SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2020, Vol. 28 ›› Issue (2): 466-476.DOI: 10.1016/j.cjche.2019.08.009

• Process Systems Engineering and Process Safety • Previous Articles     Next Articles

Direct image-based fractal characterization of micromorphology of calcium carbonate fouling crystals

Xiaokai Xing1, Zhonghua Zhao2, Jianhang Wu1   

  1. 1 National Engineering Laboratory for Pipeline Safety, Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing, Beijing 102249, China;
    2 Dalian Port (PDA) Company Limited, Dayaowan Business Building, Dalian 116000, China
  • Received:2018-11-15 Revised:2019-07-25 Online:2020-05-21 Published:2020-02-28
  • Contact: Xiaokai Xing
  • Supported by:
    This work was supported by the National Natural Science Foundation of China “Research on the Mixing Deposition of Crude Oil and Inorganic Salts in Stratified Flow of High Water and Low Oil Through a Pipeline” [grant number 51574259], and Research Foundation of China University of Petroleum-Beijing At Karamay (grant number YJ2018B02001).

Direct image-based fractal characterization of micromorphology of calcium carbonate fouling crystals

Xiaokai Xing1, Zhonghua Zhao2, Jianhang Wu1   

  1. 1 National Engineering Laboratory for Pipeline Safety, Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum-Beijing, Beijing 102249, China;
    2 Dalian Port (PDA) Company Limited, Dayaowan Business Building, Dalian 116000, China
  • 通讯作者: Xiaokai Xing
  • 基金资助:
    This work was supported by the National Natural Science Foundation of China “Research on the Mixing Deposition of Crude Oil and Inorganic Salts in Stratified Flow of High Water and Low Oil Through a Pipeline” [grant number 51574259], and Research Foundation of China University of Petroleum-Beijing At Karamay (grant number YJ2018B02001).

Abstract: Researches on macroscopic fouling behavior and micromorphology are usually conducted separately. In this paper, the relationship between the macroscopic fouling behavior and micromorphology on different materials is established. A direct fractal-characterization approach based on the micrographs of calcium carbonate fouling crystals is presented. The box-counting method is used to characterize the fouling crystals. For fractal measurements, t-distribution tests of linear regression hypothesis are performed at the significance level of 0.01. If all listed absolute t-statistics with the minimum of 164 are higher than the corresponding t value, the fouling crystals are determined as fractal, with a confidence level of 99%. The fractal dimensions obtained from the micrographs of different visual fields of a specimen are demonstrated to be almost identical, with maximum and minimum relative values of 4.42% and 0.75%, respectively, and standard deviations ranging from 0.0062 to 0.0266. The irregularity of the crystal morphology indicates larger fractal dimensions. Comparison and analysis of the relationship between macroscopic fouling behavior and micromorphology show that the larger fractal dimension of crystal morphology suggests a small amount of surface fouling. Thus, the reasons for the differences in the macroscopic fouling behaviors of different materials are revealed geometrically.

Key words: Calcium carbonate, Fouling, Fractal dimension, Micromorphology

摘要: Researches on macroscopic fouling behavior and micromorphology are usually conducted separately. In this paper, the relationship between the macroscopic fouling behavior and micromorphology on different materials is established. A direct fractal-characterization approach based on the micrographs of calcium carbonate fouling crystals is presented. The box-counting method is used to characterize the fouling crystals. For fractal measurements, t-distribution tests of linear regression hypothesis are performed at the significance level of 0.01. If all listed absolute t-statistics with the minimum of 164 are higher than the corresponding t value, the fouling crystals are determined as fractal, with a confidence level of 99%. The fractal dimensions obtained from the micrographs of different visual fields of a specimen are demonstrated to be almost identical, with maximum and minimum relative values of 4.42% and 0.75%, respectively, and standard deviations ranging from 0.0062 to 0.0266. The irregularity of the crystal morphology indicates larger fractal dimensions. Comparison and analysis of the relationship between macroscopic fouling behavior and micromorphology show that the larger fractal dimension of crystal morphology suggests a small amount of surface fouling. Thus, the reasons for the differences in the macroscopic fouling behaviors of different materials are revealed geometrically.

关键词: Calcium carbonate, Fouling, Fractal dimension, Micromorphology