摘要:

AbstractThis review concerns the mathematical modeling of fire phenomena. The fire is treated as a head and mass source driving a fluid flow process. Combustion is not included. It deals in detail with the field modeling approach incorporating the effects of turbulence, strong buoyancy and variable density on the transport of momentum, heat and mass. For the sake of simplicity, other effects such as those due to the interactions of the above mechanisms with the wall, radiation, etc., which may be crucial to the dynamics of the fire phenomenon, are not dealt with in this review. These effects will be the subject of future work.

ISSN:0308-0501    

DOI:10.1002/fam.810070102

出版商:John Wiley&Sons Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractStudies have been made of the influence on smoke generation from polystyrene of the incorporation of a number of apparently inert solids, the smoke‐producing tendency being expressed in terms of the maximum specific optical density of smoke per unit weight of polymer consumed. Of the compounds investigated, by far the most efficient smoke suppressant is pyrogenic silica, the effect of which is, over a wide range, directly proportional to the total surface area of the material introduced. Examination of partially burned polystyrene‐pyrogenic silica composites reveals the presence at the surface of a hard rigid skin, which is not observer with polystyrene alone of with polymer samples containing other additives. The formation of a protective skin is also indicated by the kinetics of forced burning of these composites where the weight loss is a linear function of log time and by measurements of the rate of change of thickness of polymer samples during combustion. Thermogravimetric experiments in which polystyrene and pyrogenic silica are heated in contact with one another show that the silica encourages the formation of a carbon residue from the polymer. A mechanism of skin production is proposed which involves the build‐up of layers of tangential spherical silica particles cemented together by cross‐linked poly

ISSN:0308-0501    

DOI:10.1002/fam.810070103

出版商:John Wiley&Sons Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractRaman scattering is a possible technique for analysing gas mixtures. In the work here described Raman scattering was used for detection of gases extracted from different model fires, where wood, polymethylmetachrylate (PMMA) and polystyrene were used as test materials. Raman spectra of gas samples from differently ventilated model fires are presented as well as the variation of O2, CO2and CO concentrations as a function of time with an effective time constant of less than 5 s. The sensitivity of the experimental set‐up was estimated to be about 1000 ppm, but suggestions are given how to reach a detection limit of about 1 ppm. The feasibility of the technique and various ways of improving it are briefly discusse

ISSN:0308-0501    

DOI:10.1002/fam.810070104

出版商:John Wiley&Sons Ltd.    

年代:1983

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810070105

出版商:John Wiley&Sons Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractA study has been made of the effect of molybdenum trioxide on the thermal degradation of a series of chlorinated and brominated polyester thermosets. Like antimony oxide, it showed flame retardant activity in all the halogenated polyesters. It was shown to affect the char yield, and the temperature and weight loss of each degradation step. X‐Ray diffraction studies of the degraded dibromoneopentyl glycol polyesters showed that in air a near‐quantitative yield of molybdenum trioxide was present above 550 °C. Some dioxide was present before the final char oxidation step occurred. In a nitrogen atmoshphere the trioxide was reduced to the dioxide at first, but this finally reacted to give the carbide at around 900 °C. Infrared spectroscopy showed that inclusion of the molybdenum trioxide resulted in structural changes in the high‐temperature polyester residues which were more prominent when bromine was present. Elemental analysis of the residues indicated that the presence of the trioxide in the brominated polyesters accelerated the release of bromine at high temperatures and confirmed its char‐promoting t

ISSN:0308-0501    

DOI:10.1002/fam.810070106

出版商:John Wiley&Sons Ltd.    

年代:1983

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810070101

出版商:John Wiley&Sons Ltd.    

年代:1983

数据来源: WILEY