Transforming water plant equipment maintenance through condition-based monitoring

Wastewater and water treatment equipment is susceptible to failure for many reasons. Equipment networks are dispersed across a wide range of locations, most are unmanned which means many of the assets tend to receive limited, structured maintenance. There are many incidents when maintenance is reactive only when a failure is reported which is always costly. Having the ability to easily monitor a wide range of industrial equipment and detect the early onset of problems increases operational efficiency and maximises the effectiveness of maintenance resources.

In water operations and particularly in wastewater, many of the remote assets such as pumps and motors are often the root cause of problems – however the problem can be identified further through the system. This can make troubleshooting difficult, costly and time consuming. Added to this, the unpredictable nature of the external environment caused by elements such as rainfall levels, debris and sewage levels can further complicate plant management. The current estimate for the cost of maintenance of wastewater treatment plants is between 15-25% of total operational costs (Source: Hamburg Public Sewage). This is dependent on the age and historical maintenance levels of the plant equipment. We have seen figures that suggest reactive maintenance is the most expensive with the cost currently estimated at £5M-£15M per annum for a UK WASC to maintain a large sewage pumping station. These figures show there is a clear need to balance the visibility of the condition of the wastewater equipment and costs of monitoring.

Normally vibration is seen as a bad thing in plant equipment and something that engineers try to remove, but it can hold a vital clue on the condition of motors, pumps and other equipment. Vibration can be utilised to give an easy to monitor source of information. Using one of the new generation of low power, multi-axis accelerometers to monitor an asset’s health via vibration you can yield lots of useful information. Just from vibration alone it is possible to record an asset’s start and stop times, its total duty cycle and its energy usage. By simple analysis of the vibration traces you can detect if the asset has been set up correctly for time of day operation. Further analysis can also show if there are signs of blockages, bearing wear, chipped gears, shaft misalignment or surface degradation. Currently it is estimated that 30% of all sewage pumping stations contain at least one blocked or restricted element of functionality creating inefficiency and excess energy usage. Being able to easily monitor the health of these remote stations will enable a more effective maintenance approach by highlighting when assets need attention. This allows asset managers and operators to prioritise and allocate maintenance resources to the most affected sites with the target to reduce reactive maintenance costs and minimize asset downtime.

8power have engineered a small footprint, self-powered, scalable, solution that enables remote condition monitoring across a fleet of water industry assets. We use vibration to power our retrofittable, wireless sensor system. Without the constraints of battery power our devices can perform much of the vibration analysis locally on the sensor using the high-performance embedded ARM processor.

We are seeing that condition monitoring of all assets is becoming a critical business need for water treatment and wastewater processing.

Currently 8power are conducting remote condition monitoring pilot programs with water companies in the UK and Europe and will be publishing the results of these later in the year.