Adsorption Of Static-Dynamic Crystallization Based On Conductivity Detection

Industrial cooling water, as the major part of industrial water, accounts for about 70% of the total. Because of the severe shortage of freshwater resources, industrial cooling water is generally used by the way of recycling. In the recycling, continued evaporation, weathering and impurities carried of the water often cause cooling water system to appear concentrated crystal, the most common of which is calcium carbonate fouling, which has effect on the safe and economic operation of the circulating cooling water system. To solve this problem, this paper from the crystal adsorption theory, studies the adsorption mechanism of calcium carbonate crystals with the method of electrical conductivity monitoring and provides a theoretical reference for the anti-scaling, scale and scaling.On the basis of existing theories of the adsorption crystallization analysis, this subject proposes theoretical model based on crystal adsorption calculating conductometric titration and verifies the feasibility by static and dynamic experiments. First of all, on the basis of that the performance evaluator of inhibitor has been developed based on conductivity titration by our Laboratory, this subject develops further and perfects the performance evaluator of inhibitor including optimizing the conductivity electrode input frequency, designing temperature conditioning circuit, extensing the temperature range, making better of droplet control titration, improving the accuracy of titration and measurement and perfecting electrode pollution control measures to make the stability and accuracy of the instrument better.The second, based on analysis of the conductivity signal characteristics of titration, on the basis of monolayer adsorption mechanism, according to responses generated by the consumption of calcium carbonate and calcium carbonate, starting from the mass action law, conductometric titration of solid - liquid interface adsorption kinetics equation is established. At last, the static and dynamic experiment is made according to the adsorption process of different CaCO3 solution supersaturation degree in carbon steel surface. In the static experiment, take advantage of titration of sodium carbonate to calcium chloride, study different CaCO3 supersaturation of solution adsorption at the carbon steel surface with detecting the CaCO3 supersaturation controlled by the electrical conductivity, then calculate the amount of carbon adsorption according to the relationship of Ionic and Conductivity and solid-liquid interface adsorption kinetics equation. The results show that different CaCO3 supersaturation different solution in the carbon steel surface of the adsorption process follows the solid - liquid interface adsorption kinetics equation of the law and also be consistent with monolayer adsorption mechanism. In order to understand further crystallization of calcium carbonate scale adsorption and prove the reliability of this method, this subject makes dynamic experiment, the result of which indicates that calcium carbonate adsorption on the surface of heat exchanger is consistent with fouling thermal resistance change.