Content area
Full Text
Abstract
Water mist fire suppression systems are being seriously considered as replacements for Halon 1301 total flooding systems in machinery space applications. A "total flooding" water mist system is designed to discharge mist uniformly throughout the entire enclosure/compartment. The tests conducted to date form a substantial database for water mist systems installed in machinery spaces with volumes from 100 m^sup 3^ to 1,000 m^sup 3^ and varying degrees of ventilation. These tests have also identified the strengths and limitations of water mist in these applications. This report describes the capabilities of total flooding water mist fire suppression systems in machinery space applications.
Key words: fire, fire tests, extinguishment, suppression, Halon 1301, Halon alternatives, water mist, total flooding, machinery space
Introduction
The U.S. Army,1 the U.S. Coast Guard,2,3,4,5 and the U.S. Navy6,7,8 have each conducted separate investigations into the use of water mist in machinery space applications. The Navy's investigations were conducted in a closed compartment. The Army and Coast Guard investigations were based on the International Maritime Organization's (IMO) test protocol for evaluating alternative arrangements for Halon fire extinguishing systems (MSC Circular 668(9)). These IMO tests were conducted in well-ventilated compartments with a 2 by 2 m vent opening. The tests conducted to date form a substantial database for water mist systems installed in machinery spaces having volumes between 100 m^sup 3^ to 1,000 m^sup 3^ and varying degrees of ventilation. This paper describes the capabilities and limitations of total flooding water mist, fire suppression systems as defined by this database of results.
Experimental Set-Up
Eight full-scale experimental test programs form the database for this discussion. The programs include the U. S. Army's investigation,1 four U. S. Coast Guard investigations,2,3,4,5 and three U. S, Navy programs.6,7,8 The test objectives and test compartment configuration varied between test series.
Test Compartments
The investigations were conducted in simulated machinery spaces of various size and shapes with a range of ventilation conditions. The spaces ranged in volume from 100 m^sup 3^ to 1,000 m^sup 3^. The ventilation conditions included closed, relatively air-tight compartments; natural ventilation, using a range of opening sizes; and forced ventilation at a rate of 12 to 15 air changes per hour. The U.S. Navy's machinery space was equipped with sheet metal...