Comprehensive Theoretical and Experimental Studies on the CF3H Fire-extinguishing Mechanism

2011 ◽  
Vol 29 (7) ◽  
pp. 1335-1350 ◽  
Author(s):  
Xiaomeng Zhou ◽  
Biao Zhou
Keyword(s):  
Experimental Studies ◽  
Fire Extinguishing

The Study of Fire-extinguishing Process of Modelled Fire Seats

2021 ◽  
pp. 57-62
Author(s):  
V.N. Bordakov ◽  
Keyword(s):  
Flow Rate ◽  
Experimental Studies ◽  
Physical Modelling ◽  
Specific Flow Rate ◽  
Specific Flow ◽  
Acceptable Error ◽  
Fire Extinguishing ◽  
Fire Zone ◽  
Analysis Of Results ◽  
Fire Extinguishers

Test-fires to determine fire-extinguishers’ efficiency for extinguishing B class fires are conducted by operators equipped with working clothes, which does not comply with the requirements of physical modelling. This is why the ranks of extinguished modelled seats are significantly overestimated. The quantitative results of fire seats’ extinguishing can be comparatively evaluated in accordance with the value of specific flow rate of a fire-extinguishing agent. As it was detected, the specific flow rate of a fire-extinguishing agent does not actually depend on the rank of modelled fire seat when extinguished by an operator wearing thermal-protective clothes. At the same time, it is increasing along with the expansion of the fire zone scale in case the fire is extinguished without special protective clothes. Consequently, to increase the fire-extinguisher’s efficiency data reliability, the certifying tests should be conducted in conditions close to the real application conditions when the first person to firefight is not equipped with such special protective clothes. The experimental studies to determine the specific flow rate of a fire-extinguishing agent used modelled fire seats of various ranks. The analysis of results showed that the fire-extinguishers ensuring generation of drops of prevailing size more than 0,5 mm are required to extinguish the modelled sire seats. The degree of increasing flow rate for the fire-extinguishing agent to eliminate a fire and observation of a safe distance from the flame for an operator are conditioned by the scale of fire zone and affect the specific flow rate of agent required to ensure stable fire-extinguishing. Based on the results of extinguishing the fire seats «34В» or «55В», it is demonstrated that via using a correction factor it is possible, assuming an acceptable error, to evaluate the flow rate of fire-extinguishing agent to extinguish a modelled fire seat of any rank.

scholarly journals New classification of foaming agents for fire extinguishing

2018 ◽  
Vol 193 ◽  
pp. 02032 ◽  
Author(s):  
Evgeniy Degaev
Keyword(s):  
Experimental Studies ◽  
Petroleum Products ◽  
Spreading Coefficient ◽  
Industrial Facilities ◽  
Foaming Agents ◽  
Fire Extinguishing ◽  
Foam Forming ◽  
Capital Construction ◽  
Oil Tanks

Extinguishing fires of petroleum products during emergency spill at industrial facilities of capital construction, transport, gas stations and the destruction of oil tanks is most effective when using foamers. Classification of foaming agents intended for extinguishing of fires of oil products, which is based on the structure of spreading coefficient of water foam-forming solution over hydrocarbon surface is presented. Results of experimental studies using various foaming agents with different structure of spreading coefficient are given. It is determined which of homologs of a number of sodium primary alkylsulfates differ in foaming capacity and fire extinguishing efficiency. It is revealed that decrease of interfacial tension value leads to reduction of extinguishing time of a heptane flame.

scholarly journals APPLICATION OF A MODEL INSTALLATION FOR EVALUATION OF EFFICIENCY OF PHYTOREMEDIATION METHODS OF SURFACE WASTEWATER TREATMENT

2021 ◽  
pp. 36-43
Author(s):  
Oleksii Ilinskyi ◽  
Olha Rybalova ◽  
Olena Bryhada ◽  
Alexander Bondarenko ◽  
Sergey Artemiev
Keyword(s):  
Wastewater Treatment ◽  
Surface Runoff ◽  
Anionic Surfactants ◽  
Harmful Effect ◽  
Experimental Studies ◽  
Research Model ◽  
Waste Waters ◽  
Passive Protection ◽  
Foaming Agents ◽  
Fire Extinguishing

