Correlation of Burning Rate with Spread Rate for Downward Flame Spread Over PMMA

An experimental study on downward flame spread over extruded polystyrene (XPS) foam at a high elevation is presented. The flame shape, flame height, mass loss rate and flame spread rate were measured. The influences of width and high altitude were investigated. The flame fronts are approximately horizontal. Both the intensity of flame pulsation and the average flame height increase with the rise of sample width. The flame spread rate first drops and then rises with an increase in width. The average flame height, mass loss rate and flame spread rate at the higher elevation is smaller than that at a low elevation, which demonstrates that the XPS fire risk at the higher elevation area is lower. The experimental results agree well with the theoretical analysis. This work is vital to the fire safety design of building energy conservation system.

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Bounds for Downward Flame Spread Rate in Solid Fuels and Comparison to Experiments

Combustion Science and Technology ◽

10.1080/00102202.2011.584089 ◽

2011 ◽

Vol 183 (10) ◽

pp. 1083-1106 ◽

Cited By ~ 6

Author(s):

Toni Pujol ◽

Bruna Comas

Keyword(s):

Flame Spread ◽

Solid Fuels ◽

Spread Rate ◽

Flame Spread Rate ◽

Downward Flame Spread

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Experimental Study on Downward Flame Spread across XPS Surface

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.753-755.445 ◽

2013 ◽

Vol 753-755 ◽

pp. 445-451

Author(s):

Wei Guang An ◽

Hua Hua Xiao ◽

Jin Hua Sun ◽

Wei Gang Yan ◽

Yang Zhou ◽

...

Keyword(s):

Mass Loss ◽

Flame Spread ◽

Loss Rate ◽

Mass Loss Rate ◽

Flame Height ◽

Spread Rate ◽

Flame Spread Rate ◽

Stage 1 ◽

Exponential Change ◽

Downward Flame Spread

To study downward flame spread across XPS surface, a series of laboratory-scale experiments were conducted. Typical flame spread characteristics were obtained. The flame spread process comprises four stages. There are twice accelerations during flame spread. The influence of maximum flame height on flame spread rate is not significant. The predicted flame spread rate utilizing mass loss rate is lower than the measured value. Three stages: increasing stage, stable stage and decreasing stage are observed in both change of maximum flame height and flame area. The changing trend of mass loss rate is similar to that of maximum flame height. For stage 1 and stage 3, exponential change of mass loss rate with time is found. The mass loss rate is constant for stage 2. The heat flux to the preheating zone is higher than that to surrounding environment. Experimental results agree well with theoretical analysis.

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Experimental Investigation of Downward Flame Spread over RPU Samples

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.328.921 ◽

2013 ◽

Vol 328 ◽

pp. 921-925

Author(s):

Yuan Ming Wang ◽

Yong Ming Zhang ◽

Heng Ze Zhao ◽

Lan Ming Zhao

Keyword(s):

Flame Spread ◽

Combustion Process ◽

Flame Height ◽

Pulsation Frequency ◽

Insulation Material ◽

Spread Rate ◽

Energy Feedback ◽

Flame Spread Rate ◽

Sample Width ◽

Downward Flame Spread

The combustion process of polymer is a complex coupling of energy feedback from flame to fuel surface with degradation of polymer. In this paper, a series of comparative laboratory-scale experiments were carried out to study the effect of sample width on downward flame spread over the rigid polyurethane (RPU) foam, a typical thermal insulation material. The variations of some important parameters such as flame height, pulsation frequency and flame spread rate were measured and analyzed. Results show that if the width fixed, the parameters mentioned above independent with time. If the width less than 25cm, the sample can not burn completely. With the expand of width, average flame height and flame spread rate present the same chang trend that increase first and then decrease and finally reach a steady state, flame pulsation frequency increases first and then decreases since sample width more than 20cm. The heat transfer from flame and pyrolysis zone to virgin region is proportional to the height of flame, and mainly dominated by radioactive regime.

