Spray Granulation
Compact, dust-free granules from liquids containing solids.
Drying and shaping in one step.
The optimal solution for converting liquid substances into a solid product form
Fluid bed or spouted bed spray granulation is a process for obtaining flowable granules directly from liquids: drying + shaping in one step. It finds various applications in diverse industries, as the product properties can be varied in many ways by process engineering parameters and configurations. Due to their often round shape, the granules are also very suitable for subsequent coating.
Many industrial applications require the conversion of liquid substances into a stable product form with precisely defined properties – whether for further processing as solids in food, animal feed, cosmetics, detergents, fertilizers or crop protection products and numerous other applications. The granular form in all these applications is ideal for reducing product volume for transport and storage, for increasing stability in chemical substances, or for treating thermally sensitive products such as enzymes, proteins or microorganisms.
Spray granulation usually takes place in fluid bed systems or spouted bed systems in continuous operation.
Product properties of granules from spray granulation by fluid bed or spouted bed at a glance:
Dust free
Particles
Round
Pellets
Compact
Structure
High
Particle Density
High
Bulk Density
Low
Specific Surface Area
High
Particle Hardness
High
Abrasion Resistance
Adjustable
Particle Size
Defined
Particle Size Distribution
Very Good
Dosability
Excellent
Flow Behavior
Good
Solubility
Good
Dispersibility
Low
Hygroscopicity
The spray granulation process can be used to produce granules with average particle sizes of 100 micrometers to 4 millimeters.
The process combines drying of liquids with simultaneous granule build-up. Liquids are sprayed onto fluidized particles and dry on their surface, initiating layer-by-layer particle growth. The small particles required to maintain granule build-up are generated in the process itself. Only the liquid raw material is required.
Spray granulation imparts desired properties to solids, such as flowability, abrasion resistance, good solubility or optimum dosability. The dust-free granules have a dense surface structure and high bulk density, and their reduced surface area makes them less hygroscopic. Parameters such as particle size, residual moisture and bulk density can be specifically influenced to achieve a wide variety of product properties.
Addition of solids
In addition, it is possible to add powdery or finely divided solids to the process in a targeted manner in order to incorporate them homogeneously into the granule structure or to use them as external starter cores for granule growth.
Protection of sensitive substances
Valuable substances that require special protection can be embedded in a protective matrix by means of micro-encapsulation and – homogeneously distributed – gently granulated.
Copyright by Glatt
Copyright: Glatt