The experimental investigation on mitigation of methane-coal dust hybrid explosion contain obstacles with ultra-fine water mist is presented in this article. Different diameters of coal dust and volume fluxes of ultra-fine water mist were considered. The parameters of explosion overpressure, the maximum rate of overpressure rise, the critical volume flux of ultra-fine water mist, and the deflagration index were determined and analyzed. The results show that the hybrid explosion is mainly influenced by coal dust diameter and the obstacle. The maximum explosion pressure (gauge pressure), the maximum rate of overpressure rise, and the critical volume flux of the ultra-fine water mist decreased with the increase of coal dust diameter; only when the volume flux of water mist increased to a certain range, the hybrid explosion would be completely mitigated.
{"title":"EFFECTS OF OBSTACLE ON METHANE-COAL DUST HYBRID EXPLOSION AND ITS MITIGATION WITH ULTRA-FINE WATER MIST*","authors":"H. Xu, P. Zhu, Yun Li, X. S. Wang, H. P. Zhang","doi":"10.2190/AF.23.2.C","DOIUrl":"https://doi.org/10.2190/AF.23.2.C","url":null,"abstract":"The experimental investigation on mitigation of methane-coal dust hybrid explosion contain obstacles with ultra-fine water mist is presented in this article. Different diameters of coal dust and volume fluxes of ultra-fine water mist were considered. The parameters of explosion overpressure, the maximum rate of overpressure rise, the critical volume flux of ultra-fine water mist, and the deflagration index were determined and analyzed. The results show that the hybrid explosion is mainly influenced by coal dust diameter and the obstacle. The maximum explosion pressure (gauge pressure), the maximum rate of overpressure rise, and the critical volume flux of the ultra-fine water mist decreased with the increase of coal dust diameter; only when the volume flux of water mist increased to a certain range, the hybrid explosion would be completely mitigated.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"44 1","pages":"143-155"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87545758","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}
This study was intended to establish a mobile instrument for smoke control tests that is capable of controlling pressure and measuring flow rates. A basic chamber leak test and a leak test performed using a circular hole proved that the instrument proposed complied with CNS 15038. A steel door for building purpose was used as the experiment specimen. By referring to the results of previous experiments, it is proven that the test instrument proposed could provide the amount of leak through a door in a building. The structure of the instrument designed can be used as a reference for the set up of lab instrumentation.
{"title":"Study on application and development of a movable smoke leakage test apparatus across building opening assemblies","authors":"S. Kuo","doi":"10.2190/AF.23.3.D","DOIUrl":"https://doi.org/10.2190/AF.23.3.D","url":null,"abstract":"This study was intended to establish a mobile instrument for smoke control tests that is capable of controlling pressure and measuring flow rates. A basic chamber leak test and a leak test performed using a circular hole proved that the instrument proposed complied with CNS 15038. A steel door for building purpose was used as the experiment specimen. By referring to the results of previous experiments, it is proven that the test instrument proposed could provide the amount of leak through a door in a building. The structure of the instrument designed can be used as a reference for the set up of lab instrumentation.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"7 1","pages":"307-317"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84951092","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":"Numerical Evaluation of Stationary Vehicular Blockage Ratio on Carbon Monoxide Stratification in Large Tunnel Fires","authors":"A. Sojoudi, H. Afshin, B. Farhanieh","doi":"10.2190/AF.23.4.E","DOIUrl":"https://doi.org/10.2190/AF.23.4.E","url":null,"abstract":"","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"64 1","pages":"435-452"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84223819","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":"Experimental studies on \"Bare Cabin\" fires","authors":"Jin Xuhui, Huo Ran, W. Chow","doi":"10.2190/AF.23.3.A","DOIUrl":"https://doi.org/10.2190/AF.23.3.A","url":null,"abstract":"","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"46 1","pages":"269-281"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85321477","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}
The function of air jet smoke prevention system is blowing air from the lineal vent installed on either sides or single side of the wall to prevent the smoke spread from fire sites. The system has the advantages for using in the hospitals, nursing homes, or underground tunnels which have a large number of weaker evacuees that may cause trouble by fire door or smoke curtain and other smoke devices. The corridors are designed to connect emergency exit and stairs as an evacuate route in most buildings. Therefore, stopping the hot smoke from corridor to stairs becomes an important fire safety design. The corridors may have various widths in existing buildings. Thus, three different size (2 m, 4 m, and 6 m) corridor widths are examined experimentally in this study. Referring to the test data, the air jet smoke prevention system applied in 2 m and 4 m width corridors are able to create a smoke-free area during the fire tests. Under the design supply air volume, air jet smoke prevention system fails to protect the 6 m width corridor.
