Agglomeration Advisor: Introduction to fluid-bed rewet agglomeration
Many dry bulk materials are agglomerated to improve their handling characteristics and performance -- for instance, to make them nondusty, better flowing, and easier to dissolve.
Agglomeration is simply the formation of a larger particle from several smaller particles so that the larger particle becomes a permanent entity. When making an instantly dissolving agglomerate, such as a powdered food or dairy product, it's critical that the larger particle retain the smaller particles in identifiable form. This creates interstitial space within the agglomerate that pulls the water inside it through capillary action, enhancing the agglomerate's wetting and dissolution. Instantly dissolving agglomerates can be produced in a spray dryer (through fines reinjection), a fluid-bed rewet agglomerator, or a combination of these. No matter which method is chosen, the final agglomerate's qualities must be a careful balance of mechanical strength, bulk density, and mixability. This column will concentrate on how a continuous fluid-bed rewet agglomerator can achieve this balance.