Research Of Electromagnetic Anti-fouling Technology On Heat Transfer Equipment

With China’s sustained and rapid development of industry, the proportion of industrial water increases every year, followed by a situation that water system scaling becomes increasingly severe, especially in the power, chemical, petroleum, metallurgy and other industries .On one hand scaling reduces the heat transfer efficiency of the heat exchanger and increases energy waste, on the other hand it shorten the service life of equipment and leads to accidents. Therefore, research and application of scale prevention and removal will be very significantly economic and socially benefit.Based on the theory of electromagnetic field, moving cation and anion are affected by the electric field force and Lorenz force which are in reverse direction. The electric and magnetic field reverse in high frequency, so that Ca2+ and CO32- are forced by opponent electric forces and Lorentz forces which change the direction in high frequency, so that Ca2+and CO32- have high frequency oscillatory motion. Greatly increase the fouling ion collisions with probability. So as to promote the formation and growth of CaCO3 crystal core suspended in solution. Avoid or reduce the formation and growth of CaCO3 on the surface of heat transfer. So as to achieve the purpose of anti scaling, scale removal.In the article, the main mechanism of scale prevention and removal of alternating electromagnetic field method is studied. The critical theory of electromagnetic anti fouling technology is studied and numerical analysis. The crystal structure changes in electromagnetic anti-fouling technology; best form of electromagnetic field is analyzed. The mathematical model of the electromagnetic field intensity inside the coil, current inside the water, electric spiral of the coil and circulating cooling water fluid characteristics is established. The relationship between electromagnetic field and the number of turns of coil, current, frequency,size of coil and other parameters is researched. The model of electromagnetic field is analyzed by using ANSYS software. The influence of material of pipe and number of turns of coil and is researched. The effect of the speed of the water and diameter of the pipe on the fluid flow characteristics is determined. The best parameters of electromagnetic field and fluid flow characteristics are obtained. The hardware circuit of electromagnetic anti-fouling signal generator is designed. Alternating square wave signal of fixed frequency, PWM and sweep frequency can be output. The effect of Electromagnetic cleaning is also affected by the actual working condition,fluid parameters and arranged form,and then a set of electromagnetic treatment system was build. Electromagnetic parameters can be changed and a serious of experiment is made. The effects of different coil turns, frequency, wave forms is checked by measure the mass of scale and take SEM and XRD pictures. The best electromagnetic anti-scaling parameters in general condition are explored. And the effect of anti-fouling of the best parameters is verified with experiment.