Foams and gels as fire protection agents

Fire protection foams and gels are used as temporary barriers to protect samples from incident thermal radiation thus delaying their ignition. Comparative measurements of the thermal behavior of these agents are made using a radiant heat exposure. The results of this comparison clearly show that thermal protection is obtained by two different mechanisms. The conduction-dominated gel operates at near saturation conditions (100°C). The radiation-dominated foam provides complete protection at ambient conditions (20–30°C) for about half the transient duration. Thereafter, the residual foam layer cannot prevent a rapid heat-up of the sample. Tests are performed applying the agents to a flat sample that is then positioned vertically and exposed to radiant heat. The lateral ignition and flame spread test (LIFT) apparatus is used to determine the ignition delay time for the gel. Due to the sample size restrictions associated with the LIFT apparatus, data collection for foams is not possible. Therefore, measurements are conducted in a Radiant Exposure Apparatus (REA) which allows for larger samples subjected to uniform heat fluxes up to 18 kW/m². The data gathered from the LIFT and REA are compared to establish the consistency between the two measurement sets.