AN OUTLINE METHOD FOR TROUBLESHOOTING AND PROBLEM-SOLVING IN DRYERS

Abstract

Dryer troubleshooting is of great practical importance but has been neglected in the academic literature. Problems are often case-specific, non-quantitative and difficult to categorise. This paper outlines a systematic method for problem-solving in dryers. Problems tend to fall into one of three main categories; underperformance, materials handling, and product quality (non-moisture). Other problems include mechanical breakdown and SHE (safety/health/environment). Further categorisation may be useful; for example, the causes of dryer underperformance can be subdivided into heat and mass balance problems, drying kinetics and drying equilibria. The possible causes of the problem can then be listed, and process and equipment data is collected to allow these to be confirmed or dismissed, and to identify the root cause. Possible solutions can be considered, casting the net as widely as possible; some apparently unlikely suggestions may turn out to be feasible, or lead to a novel and better idea. The overall algorithm follows a convergent-divergent pattern (brainstorming technique). Certain types of dryer are particularly susceptible to certain types of problem. A range of case studies illustrates the application of the techniques in many different circumstances.

Keywords:

• Performance
• Debottlenecking
• Solids handling
• Product quality
• Case studies
• Heat and mass balance
• Kinetics
• Drying equilibria

ACKNOWLEDGMENT

The survey and resulting procedure were funded as part of the work programme of SPS (Separation Processes Service, Harwell, UK) whom the authors thank for permission to publish this paper.