超声波衰减谱法在线测量微纳米颗粒粒度分布的研究

发布时间：2018-10-19 09:25

【摘要】：颗粒尺寸是衡量产品质量的重要指标,对于产品的稳定性、溶解性及流动性有着重要影响。随着科学技术的进步和工业水平的提高,人们对颗粒尺寸的测量提出了更高的要求。近年来,随着超声技术的快速发展,在医药、石油化工、食品等领域,采用超声衰减谱(UAS)法测量悬浮液和乳状液中颗粒的粒度分布(PSD)得到了人们广泛的关注。超声波具有穿透性强、频率范围宽、响应速度快及非接触的特点,适用于高浓度悬浮液颗粒体系的在线测量,有着其他测量方法无法比拟的突出优势。本文基于本课题组新近自主研发的一套探头式超声波颗粒粒度测量仪,深入研究了该仪器在实际应用中需要解决的一些关键问题。首先对不同浓度的纳米二氧化钛-水悬浮液和微米二氧化硅-水悬浮液的PSD进行了测量,并与其他粒度测量技术对比,验证了测量方法和开发装置的可靠性与稳定性。然后,将其与多种在线测量工具联用,对阿司匹林药物结晶过程中晶体尺寸分布(CSD)、浊度、浓度等多个质量和过程参数进行实时测量,成功监测该过程。在深入研究超声衰减理论和验证实验装置可行性的基础上,针对理论模型所需的连续相介质和分散相颗粒的物性参数测量困难这一问题,论文最后提出采用最优化算法对未知物性参数进行数值模拟,并进行了理论和实验研究。结果显示,已知物系的物性参数模拟优化值与真实值误差很小,使用物性参数模拟优化值进行超声衰减测量得到的PSD与其真实值接近。同时,对于未知体系利用该方法,同样可以准确估计未知参数进而得到准确的PSD。该方法对利用超声衰减颗粒测量技术对复杂体系的测量具有一定的指导意义和实用价值。
[Abstract]:Particle size is an important index to measure product quality, and has an important effect on product stability, solubility and fluidity. With the progress of science and technology and the improvement of industrial level, people put forward higher requirements for particle size measurement. In recent years, with the rapid development of ultrasonic technology, in medicine, petrochemical, food and other fields, the measurement of particle size distribution (PSD) in suspension and emulsion by ultrasonic attenuation spectrum (UAS) method has been widely concerned. Ultrasonic wave has the characteristics of strong penetration, wide frequency range, fast response speed and non-contact. It is suitable for on-line measurement of high concentration suspension particle system and has outstanding advantages compared with other measuring methods. Based on a probe ultrasonic particle size measuring instrument developed recently by our team, some key problems that need to be solved in practical application of the instrument are studied in this paper. First, the PSD of different concentrations of nano-TiO2 water suspension and micron silica water suspension were measured, and compared with other particle size measurement techniques, the reliability and stability of the measuring method and the development device were verified. Then, it is combined with many on-line measurement tools to measure the crystal size distribution, (CSD), turbidity and concentration in the process of crystallization of aspirin drugs in real time, and to monitor the process successfully. On the basis of deeply studying the ultrasonic attenuation theory and verifying the feasibility of the experimental device, it is difficult to measure the physical property parameters of the continuous phase medium and dispersed phase particles required by the theoretical model. In the end, the optimization algorithm is used to simulate the unknown physical parameters, and the theoretical and experimental studies are carried out. The results show that the error between the simulation optimization value and the real value of the physical parameters is very small, and the PSD obtained by ultrasonic attenuation measurement by using the physical parameter simulation optimization value is close to its real value. At the same time, the unknown parameters can be estimated accurately by using this method for the unknown system, and then the accurate PSD. can be obtained. This method has certain guiding significance and practical value for the measurement of complex system by ultrasonic attenuation particle measurement technology.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB383.1

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