Pozharovzryvobezopasnost/Fire and Explosion Safety最新文献

{"title":"Explosibility of nuclear graphite measured in a 1 m3 chamber","authors":"N. Poletaev","doi":"10.22227/0869-7493.2022.31.02.15-21","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.02.15-21","url":null,"abstract":"Introduction. Nuclear graphite poses a threat due to the formation of the graphite dust – air mixture (GDAM) during the dismantling of decommissioned nuclear reactors. However, there is no clear answer to the question on the GDAM explosibility. A review of international studies suggests that GDAM is either inexplosive or its explosibility is weak (Phylaktou H.N. et al., 2015). In this paper, the authors advance arguments for the explosion safety of GDAM.Selected research result. The authors considered a well-known result of a study on the combustion of GDAM with an average particle size of 5 μm, the concentration of about 450 g/m3 in a 1.138 m3 chamber, and an ignitionsource made by Fr. Sobbe GmbH («Sobbe 10 kJ»). The maximum overpressure ΔPmax was 0.47 bar in the chamber, and it fitted the case of an explosive air suspension, according to EN 14034-3 (1 bar = 100 kPa).Interpretation of the research result. Pressure oscillograms were compared for the following two cases: the case of the maximum manifestation of the GDAM explosion hazard (ΔPmax = 0.47 bar; dP/dt|max = 3.8 bar/s) and the case of combustion of an ignition source in the absence of air suspension (ΔPmax = 0.027 bar; dP/dt|max = 2.7 bar/s). The comparison shows that the first 20 ms of a pressure change inside the chamber is mainly due to the combustion of the ignition source: the characteristic values ΔP = 0.03 bar and (dP/dt) ≈ 3.8 bar/s are close to the «Sobbe 10kJ» combustion index in the absence of GDAM. A further increase in ΔP is accompanied by the constant or sharply decreasing value of (dP/dt), which means a monotonous decrease in the flame velocity and proves the incombustibility of GDAM.Conclusions. Due to the smallness of ΔPmax, GDAM can be considered nonexplosive under normal atmospheric conditions. Dependency diagrams, relating the pressure of combustion products and its growth to time offer important information about the combustion of the air suspension in explosion chambers under the condition of a low dust explosion hazard.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130529828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of a methodological approach to assessing the fire hazard of mattresses","authors":"N. Konstantinova, A. Zuban, A. A. Bulgakova","doi":"10.22227/0869-7493.2022.31.02.22-32","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.02.22-32","url":null,"abstract":"Introduction. Textile materials and products (upholstered furniture, curtains, bedding, decorative items, etc.) are among the most flammable materials in residential and public buildings. They largely affect the fire propagation speed and formation of dangerous fire factors in combustion. Therefore, the issues of improving the requirements governing their fire-safe use are particularly relevant.Aims and purposes. Presently, the fire safety of furniture products is regulated by the Technical Regulations of the Customs Union 025/2012 «On safety of furniture products» in Russia. However, differences in testing procedures and evaluation criteria, demonstrated by the applicable standards, do not always allow objectively assessing the flammability of upholstered furniture products and predicting their behaviour in case of fire. There is also no method for assessing the flammability of mattresses, and the currently used testing method, set by GOST R 53294–2009 (p. 5) cannot ensure a correct assessment and, hence, it results are distorted. The purpose of this work is to conduct an analytical study on foreign regulatory frameworks for the fire-safe use of upholstered furniture elements in public and residential buildings, to make an experimental assessment of the flammability parameters of materials and upholstered furniture, as well as develop proposals for improving the methodological approach to the fire hazard assessment and the use of mattresses in public and residential buildings.Results and discussion. The analytical studies have proven that fairly developed regulatory and methodological frameworks are in effect abroad. They ensure the fire-safe use of items of upholstered furniture on the premises of residential and public buildings and structures. Comparative experimental studies were conducted to assess the flammability of various composite combinations of mattresses and upholstered elements of furniture using GOST R 53294–2009 methods (p. 4 and 5), which identified large discrepancies between the test results due to the difference in the conditions of the thermal exposure in the course of testing.Conclusions. It is necessary to develop and introduce a standard method of testing the flammability of mattresses into the domestic regulatory practice. It is advisable to set the requirements limiting the use of flammable elements of upholstered furniture in places of the mass presence of people to reduce fire propagation in case of ignition and formation of dangerous factors.