Towards estimating entrainment fraction for dust layers

Fire Protection Research Foundation report: "Towards Estimating Entrainment Fraction for Dust Layers"
Author: Erdem A. Ural, Loss Prevention Science and Technologies, Inc.
Date of issue: June 2011

Foreword

Recently there has been an increased awareness of the explosion hazard associated with combustible dusts. NFPA 654/A.2.2.3.1 includes criteria that have been used for determining whether an explosion hazard exists in a building compartment. There is, however, genuine concern over the technical pedigree of those criteria. Recently, federal governmental agencies have begun using NFPA 654 as a standard for assessing compliance with the General Duty Clause of the OSH Act of 1970. This has precipitated a genuine concern that the criteria currently in NFPA 654 do not have sufficient technical justification to be used as a law enforcement criterion.

The objective of this project is to establish the technical basis for quantitative criteria for determining that a compartment is a “dust explosion hazard” that can be incorporated into NFPA 654 and other relevant safety codes and standards. This report presents the results of the Phase I portion of the study which is the development of a strawman method to assess the dust hazard.

NFPA (National Fire Protection Association)
1 Batterymarch Park, Quincy, MA 02169-7471 USA
Telephone: +1 617 770-3000 Fax: +1 617 770-0700