PERFORMANCE OF SPRAY DRYER WITH INTEGRATED FILTER AND FLUID BED

Abstract

Spray dryers featuring a fluid bed integrated into the base of a spray drying chamber have proved one of the most significant developments introduced into industry during the last decade, producing dust-free particulates under low product temperature conditions. The latest design development involves all particulate collection and exhaust air cleaning within the drying chamber with the use of integrated metallic filter elements (with CIP capability). This eliminates handling of fines outside the drying chamber and simplifies the exhaust air system contributing to lower pressure drop losses and lower overall energy consumption. This paper describes the performance of a pilot plant sized spray dryer featuring a drying chamber with both integrated particulate filters and fluid bed. Various products were tested. The results showed that the placing of particulate filters inside the drying chamber does not adversely affect the agglomeration process and that the powder quality compared with that achieved in a standard Fluidized Spray Dryer can be reproduced in this new design concept, with every possibility for improved quality due to no powder handling outside the drying chamber. The work also showed that by containing the powder within the drying chamber, notable operational advantages are apparent and that scale-up of the design concept represents no apparent difficulties.

Keywords:

• Spray drying
• New design concept
• Integrated particulate filter
• Powder containment
• Operational advantages

ACKNOLEDGMENT

The authors wish to thank the Niro Group for permission to publish their findings, and for use of photographic material.