Toxic product in fire disasters is the most important reason for fire casualties. With wide application of polymer material, the toxic products in fire effluents are getting more and more diversified and complicated. Polyurethane is one of the most widely used materials. In this article, the fire toxicant release has been evaluated for thermoplastic polyurethane (TPU) and its flame-retardant composites. Ammonium polyphosphate (APP), aluminum hydroxide (ATH), and nano-montmorillonite (MMT) were combined into different flame-retardant combinations at certain ratios. Three kinds of flame-retardant combinations (APP-ATH, APP-MMT, and APP-ATH-MMT) were blended to reduce toxicity of TPU. The properties of thermal stability and decomposition were characterized by thermogravimetric analysis (TGA). TGA/infrared spectrometry, static tube furnace, and steady-state tube furnace were used to evaluate the toxic gases, including CO and HCN. Fractional effective dose (FED) was calculated based on the concentrations of CO, CO2, and HCN. The results showed that more than 50% toxicity effect in FED was accounted for HCN. The comprehensive toxicity of TPU was reduced in the samples with APP-ATH and APP-ATH-MMT. The yields of CO, CO2, and O2 consumption were indicated much lower in the samples with APP-ATH-MMT than the other two combinations.
A series of experimental and theoretical works are performed to enrich the previous research concerning single water drop impacting on burning ethanol surface. Three typical impact regimes including crater-first-jet, crater-second-jet, and surface bubble are discussed in detail, and an impact regime map is built up. For crater-first-jet and crater-second-jet regimes, the dimensionless maximum crater depth increases with the impact Weber number, but there is a sharp decrease for the regime transitioning from cratersecond-jet to surface bubble. In addition, the theoretical maximum crater depth and jet length scales are derived based on energy conservation and conversion. For crater formation, as the drop initial total energy increases, gravity gradually dominates the surface tension effects. For jet formation, however, the surface energy is around nine-times larger than gravitational potential energy when the energy stored in crater is the lowest.
Above ground petroleum product storage tanks are tanks or other containers that are above ground, partially buried, bunkered, or in a subterranean vault. These are built to store petroleum product for pipeline system, oilfield and refinery.
Tank fires are one of the most terrible accidents in oil pipeline transportation stations. Tank fires pose a significant hazard to people, buildings, process piping, the environment and other facilities as a result of thermal radiation exposure. It is necessary and meaningful to study the distribution of the thermal radiation of a tank fire for emergency response, prevention and reducing loss.
To analyze potential tank fire incidents at a pipeline station, a three-dimensional station model was built using a computational fluid dynamics (Abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows) software package to evaluate the thermal radiation distribution under different conditions. Numerical simulations were carried out for a total of six simulation scenarios to analyze 3 types of potential fires for 2 different liquid products (gasoline and diesel). The three kinds of fires that were modeled included: 1) disk pool fire on top of the tank; 2) ring pool fire on the top of a tank; and 3) pool fire in a dike. The simulation evaluates the effect of the thermal radiation on facilities and people.
The simulation results show that the water cooling system is effective at decreasing the magnitude of thermal radiation exposure and as a result is effective at protecting nearby tanks and facilities. Without water protection, the disk fire or ring fire can destroy or damage nearby structures significantly. The results of the simulation also show that the dike pool fire can have a catastrophic consequence to nearby facilities. Further the analysis showed that environmental wind does not change the thermal radiation distribution significantly. The results of the simulation point out countermeasure activities to enhance fire prevention at oil pipeline transportation stations in a scientific way.
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