Water and Effluent Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/721218
SEPTEMBER 2016 WET NEWS 21 Pressure transmitters are situated around the process to help ensure the correct pressure conditions are being maintained for optimum performance Both pressure and level transmitters have been used to measure sludge levels inside the digestion tanks to fine-tune the process and prove that it could work on a larger scale." To help provide this data, ABB has supplied a combined package of flow, pressure, temperature and level instrumentation that is used to help measure performance throughout the plant. "As this is a pilot plant, we have more instruments than you'd normally have on a proven process," says Aurélien Perrault, innovation sludge and energy manager for Thames Water. "In this way, we can get the best possible picture of what's happening, which can sometimes produce some quite surprising information." By drawing on this expertise, ABB's engineers were able to provide advice and support throughout the project, including guidance on the best types of instrumentation technologies. "I and my colleagues have received good support from ABB when we've needed it," says Manocher Asaadi, of consulting firm AD Technologies, which made the initial decision to go with ABB at the outset of the project. "The support we have received from ABB has been excellent. Even at the tendering stage, Steve Wilding and his team were offering advice on ways we could improve things, which was one of the factors that convinced us to choose ABB. "This same level of support has continued throughout the project. As this is an experimental plant, there were areas that we were not quite sure about. ABB worked with us to help us to iron out any uncertainties and was heavily involved throughout the development phase of the project." Together, ABB's instruments help to provide a comprehensive picture of what is happening around the plant. ABB's FSM4000 magnetic flowmeters are being used to both measure and control the flow of sludge between the tanks. The high level of solids in sludge can present a particular challenge when it comes to measuring flow. Conventional DC excitation magnetic flow meters are unsuitable for use with high- solids media, because the solids generate an unacceptable level of noise in the signal. Widely used in pulp and paper processes for similar reasons, ABB's FSM4000 flowmeters use AC excitation, which produces a much less noisy signal, resulting in more accurate flow measurement. In the Basingstoke installation, data from the meters is relayed to the plant's SCADA system where it can be viewed and analysed to provide an immediate overview of performance. The data is also relayed to Norwegian company Cambi AS. As the owner of the patent on the ITHP process, Cambi uses the data to assess and optimise the performance of the plant.