Eulàlia Planas-Cuchi

A Survey of the Origin, Type and Consequences of Fire Accidents in Process Plants and in the Transportation of Hazardous Materials

A survey has been made of the accidents involving fire contained in the MHIDAS database. Of all the accidents that occurred up to the end of 1993, 41.5% (2283) involved fire. These fire accidents occurred in process plants (28%), transport (27%), storage plants (21%) and loading/unloading (7%). The type of accident is studied, as well as its effects on the population (number of deaths or people injured). The accumulated frequency-fatality curve is plotted; the line follows approximately a straight line, with a slope of -0.91. Finally, some conclusions are derived about the severity of fire accidents and the importance of increasing safety in the future.

Determination of flame emissivity in hydrocarbon pool fires using infrared thermography

A methodology is proposed for the determination of flame emissivity in hydrocarbon pool fires using infrared thermography. Experiments on gasoline and diesel oil pool fires with diameters of 0.13, 0.18 and 0.5 m were carried out, determining the flame emissivity for these types of fires in transition regime and turbulent regime. Also analysed was the evolution of the flame emissivity depending on the pool diameter, and a new correlation for the estimation of the emissivity depending on the above mentioned diameter was obtained.

Flame temperature distribution in a pool-fire

Abstract The variation of flame temperature with time and height (for the initial steps as well as for fully developed fire) has been studied in hydrocarbon pool-fires. Experimental data (temperatures measured with thermocouples and radiometers) measured with hexane (4 m2) and kerosene (12 m2) pool-fires were used to obtain the value of flame temperature. A significant difficulty was found to deduce this parameter from experimental values. A correlation is proposed to predict flame temperature as a function of time and height.

Modelling temperature evolution in equipment engulfed in a pool-fire

Abstract A method is presented to calculate the incident radiant heat flux and the temperatures reached on any point of a tank surface when this tank is engulfed in a pool-fire during the fire transitory state (developing phase). The method used to calculate the radiant heat flux on the cylinder is based on a three-dimensional formulation and uses the definition of a surface to establish the flame contour (according to a rectangular pool) taking into account the temperature changes with height and time. The results are compared to experimental data obtained with large scale pool-fires of hexane and kerosene, and show a good agreement. Finally, some conclusions are derived.

Prediction of flammability limits at reduced pressures

This work presents a method to estimate the variation of flammability limits as a function of the pressure of fuel–air mixtures at conditions of reduced pressure, for CmHnOx type fuels. The accuracy of the method has been tested through the comparison with experimental values of methane–air, ethane–air, propane–air and butane–air mixtures drawn from the bibliography; the agreement between the predicted values and the experimental data is very good.

Fire and explosion hazards during filling/emptying of tanks

Abstract Loading and unloading operations produce 8% of all accidents which occur in process plants and in the transportation of hazardous materials. A survey of 738 accidents was performed, allowing the identification of the accident type distribution and of their cause. Some considerations on flammable mixtures are also presented, and the procedures to avoid these mixtures occurring when filling or emptying a tank are briefly discussed.

Protection of equipment engulfed in a pool fire

Abstract When process equipment is engulfed in a fire, the protection system should extinguish the fire and simultaneously cool the equipment. Therefore, the behaviour of equipment engulfed in a fire, as well as its eventual influence on the fire, should be known. In this article, experimental data from pool fires of hexane (4 m2) and kerosene (12 m2) are discussed. The evolution of the fire up to its full engulfment is studied, as is the evolution of temperatures at different points of a tank engulfed in it. The heat release rates under the different operating conditions are studied. A method is developed to calculate the maximum combustion rate, both for the developing stage and for the fully developed fire. The hindering effect of the tank on the fire is discussed and quantified in terms of ‘efficiency of hindered combustion’.

Effects of fire on a container storage system—a case study

The transportation of chemicals is often carried out using containers; a system characterised by the high density of the storage. In such cases, if there is a fire in one container it will affect the adjacent ones. The effects of such an accident are studied through the analysis of a case: a fire on two containers located on a ship. The possibility of BLEVE occurrence is analysed, as is the thermal radiation and the dispersion of smoke.

Information on the risks of chemical accidents to the civil population. The experience of Baix Llobregat

The population has the right to know the risk to which they are exposed due to the existence of certain industrial plants. Furthermore, the knowledge of this risk and of several simple rules to be applied during an emergency will increase considerably the safety of the population. However, giving the adequate information is not easy, as there is the possibility of creating anxiety and fear instead of calming the population down. This communication describes the experience developed in the strongly industrialized zone of Baix Llobregat (Catalonia), where an acoustic alarm system was set up: a set of informative sessions (55) were carried out to different collectives of nine villages. The public were of very different education profiles (from engineers to people with a low cultural level). Supplementary illustrative material was distributed. As a whole, the results were satisfactory, although several difficulties were found.

Sheltering as a protective measure against airborne virus spread

The dispersion of airborne viruses can play an important role in the spread of a disease. Especially for short or moderate emission periods - such as emissions from farms or accidental releases from laboratories or industrial plants - indoor concentrations can be significantly lower than outdoor concentrations. The relationships between these two concentrations are analysed for continuous, temporary and instantaneous releases. The efficiency of sheltering as a protective measure for persons or animals is discussed.