Rotork IQ Profibus actuators control the flow at Thames Water's flagship project


Rotork IQ Profibus actuators control the flow at Thames Water's flagship project

Rotork IQ intelligent electric valve actuators are installed throughout the advanced new Reading Sewage Treatment Works, described by Terry Bane, Project Director at Thames Water as "one of Thames Water's flagship projects, where some of the most innovative technology has been used to design and build the site".

Built on former waste disposal land adjacent to several new business parks, the new plant serves a population approaching 300,000 as well as a local brewery, necessitating an emphasis on odour control, biological nutrient removal, energy recovery and sludge recovery that is unique to this site. The facility's buildings are therefore designed to blend with future developments in the area, whilst acting as an envelope to capture emissions, conceal processing plant and minimise noise. The site features four distinctive 20 metre high egg-shaped aluminium clad digesters and extensive landscaping, including 20,000 trees and shrubs. The technically advanced equipment that it houses matches the state-of-the-art appearance of the site.

Approximately 150 Rotork actuators control the movement of flows throughout the site, from the fully enclosed inlet works to the tertiary filters from where the treated wastewater is returned to the local watercourse in line with the latest EU and Environment Agency standards. Data loggers in the actuators store historical operating data and valve torque profiles, information that can be downloaded and analysed utilising Rotork IQ-Insight software. The collected data can help to optimise plant performance by identifying potential problems and facilitating predictive maintenance.

An equally advanced control system has been installed, utilising twenty-three Profibus 2-wire segments for the instrumentation, actuators and package plant, which are linked to several latest generation PLCs situated throughout the site. The PLCs communicate between each other and with the SCADA central control room using Ethernet over fibre optic cable, facilitating the use of simple web browsers for viewing SCADA screens in the control room or at other onsite and offsite locations. The central focus of the control room is a 50 inch wide screen plasma display, whilst workstations in the control room and touch screens within the plant itself facilitate centralised and local access to SCADA displays.

Virtually all of the Rotork actuators installed are IQ multi-turn or IQT quarter-turn models, the majority factory fitted with the Rotork Profibus DP card. Reading Sewage Treatment Works is the first Thames Water site to make extensive use of the Profibus protocol, which was selected as being the fieldbus system that is most universally available from equipment suppliers. Designed and built by the Target Alliance, a team formed by Thames Water, Taylor Woodrow and Black & Veatch, the plant was officially opened in January 2005.