{"title":"The corridor width effects on air jet smoke prevention system","authors":"K. Chung, Y. R. Zheng","doi":"10.2190/AF.23.3.F","DOIUrl":"https://doi.org/10.2190/AF.23.3.F","url":null,"abstract":"The function of air jet smoke prevention system is blowing air from the lineal vent installed on either sides or single side of the wall to prevent the smoke spread from fire sites. The system has the advantages for using in the hospitals, nursing homes, or underground tunnels which have a large number of weaker evacuees that may cause trouble by fire door or smoke curtain and other smoke devices. The corridors are designed to connect emergency exit and stairs as an evacuate route in most buildings. Therefore, stopping the hot smoke from corridor to stairs becomes an important fire safety design. The corridors may have various widths in existing buildings. Thus, three different size (2 m, 4 m, and 6 m) corridor widths are examined experimentally in this study. Referring to the test data, the air jet smoke prevention system applied in 2 m and 4 m width corridors are able to create a smoke-free area during the fire tests. Under the design supply air volume, air jet smoke prevention system fails to protect the 6 m width corridor.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"15 1","pages":"337-348"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78562118","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}
The present article studies the method of locating evacuation signs in a room full of smoke and a two steps optimization algorithm is proposed to obtain the best locations of evacuation signs in a building room. The efficiency of signs is validated by evacuation simulation with a cellular automaton (CA) model. The problem of signs location is divided into two optimization problems: maximal covering location problem and P-center problem, which are foundational problems in facility location problems. Maximal covering location problem is solved with Greedy Adding algorithm to obtain the initial locations of evacuation signs, which is not necessarily the best result. P-center problem is solved with an enumeration-like algorithm to obtain the final locations of all signs. The result of optimization shows pedestrians in a room full of smoke can find the shortest path to exit with the guidance of evacuation signs, so the evacuation time is shortest and people are safest.
{"title":"Location optimization for evacuation signs and cellular automaton model simulation for evacuation in smoke","authors":"Yafei Wang, Xiaoping Zheng","doi":"10.2190/AF.23.3.B","DOIUrl":"https://doi.org/10.2190/AF.23.3.B","url":null,"abstract":"The present article studies the method of locating evacuation signs in a room full of smoke and a two steps optimization algorithm is proposed to obtain the best locations of evacuation signs in a building room. The efficiency of signs is validated by evacuation simulation with a cellular automaton (CA) model. The problem of signs location is divided into two optimization problems: maximal covering location problem and P-center problem, which are foundational problems in facility location problems. Maximal covering location problem is solved with Greedy Adding algorithm to obtain the initial locations of evacuation signs, which is not necessarily the best result. P-center problem is solved with an enumeration-like algorithm to obtain the final locations of all signs. The result of optimization shows pedestrians in a room full of smoke can find the shortest path to exit with the guidance of evacuation signs, so the evacuation time is shortest and people are safest.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"95 1","pages":"283-297"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81844500","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":"Studies on Criteria of Wood Ignition in Case of Enclosure Fires","authors":"Aiping Chen, Liang Zhou, Guilai Niu","doi":"10.2190/AF.23.4.H","DOIUrl":"https://doi.org/10.2190/AF.23.4.H","url":null,"abstract":"","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"25 1","pages":"495-507"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82392543","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}
A large area of mature mixed-oak (Quercus spp.) forest was clearcut in the early 1990s on a dry mountain plateau in south-central Pennsylvania. The majority of the developing forest was burned from an intense wildfire in 2005. Our 2009 vegetation survey revealed that the unburned areas contained a high density (3579 stems per acre) of sapling and pole-sized trees dominated by mixed-oaks, red maple (Acer rubrum), sweet birch (Betula lenta), and black cherry (Prunus serotina). The burned areas had 43% lower tree density, including fewer oaks and black cherry, but a higher proportion of lower value trees (e.g., black locust; Robinia pseudoacacia). In the burned areas, 91% of surviving oaks had basal fire scars averaging 39” in length, were overwhelmingly multiple-stemmed after being top-killed by fire, and shorter in height and smaller in diameter than the oaks in the unburned units. The burned units had higher cover of shrub and herbaceous species. The results of this study suggest that intense wildfire can significantly damage young oak forests, and that the negative direct and indirect effects of this will persist long into the future.
