Application of alternating electric field scale inhibition device in heat exchange station

Abstract

The present study introduces an alternating electric field device that can effectively inhibit the growth of scale on industrial heat exchangers. The 5–70 V voltage and alternating electric field (AEF) of 80–300 kHz frequency are transferred by the device in water where they can inhibit scale formation on tube walls by changing the precipitation mode of mineral ions. After the alternating electric field device is used, the scale thickness on the heat exchange surface becomes significantly thinner, and the maximum fouling resistance decreases by 58% (from 8.54 10−4m2K/W to 3.58 10−4m2K/W). Scanning electron microscopy (SEM) results show that after the use of the alternating electric field device, the scale on the heat exchange surface changed from dense crystals with irregular, sharp shape to loose crystals with spherical shape, and X-ray diffraction (XRD) analysis showed that most crystals changed from calcite to aragonite. X-ray energy dispersion spectroscopy (EDS) analysis showed that the weight percentage of Fe in the scale decreased by 9.81%. This shows that scale and corrosion on the heat exchange surface can be effectively improved under the action of an electric field.