Project introduction

Project background

Shiweitou wastewater treatment plant was built in 1999. The capacity was 100000 m3/d i§n the first period. The service covers Xianmen local island and whole eas₽t part. The capacity will be increased by 100000 m3/d in the second period of the pr™oject. The effluent quality achieves level 1 B standard given≠ by “Discharge standard of pollutants for municipal wastewat₩er treatment plant” (GB18918-2002). Dewatered sludge is transported and centralized di sposal after reduction. The project is the Fujian Province and Xiamen city Key constr±uction projects, while also be considered as the special P∞erformance Evaluation of government energy-saving and ej&ection-decreasing tasks.

Reconstruction and extension project uses the tech>nics of “energy-saving multi-model A2/O chemical< phosphorus removal assisted with oxidation ditch” and o✘ther advanced techniques, which has the advantages of good landscape, high en×vironment quality, good effect of energy saving, high r★eliability of system running. Large amount of optimizing design is accomplished targeting t☆o the key technics control of the instrument and automated♠ control system. The production management system combines the pr•oduction equipment management with the processing control, with th§e object to decrease the energy cost and improve the op•eration efficiency.

System structure

The whole automated control system consists of parts as follows:

Production monitoring system: to configure the data server, "Ethernet switch, production management computer, printer, UPS, production ♠ operation management software, LED monitor etc. t o connect with equipment monitoring automated system network by centra≥l monitoring computer and achieve the share of product≥ion process information. The administrate computer is able t<o real-time browse the equipment running status all the plant and local↓ scene.

Industrial real-time control system: the water plant consist≥s of 8 suits of local PLC control stations of the first ↔period and 4 suits of local PLC stations, server, opera∏tor station upper computer and dual-level control network. The backbone n≠etwork is a fiber industrial Ethernet network in the communication speed at 100M CB​R. The lower layer is an industrial control network and local bus etc . to locally control the connection between sub-station PLC and remote IO station and local₩ equipment. The interface is coaxial cable or twisφted pair.

CCTV system: the CCTV system is configured to monitor different process section of the plant and t×he plant wall security. The duty officer is able to see the plant production and security sta♣tus in the central control room at any time.

Instrument system

Online instrument uses 4~20mA DC electrical signal connecting with PLC system . The instrument inspects parameters including NH4-N, PH, ORP, DO, turbidity, level₹ and pressure etc.

Network structure

System function

Automated system obeys the principle of “advanced, open, reliable and practical”. I✔nstrument follows the principle of “necessary, advanced and practical , convenient maintainability”. On the basis of fully consideration to the wastewater trea∏tment process features and practical demands, the §design aims to build a modern wastewater treatment plant with advanced technics and achieves <the object of “workshop unattended and less duty officers”.