Abstract
The ultrasonic attenuation (UA) technique was developed to measure not only particle size distribution (PSD) but also concentration for on-line and off-line analysis of high concentration dispersions. Another significant characteristic along with particle size is particle shape. Particle shape influences the apparent particle size as measured by various instruments. Currently, acquiring particle size along with shape measurement is not readily achieved. Image analysis measures shape with size distribution but only for very small samples, not generally practical for the process industries. Shape factors have been calculated from microscopic images using conventional image analysis (IA) techniques. Particle sizing data measured by UA is more representative than by IA because much larger samples are used for analysis. In this paper, size distributions obtained by ultrasonic attenuation (UA), laser diffraction (LD), focused beam reflectance measurement (FBRM) and image analysis (IA) are compared and the influence of crystal shape on size measurements is investigated. Data obtained from UA has been combined with information on shape factor from imaging to obtain equivalent particle size distributions. Data obtained from LD have been converted with a shape factor (sphericity) from imaging to obtain true Crystal size distribution (CSD). In a previous study [1], the influence of shape on size measurement has been investigated using different sizing techniques for non-fragile materials. These particles showed significant variation in measured PSD with their different shapes. In this paper, the same phenomenon was observed with evolving polymorphs of L-glutamate crystals (a and (3 form) and non-polymorphic oxalic acid and copper sulphate.
| Original language | English |
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| Title of host publication | AIChE Annual Meeting, Conference Proceedings |
| Subtitle of host publication | 2006 AIChE Spring National Meeting - 5th World Congress on Particle Technology; Orlando, FL; United States; 23 April 2006 through 27 April 2006 |
| Publication status | Published - 2006 |
| Event | 2006 AIChE Spring National Meeting - 5th World Congress on Particle Technology - Orlando, FL, United States Duration: 23 Apr 2006 → 27 Apr 2006 |
Conference
| Conference | 2006 AIChE Spring National Meeting - 5th World Congress on Particle Technology |
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| Country/Territory | United States |
| City | Orlando, FL |
| Period | 23/04/06 → 27/04/06 |
Keywords
- Crystal size and shape
- Image analysis
- Laser diffraction
- Ultrasonic attenuation and focused beam reflectance measurement