声信号R/S分析与环管反应器中浆液质量浓度测量  

R/S analysis of acoustic emission and measurement of slurry mass concentration in loop reactor

作　　者：姜晓静[1] 张晓欢[1] 吕淼[1] 王靖岱[1] 阳永荣[1] 

机构地区：[1]浙江大学化学工程国家重点实验室,化学工程与生物工程学系,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2008年第4期691-696,共6页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金重大资助项目(20490205);国家“863”高技术研究发展计划资助项目(G20070040)

摘　　要：根据固体颗粒碰撞壁面产生不同频段声信号的机理,结合小波分解及R/S分析手段,获得了代表固体颗粒运动的声信号特征频段,并建立了环管反应器中浆液质量浓度的声发射预测模型.在环管反应器中,以水-玻璃珠体系为研究对象,分别考察了在流速为5-8 m/s的条件下特征频段能量与浆液质量浓度的关系.发现在流动稳定的情况下,将声发射信号在0-100 kHz做二阶Daubechies 9尺度小波分解并结合R/S分析,得到代表固体颗粒运动的特征频段,特征频段下的声发射信号能量和流体速度的3次方之比与浆液质量浓度之间存在线性关系.浆液质量浓度的模型计算值与实测值之间的平均相对误差为11.8%,表明声发射技术能快速、准确、非插入地实现环管反应器中浆液质量浓度的在线测量.According to the mechanism that acoustic emission （AE） signals with different frequency ranges were emitted when solid particles impacted the wall, the characteristic frequency ranges of the signals representing the movement of solid particles were obtained, and a model for predicting the slurry concentration in a loop reactor was established based on wavelet transform and R/S analysis. The water-beading system in a loop reactor was used as an example to investigate the relationship between characteristic AE energy and slurry mass concentration at the flow rate ranging from 5 m/s to 8 m/s. AE signals with the frequency of 0-100 kHz were analyzed by 9 scales wavelet transform and R/S analysis at a constant flow rate. It is found that d1 and d2 frequency ranges can be the characteristic frequency ranges representing the movement of solid particles. The ratio between the sum of the AE energy in the first two detail frequency range d1, d2 and the 3rd power of the flow rate is proportional to the slurry mass concentration. Results show that the slurry mass concentration can be successfully predicted with the average relative errors of 11.8%, which indicates that AE technique can on-line measure the slurry mass concentration in loop reactors fast, non-intrusively and with good accuracy.

关 键 词：声发射 浆液质量浓度 R/S分析 环管反应器 小波分析 

分 类 号：TQ022.4[化学工程]