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124518799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current requirements to designing fire protection systems for educational establishments","authors":"A. Pekhotikov, A. N. Poletaev, A. Gomozov, S. Usolkin","doi":"10.22227/0869-7493.2022.31.02.5-14","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.02.5-14","url":null,"abstract":"Introduction. It is necessary to update requirements for designing fire protection systems for these facilities in terms of the safe evacuation and rescue of children and personnel, increase the efficiency of fire emergency response units conducting rescue operations, as well as optimize space planning and structural solutions to ensure a high level of fire safety inside buildings of preschool and general education organizations.Goals and objectives. The purpose of the article is to validate the updated requirements for designing fire protection systems for buildings of preschool and general education organizations in compliance with the Federal Law of the Russian Federation dated July 22, 2008 № 123-FZ «Technical regulations governing fire safety requirements» (hereinafter – «№Law 123-FZ»).Methods. An analytical method is used to formulate and substantiate the requirements for designing fire protection systems for educational establishments within the framework of the integrated application of Law 123-FZ and with regard for current trends in architecture and structural design of similar buildings, as well as fire risk calculations.Results. The results of the work are contributed to the amended sets of effective fire safety rules, such as SP 1.13130.2020 «Fire protection systems. Evacuation routes and exits», SP 2.13130.2020 «Fire protection systems. The fire resistance of protected facilities», SP 4.13130.2013 «Fire protection systems. Restricting fire spread throughout protected facilities. Requirements for space planning and structural solutions» (Amendment 1), etc., as well as SP 251.1325800.2016 «Buildings of general education organizations. Design rules» (Amendment 3).Conclusion. The research findings were employed to substantiate the current requirements for designing fire protection systems for educational establishments to improve the safety of children in the process of evacuation and rescue, if these buildings have premises featuring various classes of functional fire hazard, fire resistance limits and fire hazard classes of building structures, building materials and engineering installations.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132747745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The spread of fire from an open car park on the ground floor of a residential building","authors":"I. Khasanov, S. A. Zuev, A. Abashkin, A. S. Zuevа","doi":"10.22227/0869-7493.2022.31.01.77-87","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.01.77-87","url":null,"abstract":"Introduction. The problem of car parks and parking spaces is relevant in many large cities, and it requiresthe optimization of parking spaces. The arrangement of open car parks on the ground floors of apartment buil­dings is an effective way to organize car parks in a house in addition to covered parking lots. In this regard, in order to assess the fire hazard of such a design solution, it is necessary to study the spreadability of fire from an open ground floor parking lot to upper floors and develop reasonable proposals for the development of new and optimization of effective fire safety requirements.Goals and objectives. The goal of this work is to study the spread of fire hazards using the field modeling of the car burning process in an open parking lot on the ground floor of an apartment building and to assess the possibility of the fire safe arrangement of such parking lots in residential buildings.Method. To achieve the purpose of the study, the field (CFD) modeling of the fire development pattern was performed using FDS computer software. In the course of modeling, the authors analyzed the spread of the fire hazard from an open parking lot, located on the ground floor, to the upper floors of a residential building.Results and discussion. Temperature distributions, smoke and heat flows at various points in time were obtained as a result of modeling the development of fire in a parking lot. The results of calculations allowed to evaluate the effectiveness of various types of fire barriers and determine their parameters to meet the condition of the non-proliferation of fire. The most optimal solution is a non-combustible visor made of fire-resistant materials and installed above the opening leading to a parking lot. Given the results of the work, a set of necessary fire-figh­ting actions are proposed to ensure the possibility of arranging open parking lots in residential apartment buildings.Conclusions. It is shown that the fire safety of residential apartment buildings that have open single-level parking lots is achievable in case of the use of fire-resistant bearing and enclosing building structures, non-combustible materials for cladding, finishing the facade of a building, as well as in the case of making a canopy, a balcony or a gallery above the opening that leads to the parking lot.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114500154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The calculation of loads on buildings and structures caused by outdoor explosions of the fuel-air mixture","authors":"M. A. Liplenko, A. N. Borodenko, G. V. Mosolov","doi":"10.22227/0869-7493.2022.31.01.88-98","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.01.88-98","url":null,"abstract":"Introduction. An important engineering task, to be solved in the process of designing buildings and structures for hazardous industrial facilities, is to determine values of loads caused by outdoor explosions of the fuel-air mixture. Nowadays software packages, that use the computational fluid dynamics (CFD) approach, are widely applied in the design practice to assess various effects on building structures. In this regard, it is necessary to develop a load calculation method, that employs numerical simulation, and verify it in comparison with the experimental data.Goals and objectives. The purpose of this work is to use the method of computational fluid dynamics to analyze external sympathetic detonation loads on various types of buildings and structures.The body of the article. The article addresses the “compressed balloon” method used to analyze loads, caused by outdoor explosions of gas. Dependencies, proposed in the article, are needed to set the input data and make numerical calculations using the computational fluid dynamics (CFD) technique. The numerical modeling of various experiments in the ANSYS Fluent software package was conducted. The authors compared the results of numerical modeling and standard engineering methods with various experiments to assess the accuracy of the “compressed balloon” method used to analyze an outdoor detonation explosion.Conclusions. The authors have proven the qualitative and quantitative convergence of the numerical model of blast wave propagation and the experimental data. This calculation method allows to accurately apply the pressure profile to any surface of a building or structure in the course of an outdoor detonation explosion and estimate the bearing capacity of building structures. The proposed method can be used in the design of buildings or structures that feature various configurations.