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A programme of large-scale experiments for atmospheric dispersion was carried out by INERIS over a period extending from December 1996 to April 1997. The objectives of the test campaign were to measure anhydrous ammonia concentrations in a range of few meters to 2 km from the release, in order to generate data to be used to improve 2-phase release modelling.The discharges were released from a 6-tonne storage tank of pressurised liquid ammonia and through a discharge device with an outlet diameter of 2 inches. Fifteen trials were carried out with various release configurations corresponding to industrial situations (impinging jets on the ground and on a wall at various distances, release through a flange without seal...). The quantity of ammonia discharged from the liquid phase varied according to the tests, from 1.4 ton to 3.5 tons for durations between 7 and 14 minutes and, therefore, at flow rates between 2 and 4.5 kg/s. Approximately 200 sensors were settled downwind to measure ammonia concentrations and temperature in the plume. These tests showed that for discharges with identical flow rates the distances corresponding to the same concentration vary a lot according to the configurations. These distances tend to be reduced by the presence of obstacles or bounds that collected liquid ammonia. In the paper, the main experimental results are presented in order to enable the comparisons with numerical predictions.

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The NANOFEU project supported by the French Research Agency (ANR) aims to characterise the fire behaviour of nanoparticles filled polymer materials. Day after day, new applications of nanoparticles appear in industry. Among multiple applications in various domains, the role played by nanostructures particularly in combustion and flame retardancy phenomena needs to be quantified by modelling, experimental and numerical validations, since the use of these new components is increasing to upgrade polymer performances. Their employment could represent nowadays a valuable alternative or could be used in synergy with the conventional flame retardants systems. Nanocomposites based on several categories of polymers will be designed, incorporating suitable nanoparticles. Multiscale modelling of material, investigation of thermal degradation processes, and influence of interfacial modifications of nanoparticles, characterisation of effluents, particles released (size and morphology) and smoke toxicity will be made, developing original experimental and numerical means. We will particularly focus on fire performance, smoke toxicity and morphological modification of particles in the effluents, to weight the various impacts of the introduction of these nanofillers. A traceability of nanoparticles affected by combustion will be done through the analysis of effluents. In a first part, this paper includes a detailed presentation of the project by clarifying the partners' roles and objectives expected at the end of the project. In a second part, the foreseen experimental and numerical tools will be developed in order to improve the knowledge of mechanisms involved in combustion.

When a fixed roof storage tank is surrounded by a pool fire, and when the vents are not correctly dimensioned, the inside pressure can raise until the mechanical limits of the structure. The aim of this study is to develop a tool that will allow to follow the variations of the pressure and temperature in the gas phase, as a function of the size of the vent. This will help the sizing of new tank's vents or evaluating the risk of already build structures. The model also gives the temperature's distribution in the liquid phase, at each time step. In case of undersized vents, this information will be convenient to describe the phenomenological aspect of the accident after the rupture of the tank, i.e., to qualify and quantify the fire ball generated and its effect on persons and structures. Currently, if few analytical models exist to quantify the fire ball and its effects after the rupture, none are able to describe with accuracy the prerupture phenomena. The tool developed takes into account the two phases of the accident and allows to study complete and consistent scenarii. © 2010 American Institute of Chemical Engineers Process Saf Prog, 2011