To Establish An Automatic Coagulant Addition System Of Water Works By Mathematical Model

We establish an automatic coagulant addition system which core is establishing mathematical model on the basis of the actuality of Water Works, and we successfully resolved the problem that the ordinary coagulant addition system is always unreliable. The automatic coagulant addition system, which can be used in different Water Works, is economical and reliable.We analyze several factors, which influence the addition quantity of coagulant. According to analyzing how the factor (example, temperature of the raw water) which continuously changes influence the addition quantity of coagulant, we found the addition quantity did not change in a narrow range of the temperature, so we give a data in every range of the temperature, and we regard it as a constant in every range. At the same time, we found the factors (example, Alkalinity of the raw water, pH of the raw water) change always in a narrow rang, and we regard it as a constant too. Finally, we can establish a mathematical model, a simply function with the addition quantity of coagulant and the raw water turbidity, and there is only one variable in the function.According to collecting original data, filtering invalid data and using method of least squares, we found a function with the addition quantity of coagulant and the raw water turbidity, and then we validated that the function is valid and adaptive. Accordingly we establish an automatic coagulant addition system which core is establishing mathematical model on the basis of the actuality of Water Works. It proves that the automatic coagulant addition system is stable and reliable in practice. The automatic coagulant addition system has been used in No.2 Water Works of Chengdu Water Supply Company for 2 years, and it has achieved good results.