Automatic Control System of Municipal Sewage Treatment.pdf

(1) System Structure

The scale of modern sewage treatment plants is becoming larger and larger and its automation level is rising higher and higher. There are many steps in the treatment period, including coarse fraction, fine fraction, sand-settling, pre-cleaning, chemical treatment, cleaning and sludge treatment.

The system is a centralized monitoring system based on the distributed network and can be divided into three parts. They are the central control system in CCR (Central Control Room), which performs monitoring and data management by upper level computers; the communication network which performs data transfer between control center and process segments; and the field control systems which perform data measurement and executive components driving via PLC and I/O modules.

(2) Requirements of Network

In terms of equipment distribution of the sewage treatment plant, the communication network is a redundant optic industrial Ethernet network designed to guarantee the stability and reliability of data transfer. In addition, due to environmental factors such as erosion and electromagnetic radiation in the plant, the industrial Ethernet switches are required to be qualified as corrosion-resistant and EMC.

(3) Implementation

Industrial Ethernet switches such as KIEN2000, KIEN6000 and SICOM3000 are widely employed in the communication networks all over the sewage treatment plant.

(4) Topology of Network

Click to Enlarge