The article provides an assessment of the phytoremediation method as a promising direction of passive protection of soils and water bodies from pollution by surface waste waters, especially those contaminated as a result of fire extinguishing processes. Particular attention is paid to the danger of contamination with anionic surfactants. Natural methods of surface runoff purification have been analyzed, the efficiency of wastewater treatment in troughs with the use of industrial waste has been investigated. The prospects of using environmentally friendly plastic waste (PET, polypropylene, etc.) for the creation of artificial bioengineering structures are noted. An experimental model installation was developed and installed for testing and evaluating the effectiveness of various methods and methods of phytoremediation. Based on the results of experimental studies, a method is proposed for assessing the effectiveness of using various types of filtering nozzles in troughs for purifying wastewater and various types of vegetation in a research model installation. The effectiveness of phytoremediation to reduce the harmful effect of anionic surfactants on the composition of wastewater after the use of foaming agents in extinguishing fires has been analyzed. An analysis of the use of a filter nozzle from defibrated PET containers showed an increase in the efficiency of phytoremediation processes.

Extinguishing the smoldering combustion of sawdust

2020 ◽  
pp. 55-61
Author(s):  
Алексей Викторович Попов ◽  
Алексей Васильевич Казаков ◽  
Дмитрий Викторович Бухтояров ◽  
Денис Владимирович Полтавец ◽  
Светлана Юрьевна Хатунцева
Keyword(s):  
Experimental Studies ◽  
Laboratory Method ◽  
Maximum Temperature ◽  
Combustion Model ◽  
Volatile Components ◽  
Final Phase ◽  
Coniferous Species ◽  
Smoldering Combustion ◽  
Fire Extinguishing ◽  
Fibrous Carbon

Проанализированы теоретические и известные экспериментальные исследования по тлеющему горению опилок. Разработана методика определения характеристик очагов тлеющего горения. Экспериментально обоснован модельный очаг тлеющего горения. Показано изменение скорости тлеющего горения, массы опилок в зависимости от их дисперсности. Разработана лабораторная методика определения эффективности тушения различными огнетушащими веществами тлеющего горения опилок. Получены экспериментальные результаты по тушению опилок газовыми огнетушащими веществами (ГОТВ), тонкораспыленной водой, а также огнетушащим порошком. The analysis of existing theoretical and experimental studies on smoldering combustion of sawdust is carried out. There are considered the types of smoldering combustion. Practically, there is observed the implementation of three types of smoldering combustion. The first type is the process of oil-carbon sludge smoldering in the final phase of wood burning. The second type is smoldering combustion in dispersed, layered or fibrous carbon-containing materials. The third type of smoldering combustion is typical for carbonaceous materials that do not contain volatile components such as activated carbon. The method for determining the characteristics of seats of smoldering combustion is developed. Wood sawdust of coniferous species of different fractions was used for research. Experimental seats were cylindrical containers with a wall thickness of 1 mm: d = 66 mm, h = 100 mm; d = 72 mm, h = 80 mm; d = 54 mm, h = 100 mm; d = 65 mm, h = 115; d = 100 mm, h = 40 mm; d = 85 mm, h = 85 mm; d = 100 mm, h = 125 mm (d - diameter, h - height of the seat). Smoldering combustion model seat is experimentally proved. Based on the tests performed, a model seat with the height of 85 mm and the diameter of 85 mm was selected for further research (the criterion for seat selecting was the optimal degree of sawdust burnout), in which thermocouples were placed, according to Fig.1. There were used sawdust fractions of less than 0,1 mm, 0,1-0,2 mm, 0,2-0,4 mm and 0,4-1 mm. Sawdust moisture content w = 5 %. Tests were conducted to determine the rate of sawdust smoldering combustion and the maximum temperature of smoldering combustion. There is shown the change both of smoldering combustion rate and the sawdust mass depending on its dispersion. A laboratory method for determining the extinguishing effectiveness of sawdust smoldering combustion with various fire extinguishing agents was developed. The seat was placed into the conventionally sealed chamber of 1 m x 1 m x 1 m at the distance of 0,5 m from the walls. The chamber has lines for supplying bulk fire extinguishing agents, as well as devices for supplying fire extinguishing powders. There are obtained experimental results for extinguishing sawdust with gas fire extinguishing agents, dispersed water as well as with fire extinguishing powder

