| Corroding and scaling are the primary factors for reducing the efficiency of heat exchange and work life of industrial circulation cooling water system, the worst result is to hinder the normal industrial process. After analyzing existing various water treatment techniques, this paper proposes a specific water treatment technology named as hybrid electromagnetic fields. This method combines low-frequency high-voltage steep pulse signals with high frequency pulse signals as sources, which lead to the physical and chemical effects in the circulation water as defouling and anti-scaling function. In this paper, we designed a set of signal generators and two treatment cavities, and a home-made cooling water system. They are separated or combined to conduct various experiments to verify the feasibility of this method.First of all, a low-frequency high-voltage steep pulse generator and a high-frequency low-voltage pulse generator are developed respectively. The rise time can be as short as 80ns for the high-voltage steep pulse and the peak voltage is nearly 15kV . In addition, signal frequency ranges from 2MHz to 500kHz for the high-frequency low-voltage pulse generator, the maximum output voltage is 100V. Moreover, two treatment cavities are designed and made to enhance pulse electric fields effects on circulation water, electromagnetic simulation software is applied to analyze electromagnetic field distribution in different structures, which is very useful to guide its further improvement.Then, we developed three different experiment system to verify the effectiveness of this method and study the mechanism of anti-scaling and removing biofouling. In order to detect various parameters during water treatment period, a set of detection device is developed for the conductivity of solution, PH value, temperature and other parameters. Finally, we did various experiments in the self-made water treatment system clssified as follows,1) killing bacteria experiments. It tested the function of high-voltage steep pulses in circulating water system by calculating the number of bacteria in different time. Final data showed the ratio of killing bacteria is as high as 91%, which prove the feasibility of high-voltage steep pulses on killing bacteria or microorganism.2) Anti-scaling experiment of high-frequency pulses. It detected the level of anti-scaling by comparing the weight or friability of scale. Final data showed the ratio of anti-scaling is 71% which prove the feasibility of high-frequency pulses on anti-scaling. 3) Removing scale experiment of high-frequency pulses. It detected if the weight of adamant scale was decreasing or not. Final data showed it was possible for high-frequency pulses to remove the adamant scale.4) The study on mechanism of high-frequency pulses on anti-scaling and scale-removing. During the specific experiments, we measured the electrical conductivity value of the solution to identify if there was special relationship between signal frequency and solution conductivity, and find out the influence of frequency parameter on the anti-scaling process. However, experiments of this stage could not settle down the relationship between signal frequency and solution conductivity because of complicated experiment condition.The experimental results show that the water treatment technology through hybrid electromagnetic field has admirable effect on killing micro-organisms and removing scales, which make it possible to be adopted to solve the corroding and scaling problem in industrial circulation cooling water system.
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