Background / Issues
99% of households in Germany are linked to wastewater treatment plants and are using these essential facilities daily. Wastewater treatment plants are required to purify and circulate wastewater, non-stop, 365 days a year so that it can be safely returned to rivers and waterways.
However, at the wastewater treatment plant of Germany’s public utility company Stadtwerke Rotenburg an der Fulda, failures frequently occurred due to problems with the design. When partial mechanical damage occurred, an entire pump needed to be replaced, thereby incurring unplanned costs in addition to the service downtime. In order to protect people’s livelihood, it became necessary to find solutions to prevent failures by discovering issues at an early stage.
At Stadtwerke Rotenburg a.d. Fulda, a condition monitoring solution was implemented in order to solve failure issues at the wastewater treatment facilities.
Through detailed monitoring and data analysis, we observed vibration changes at an early stage which are normally undetectable by humans. By sending out real-time alerts before the vibrations get to a critical level, maintenance could be scheduled so parts could be replaced prior to failures occurring. By preventing failures, pumps were able to be used with minimum downtime, thereby creating substantial cost reduction. Moreover, a 24-hour nonstop, stable and efficient operation, which is an essential element of public infrastructure, was realized.
Successfully maintaining up-time while reducing the cost of failure by 30%
Repairs after a failure can cause inestimable costs and extended outages during the repair period, but this monitoring solution enables preventive maintenance to be planned and executed at the optimal time, reducing both cost and downtime. In this particular case, due to the particular failure condition, the repair costs were reduced by 30%.
Moreover, the operational efficiency of the plant as a whole was improved by minimizing pump lifecycle costs – such as only replacing worn parts when needed, whereas in the past the pump’s entire motor and gearbox needed to be replaced even when the damage was only partial.
STEP IA2 :Data collecting
STEP IIC2 :Analyze/utilize data (real-time processing of data)
STEP IIID2 :Optimizing the workplace
To be able to catch failures ahead of time a Condition Monitoring System was implemented. This process began by installing additional vibration sensors to collect operational data which was analyzed in real-time to detect early signs of failure and then send out pre-emptive alerts to maintenance staff. Furthermore, all data was reported back to a remote control center so that further optimization and comparison between multiple pump systems could be made.
Michael Böttner, programmer at Willich, the system’s integrator working with Stadtwerke Rotenburg, and who proposed the monitoring system implementation to Rotenburg, said, “Since the test results were so good at Rotenburg, we can easily clarify the solutions benefits when proposing it to customers in the future,”.