Troubleshooting and problem-solving in industrial dryers

Abstract

Dryers are designed once but then operate for many years, and it is important to have systematic methods to solve problems when they arise. Kemp and Gardiner proposed a systematic methodology in 2001, based on categorization of problems into five main types and a divergent-convergent algorithm to identify both root causes and potential solutions. This approach to troubleshooting has proved successful for dryers in a range of industries. This article reviews the experience gained, some resulting improvements, and overlap and synergy with other investigation methods such as Lean Six Sigma techniques. An extensive range of case studies is given, illustrating the successful application of the methodology to many different situations and dryer types. The broad approach has remained the same but various points of detail have been added. Appropriate theoretical models can give useful insights, often using quite simple methods such as heat and mass balances and drying times estimated with first-order kinetics. The insights can solve other drying-related problems such as caking in storage. The methods can also be used for process improvement, debottlenecking, and enhanced product quality.