摘要:

AbstractThe use of differential thermal analysis has enabled spontaneous ignition behaviour of cotton cellulose to be investigate. The temperature.Ti, at which the onset of spontaneous ignition occurs is recorded as a function of the oxygen concentration of the flowing oxygen‐nitrogen atmosphere to which the cellulose sample is exposed in the DTA furnace, when heated at a defined heating rate. The dependence ofTi, on heating rate has enabled the activation energy,Ep, of the rate‐determining flammable pyrolysis product reaction to the determined using both a previously derived simple kinetic model and the technique of Ozawa.Ep, increases from a lower limiting value of 112 kJ mol−1at zero oxygen concentration to an asymptote value of 169 kJ mol−1at oxygen volume concentrations above 30%. This effect is described in terms of oxygen catalysis of competing pyrolysis routes. At a given heating rate, increased oxygen concentration reducesTi. A plot of 1/Tiversus In [O2] gives two liner regions which intersect at an oxygen concentration of about 20%, suggesting that two combustion mechanisms exist, one above and the other below this value. Below this concentration, which is similar to the conventional limiting oxygen for cellulose, significant char remains, suggesting that ignition of gaseous products only occurs. If the difference in slopes is sttributed to the variations inEpwith oxygen concentration, then a value for the activation energy of gaseous product oxidation,Eox= 215 kJ mol−1i

ISSN:0308-0501    

DOI:10.1002/fam.810090202

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

摘要:

AbstractAn examination of the correlative relationship between room fire intensity (temperature) and flammability data for materials, ASTM E–84 flame ratings and energy release rate from calorimertry devices is presented for fire spread on lings. The results of the analysis show the significance of two modes of flame spread—wind‐aided and opposed‐flow spread. The factors important in these spread modes are considered from approximate solutions developed for turbulent flow. As the importance of energy release rate to flame spread in the tunnel test (E–84) and in upward or wind‐aided spread is illustrated. The results suggest a possible reason why the ASTM E–84 and in upward or wind‐aided spread is illustrated. The results suggest a possible reason why the ASTM E–84 ratings may not be applicable to the performance of low‐density combustible linings in wall fires. In the analyses, flame radiation has not been considered. Also the interpretation of energy release rate data for difference scale and orientation effects has been ignored. These two factors must ulti

ISSN:0308-0501    

DOI:10.1002/fam.810090203

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

摘要:

AbstractTraditional material‐flammability tests are discussed in terms of their empirical foundation and oversimplified interpretation of fire phenomena. More recent rate of heat‐release tests overcome some of these problems by measuring a material's response to different levels of fire exposure. However, no existing small‐scale tests are sensitive to the radiant emission from the material's own flames. This radiant emission controls large‐scale fire hazards. As a result, existing flammability tests canot be xpected to adequately characterize large‐scale hazards. Some new approaches to this problem are discussed and a specific bench‐scale test method is suggested which may overcome the identified problems of existing t

ISSN:0308-0501    

DOI:10.1002/fam.810090204

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

摘要:

AbstractThe Harvard Computer Fire Code Mark V has been used to simulate full‐scale furniture fires. Simulations were run with one sofa burning in the open and another burning in a small room. To obtain better agreement between experiment and simulation, changes were made in the code to include heating of the lower surfaces in the room. A simulation of a mattress test, conducted at NBS, is included. Comparison with a zone model using a different plume equation is also presente

ISSN:0308-0501    

DOI:10.1002/fam.810090205

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

摘要:

AbstractNo standard method has been developed for measureing the evolution of specific toxic gases from building lings when involved in fire. The British Fire Propagation test (BS 476 Part 6) operated in an instrumented room has been proposed for this purpose previously but has not found general acceptance. It is considered further in this report, which investigates the movement and measurement of smoke and specific fire gases under different conditions of room stirring and the effect of the latter on fire propagation indexes. Stiring has been found to have no statistically significant effect on fire propagation indexes provided that the effects of this on calibration of the apparatus are taken into account. Stirring also had little effect upon smoke productionper se.Under unstire conditions smoke and toxic gases stratify in the same layer early in the test, and measurement of their production at any single room location will be subject to the location, the way the room influences stratification and how the room is instrumentee, as well as by the prpduct performance. Under stirred room conditions smoke and toxic gases are evenly distributed and product performance can be assessed more simply from concurrent measurements of fire, smoke and toxic gas parameters. The latter procedure is proposed for obtaining relative data on building linings and for examination in further studies for correlation to room and corridor burns.

ISSN:0308-0501    

DOI:10.1002/fam.810090206

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

摘要:

AbstractExtension of the British Standard Fire Propagation test (BS 476 Part 6) as a combustion mode for measuring smoke and toxic gas production from small panels of UPVC building products has been investigated. Hydrogen chloride gas concenatrations in the test room have been measured continuously with a method developed to ensure high collection efficiency from the fire gases. Using this method, the influences of test conditions (room temperature and humidity, room surface finish, reactivity of fire box interior) on HCl gas concentrations were examined to explain the fate of HCl gas after its evolution. The relative humidity (RH) in the room was the most critical factor influencing HCl gas concentrations during tests. Although HCl evolution early in the test was influenced little by RH and closely matched smoke production, maximum HCl gas concentrations in the room attained later varied markedly with RH. Generally, no more than one‐third of the HCl expected theoretically remained airborne under any test condition. Further investigations suggested that this loss and the effect of RH are associated with HCl plate‐out on room surfaces. Using test conditions set to minimize the influence of RH, HCl evolution from a series of UPVC building products was investigated. HCl concentrations in the test room did not exceed incapacitating levels for those products where less than a certain quantity of UPVC was combusted. This observation is discussed in relation to French regulations, which limit the total quantity of chlorine in some synthetic materials within building compartme

ISSN:0308-0501    

DOI:10.1002/fam.810090207

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

摘要:

AbstractA range of basic fillers has been incorporated into UPVC formulations and assessed for effectiveness in suppressing HCl evolution and influence on other fire properties. Investigations were carried out with the British Fire Propagation test (BS 476 Part 6) in a room previously used for assessing the fire behaviour of UPVC building products. HCl evolution was also studied following degradation in a pyrolysis tube furnace. Despite notable differences in these methods of assessment, good correlation was found between them. Varying degrees of HCl suppression were obtained and for formulations containing stronger bases effectiveness was found between them. Varying degrees of HCl suppression were obtained and for formulations containing stronger bases effectiveness was approximately stoichiometric to the amount of base present. Lithium hydroxide was thus the most effective HCl absorber on a weight basis. A formulation with 40 parts per hundred resin of this filler evolved only 2% of its theoretical HCl, although at the expense of increased fire propagation indexes. Smoke properties were not greatly influenced by the formulations. Precipitated calcite was considered the most promising acid‐absorbing filler for practical use. At 40 parts per hundred resin it reduced HCl evolution to 34% of theoretical and markedly delayed the onset of incapacitating HCl concentrations in the room, with little influence on fire propagation properties of the UPV

ISSN:0308-0501    

DOI:10.1002/fam.810090208

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810090209

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

摘要:

AbstractThe June 1984 meeting of ASTM Committee E5 on Fire Standards in Denver comprised a complete schedule of technical meetings plus a two‐day Symposium on Application on Fire Science to Fire Engineering. This is a brief summary of selected highlight

ISSN:0308-0501    

DOI:10.1002/fam.810090210

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810090201

出版商:John Wiley&Sons Limited    

年代:1985

数据来源: WILEY