Dryer Selection and Introduction

Abstract

Background: Drying is a fundamental process in powder technology, involving the removal of moisture from materials through the application of heat. Industrial dryers vary widely in design and operating principles, and no single dryer type is universally applicable to all materials or processes. The selection of an appropriate dryer depends heavily on the physical properties of the raw material and the desired drying performance.

Classification of Dryers: This study categorizes dryers into two main types based on heating method—direct heating and indirect heating—and two types based on operation mode—continuous and batch. Direct heating dryers utilize convective heat transfer by exposing materials to hot air, while indirect heating dryers rely on conductive heat transfer through heated surfaces such as walls or paddles. Each type has distinct advantages and limitations depending on the material’s moisture content, stickiness, and sensitivity to temperature.

Dryer Models Introduced: Four representative dryers manufactured by Hosokawa Micron Corporation are introduced, each designed to address specific material properties and processing requirements through distinct heating mechanisms and operational modes:

• Drymeister^® H-type (DMR-H): A continuous direct heating dryer with strong dispersion capability, suitable for low-moisture powders and sticky materials.

• Nauta Mixer^®: A batch-type indirect heating dryer with vacuum and freeze-drying capabilities, ideal for heat-sensitive and solvent-containing materials.

• TorusDisc (TD): A versatile indirect heating dryer with a large heat transfer area, capable of both continuous and batch operation, suitable for resin drying and thermal treatment.

• Solidaire (SJ): A continuous indirect heating dryer with high thermal efficiency and adjustable paddle configurations, effective for crystallization and drying of chemical and polymer materials.

Conclusion: By analyzing the structural features, drying mechanisms, and material compatibility of each dryer, this report provides practical guidance for selecting suitable drying equipment. The classification framework and case studies presented herein aim to support engineers and researchers in optimizing drying processes for diverse industrial applications. These insights facilitate cost-effective equipment selection and enhanced process efficiency in powder processing operations.