Improving Water Spray Efficacy for Fire Suppression via CO2 Addition at High Pressures and Low Temperatures: Evidence for CO2 Clathrate Hydrate Formation
APPLIED RESEARCH ASSOCIATES INC TYNDALL AFB FL
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This paper describes a technique for achieving a compact aqueous spray that incorporates CO2 into the spray at low temperatures T 10C and high pressures P 10 MPa. A high-pressure spray apparatus was used to explore the effects of temperature 4-25 C, nominal CO2 mole fraction 0-0.12, in-line filter pore size 0.5-7 micrometer, and additives on the high-pressure 12-19 MPa water spray patterns. Divergence of the high-pressure H2O-CO2 spray was significantly reduced at low temperatures, with addition of sodium lauryl sulfate or aqueous film-forming foam AFFF, and with a small-pore-size 0.5 micrometer filter. The observed trends, based on digital images, can be explained by the formation of CO2 clathrate hydrate within the continuous-flow system. The concepts discussed herein may be applied to conventional H2OAFFF fire-suppression systems, where the introduction of CO2 as a foaming agent can increase fire-suppression efficacy.
- Inorganic Chemistry
- Organic Chemistry
- Safety Engineering