An apparatus for applying fire-like heat flux to bench-scale samples

The research study presented in this paper concerns an experimental electricity-powered apparatus for applying fire-like heat flux to bench-scale samples. It consists of various elements, of which the most important are ceramic heating pads used to impose a defined heat flux on the exposed side of the sample mounted in a steel holder. The test method allows to control the heating pads’ temperature as well as to adjust the distance between the heating pads and the specimen to obtain heat fluxes up to 150 kW/m2. The thickness of the convective boundary layer at the heating pads’ surface is estimated to be around 3 cm, significantly lower than in case of gas-fired radiant panels. The performance of the apparatus was analysed in a case study on soda-lime-silica glass specimen. Experimental results were compared to numerical modelling. This analysis showed that a thermal exposure compared to the ISO 834 fire curve can be imposed on the exposed side of the specimen. There are many research possibilities for future applications of the presented experimental methodology: among others, tests with bigger specimens with heating pads surface up to 1.34 m2, and tests in controlled atmosphere.