Modern Regulatory Requirements for Gas Fire Extinguishing to Improve the Safety of Facilities

2020 ◽  
pp. 55-60
Author(s):  
N.V. Smirnov ◽  
◽  
A.V. Kazakov ◽  
D.V. Bukhtoyarov ◽  
◽  
...  
Keyword(s):  
Experimental Studies ◽  
Combustion Time ◽  
Regulatory Requirements ◽  
Fire Extinguishing ◽  
Eurasian Economic Union ◽  
Flammable Liquids ◽  
Fire Experiment ◽  
Economic Union ◽  
Selection Of

To implement the technical regulations of the Eurasian Economic Union «On the requirements for fire safety and fire extinguishing equipment» (TR EAEU 043/2017), modern regulatory requirements were developed based on the advanced domestic and foreign research in order to increase the efficiency of using automatic gas fire extinguishing installations. The domestic methodology of experimental determination of the gas extinguishing concentration in the fire chamber has a number of advantages in comparison with the foreign analogues. It is established that it is necessary to take into account the conditions of fire experience for the selection of equipment for a fire extinguishing installation with FK-5-1-12 in the process of its design, in order to ensure more complete evaporation of the liquid phase of FK-5-1-12 after leaving the nozzles. An assumption was substantiated that allows setting the normative concentration of fire extinguishing gases at the level of heptane without conducting a fire experiment to extinguish fires of flammable liquids with a flash point of more than 61 оC. In this case, the concentration value can be taken 15 % less than according to the requirements of ISO 12854: 2009. Experimental studies on extinguishing smoldering materials with gases were conducted. It was established that nitrogen, CO2, freons 114B2 and 227ea at a concentration for extinguishing heptane eliminate not only flame combustion, but also smoldering if the free combustion time does not exceed 3 min. With free combustion for more than 6 minutes, reliable suppression of smoldering is achieved when the oxygen content in the volume of the fire chamber is up to 2.5 % vol. The results of the experiments were taken into account in the draft norms for the design of fire extinguishing installations. Additional requirements were developed for gas fire extinguishing containers and selector valves, which will make it possible to exclude the use of low-quality or obsolete products as part of gas fire extinguishing installations in the territory of the Eurasian Economic Union. The developed modern requirements are included in the drafts of new regulatory documents, which were publicly discussed, and are at the approval stage.

scholarly journals Features of propagation of droplets of water and special water-based compositions in a sample of forest fuel material

2019 ◽  
Vol 23 (6 Part A) ◽  
pp. 3339-3350
Author(s):  
Dmitrii Antonov ◽  
Alena Zhdanova ◽  
Nikita Shlegel ◽  
Ivan Voytkov ◽  
Konstantin Osipov ◽  
...  
Keyword(s):  
High Speed ◽  
Video Recording ◽  
Experimental Studies ◽  
Additional Energy ◽  
Foaming Agents ◽  
Fire Extinguishing ◽  
Forest Fuel ◽  
Water Based ◽  
Flaming Combustion ◽  
Water Drops

