FIRE BEHAVIOR OF BED MATTRESS ON THE VIEWPOINT OF FLAME-SPREAD: Experiments on conditions with different heights of mattress’s installation

摘要

To understand the combustion behavior of a bed mattress on fire, a series of experiments wasrnconducted by using a single-size pocket coil spring mattress at various installation heights above thernfloor (0–515 mm) according to ISO 12949. This paper reports the effects of the installation height onrnthe bed mattress’ combustion behavior through analysis of the flame spread burn area and flamernheight based on an existing calculation model.rnThe experimental results revealed that a higher installation height of the mattress increased the firerngrowth rate and maximum heat release rate. Furthermore, the flame height increased as the flame ofrnthe burning mattress merged with the flame on the floor formed by melted mattress materials. Thus,rnthe combustion behavior of the mattress is affected by its installation height and the combustion of itsrnmelted materials.rnThe measured flame spread burn area on the bed mattress disagreed with the results calculated fromrnapplying the existing model for opposed-flow flame spread over a solid fuel. The combustion of thernmelted materials on the floor may have increased the difference between the measured and calculatedrnresults and accelerated the rate of the flame spread burn area on the mattress. Conventionally, thernflame spread speed is determined by the incident heat flux (qf) at the upper surface of the mattressrnfrom the effect of radiation adjacent to the flame. However, a modified model is proposed where qfrnconsiders the effects from both the radiant heat flux by flame and convection heat flux by thermal airrnflow to the vertical section of the mattress. The results of the modified model were mostly consistentrnwith the experimental results.