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126803465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The thermal analysis of fire test results obtained for loaded cast iron tubing used to line subway tunnels, their rational fire protection and pre-set fire resistance","authors":"A. Garashchenko, A. Danilov, S. Antonov, S. V. Marchenkova, V. Pavlov","doi":"10.22227/0869-7493.2022.31.01.21-39","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.01.21-39","url":null,"abstract":"Introduction. The article addresses the fireproofing limit of the cast-iron tubing that lines subway tunnels. These structures have been fire tested neither in our country, nor abroad, and therefore, no fire test results have been analyzed, although this analysis is necessary to guarantee structural performance.Purpose and objective. The purpose of the study is to analyze the results of two fire experiments, including the testing of the cast iron tubing without fire proofing, and the testing of the tubing protected by a fireproof plate. The objective of the study is to choose and use a rational thermal analysis methodology.Methods. A standardized methodology was applied to test the fire resistance of loaded full-scale tubing specimens in a fire furnace, where thermocouple measurements of tested specimens were taken. The thermal analysis of these measurement results was conducted, using the methods and software for the numerical calculation of non-stationary temperature fields inside fireproof structures in one- and two-dimensional settings.Results. It has been established that the fire resistance limit of the 5.6-25-NU cast-iron tubing tested under constant static loading (150 kN) without any fire protection is 54 minutes, which corresponds to classification R 45, while the fire resistance limit of the same tubing, fireproofed by PROSASK fire panel plates, that are 25 mm thick, is, at least, 121 min (R 120). Calculations allow to prognosticate a change in the fire resistance, if account is taken of the difference between the test environment and the one of the tubing when in operation. The authors present the results of calculations for various fire protection options and show that the fire protection and fire resistance limits of the cast-iron tubing are high, if PROSASK fire plates are used. The authors also demonstrate the projectability of the fire resistance values, if the modes of exposure differ from the standard temperature mode.Conclusions. The thermal analysis of the results of two fire experiments, conducted to evaluate the fire resistance of the cast-iron tubing as the tunnel lining allows to obtain the information that is essential for the fire protection and pre-set fire resistance of critical subway structures as well as the further development of this area of experimental and theoretical research. The authors demonstrate the efficiency of thermal calculations as an instrument for the evaluation of fire protection parameters/fire resistance of tubing and the reduction in the number of costly fire tests.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126528892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An approach to modeling the maintenance of stationary thermochemical gas analyzers at an oil refinery","authors":"I. Samarin, A. V. Kryuchkov, A. Strogonov","doi":"10.22227/0869-7493.2022.31.01.40-48","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.01.40-48","url":null,"abstract":"Introduction. The authors draw attention to the importance of the pre-explosive concentration detectors to assure the fire safety (FS) of fire and explosion hazardous facilities at oil refineries. The problem of the principle of pla­cing detectors close to sources of potential leaks is identified. The subject of research is the process of the maintenance of stationary thermochemical gas analyzers and their detectors installed around open-air facilities (OAF).Theoretical fundamentals. The notion of the discipline of the maintenance of stationary thermochemical gas analyzers is addressed in this section. The authors justify the choice of this type of devices according to the classification based on physical methods of analysis. Maintenance as a process, focused on the fire and explosion safety at oil refineries, depends on environmental and meteorological parameters, as well as the parameters of the process equipment. The release of catalytic poisons in the process of oil refining at OAFs, which negatively affect the sensitive elements (SE) of thermochemical detectors, and weather conditions may reduce calibration adjustment intervals or cause an accelerated failure of sensitive elements. The impact of environmental factors makes it necessary to adjust the detector calibration dates with account taken of the standard ones specified in the engineering documentation.Research results. The work sets the goals in terms of the values of the function of groups of parameters that substantiate the implementation of measures focused on the maintenance of detectors in the condition required by the documentation. The maintenance evaluation criterion is expressed as a vector of objective functions that convey the dependencies between groups of climatic, personnel work performance, specific, and other parameters. The integral criterion of the maintenance efficiency is provided in the form of a rectangular matrix and a convolution that takes into account three vectors of objective functions. The discipline of the maintenance of gas analyzers is presented in the form of a discrete subprocess of the process of fire and explosion safety assurance.Conclusions. This research work addresses an approach to modeling the discipline of the maintenance of stationary thermochemical gas analyzers installed around the open-air facilities (OAF) of an oil refinery. In further studies it is necessary to analyze the spatial location of the gas analyzer detectors to determine their number depending on the perimeter of the oil refinery’s open-air facilities.