Investigation of the strengthening mechanisms and laws of ultrasound fields on the crystallization process of Paraxylene

This paper introduces an ultrasonic field into the PX (Paraxylene) suspension crystallization process and innovatively adopts in situ imaging and image analysis techniques to analyze the effects of different ultrasonic parameters on the phase transition and crystallization characteristics of the crystals in real time. Using the “comprehensive benefit enhancement ratio” first proposed in this paper, summarizes the synergistic enhancement mechanism of the ultrasonic external field and the PX crystallization multiphase field. Results show that ultrasonic cavitation effect and acoustic flow effect can increase the crystal roundness by 21.6–27.7 %, and reduce the fractal dimension by 6.98–11.2 %. Continuous ultrasound leads to deterioration in crystal properties and distribution. Ultrasound affects the coalescence process of solute clusters by altering the cavitation intensity and the oscillation of bubbles. Ultrasound effectively improves the PX crystal purity and size distribution uniformity, increasing the comprehensive benefit enhancement ratio by 1.209 times.