Blowers for aeration tank oxygenation
Reduce electrical energy demand by more than 20 percent! This dream was made a reality through modernisation of the old air compression system with a new blower station from Kaeser Kompressoren.
After 14 years of operation, the central blower station at a municipal wastewater treatment plant with a 85,000 population equivalent needed to be modernised. Produced by four ageing frequency-controlled rotary lobe blowers, the compressed air was distributed to the individual aeration zones via a header pipe equipped with gate control valves. Key requirements for the new compressed air production concept included a significant reduction in electrical energy requirement and better adaptation of the interconnected compressed air producing equipment to, for example, seasonal heavily fluctuating air demand resulting from the grape harvest. Half of all cascades are intermittently aerated. Furthermore, the new compressors, as well as all associated necessary components for operation, had to pass a performance inspection as per ISO 1217 Annex C or E prior to delivery.
Following meticulous analysis of the seasonal air demand and operating pressure, and after drawing on decades of compressed air engineering experience, the Kaeser experts came up with a solution that enabled every demand point to be met with minimal use of machines and loss-associated frequency control: two EB 380S-SFC (each 55kW, frequency controlled) type rotary screw blowers, one EB 380S-STC (37kW, Y/D-starter) and one BB 89C-STC (11kW, Y/D-starter) rotary lobe blower.
A control range of 315 to 5515 Nm³/h (approx. 1:17) was achieved for the produced compressed air. The SIGMA AIR MANAGER master controller actuates the most effective combination of machines in order to meet actual requirement. This powerful controller also manages back-up capacities in the event of machine shutdown or if servicing is required. The SIGMA AIR MANAGER communicates via data bus with the process control system, exchanges operating and status data and simultaneously implements pressure regulation.
When looking at comparable reference periods over the last few years, energy production requirement has been reduced by 23 percent, which is even better than expected.
Furthermore, the compressor station - which is ventilated with ambient air in the machine room - was completely unaffected by the record-breaking 40+ °C heat of 2015, since KAESER rotary screw blowers are designed to operate at ambient temperatures of up to 45°C as standard.
Last, but not least, should optimisation be required - whether from a mechanical, machine controller, electrical, operational or compressor communications perspective - a contact person is available who can be on-site quickly and who can seamlessly examine and reproduce these operational interrelationships – according to operators, this provides the perfect solution in combination with KAESER Service.