Rotork multi-turn electric actuators have been installed to control rainwater retention along a new road which has been built in Poland.
CK range actuators powered using solar panels are operating knife gate valves to control the emptying of rainwater storage tanks along the road in the central Polish city of Kalisz. This is the first time the CK has been used with photovoltaics in Poland.
The project has connected two existing roads to improve links and communication in one of the city’s largest housing estates, which involved improving infrastructure including surface, drainage, lighting and marking.
Several storage tanks to contain rainwater runoff from the new road have been designed. Runoff from the road is stored during rainfall and outflow from other surfaces while discharge from the tanks, controlled by the CK solar solution, begins when this flow stops. This allows outflow from various surfaces to pass each other in time, so the actuators open the knife gate valves at a minimum of 30 minute intervals to fit the schedule.
Rotork’s CK was selected as offering the best option for the required operating parameters while the solution of using electric drives powered by solar energy was deemed the most effective way to operate the actuators.
CK actuators are available in both single-phase and three-phase variants, and can provide a direct output torque range from 10 Nm to 500 Nm (7 to 369 lbf.ft). This can increase up to 10,800 Nm (8,000 lbf.ft) with a multi-turn gearbox and 205,600 Nm (151,6000 lbf.ft) when fitted to a quarter-turn gearbox.
The plug and socket modularity of the CK means a standard unit can easily be fitted with Centronik controls, which can be close coupled or installed up to 100 m away from the actuator, to provide a multilingual display for status and configuration. Operation can be carried out using a Rotork Bluetooth Setting Tool which can also be used to extract data such as open / close switch trips, open / close torque trips and motor starts. This information can be analysed on a PC running Rotork’s Insight 2 diagnostics software.
The CK has IP68 watertight certification (submersible for up to 96 hours at a depth of 8 metres) while double sealing is provided as standard. The actuator can safely operate in a temperature range from -30 °C to +70 °C (-22 °F to +158 °F) with a low temperature option available from -50 °C to +60 °C (-40 °F to +140 °F) with a change of lubricant and bearings. A single-stage worm-and-wheel gear drive operates in an oil bath for effective lubrication within this temperature range while food grade and low temperature lubricants are also available.
A handwheel drive, certified to EN12570 standard, is independent of the motor drive and can be selected using a lockable hand/auto lever acting on a slow speed clutch to allow for safe manual operation.