The Coagulant Dosage Automatic Control System Based On Mathematics Model

Coagulant Dosage Process is a very important procedure in water supply. How to implement the automation of coagulant dosage is one of remarkable tasks in water trade for a long time. Because of the influences of the turbidity, PH of raw water, current, temperature and the pollutions of raw water, the process of coagulant dosage is a very complex reaction. To find out the automation of coagulant dosage and reduce the cost of the coagulant, many domestic and international scientific research organizations make research into the theory and mechanism of automation of coagulant dosage, such as the Streaming Current Control method (SCD), the Emulation Experimenting method in spot, mathematics model, Flocculation Control Device (FCD). After studying large quantity of data, combining with our experience, Water Plant Six of Chengdu City selected mathematics model to establishing Coagulant Dosage Automatic Controlling System. The dissertation introduces the process how the Coagulant Dosage Automatic Controlling System was established and the resoult of research. (1) Because different raw water need right coagulant PAC, we selected appropriate coagulant to fit into our condition.(2) By establishing PLC control net, we can collect and storage data with computer, for mathematics model analyzing. (3) The equipments, including the turbidimeter, flowmeter and metering pump was selected to establish the hardware system.(4) By Coagulation-Flocculation Jar Test, we found out the pivotal element affecting coagulant dosage. Then, we used method for Correlativity and Regression analytical to analyze data. At last we successfully establish the mathematics model based on a three square equation. After the system running, the cost of the coagulant got obviously lower, having come to the anticipant. The qualified rate of turbidity after deposition water increase from 83.42% to 92.23%, average heightened 8.81% yearly. The Coagulant Dosage Automatic Controlling System in Water plant six current rare and real realize the system of full-automatic control. Running rate of the system is above amount to 99.8%. Theexperts of England John Summer Water Management Bureau think it has already attained the equal level abroad.