A new publication available on the
Malvern Panalytical website describes the use of the Spraytec laser diffraction particle size analyzer in the study of fire suppression systems.
The work carried out by Professor André Marshall and colleagues in the Department of Fire Protection Engineering at the University of Maryland, supports the development of surfactant enhanced water mist fire suppression systems. These are intended to target difficult environments, such as fires in machinery spaces, which are traditionally extinguished using harmful gaseous suppressants.
For certain fires, applying water in a fine spray or mist can be particularly effective, reducing water usage and minimizing equipment damage. However, where fuel isolation is required, foams are particularly effective and a system that combines the benefits of water mists with those of fuel isolation using foams is one of the aims of this research. Surfactants, the principal components of foam concentrates, facilitate the formation and spread of air-water foams. The Spraytec was used in programmes designed to gain a greater understanding of the mechanisms underlying spray behaviours and to determine the impact of surfactants on the effectiveness of water mists.
The high concentrations, wide plume widths and high exit velocities of fire suppressing mists make accurate measurement of their droplet size characteristics challenging. However, the Spraytec overcomes these issues, which are common to many industrial sprays. Its high data acquisition rate enables rapid measurements to be made, capturing the dynamics of any spray process in great detail over a wide droplet size range (0.1 to 2000 microns).
Patented algorithms automatically correct for the multiple scattering encountered with high concentration sprays, and its versatile optical bench allows the Spraytec to be used for sprays of all types.