Rushton搅拌釜气含率分布CT彩色数字成像模型研究  

Research on a computed tomography colour digital imaging model for gas hold-up distribution in a Rushton gas-liquid stirred tank

作　　者：刘跃进[1] 孔丽娜[1] 白鸽[1] 韩路长[1] 曹杨[1] 罗和安[1] 

机构地区：[1]湘潭大学化工学院化工过程模拟与优化教育部工程研究中心,湖南湘潭411105

出　　处：《哈尔滨工程大学学报》2011年第10期1374-1380,共7页Journal of Harbin Engineering University

基　　金：国家自然科学基金资助项目(20776121)

摘　　要：为了建立和实现137Csγ射线CT(computed tomography)测量Rushton气液搅拌釜气含率分布彩色数字成像模型,根据137Cs发射γ射线信号和探测器接受信号的Poisson分布模型和气液两相流体吸收衰减辐射信号的二项分布模型,在给出接受信号实验样本空间条件下,采用最大似然参数估计法,对容器断面气液两相流体吸收衰减γ射线信号二维空间进行了参数估计,推导和建立了其参数估计的数学模型.在不同通气量、不同搅拌速率及不同气体分布器状态下,对Rushton气液搅拌釜断面气含率进行了CT实验测定、数据处理和图像重建.通过对CT彩色数字图像与平均气含率沿无因次半径变化实验值的比较研究,证明所构建的CT测量气含率分布彩色数字成像的模型有效可行,所重建的CT彩色数字图像清晰准确、对比度好、分辨率高、受噪声影响小.In order to measure gas hold-up distribution in a Rushton gas-liquid stirred tank, a 137Cs γ-CT（ computed tomography） colour digital imaging model was established. Based on the Poisson distribution models for both emitting signals from a radioactive source and receiving signals from detectors, and on the binomial distribution mod- el between absorbed and attenuated signals by gas-liquid phase fluids, the parameter distribution of absorbed and attenuated ＂y-ray signals through pixels of a horizontal cross section of gas-liquid phase fluids in a container was estimated. This estimation was performed using a linear estimation maximization likelihood method under the condition of accepting complete data of γ-ray signals by detectors. The mathematical model for the parameter distribution esti- mate of gas hold-up was deduced and established. 137Cs γ-ray CT experimental measurement, data processing, and the image reconstruction for stirred gas-liquid states in a Rushton tank were carried out in various ventilations, agitation rates, and gas spargers. The CT color digital images with the average gas holdup of the experimental data were compared. The clarity and accuracy of the constructed CT color digital images were verified, high contrast, res- olution and Low noise impact was also established.

关 键 词：γ射线CT 气含率分布 彩色数字成像 数学模型 Rushton气液搅拌釜 

分 类 号：TP391[自动化与计算机技术—计算机应用技术] TQ027[自动化与计算机技术—计算机科学与技术]