The article presents the results of experimental studies of water droplets propagation through the sample of typical forest fuel materials: needles, leaves, and their mixture. Different conditions are considered: without any additional energy supply, with heating, in the course of intensive thermal decomposition and flaming combustion. Three methods of registration are applied: thermocouple measurements, control of the weight of the sample as a whole and of its individual layers, and high-speed video recording. Water-based compositions with special additives (bentonite, bischofite, and foaming agents) typical for forest fire extinguishing systems are used. The experiments are carried out using aerosol and single water drops, as well as a small group of the latter. It is shown that the mechanisms, conditions and characteristics of droplet propagation through the layers of needles, leaves and their mixtures differ significantly. The scientific novelty of the work is the determining of the values of all the key characteristics of these processes in the conditions of intensive pyrolysis of the material, as well as through its inert layers.

scholarly journals THE INFLUENCE OF PRESSURE, NOSE DIAMETER AND TILT ANGLE LENGTH WHOLE SHOULDER

Fire Safety ◽  
2020 ◽  
Vol 35 ◽  
pp. 10-15
Author(s):  
E. Hulida ◽  
V. Lendіel ◽  
M. Smolinska ◽  
O. Mulko
Keyword(s):  
Mathematical Model ◽  
Water Supply ◽  
Forest Fires ◽  
Fluid Pressure ◽  
Experimental Studies ◽  
Nonlinear Mathematical Model ◽  
Step Method ◽  
Fire Extinguishing ◽  
Flow Length ◽  
Continuous Stream

The results of the analysis of the technical and reference literature related to the technical fire extinguishing means showed that there is no complete data regarding the technical characteristics of the carriage trunks, which relate to the length of the continuous water jet depending on the fluid pressure, the diameter of the nozzle, the angle of its inclination and placement heights above the ground. The firefighting barrel trunks are mainly used for localization and extinguishing of open fires (for example, in open warehouses of timber, forest fires, etc.). In the process of eliminating such fires, it is necessary to control the flow of a continuous jet into the fire cell by changing the pressure, the diameter of the nozzle, the angle of the barrel and the like. Therefore, to solve this problem in terms of controlling the process of extinguishing a fire, the task is to conduct experimental studies and to obtain on the basis of the experimental results of an empirical mathematical model, which would take into account the influence on the length of the continuous jet of the above factors. According to the results of experimental studies, to obtain a mathematical model for determining the length of flow of a continuous stream of water by a flap barrel from the variables that influence the process of its control during the elimination of fire. To achieve this goal, it is necessary to solve the following tasks: 1) to carry out experimental studies to determine the length of the flow of continuous jet of water with a pallet barrel from the variables that affect the process of its management in the elimination of fire; 2) mathematically process the results of the experiment and obtain a mathematical model to determine the flow length of a continuous stream of water supplied by a carriage shaft; 3) to develop a methodology for controlling the process of choosing the length of a continuous stream of water, which is fed by a carriage barrel when extinguishing a fire. Experimental studies were conducted using a fractional experiment to solve the first problem. For experimental research used: 1) fire truck MAZ AC-4-60 (5309) -505M; 2) PLS-20P carriage barrel; 3) fire hoses for connecting the carriage barrel to the centrifugal pump of the fire tanker; 4) roulette at 5 m; 5) a goniometer for measuring and setting the angle of the barrel relative to the earth's surface; 6) barrel nozzles d = 25 mm and d = 32 mm. Based on the results of the experiment, a nonlinear mathematical model was developed to determine the flow length of a continuous stream of water supplied by a carriage shaft. The model developed also takes into account the effect on the length of the jet supply the height of placement of the carriage trunk above the ground. The mathematical model for determining the flow length of a continuous jet of water with a carriage trunk gave the opportunity to develop a method of controlling the flow length of a continuous jet of water. Conclusions and specific suggestions: The results of experimental studies to determine the length of the flow of continuous jet of water by a barrel trunk from variable factors made it possible to clarify the technical capabilities of carriage trunks and to develop a method of controlling the process of water supply in the event of fire elimination. A nonlinear mathematical model was developed to determine the flow length of a continuous jet of water by a carriage barrel, the adequacy of which was tested according to the Fisher criterion. To control the process of water supply, depending on the required distance to the fire, a step-by-step method is proposed to increase or decrease the length of the continuous flow of water by a flap barrel.

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