Balance The Alkalinity Of The Circulating Cooling Water System To Predict

At present, open cooling water is applied in industry. Water quality of cooling water affects directly scaling, corroding and microbes multiplying etc., among them, total alkalinity and pH of cooling water are two important indices judging water quality. In the past, almost of total alkalinity and pH researches of cooling water came from experience. These researches considered only parts of factors, so they exhibited certain limitation.Theory: from thermodynamics, considering the cycle, activity coefficient, makeup water quality (total alkalinity, pH and total dissolved solid), part pressure of CO2 in atmosphere and system equilibrium etc, in the light of carbonate equilibrium and before scaling, we have calculated ail carbonate substances concentrations before and after concentration in cooling water. Based on definition of total alkalinity and pH, their theoretical expressions can be obtained in cooling water and can be predicted through Visual Basic program.Experiment: by bubbling and concentrating confecting water samples and parts of on-the-spot water samples up to before scaling, then total alkalinity and pH of cooling water can be analyzed under different cycles. Variations of total alkalinity and pH of different water samples with the cycles are to be summaried from experiments.Finding out and explaining the differences between experiments and theories, in accordance with different environments and the degree of getting to system equilibrium, amending coefficients are to be selected reasonally, so under a certain condition theoretical expressions of total alkalinity and pH in cooling water can be decided finally.