Study on Distance Effect to Vertical Flame Spread over PMMA

Some previous experimental studies has reported width effect for upward flame spread rate on thermally thin materials. But less of study on different distance. This study concerned about this topic by performing experiments using 2 mm thick, 85 mm width and 200 mm tall PMMA slabs with distances 2 mm, 7 mm, 13 mm, 19 mm and 25 mm to wall. Data were taken to show the flame spread characteristics of thin materials burning on different distances to wall. The data include flame height, pyrolysis height, flame spread rate and flame acceleration factor (FAF). Results showed that the ratio of flame height and pyrolysis height reduced linear and as constant when the distance is 7 mm, the biggest rate is 13 mm and the smallest rate is 2 mm. When the distance is 13 mm, the flame spread rate is bigger than the others, and 25 mm is second to 13 mm, the smallest is 2 mm. The FAF is between -1.0 and 1.0.