(111b) Safe Thickness for Combustible Dust Layers (Webcast Not Available)

In order to prevent devastating secondary dust explosions, plant operators establish housekeeping policies and cleaning frequencies which will ensure dust deposit thicknesses will not exceed a maximum critical value specified in appropriate standards and regulations.

Makers and the Users of combustible dust standards and regulations are grappling with the conflicting requirements for maximum allowable ?safe? layer thickness specified in different standards. In fact, most users feel that existing housekeeping requirements are too conservative.

This presentation reviews and critically examines the latest prescriptive requirements for allowable dust deposit thickness. Analysis employs the performance based design concepts available in relevant NFPA standards, our knowledge of deflagration dynamics, and the physics of explosible cloud generation from dust layers.

The results show that current thickness requirements are in fact too conservative in some applications, while they are unsafe in others.

Proposed for Presentation at the

American Institute of Chemical Engineers

43rd Annual Loss Prevention Symposium

Tampa, FL

Copyright © 2008 by Loss Prevention Science and Technologies, Inc., All rights reserved.