Patent ID: 6308434
Filing Date: 2001-10-30
Classification: B01D,B01J

Abstract:
A method of making particles comprising(a) spraying an emulsion, solution or suspension which comprises a solvent and a bulk material through an atomizer, in a primary drying chamber having a discharge outlet and containing a drying gas, to form droplets of the solvent and bulk material dispersed in the drying gas;(b) evaporating a portion of the solvent into the drying gas to solidify the droplets and form particles;(c) flowing the particle and drying gas through a secondary drying apparatus comprising tubing having an inlet in fluid communication with the discharge outlet of the primary drying chamber, to evaporate a second portion of the solvent into the drying gas,wherein the ratio of the cross-sectional area of the primary drying chamber to the cross-sectional area of the tubing is at least 4:3, andwherein the ratio of the length of the tubing to the length of the primary drying chamber is at least 2:1.