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Numerical analysis of the effect of fuel load on downward flame spread

Journal of Physics Conference Series ◽

10.1088/1742-6596/1777/1/012062 ◽

2021 ◽

Vol 1777 (1) ◽

pp. 012062

Author(s):

X L Zhu ◽

Y Jiang

Keyword(s):

Numerical Analysis ◽

Flame Spread ◽

Fuel Load ◽

Downward Flame Spread

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Thermodynamic and Kinetic Characteristics of Combustion of Discrete Polymethyl Methacrylate Plates with Different Spacings in Concave Building Facades

Polymers ◽

10.3390/polym13010167 ◽

2021 ◽

Vol 13 (1) ◽

pp. 167

Author(s):

Weiguang An ◽

Lujun Peng ◽

Minglun Cai ◽

Kaiyang Hu ◽

Song Li ◽

...

Keyword(s):

Polymethyl Methacrylate ◽

Flame Spread ◽

Structure Factor ◽

Turning Point ◽

Fire Risk ◽

Flame Height ◽

Hazard Evaluation ◽

Spread Rate ◽

Building Facades ◽

Flame Spread Rate

Polymethyl methacrylate plates are widely applied to buildings, producing significant fire hazards. It lacks a theoretical basis for the fire risk assessment of polymethyl methacrylate in concave building facades. Therefore, experimental methods are used to investigate combustion characteristics of discrete polymethyl methacrylate plates in a concave building facade. Influences of fuel coverage and structure factor are investigated, which is scant in previous works. When structure factor is invariable, average flame height increases first and then decreases as fuel coverage increases, and the turning point is between 0.64 and 0.76. In total, three different patterns of pyrolysis front propagation are first observed for different fuel coverages. Flame spread rate first increases and then decreases as fuel coverage rises, and the turning point is also between 0.64 and 0.76. When fuel coverage is invariable, the flame spread rate first increases and then decreases with increasing structure factor, and the turning point is 1.2. A model for predicting the flame spread rate of discrete polymethyl methacrylate is also developed. The predicted values are consistent with experimental results. Fuel spread rate of discrete polymethyl methacrylate rises as the fuel coverage increases. The above results are beneficial for thermal hazard evaluation and fire safety design of polymethyl methacrylate used in buildings.

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Experimental study of moisture content effects on horizontal flame spread over thin cotton fabric

Textile Research Journal ◽

10.1177/0040517518807450 ◽

2018 ◽

Vol 89 (15) ◽

pp. 3189-3200 ◽

Cited By ~ 1

Author(s):

Yunji Gao ◽

Guoqing Zhu ◽

Hui Zhu ◽

Weiguang An ◽

Yu Xia

Keyword(s):

Moisture Content ◽

Cotton Fabric ◽

Flame Spread ◽

Extreme Values ◽

Ignition Time ◽

Convective Heat Transfer Coefficient ◽

Flame Height ◽

Spread Rate ◽

Untreated Cotton ◽

Flame Spread Rate

In this paper, moisture content effects on horizontal flame spread were experimentally investigated using 0.245 mm thick, 28 cm tall and 28 cm wide untreated cotton fabric sheets with various moisture contents varying from 0 to 34%. The pyrolysis spread rates, flame heights and ignition times were obtained and analyzed. The corresponding results are as follows: as moisture content increases, the flame height and spread rate first increase and then decrease. In contrast, the ignition time shows an opposite trend with moisture content. The extreme values are observed in cases of 2% moisture content samples. Moreover, the flame spread rate in the warp direction is larger than that in the weft direction. For horizontal flame spread, the moisture content has the effect of consuming part of the heat feedback, which can play a role in reducing the flame spread rate; simultaneously, the moisture content can enlarge flame size and increase the convective heat transfer coefficient, thereby resulting in an increase in flame spread rate. The non-monotonous trend in pyrolysis spread rate is the result of competition between these effects.

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