient and quiet solution. Their existing 75 HP PD blowers were installed outdoors near the digester, uncovered and approximately 100 feet from the office and control room. The pulsing of the existing PD blowers could be heard throughout the office and control room. Nixa wanted a reliable high efficiency solution which could be utilized outdoors and without a cover. Thus, the challenge for the Nixa facility was to keep the current blower location for budget purposes but still have smoother, quieter operating blowers and use the existing MCC. The addition of a new MCC room or blower building would have made the project too expensive. Knowing Inovair’s (IE) model integrally-geared turbo blower would provide the lowest total cost of ownership while also meeting the plants goals on noise and efficiency, Nixa worked with Inovair to apply their solution.

Solution

Inovair’s (IE) model integrally-geared turbo blower package was the perfect solution for Nixa. The robust (IE) integrated blower enclosure, which is designed to be installed outdoors without any additional protection or cover while also reducing sound1, was the perfect solution to meet the plant’s requirements. The plant operators were incredibly happy being able to install the new blowers in the same location while reducing the bothersome noise associated with the old blowers. The sound reduction was instantly noticed, and the plant operator remarked “We are ecstatic on how quiet they are compared to the old blowers”.

A big concern for other high-speed turbo blowers is contamination from the environment such as dirt, dust, and pollen. Inovair blower packages draw the process air directly into the impeller through a filter, which removes 98% of particles 10 micron or larger, ensuring that there is no bypass air around outdated panel filters or through poorly constructed enclosures negatively affecting the life of the blower. Additionally, the highly efficient air end of the Inovair (IE) model blowers allowed Inovair to meet the required flow with only 50 HP which is 33% lower HP than the 75HP required by the previous PD blowers. This highly reliable integrally-geared airhead with non-contact oil-film bearings on the high-speed shaft has eliminated any unplanned downtime and the blowers have been available for service 99% of the time. With only minor routine maintenance needed, the plant has been extremely happy with the performance and reliability of the Inovair (IE) model integrally-geared turbo blower. Nixa facility management remarked “We love how easy these are to maintain.“ An added benefit has been the realization that since Inovair uses industry standard motors the plant has piece of mind if there is ever a need to replace the motor. They could locally supply or easily service the motor. Inovair’s ability to connect to the existing MCC was crucial to avoid any budget over runs and the ability to use a lower HP due to its high efficiency ensured there were no expensive MCC room upgrades. Because of the design advantages of the this integrally-geared turbo blower package, Inovair was the only manufacturer to be able to meet all of the requirements for the Nixa WWTP plant upgrade and do it within budget. Over the last six years the Inovair blower has proven to provide the lowest total cost of ownership.
1The Inovair IM model also provides these benefits, but was not yet available at the time of Nixa’s project


Not Your Typical Turbo Blower

A wastewater treatment plant in New Holstein, WI replaced the PD blowers utilized in thir aeration and digester processes with Inovair integrally geared turbo blowers. The PD blowers were inefficient and unreliable, at the end of their useful life. This project resulted in not only substantially energy savings and improved process control, but also substantially improved reliability. A unique aspect of the digester process was a high number of start/stop cycles, with some blowers having over 60 start/stop cycles in a single day. A case study of these blower improvements was presented at the Wisconsin Wastewater Operator’s Association conference in 2016.


Operates on Same Header with Multi-Stage Centrifugals

Inovair replaced an aging multi-stage centrifugal blowers in two separate applications at this New York plant. Inovair blowers operate alongside and on the same discharge header as the remaining centrifugals. With a wider turndown ability than the existing centrifugals, the Inovair blowers function as energy-saving trim blowers.
Flow:890 scfm / 1320 scfm
Pressure:9.2 psig / 8.9 psig
Horsepower:50 HP / 75 HP

Wide Operational Range

Customer was looking for a cost effective solution that could provide good energy savings and a wide operational range. They are close to a residential area and need an option that was much quieter than their original PD blowers.
Flow:965 scfm
Pressure:9.0 psig
Horsepower:60 HP

High Efficiency SBR System

A new lagoon process technology involves intermittent decants, requiring the blowers to start and stop multiple times per day. Inovair blowers were selected for this ability, coupled with a need to cut high electrical costs previously experienced with the original positive displacement blowers.
Flow:965 scfm
Pressure:9.0 psig
Horsepower:60 HP


Lagoon Application

A central Illinois town with a lagoon system and no additional treatment process was unable to meet their states new requirements. They investigated several alternatives and decided on diffused air as the most cost effective solution. They reached out to a local supplier of diffused air systems for lagoons who offers both PD and Inovair blowers with their systems. The customer chose Inovair because of its higher efficiency and the temperature compensation feature of their built in controls. This feature provides consistent oxygen delivery over the wide varying temperatures they experience in the Midwest, as well as, additional energy savings over the PD offering.
Flow:575 scfm
Pressure:10 psig
Horsepower:40 HP

MBR Application

A national beverage manufacturer in central Florida needed to upgrade their lagoon (with high speed floating aerators) to meet increased production. Timing demanded the design-build project occur on a very fast pace. An MBR was chosen to meet their production needs, as well as, to minimize environmental impact. Inovair was selected because of their high efficiency and robust design capable of handling the harsh Florida environment, as well as, their ability to deliver on a shortened time frame. Although the project had several challenges during the start-up phase, Inovair was commended for their service and willingness to help the plant through these initial issues. The plant is now operating at peak efficiency and meeting its goal of being an environmental steward for the company.
Flow:1,100 scfm
Pressure:11 psig
Horsepower:75 HP