Design And Implementation Of The Sewage Treatment Control And Communication System

With the rapid development of the industry and economy, the larger and larger amount of sewage is discharged. Especially, china is a country short of water resources and using water effectively can satisfy people’s growing demand for water, so sewage treatment is of great urgency.In this thesis, aming at the sewage treatment plant in Bailonggang Expansion Phase Ⅱ of Shanghai, an automatic control system is designed. The system structure is established based on Rockwell large scale controller-ControlLogix and the control requirements of the devices are analyzed, which is further programmed, tested by RSLogix5000of Rockwell so as to achieve the automatic control of the sewage treatment system. In the plant, there are three layers of networks and a great number of devices which provide only single communicate interface. Hence, the gateways aiming to transfer two different protocol should be configured, which makes the upper-computer, control station, sub-control station and the device level come to a network. Finally, the system can achieve the data sharing, centralized management and distributed control, and satisfy a safe and reliable principle.Since the project has applied, the devices have a steady running status and the communication remains normal. These parameters show that the quality of output water comes up to national standards.