The Town of Ipswich in Massachusetts, USA has reduced the energy consumption in its wastewater treatment plant’s blower room by 47%. This has been achieved by upgrading its blower station with four KAESER rotary screw blowers, controlled by a SIGMA AIR MANAGER 4.0.
The Town of Ipswich has a history of advocating for the responsible use of rate payer funds dating back to 1687, and a tradition that continues today. When their wastewater treatment plant (WWTP) required a new aeration system, they sought a solution that provided long-term value. Working with consulting firm Tighe & Bond, they leveraged Massachusetts Chapter 30B’s pre-selection process to assess lifecycle costs, efficiency, and supplier qualifications. This approach ensured they could select the best system based on overall value rather than just upfront cost.
Project Scope
Upgrading aeration efficiency for sustainable wastewater treatment
The Ipswich WWTP’s existing turbo blowers were ageing, oversized, and unable to adjust to the plant’s variable oxygen demands efficiently. The plant needed a system that could provide better turn-down control, adapt to fluctuating loads caused by diurnal swings and daytime septage loadings, and improve total nitrogen removal. The project scope included the replacement of two ageing 55 kW (75 HP) geared turbo blowers.
KAESER Solution
The Midas touch
The new KAESER system at the Ipswich wastewater treatment plant has improved efficiency and lowered operation costs.
After careful evaluation, KAESER Compressors was chosen for its ability to meet the plant’s strict aeration and energy efficiency requirements.
KAESER and Tech Sales NE collaborated with the engineering team and contractor throughout the design, installation, and testing phases. The chosen solution included four KAESER EBS 410 CL SFC rotary screw blowers with variable speed control and 37 kW (50 HP) motors, a SIGMA AIR MANAGER 4.0 (SAM 4.0) master blower station controller, along with new aeration control PLCs, updated valves, reconfigured piping, and new flow meters.
This configuration expanded the plant’s station flow range from 510 to 9,516 Nm3/h (300 to 5,600 SCFM), compared to the previous system’s 1,869 to 7,816 Nm3/h (1,100 to 4,600 SCFM). The SAM 4.0 controller dynamically adjusts pressure setpoints, ensuring optimal efficiency by automatically balancing blower loads and providing redundancy.
With pandemic-related supply chain delays affecting project timelines, KAESER provided a complimentary rental blower, while Tech Sales NE supplied a generator and necessary piping to keep the project on schedule. This temporary setup allowed the plant to continue operations without disruption while awaiting permanent equipment installation.
Project Outcomes
The gold standard in performance
The plant’s dedicated power meter provided precise data on energy consumption before and after the upgrade. Post-installation analysis showed that the blower room’s energy consumption decreased by an average of 47%.
The new rotary screw blowers from KAESER not only offered superior turn-down control and higher peak airflow, but they also delivered consistent efficiency across all operating speeds - unlike turbo blowers, which tend to lose efficiency at lower speeds.
By optimizing blower performance and reducing energy waste, the plant significantly lowered operating costs, benefiting both municipal budgets and rate payers. The upgrade also ensured more stable dissolved oxygen levels within the activated sludge process, improving overall wastewater treatment performance.
The SAM 4.0 controller dynamically adjusts pressure setpoints, ensuring optimal efficiency by automatically balancing blower loads and providing redundancy.
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