Drying of combustible powders – Risk & mitigation

Abstract

This paper provides an overview of the various processes for drying combustible powders with particular emphasis on spray, fluid bed and ring dryers. Clients of FM Global, an industrial property insurance company, have experienced numerous explosion and fire losses in dryers and the primary causes and equipment involved in recent events are reviewed. Several case examples are provided. Key operating parameters that can impact the hazard created by processing combustible dusts are highlighted. For each dryer type the key controls, alarms and interlocks are addressed as well as the protection and mitigation features that can be installed. This will emphasize FM Global loss prevention guidelines but will also point out differences with NFPA and EU codes.