摘要:

AbstractNumerical solutions of the post‐flashover fire are considered and a computer program is presented. The solutions are compared with experiment and the sensitivity of the solutions to a number of variables is discussed. It is shown that increasing the ventilation may either increase or decrease fire intensity, and the importasnce of the ventilation controlled phase of the fire is discussed. Application of the model to calculate the expected time‐temperature history is illustrated and its significance is discussed. The deterministic approach is compared with a new method for calculating the most severe fire by letting one variable take any value between certain limits. The latter method is called pessimization. The significance for designers is no

ISSN:0308-0501    

DOI:10.1002/fam.810030102

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractSamples of current Australian production of unplasticized polyvinyl chloride pipe and fitting materials have been examined in relation to combustion characteristics. Small scale laboratory assessment of piloted radiant ignition flame propagation and smoke generation have been investigated. Where necessary, improvements to methods of test or analysis of data have been developed and factors that influence results have been investigated. Piloted radiant ignititon and smoke production under flaming conditions are shfown to be the important combustion characteristics of UPVC materials for improvement.

ISSN:0308-0501    

DOI:10.1002/fam.810030103

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractData are presented which show the effect of elevated environmental temperature upon smoke particle characteristics of wood (Douglas fir) and a rigid PVC, under both flaming and nonflaming combustion in air. The physical data obtainbed include the smoke particle average diameter, the smoke optical densities in red and blue light, and the weight loss of the sample. The average particle dimeter, the smoke optical densities in red and blue light, and the weight loss of the sample. The average particle diameter and optical densities in red and blue light, and the weight loss of the sample. The average particle dimater and optical densities were obtained uwing inin situoptical system which measures forward scattered light at two angles and transmitte light at two wavelengths. Data were taken for vertically mounted samples exposed to a radiant flux of 5 W cm−2in environments at a room temperatures, 100°C, 200°C and 300°C. The result indicate that in flaming test higher environmental temperatures general result in greater smoke optical densities and larger smoke particles, while in nonflaming tests higherl temperatures in lower smoke densities and smaller smoke particles, for wood. These results may explain why small‐scale test data (room temperature environment) do not often correlate well with full‐scale data (often at elevated environmental tempe

ISSN:0308-0501    

DOI:10.1002/fam.810030104

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810030105

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractA theory is developed for calculating the heat transferred from a buoyant layer of fire gases and smoke, to a sprinkler spray. The theory involves calculating the heat transfer to a single water drop as it describes its trajectory, and uses experimentally derived information on the nature and structure of such sprays to calculate heat transfer to the whole spray. Because such experimental information is sparse for sprinklers, a very simple model of the ballistic properties of a sprinkler spray is adopted. Calculations using the teory suggest that the practive of installing sprinklers in the smoke reservoirs of shopping malls would, in some cases at least, reduce the effectiveness of natural venting of smoke by reducing the buoyancy of the hot smoky gases.

ISSN:0308-0501    

DOI:10.1002/fam.810030106

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractAn experiment is described which measures the heat transferred from a hot, flowing, buoyant gas layer in a mall, to a sprinkler spray. Interpolation techniques are described which allow for the large heat losses occurring within the apparatus (a large‐scale model mall). The results are compared with predictions based on the method developed in Part 1 and found to be consistently 150% of the predicted heat transfer rates. Given the assumptions required by the predictive calculations this is thought to be reasonable degree of agreement. The largest heat transfer rate to the one sprinkler spray in this experiment was 157 kW ± 38

ISSN:0308-0501    

DOI:10.1002/fam.810030107

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractThe Critical Oxygen Index test has been used as a measure of the flammability of a wide range of substances, including plastics, textiles and liquids, since its introduction in 1966. The index, however, is only appropriate to the configuration and conditions used in the test, and extrapolation in order to predict the flammability of materials in a large‐scale fire is not valid. The index is dependent on a number of sample and test parameters and these are reviewed; the ASTM test standard, the reproducibility of the results, and certain theoretical aspects are also discusse

ISSN:0308-0501    

DOI:10.1002/fam.810030108

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractThe coupling between the constituent reactions of a burning process, namely pyrolysis, combustion of volatiles, and (possibly) oxidation of char, is on the whole quite different for fires occurring in the open and for those that develop in an enclosure. Consequently, knowledge of the characteristics of free burning fires is of only limited value in studies related to compartment fire. Since the singe‐rout communication between the fire compartment and its environment, always assumed in classical fire studies, is not at all common in real world fires, great sophistication in the mathematical modeling of classical fires is rarely warranted. An examination of pool‐like fires and pile fires of noncharring fuels has shown that the severity of such fires in the fire compartment, as characterized by the so‐called ‘fire severity product’, decreases slightly with an increase in ventilation. The principal danger presented by these fires, however, is not so much to the fire compartment itself as to the surrounding spaces.An interesting feature of fires involving charring fuels, cellulosies in particular, is that the rate of consumption of fuel, the so‐called ‘rate of burning’, is practically independent of all process variables except ventilation. The severity of fires of cellulosics is, as a rule, much higher than that of fires of noncharring fuels. It exhibits a maximum at relatively low ventilations. From the point of view of spread of fire to the surrounding spaces, cellulosics are generally less dangerous than noncharring plastics. Fires involving cellulosics mixed with smaller amounts of noncharring plastics can be characterized as basically cellulosics fires, with a superimposed initial period of very high s

ISSN:0308-0501    

DOI:10.1002/fam.810030109

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810030113

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY