New developments in particle characterization by laser diffraction: size and shape

Citation
Zh. Ma et al., New developments in particle characterization by laser diffraction: size and shape, POWD TECH, 111(1-2), 2000, pp. 66-78
Citations number
37
Categorie Soggetti
Chemical Engineering
Journal title
POWDER TECHNOLOGY
ISSN journal
00325910 → ACNP
Volume
111
Issue
1-2
Year of publication
2000
Pages
66 - 78
Database
ISI
SICI code
0032-5910(20000821)111:1-2<66:NDIPCB>2.0.ZU;2-E
Abstract
Laser diffraction has become a popular technique in many fields for measuri ng particle size distributions (PSDs). It is not only one of the standard t echniques for laboratory measurements but is also gaining importance for on -line process monitoring and process control. This article reports some dev elopments of this technique while recognizing the potential that still exis ts. In this report both particle size and shape are taken into account. For optimum results, both effective sensing and analysis of the diffraction pa ttern are required. This is the goal of our present study with a special in terest in on-line application. In this paper, a statistical approach - prin cipal component analysis (PCA) - to the scattered Light signals from a conv entional detector array is shown to improve the sensitivity to a few large particles relative to the main size distribution. For determining particle shape, a wedge-type photo-detector for sensing the azimuthal Light intensit y has been applied together with the procedures of cross-correlation, sweep selection for single particle presence and Fourier analysis. Finally, a no vel light scattering sensor is presented, which enables the measurement of both size and shape and which offers even more promising applications for o n-line process control. (C) 2000 Elsevier Science S.A. All rights reserved.