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128017958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the bearing capacity of socket contacts within the framework of a fire investigation","authors":"A. I. Nedobitkov, B. Abdeyev","doi":"10.22227/0869-7493.2022.31.01.65-76","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.01.65-76","url":null,"abstract":"Introduction. The data, provided in the article, demonstrate the relevance of the socket fire safety improvement in the course of operation. The purpose of the article is to develop a research-backed method of examining the socket contacts that feature high transient resistance or change in shape. The method can be subsequently used to identify causes of damages in a fire investigation.Materials and methods. A JSM-6390LV scanning electron microscope with a module designated for the energy dispersive microanalysis is used in the research. The subjects of research are type C (EU Type C) and type F (EU Type F) sockets. The failure surfaces of socket contacts were analyzed without preliminary sample preparation.Theoretical fundamentals (theory and calculations). A physical and mathematical model of the limit bearing capacity of socket contacts, similar to the real construction, has been developed. The model serves as the framework for a practical computational algorithm of the expert analysis of mechanical and geometrical characteristics. The solution is reduced to short calculation formulas, that can be used to evaluate the bearing capacity of so­cket contacts. The applicability of the developed mathematical model to fire investigations is proven in a specific ­example.Results and discussion. The authors analyze cases of socket fires, caused by the loss of the bearing capacity of socket contacts in the process of operation. Photos of the oxide film on the contact surface and its elemental composition are provided in the article. The experimental data have proven that the fusion of contacts and the presence of an oxide film, featuring high specific resistivity, are a significant criminalistic evidence that helps to identify causes of fire.Conclusions. The authors propose a method for the identification of the bearing capacity of socket contacts. The method can be used to determine if a subsequent fire is related to the socket ignition. The information, provided in the article, can be used by specialists in the course of an expert examination of socket contacts withdrawn from the site of the fire to identify the failure mechanisms and, ultimately, causes of fire.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132055148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The fire hazard of large transition resistances. From theory to practice. Part 2","authors":"A. S. Kharlamenkov","doi":"10.22227/0869-7493.2022.31.01.99-104","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.01.99-104","url":null,"abstract":"","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122477807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A research on rigid polyurethane foam resistibility to ignition from an electric arc welding spark","authors":"N. Poletaev","doi":"10.22227/0869-7493.2022.31.01.14-20","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.01.14-20","url":null,"abstract":"Introduction. A fire investigation assumes that electric arc welding sparks (hereinafter referred to as “sparks”) are effective sources of ignition. However, the spark ignition of a combustible material depends on the contact time. This work has experimentally proven that a smooth vertical wall, made of combustible rigid polyurethane foam (PUF), is not subjected to spark ignition. To explain this fact, the author calculated the time of contact between the spark and the wall τint, and compared it with the minimal estimated contact time τmin required to ignite the wall.The sample and the testing procedure. Sparks (the arc power up to 6 kW, the current up to 160 A) reached the PUF wall located at a distance of 0.1–0.15 m from the arc. An everyone experiment was continued until the electrode was burned down.Research results and discussion. Neither attempt to inflame the PUF sample by a spark was successful. Sparks bounced off the PUF sample and fell down. The characteristic dimensions of cooled iron droplets ranged from 0.2 to 3 mm.An evaluation of τint. The authors applied a model of elastic interaction between a drop of molten iron and a rigid wall, assuming that the sum of the potential energy of the drop, associated with its surface, and the kine­tic energy of a spreading drop, if flattened, is conserved. The longest contact time is achieved for drops, featuring the maximum diameter of 3 mm: τint ≈ 0.004 s.Estimation τmin. The authors applied the experimental modeling of the process, whereby the effect of an iron drop on PUF was replaced by the time-controlled effect, produced by a wooden cylinder (6 mm in diameter), inflamed at one edge. τmin ≈ 0.3 s. The ratio τint << τmin explains the inability of electric arc welding sparks to ignite the PUF wall.Conclusions. Electric arc welding sparks, having a diameter of up to 3 mm, cannot ignite a vertical wall, made of rigid combustible polyurethane foam, in case of a side impact. The lack of ignition is explained by the short-term contact between the spark and the surface of the polyurethane foam.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123190747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}