Acoustic Chemometric Monitoring of Industrial Production Processes

The main advantage of this method compared with many other on-line methods for process monitoring is the use of noninvasive, so-called clamp-on sensors which can be easily mounted onto the process eqnip-ment (pipelines, reactors). The sensor, which often is a standard accelerometer, has no moving parts, and can, for example, withstand high temperatnres, a dirty enviromnent and is easy to maintain. The aconstic spectra measured with one sensor will often contain information abont several process-relevant properties and/or analytes which makes it possible to predict several parameters of interest from the same aconstic spectrum. 

Vibrational acoustic emission from industrial processes is often considered as audible random signals only, but it has recently been proven that within this noise there is often a bonanza of hidden nsefnl information [3-11], highly relevant for processes monitoring purposes. The fact that almost all processes produce some kind of acoustic emission opens up the potential for diverse applications which depend totally on sound, sensor-technological knowledge and chemometric multivariate calibration competencies. 

Process Analytical Technology 2e Edited by Katherine Bakeev 2010 John Wiley Sons, Ltd. 

Acoustic chemometrics has its greatest benefits in cases where haditional sensors and measurement techniques, such as flow, temperature and pressure transmitters cannot be used. In many processes it is preferable to use noninvasive sensors because invasive sensors may cause disturbances, for example fouling and clogging inside the process equipment such as pipelines, reactors cyclones, etc. In this chapter we concentrate mainly on new industrial applications for acoustic chemomehics, and only discuss the necessary elements of the more technical aspects of the enabling technology below - details can be found in the extensive background literature [3-5], 

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Acoustic Chemometric Monitoring of Industrial Production Processes... 

Acoustic Chemometric Monitoring of Industrial Production Processes 285 9.3 Industrial Production Process Monitoring... 

M. Halstensen, P. de Bakker, K.H. Esbensen, Acoustic chemometric monitoring of an industrial granulation production process - a PAT feasibility study, Chemom. Intell. Lab. Syst., 84, 88-97 (2006). 

The acoustic chemometric approach can also be used to monitor industrial production processes involving particles and powders and to provide a complementary tool for process operators for more efficient process control, or to monitor particle movement in a fluidized bed [7] for example. Below we illustrate the application potential by focusing on two applications process monitoring of a granulation process and monitoring of ammonia concentration. 

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