IN-LINE PARTICLE-SIZE DETERMINATION FOR JET AGGLOMERATION PROCESSES

In jet agglomeration plants, powders are agglomerated to obtain good i nstant properties. The free-falling initial material is wetted in a sp ray cone by droplets or in a steam jet by condensation at the particle surface. In a subsequent region of high particle concentration, colli sion between particles occurs and agglomerates form, if the forces of adhesion are strong enough. A commercial measurement device, working a ccording to the principle of Fraunhofer diffraction, was modified for in-line application. It was used to measure particle size distribution s and concentrations of solid particles and droplets in jets. A model is presented to calculate local particle sizes by means of mass balanc es from integral measurements over large volumes. The results of in-li ne particle size and agglomerate size analyses show the practical impo rtance of dry agglomeration during transport and lead to a better unde rstanding of the subsequent wet agglomeration process.