Sheng, Fei (2012) Ultrasonic spectroscopy for in situ particle sizing and crystallization process monitoring. PhD thesis, University of Leeds.
Abstract
The application of ultrasonic techniques for crystal size distribution (CSD) and solid volume concentration measurements in batch crystallization processes was investigated in situ and on-line, with emphasis on the crystallization of the copper sulphate pentahydrate crystallization system. The fundamental crystal characteristics of copper sulphate pentahydrate including the solubility, metastable zone width, and induction time were assessed. The kinetic analyses carried out were independent of the acoustic measurement of the copper sulphate pentahydrate and provided the research background for the acoustic study. The potential of ultrasonic spectroscopy was demonstrated using an experimental approach, focusing on the problem of cooling crystallization of copper sulphate pentahydrate from an aqueous solution in a 20 litre scale reactor. The set up of the physical properties matrix for the system allowed the ultrasound spectra to be converted into the particle size and particle volume infonnation. Different cooling conditions were optimized due to the limitations of the instrument. The overall growth rate as a function of the relative solution supersaturation was determined from the combination of particle size and solid concentration. A new method derived from the Modified Urick equation focusing on the on-line measurement of the crystal volume concentration without the phase separation was built up, which was modified from the prototype applied in the non-soluble oil-in-water system. The extended application on the copper sulphate pentahydrate crystal volume concentration during the dynamic process was successfully developed. The third generation prototype acoustic spectroscopy Alphasizer developed by Malvern Ltd for on-line acoustic attenuation and velocity measurement was calibrated. Particle size distribution was successfully calculated from the manually calibrated attenuation spectra. The feedback closed loop supersaturation control based on Alphasizer was designed. The control algoritluns and a corrununication system were built up.
Metadata
Supervisors: | Xiaojun, Lai and Roberts, Kevin J and Wang, Xuezhong |
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Awarding institution: | University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering (Leeds) |
Academic unit: | School of Process, Environmental and Materials Engineering |
Identification Number/EthosID: | uk.bl.ethos.590149 |
Depositing User: | Ethos Import |
Date Deposited: | 17 Feb 2023 15:31 |
Last Modified: | 17 Feb 2023 15:31 |
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