Galai particle size analyzer

Fig. 12. Schematic representation of the Galai particle size analyzer showing both the laser-based time-of-flight sizing equipment and the television camera...

Fig. 6 The Galai particle-size analyzer uses a laser beam and a rotating wedge prism to measure the size of fine particles by the length of time the fine particle blocks the light reaching the photodetector. (A) Basic layout of the Galai instrument (B) the laser beam traces a circular path within the sample cell, and the logic of the instrument rejects any particles that are off-center or out of focus (C) the length of time that the laser beam is blocked is related to the size of the fine particle. (From Ref...

Galai CIS-1000 is an on-line particle size analyzer. A bypass from the process line feeds the sample into the sensor unit where it is sized and either drained off or fed back to the line. Full compatibility with the laboratory instrument is maintained since it uses the identical combination of laser-based time-of-transit particle sizing using the 1001 sensor and dynamic shape analysis using the 1002 sensor. The size range covered is from 2 pm to 3600 pm with measurement of size, area, volume, shape, concentration and estimated surface area with a cycling time of 300 s. 

All the samples were characterized using conventional methods X-ray diffraction (Rigaku, D-Max IIIB), UV-VIS (Shimadzu 240), FTIR (Perkin-Elmer 1760), EDX (JEOL-5200), SEM (Philips Model 525), Cyclic voltammetry (Rikadenki), DTA-TGA (Dupont, 951), Particle size analyzer (Galai CIS-100), BET surface areas (350-450 m /g). Chemical analysis was obtained by atomic absorption (AAS) after solubilization of the samples in HF-HCl solutions. It was ascertained that the samples were free of any phase impurity and are catalytically active. 

Galai CIS Particle Size Analyzer A sizing instrument based on the amount of time a... 

Figure 3. Pints of mean particle size versus standard deviation of two prepared mixtures of standards analyzed by selected automated electronic particle size analysers (from Syvitski et al 1991a). The expected value is shown with a black box. S SediGraph C. Coulter Counter M Malvern laser panicle. sizer G Galai CIS-1, L Lumosed photosedimentometer lA Image analysis (Syvitski et al.. 1991a).

The advantages of the Galai equipment are similar to those described above for the electroresistance analyzers (e.g., small sample size, rapid analysis) pins the problems associated with coincidence and orifice clogging are also avoided. Analyses can be run until either a specified number of particles are counted (generally >200,000) or until a desired level of confidence in the distribution is reached (95%, 98% or 99%). Because the solution in which the particles are suspended does not have to be either aqneous nor... 

Another type of time-of-flight analyzer which uses a similar type of system to the Galai instrument is known as the Lasentec instrument [49]. This system is portable and has been used for on-line monitoring of particles in a slurry or suspension, as well as for size analysis in the laboratory. The basic system used in the Lasentec instrument is illustrated in Figure 6.15. 

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