Oxygen is an oxidising gas that is in frequent use in a compressed form. Its increased concentration causes the distension of flammability thresholds of gases and liquid vapours. Solids surrounded by oxygen burn at a higher intensity, generating greater amounts of heat and higher combustion temperatures. The hazard caused by combustion of a substance in an oxygen environment not only causes its higher intensity, but due to its impact substances which in normal use conditions would not be easy to ignite, such as plastics or metals, become easily flammable in an oxygen atmosphere. Oxygen may become absorbed (in other words be accumulated) in the structure of textile materials, of which working clothing is made. Due to the possibility of warming up oxygen cylinders, it is important to know the hazards it creates, e.g. in the case of a shot, accidental opening, water cooling, and dangerous phenomena due to the presence of other flammable gases such as acetylene. The training described in the article points to the important danger when heating cylinders and the danger resulting from attempts to eliminate a hazard, e.g., during rescue and firefighting.
In the case of natural or man-made disaster, the top priority of urban search and rescue (USAR) groups is to localise the victim as quickly as possible. Even minutes might play a crucial role in the victim's survival. A number of standard operating procedures may be applied to achieve best performance. Rescue dogs are trained to search for alive victims; special inspection cameras are used, before heavy equipment is being implemented. To improve the effectiveness of USAR group operations, innovative technologies might be implemented. The most recent solution is currently designed in MOBNET project, founded by EU under the Horizon 2020 programme. The scope of the project is to combine both cellular technology and early Galileo services to localise the smartphones of potential victims. Integration tests give some promising outcomes. The following chapter looks at typical applications, real needs of public services as well as the performance of the novel system.
Fire and explosion protection in industrial conditions requires multidimensional approach. Usually the risk of hazardous zone creation is unavoidable, if the combustible material is processed. Therefore controlling of potential ignition sources is introduced. One of most popular sources of ignition is electrostatic discharge. Depending on the type of the discharge, as well as on exact discharge conditions, energy released might reach hundreds or even thousands of mJ, being able to ignite most of gaseous or dust-air hazardous mixtures. A dedicated methodology was created to record the discharge with fast camera with maximum speed of 1M fps and with the oscilloscope up to 25 GS/s. Dedicated test stand allows to obtain high voltage to create the conditions for electrostatic discharge. The aim of presented research was to analyze the course of electrostatic spark discharge in laboratory conditions and to place the outcomes in the context of explosion safety in the industrial conditions. The course of electrostatic discharge is dependent on various conditions: the polarity, distance between the electrodes, shape of electrodes, grounding conditions, etc. Understanding of the phenomenon is crucial from the point of view of explosion safety.
Air pollution, caused by explosion and/or fire of flammable substances, is typical for the majority of technological processes, e.g., flour storage and transportation systems in the food industry. If explosion venting systems are not properly designed, an explosion might lead to many causalities, substantial losses, and significant release of combustion products into the ambient atmosphere. This article presents a study on four selected types of flours: rice flour, oat flour, cornmeal, and chickpea flour. The chosen ignition and explosion indices were determined (heat of combustion, pmax, (dp/dt)max) and TGAs were conducted. The results were used to calculate the explosion venting area according to EN 14491. Despite similar origins, samples were characterized by slightly different courses of explosion, leading to significant differences in required venting areas. Chickpea dust was found to be the most distinguishing sample with the highest values of pmax, (dp/dt)max, and KSt recorded (7.7 bar, 313.08 bar/s, and 85 mbar/s, respectively). To avoid structure failure resulting in the emission of pollutants into the atmosphere, a change in the stored flour type should be preceded by a revision of safety measures taken, as the required vent area might differ significantly depending on the KSt, L/D ratio, and desired maximum static pressure.
In metallurgical processes, coke is used, among other materials, in order to implement the process of removing zinc from waste by reduction and evaporation. Due to the implemented de-carbonization policy, we are dealing with an increase in costs and decreasing availability of coke, which leads to an intensive search for other possibilities for conducting the process, which may generate a fire and explosion hazard in the technological process. This article analyzes the possibility of using soot in the process of reducing the zinc content in deposited metallurgical waste, taking into account the issue of fire and explosion safety. The results of the research proved the possibility of the safe use of the reductor, which is soot and anthracite, as a material replacing coke in pyrometallurgical processes.
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