The role of liquid-fuel vaporization and oxygen diffusion in lagging fires
Brindley, J; Griffiths, JF; Mcintosh, AC; Zhang, J
| HERO ID | 4969101 |
|---|---|
| In Press | No |
| Year | 1998 |
| Title | The role of liquid-fuel vaporization and oxygen diffusion in lagging fires |
| Authors | Brindley, J; Griffiths, JF; Mcintosh, AC; Zhang, J |
| Page Numbers | 2775-2782 |
| Abstract | Experimental and numerical studies have been performed to establish how liquid and vapor distributions of flammable liquids within an insulation matrix and that of residual oxygen may affect the propensity for spontaneous ignition to occur when the insulation is exposed to elevated external temperatures. <br> <br>The experiments were performed at temperatures up to 500 K when squalane, which is involatile, and tetralin, which is volatile, were doped into 5-cm cubes of a microporous material. The center temperature, oxygen concentration, and liquid mass loss were measured continuously The distinctions between evaporative loss without exothermic oxidation of a volatile fluid and the exothermic oxidation leading to ignition of an involatile fluid were clearly established. There were two principal features. First, oxygen is never excluded completely from the pores of the insulation material even when the block is exposed to an external temperature equal to the normal boiling point of the fluid. In fact, a "plateau temperature," which is below the bailing point, is established at the center of the block, and this is maintained until virtually all evaporation has ceased. Second, only very small proportions of oxygen are consumed during the induction time leading to thermal ignition. Complete consumption occurs within the porous structure only at an advanced stage of combustion. <br> <br>Numerical simulations were made including the chemical reaction, liquid evaporation, both fuel vapor and oxygen diffusion, and thermal transport through the block. A novel approach to the kinetic representation is used. The subtle interactions between heat and mass transport are explored, and the model is used to predict which of a series of liquid alkanes may be susceptible to ignition if they were to leak into hot lagging materials. |
| Wosid | WOS:000083308600320 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Journal:TWENTY-SEVENTH SYMPOSIUM (INTERNATIONAL) ON COMBUSTION, VOLS 1 AND 2 |
| Is Public | Yes |