Automatic Fire Extinguishing Systems (AFES) Obscuration Testing
Abstract
Since the cease of production of high ozone depleting substances such as halon 1301(bromotrifluoromethane), the US Army (USA) has relied on hydrofluorocarbon (HFC) extinguishing agents for many of its fire suppression applications. However, production of HFCs is being phased down due to their high global warming potentials (GWP). Therefore, the Army initiated a research program to evaluate potential environmentally-friendly, low-GWP chemicals as candidate fire extinguishing agents for use in automatic fire extinguishing systems (AFES) that protect the crew of Army vehicles against fire and explosions caused by combat threats. The current effort is a continuation of research conducted for ground and aviation weapon systems. This report summarizes obscuration effects of a potential alternative agent. Specifically, we present obscuration measurements KSA, a proprietary finely ground sodium bicarbonate dry chemical, compared to legacy fire extinguishing gaseous agents: halon 1301 and HFC227-BC (heptafluoropropane mixed with sodium bicarbonate dry chemical powder). KSA was developed as a potential replacement for halon 1301 in civil aviation fire protection systems. We observed prolonged obscuration in the crew compartment after a discharge of KSA, significantly longer than obscuration due to legacy agents. There are currently no Army criteria for obscuration effects in combat vehicle crew compartments. Our results indicate that such criteria may be needed to evaluate more environmentally friendly fire protection agents.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 12, 2021
- Accession Number
- AD1158590
Entities
People
- Andrew Clements
- James Slemons
- Joshua Fritsch
- Steve Hodges
- Steve Mccormick
- Thomas Whittaker