Protection systems for tanks containing hazardous materials exposed to fire

The catastrophic failure of a tank containing a pressure liquefied gas often gives rise to a physical explosion with serious consequences for the possibly exposed people and structures. In fact, the liquid is at a temperature higher than its boiling temperature at atmospheric pressure, and, once released, it will instantaneously vaporize, with the generation of a shock wave. If the involved chemical is also hazardous (flammable or toxic), additional consequences are also expected (fires or toxic cloud dispersion), so that it is important to prevent the occurrence of this phenomenon as far as possible. Few studies are available in the literature to analyze the dynamics of this scenario, and, given the complexity of setting up experimental facilities, mainly theoretical approaches have been adopted, though some useful experimental results are also reported. The models proposed over the years allow to calculating the trend of the main parameters involved in the accident, but, in most cases, reference to a bare vessel has been made, while less attention has been devoted to assess the influence of protection systems, such as thermal insulation or pressure relief devices. In the present paper, a number of reference scenarios have been simulated involving both unprotected and protected systems, and the results have been analyzed and compared, to identify a proper strategy capable of significantly reducing the probability of failure of the tank

A simplified model for improving thermal stability of Lithium-ion batteries

Lithium ion batteries represent a well established technology in a range of applications (laptops, mobile phones, etc.) but they are becoming key factors in many other areas were reliability and safety are of paramount importance (e.g. the space and automobile industries). However, a number of drawbacks still raise concerns about their wider use and hamper a more structured introduction in these additional applications. In particular, the management of heat effects remains a challenge, as an excessive temperature rise can cause reduction of cycle life, battery failures and, above all, may lead to thermal runaway of individual cells or of an entire battery pack, with associated damages to the surrounding people or environment. In the present paper, a simplified model capable of predicting the thermal behaviour of a battery pack refrigerated with a cooling fluid, is presented. It allows to quickly estimating the efficiency of a given cooling system under specific working conditions, and thus identify the range of operation within which a given energy storage system can safely operate

A severity index to assess technological and natural risks in a study area

The paper addresses the problem of assessing the overall risk in a given area properly taking in account the contribution of each technological and natural risk sources present, such as industrial activities subject to Seveso directives, transportation of dangerous goods, earthquakes, volcanic eruptions, flooding, landslides, etc., based on the available quantitative or qualitative data. To this end, a "severity index", which is a dimensionless measure of the risk level, is defined for each risk source and the corresponding severity maps are obtained dividing the study area into meshes and calculating the values of the severity index for each mesh. Hierarchical prioritization techniques based on expert judgement are then applied to determine the weights associated to technological and natural risk sources, which are then combined to obtain global severity maps for the study area, which can be compared with vulnerability maps to achieve an accurate picture of the risk in the study area. The methodology has been implemented in a GIS (Geographic Information System) tool, which assists the users along the procedure. © 2006 Taylor & Francis Group

Metodologia per la valutazione del rischio complessivo derivante da attività industriali e da catastrofi naturali in un'area di studio

Convegno GRICU 200

Risk-based indices as a tool for assessing the sustainability of industrial installations

The influence of an industrial installation on the surrounding environment is quite complex and difficult to be synthetically represented. Both positive and negative effects are usually present: availability of work places and economic advantages for the local community; environmental pollution and harmful accidental events and many others. A number of methodologies have been proposed to assess the complex interaction between industry and territory. In most cases they address specific issues of this quite complex interaction, such as the polluting effect of the ordinary emissions on the environment or on the public health; safety and health on the workplaces, etc. Recently, an increasing number of methodologies based on risk analysis are considering the accidental events which can have an impact on the surrounding population or environment. Other studies attempt to represent the vulnerability of the surrounding environment. However, these factors have been rarely considered together, to provide a comprehensive view of the interaction between the production site and the surrounding area. Besides the mentioned lack of interconnection, in many cases the methodologies are too generic to provide significant results; conversely, in other cases, the amount of input information required to calculate the indices is so large and so detailed that the procedure becomes too demanding, would the needed data actually be available. In the present work, some available methods are critically analyzed, and a new methodology is proposed, based on risk indices concerning both the negative effects of the industrial site and the sensitive targets of the surrounding environment. This may provide a more realistic representation of the industry-territory interaction, and a significant help to public authorities and decision makers in properly addressing the most critical system’s elements, thus allowing a sustainable production and a true benefit for the local and global community

Kinetic study of poly(vynyl acetate) - calcium carbonate co-grinding in a ball mill

ISBN 085 825 794

Metodologia GIS per la caratterizzazione dell’impatto degli stabilimenti soggetti alla Direttiva Seveso II sul territorio circostante

Il lavoro presenta una metodologia GIS, messa a punto nell’ambito del progetto ARAMIS (Accidental Risk Assessment Methodology for IndustrieS), finanziato dall’U.E., che consente di ottenere, secondo una procedura automatizzata, mappe relative alla vulnerabilità del territorio in cui si trova un impianto soggetto alla normativa Seveso II ed alla severità delle conseguenze degli incidenti rilevanti per il territorio stess