{"title":"WILDFIRE DAMAGE ASSESSMENT OF A YOUNG OAK FOREST IN PENNSYLVANIA","authors":"M. Abrams, S. Johnson","doi":"10.2190/AF.23.1.F","DOIUrl":"https://doi.org/10.2190/AF.23.1.F","url":null,"abstract":"A large area of mature mixed-oak (Quercus spp.) forest was clearcut in the early 1990s on a dry mountain plateau in south-central Pennsylvania. The majority of the developing forest was burned from an intense wildfire in 2005. Our 2009 vegetation survey revealed that the unburned areas contained a high density (3579 stems per acre) of sapling and pole-sized trees dominated by mixed-oaks, red maple (Acer rubrum), sweet birch (Betula lenta), and black cherry (Prunus serotina). The burned areas had 43% lower tree density, including fewer oaks and black cherry, but a higher proportion of lower value trees (e.g., black locust; Robinia pseudoacacia). In the burned areas, 91% of surviving oaks had basal fire scars averaging 39” in length, were overwhelmingly multiple-stemmed after being top-killed by fire, and shorter in height and smaller in diameter than the oaks in the unburned units. The burned units had higher cover of shrub and herbaceous species. The results of this study suggest that intense wildfire can significantly damage young oak forests, and that the negative direct and indirect effects of this will persist long into the future.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"34 1","pages":"91-104"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85518415","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}
This study examines the influence of the atmospheric disturbance caused by a fire in a semi-open parking garage and the resulting rapid drop of toxic gases on evacuation safety. According to a FDS simulation, the air pressure in an atmosphere of 1 kgf/m2 or a windless environment is used, each factor for hazardous escape does not reach a significant level (SFPE Handbook of Fire Protection Engineers). This indicates that even if two sides of an exterior wall are closed, in order to escape, a semi-open space is safe. However, in the industry, there is a debate on whether the influence of a different spatial format and the air pressure in the atmosphere needs to be re-assessed.
{"title":"The influence of atmospheric circulation on evacuation safety in a semi-open parking garage","authors":"Chieh-Hsin Tang, Y. Tseng, Yu Chang Lin","doi":"10.2190/AF.23.2.H","DOIUrl":"https://doi.org/10.2190/AF.23.2.H","url":null,"abstract":"This study examines the influence of the atmospheric disturbance caused by a fire in a semi-open parking garage and the resulting rapid drop of toxic gases on evacuation safety. According to a FDS simulation, the air pressure in an atmosphere of 1 kgf/m2 or a windless environment is used, each factor for hazardous escape does not reach a significant level (SFPE Handbook of Fire Protection Engineers). This indicates that even if two sides of an exterior wall are closed, in order to escape, a semi-open space is safe. However, in the industry, there is a debate on whether the influence of a different spatial format and the air pressure in the atmosphere needs to be re-assessed.","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"1 1","pages":"231-248"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88467119","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}
Gary Li-Kai Hsiao, Te-Chin Huang, Ching-Yuan Lin, Tzu-Sheng Shen
{"title":"Simulation of Bus Fires in the Hsuehshan Tunnel, Taiwan, Using the Software Fire Dynamics Simulator","authors":"Gary Li-Kai Hsiao, Te-Chin Huang, Ching-Yuan Lin, Tzu-Sheng Shen","doi":"10.2190/AF.23.1.C","DOIUrl":"https://doi.org/10.2190/AF.23.1.C","url":null,"abstract":"","PeriodicalId":15005,"journal":{"name":"Journal of Applied Fire Science","volume":"82 1","pages":"43-57"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83181325","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}
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