A Study on Flame Spread Rate over Conveyor and Cable in Confined Space

为了阐明受限空间中的火灾行为，在模型管道中用纸进行了实验，在全尺寸试验通道中用PMRA板进行了实验。1）尺寸条件（宽度和厚度）对受限空间火灾蔓延速率的影响比自由空间更大。可燃物越靠近管道顶板，火蔓延速率越大，但当间隙小于一定值后，火蔓延速率开始减小。在可燃性测试和实际对策中，LILIS都是重要的。3）当气流方向与火蔓延方向一致时，通风大大提高了火的蔓延速度。然而，当空气速度超过4 m时，火焰被吹灭。/s。当空气逆着火的方向流动时，4）由于火灾产生的空气浮力作用，火灾蔓延速率随管道倾斜度的增大而增大; 5）物料下表面的温度始终高于上表面的温度;相差几百摄氏度。

In order to clarify tlie behavior of fire in confined space experiments were performed with]i)ng sheets of paper in a model duct and with PMRA sheets in a full scale test gallery.Tie results obtained are summarized as follows ;1)The dimensional conditions(width and thickness)influences tlie fire spread rate more strongly in confined space than in free space.2)The fire spread rate increases as tlie combustible material nears the ceiling of duct, t)ut it begins to decrease after the clearance becomes smaller than a certain value. lliis is important both in combustibility test and in practical countermeasure. s to fire.3)Ventilation greatly enhances the spread rate when the air flow in the same direction as tile spread fire. However, the flame is blown out when the the air velocity exceeds 4 m. /s. When tile air flows against tlie movement of fire, the spread rate decreases with the air velocity and tile fire is extinguished with the velocity more than 1 m/s.4)The fire spread rate increases with the inclination of the duct because of tlie buoyancy effect of air created by the fire.5)The temperature of tlie lower surface of the material is always higher tl-ian tliat of tlie upper- one and tlie difference reaches some hundreds degree centigrades.