低频电磁场处理中水的水质稳定试验研究

Experimental Study on Water Quality Stabilization Using the Low Frequency Electromagnetic Treatment of Reclaimed Water

针对循环冷却水运行过程中常出现的结垢与腐蚀问题,采用低频梯度电磁场对中水进行水质稳定试验。通过静态正交试验对电磁场运行参数进行优化,然后将其应用到循环冷却水动态模拟试验中。结果表明,非换热界面的结垢与腐蚀问题可以得到显著控制,污垢沉积率与腐蚀率分别由静态试验条件下56.85 mg/(cm2.月)、0.834 mm/a降低到动态试验条件下35.02 mg/(cm2.月)0、.136 mm/a,并有继续下降的趋势;换热界面的结垢现象严重,污垢沉积率达184.59 mg/(cm2.月),但腐蚀率可以得到显著控制,为0.158 mm/a。经XRD分析发现,中水中的大量Mg2+一方面抑制了电磁处理的阻垢作用,另一方面在电磁处理条件下可以促进铁表面形成致密的MgFe2O4保护膜,起到缓蚀作用。

According to scaling and corrosion problems during operation process of circulating cooling water,a water quality stabilization experiment was conducted on treatment reclaimed water with low frequency gradient electromagnetic field.The effects of electromagnetic treatment on scale and corrosion inhibition were mainly investigated.The experimental results show that scaling and corrosion problems on non-heat-transfer surface could be controlled significantly.The fouling deposition rate and the corrosion rate were reduced to 35.02 mg/（cm2·month） and 0.136 mm/a under dynamic simulation test from 56.85 mg/（cm2·month） and 0.834 mm/a under static test respectively,and were both keeping decreasing.But scaling problem on heat-transfer surface was serious,the fouling deposition rate was 184.59 mg/（cm2·month）,but the corrosion rate could be controlled significantly,which was 0.158 mm/a.Through XRD（X-Ray Diffraction） analysis,it was found that the massive Mg2＋ in reclaimed water could inhibit the scale inhibition of electromagnetic treatment,while promoting the formation of compact MgFe2O4 protective film on iron surface under electromagnetic treatment,which is against corrosion.