Experimental study on the influence of an alternating magnetic field on the CaCO3 fouling of a heat transfer surface

Experiments were performed to investigate the influence of an alternating magnetic field with different magnetic induction intensities on the calcium carbonate (CaCO3) fouling of a heat transfer surface. Experimental results indicated that the alternating magnetic field could effectively inhibit the fouling deposition on the heat transfer surface by prolonging the fouling induction period and slowing down the growth rate of CaCO3 fouling. Moreover, the fouling inhibition characteristics of the alternating magnetic field presented a multi-extremum feature. The fouling inhibition effectiveness depended on the selection of operating parameters in the alternating magnetic field. The most significant period was 300 Gs in this work, during which the fouling inhibition rate was 91.57%. Meanwhile, the fouling induction period increased by 132.3% and the growth rate decreased by 38.8% compared with the blank test. According to the scanning electron microscopy and particle size distribution, the morphology of CaCO3 particles exhibited changes with the alternating magnetic field. The smaller crystal size and terrace-ledge-kink growth were two reasons that impeded CaCO3 fouling from adhering easily on the heat transfer surface. This work can provide a sound theoretical guidance for future alternating magnetic field system design and application in fouling inhibition. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Experiments show that the alternating magnetic field can effectively inhibit the formation of calcium carbonate fouling on heat transfer surfaces by extending the fouling induction period and slowing down the growth rate of fouling. The fouling inhibition effect depends on the selection of operating parameters in the alternating magnetic field, with the most significant period being 300 Gs.