THE INFLUENCE OF TEMPERATURE ON THE VISCOSITY AND DRAINAGE RATES OF MECHANICALLY PRODUCED FIRE-FIGHTING FOAMS

摘要

Within the past twenty years, the use of mechanically produced fire-fighting foams has increased tremendously. Research studies wherein these aqueous foams were generated using solution tem¬peratures of 40 , 70°, and 100°F have revealed some interesting relationships involving their physical characteristics.nSpecial equipment was utilized for generating foams of vari¬ous expansion ratios and for obtaining measurements of the sta¬bility and viscous properties of these foams. It was found that as the solution temperature is lowered from 100° to 40°F, less energy (pressure) is required to produce a foam of practically any given drainage time and apparent viscosity value within the 4 to 12 expansion range.nIt is recommended that foam solution temperatures above 100°F not be used in foam generating equipment producing foams in the expansion 4 range because of the rapid decrease in foam stability and reduction in fire-extinguishing effectiveness.