The introduction of the Profibus-enabled Rotork IQT valve actuators on a filter bed automation upgrade for UK-based Yorkshire Water has facilitated the installation of a highly economical and efficient control network. The automation programme is at Esholt, one of Yorkshire Water’s largest waste water treatment works, serving more than 300,000 homes and industry in the Bradford area. The Rotork IQT actuators are fitted to previously hand operated plug valves on the secondary treatment percolating filter beds. Constructed over fifty years ago, the filter plant consists of seventy axial beds and extends over a distance of more than a mile. Effluent arrives from the distribution chamber, where it is mixed with re-introduced final effluent to improve consistency before being gravity fed into thirty-five troughs, each serving a unit of two filter beds. The automation upgrade is designed to improve the flow performance into the beds, optimise filtration efficiency and prevent damaging problems such as dry bedding and uneven flow distribution that were difficult to avoid when the plant was manually operated.
