Further to the initial failure of the inlet pumps, there was also a requirement for the TEPS inlet pumps to be replaced with temporary pumps following the failure of these units. Exsel Pumps again provided a solution where submersible pumps could not be utilised due to restrictions in the TEPS well. Exsel utilised four 16” discharge (400mm) surface mounted immersible pumps each capable of a maximum flow of 3,000 m3/h (830 l/s) a total capacity of 12,000 m3/h (3,320 l/s).
With a suction lift of about 7.5 metres this is beyond the capability of a number of competitive pumps of smaller size but Exsel utilised the right equipment and techniques to ensure such a lift could be handled. The TEPS set-up provided restrictions on the access and pipework configuration. But Exsel overcame all these issues with it’s expertise in installation of temporary solutions. The pipework set up allows the re installation of the original TEPS pumps when returned from repair.
The pumps were controlled through two PLC control containers each controlling and monitoring two of the pumps. Therefore, providing a level of back-up in the case of any failure mode. With level sensing controls the pumps were operated through variable speed drives. The controlling of the speed and therefore the pump performance was a critical requirement for the process to ensure that the system was not overwhelmed with surges of sewage upstream as is expected with other competitive offerings. Each pump also had a dedicated stand-alone vacuum priming system to provide the suction lift capability.
The full installation was carried out by the Exsel Team utilising flanged steel pipework that provided a secure tamper-proof and leak-free solution. The installation Team worked overnight and at weekends to ensure the over pump capability was set up and running in the quickest timescale but also in the safest manner. SMS capability was included to provide notification in the event of alarms and Exsel was able to provide 24/7 support and monitoring.