扫频电磁场对换热面结垢过程的作用规律

Effect of Electromagnetic Field on Scaling Process on Heat Exchange Surface

搭建了扫频电磁场抑垢阻垢综合实验台,对经过扫频电磁场处理过的溶液在铜管外表面结垢过程进行深入研究。通过对比处理前后溶液的电导率、钙离子浓度,并利用X射线衍射分析技术(XRD)对水垢样品开展晶体结构分析。实验发现13~25 kHz扫频段实验的电导率和钙离子浓度变化较为缓慢。实验运行24 h后,13~25 kHz扫频段实验的溶液电导率比空白组实验提高了16.3%;1~13 kHz扫频段实验的溶液电导率比空白组实验提高了12.6%。这说明扫频电磁处理后的溶液中钙离子与碳酸根离子结合生成的碳酸钙水垢较少,该扫频水处理器具有一定的阻垢效果。经过13~25 kHz扫频电磁场处理后,铜管外表面所形成的水垢中方解石质量分数由100%降低为65.31%,文石的质量分数升高为34.69%,水垢变得疏松,容易随排污流走。

A comprehensive experimental platform for scale inhibition of electromagnetic field water treatment was set up,and the scale process of solutions treated by electromagnetic field on the surface of copper tube was studied.Comparative study on the electrical conductivity of solutions and calcium ion concentration before and after treatment was carried out,and crystal structures of calcium carbonate samples were analyzed by XRD.It was found that the electrical conductivity and the concentration of calcium ion in the experiment of 13-25 kHz range changed slowly.After 24 hours of experiment operation,the electrical conductivity of solutions in the frequency range of 13-25 kHz increased by 16.3%compared with the blank group experiment.The conductivity of the solution in the frequency range of 1-13 kHz increased by 12.6%.It can be inferred that the combination of calcium ions and carbonate ions into calcium carbonate scale decreased after solutions were treated by the swept-frequency electromagnetic.Therefore,the swept-frequency water processor has a certain inhibition effect on scaling.The calcite mass fraction in scale samples decreased from 100%to 65.31%,and the mass fraction of aragonite increased to 34.69%,the scale becomes loose,and it is easy to drain away.