Role of Actuator Valve in Water Treatment
A water treatment system constitutes various unit operations such as clarifiers, filters, reverse osmosis systems etc. The flow, pH and pressure are the indicators if these unit operations are functioning properly or not. When these parameters deviate from the standard values, then the signals from the flow meter/pH meter/ pressure transmitter is sent to the SCADA/Direct control system which sends out electric signals/air supply to the actuators of these actuator valves to open/close them in order to rectify the problem.
Membrane cleaning and cleaning of filters are all done with the aid of automatic valves when the pressure exceeds the standard pressure. In order to avoid overflow or preventing drying of pumps due to insufficient flow of water, the signals indicated by the flow meters are picked up by the automatic actuators which open/close the valves accordingly in order to have uninterrupted operations/services of the plant. In case the pH is too low/ high from the described limits this would affect the shell life of any unit operation. This fluctuation is detected by the pH meter and the signal to rectify is sent to the actuator of the control valve which is responsible for the addition of acid/alkali respectively.
In case of anaerobic digestion, the sludge should be suspended in the system. To keep it suspended a particular flow of water should be maintained. In case this decreases/increases above the specified flow, then this is detected by the flow meter which provides the signal to the actuators of the control valve responsible for opening/closing the water flow to the digestor.
Thus the presence of actuator valves prevents the shutdown of the water plant.