通过水听器检测技术,结合偏最小二乘法(PLS)分析,实现了对气液固三相搅拌釜内固含率的检测. 通过对水听器信号的特征分析得出了固体运动的特征频段,发现PLS建模方法能够从物理意义上反映固体运动的特征频段,并建立了PLS回归模型的固含率. 结果表明,模型所得固含率预测值与真实值的相关系数大于0.89,平均相对误差小于1.02%,预测均方差小于1.73%,具有较好的预测效果.
Solid-holdup, which is significant to the design and optimization of reactor, is an important parameter to assess solid suspension in stirred tank. In this work, solid-holdup in gas-liquid-solid system was measured by detected hydrophone signals combined with the partial least squares (PLS) analysis. It was revealed that a characteristic frequency band of hydrophone signals representing the particle motion was in accordance with the results of FFT analysis. A regression model between solid-holdup and hydrophone signal was built up. Comparing the real values with predicted results, it shows that the correlation coefficient (R) is larger than 0.89, the average relative deviation (ARD) is less than 1.02% and the root mean squared error of prediction (RMSEP) is less than 1.73%. Good precision of the prediction model has been verified. It is concluded that hydrophone is feasible for determining solid-holdup in stirred tank and it have the merit of being sensitive and accurate.