Fire Extinguishing Research Articles

Study on the preparation and characteristics of thickened slurry to prevent coal spontaneous combustion

In response to the problems of small diffusion area, short solidification time, and poor flowability of existing fire extinguishing materials in preventing coal spontaneous combustion in goaf areas of western mining areas, this paper studies a thickened slurry with good flowability and fast diffusion ability. The optimal ratio of thickened slurry was determined through orthogonal experiments, and the rheological properties, impregnation characteristics, and wall hanging characteristics of the material were studied. The results showed that when the water to soil ratio was 8:1, and the concentrations of sodium alginate (SA) and apigenin were 0.6 % and 0.5 %, the flowability and suspension performance of the thickened slurry were the best. When the soaking time is 14 days, the best soaking degree of the material can be achieved, with a soaking depth of 0.93 mm. Through wall hanging tests, it was found that the thickened slurry can naturally air dry on the surface of vertically placed coal pillars with a small sliding distance, which has good adhesion and retention characteristics. Further on-site experiments have shown that by injecting thickened slurry, the CO concentration at the return air corner is significantly reduced, indicating that thickened slurry can cover a large area of residual coal in the goaf, prevent contact between coal and O2, and effectively prevent the composite reaction between coal and oxygen.

A study on fire risk and its mitigation in gravure printing press

The gravure printing process is widely utilized for large-scale, high-quality, multi-colored printing tasks executed at high press speeds. This includes a diverse range of products such as art books, greeting cards, currency, stamps, wallpaper, magazines, and more. This thesis addresses the fire risks associated with gravure printing, acknowledging the use of highly flammable materials and the potential for static charge-related incidents. Despite its prevalence, there is limited research on fire prevention and control in gravure printing. The study employs field observations, stakeholder interviews, and an extensive review of literature on fire risk and control in printing press operations in India. It analyzes the causes of fires using the fire triangle model, emphasizing the role of heat, combustible materials, and oxygen in fire incidents within the printing press environment. The thesis categorizes preventive measures into fire prevention and fire suppression actions, focusing on reducing fire load, static charge mitigation, and implementing firefighting systems. It observes that poor housekeeping, lack of awareness, and inadequate emergency control plans contribute significantly to fire hazards in press facilities. Additionally, the research identifies key factors such as high press temperatures, low humidity, improper storage, and inadequacies in firefighting systems as potential causes of fires. It emphasizes the need for optimal environmental conditions, proper storage practices, and effective firefighting infrastructure within press facilities. The study concludes with comprehensive guidelines for loss prevention and control, including management programs, housekeeping, operator training, pre-emergency planning, preventive maintenance, and plant security. It also addresses safety measures specific to gravure printing presses, such as automatic sprinkler systems, fire hydrant system, carbon dioxide flooding systems, and portable fire extinguishers. In summary, this thesis provides valuable insights into the multifaceted nature of fire risks in gravure printing presses and recommends a holistic approach for effective fire prevention and control.

Research on Safety Assessment Indicators of Gas Extinguishing System for Urban Railway Transportation

Gas fire extinguishing system as a more widely used system in urban rail transit, its safety is related to the safety of passengers, lives and property. At present, there are few studies on the safety of gas fire extinguishing system, and there is no special standard to guide. In order to improve the safety of the subway gas fire extinguishing system, through a number of operating companies and manufacturers to conduct on-site research, and the use of theory and data analysis and other methods of gas fire extinguishing system safety indicators have been studied. Reliability analysis is carried out by using Fault Tree Analysis, and on this basis, the safety evaluation of the system is further quantified by identifying and analyzing the hazards of the gas extinguishing system and rating the risk of the system by using semi-quantitative method. The results show that the average working time index of the gas extinguishing system before hazardous failure is 173 years, and the average non-hazardous failure time is 173 years.

Autonomous firefighting using a quadruped robot

This paper presents the development of a proof-of-concept autonomous firefighting robot based on the Spot quadruped robot. Both the payload and software package for the autonomous detection, localization, and extinguishing of a small fire are discussed. A thermal camera is mounted to the front of Spot and a standard ABC fire extinguisher is mounted to the back. The thermal camera is used to autonomously detect fires and the fire extinguisher is used to put out a detected fire. The system was successfully tested at a local fire station in a controlled setting with actual fires. The results of this project have direct application in the area of autonomous first response in complex industrial environments and fire watch applications.

Inhibition effect and kinetic study of 2-BTP on the hydrogen doped biogas flames

Biogas is an efficient and environmentally friendly gaseous fuel. To ensure the safety of biogas applications, highly effective extinguishing technologies for suppressing biogas flames should be developed. In this paper, the extinguishing performance and kinetic mechanism of 2-BTP were studied experimentally and numerically. The results indicate that 2-BTP has excellent inhibition effect on biogas flames, but it depends on the ratio of hydrogen and oxygen in the reactants. For hydrogen-rich and oxygen-poor flames, 2-BTP shows efficient inhibition effect. However, it shows a little combustion promotion effect for hydrogen-poor and oxygen-rich flames at the addition of certain concentrations. The H and OH radical concentration variation and their production/consumption reactions are analyzed subsequently, and the simulation computation shows that some competing reactions involving Br-containing species lead to these results. The purpose of this research is to gain an in-depth understanding of the potential and effectiveness of 2-BTP in suppressing biogas fires, which can lead to better forecasting and optimization of its application, with the goal of enhancing the efficiency of fire extinguishment and minimizing possible adverse effects.

Mechanical properties of Q235 and 20# steel after CO2 fire extinguishing treatment

The carbon dioxide fire extinguishing process can produce temperatures as low as −80 °C. However, the effect of rapid cooling and ultralow temperatures on the properties of steel is not yet clear. To accurately evaluate the effect of CO2 fire extinguishing on the mechanical properties of crude oil tank walls (Q235-B) and accessory and pipe materials (20#), this study employs tensile, Charpy impact, and bending tests to analyze the changes in the primary mechanical properties of Q235-B and 20# steels after three pretreatments: high-temperature burning, CO2 spraying, and CO2 fire extinguishing. The results of the study show that 1) the high-temperature burning process and short-term spraying of CO2 after fire may damage the mechanical properties of steel; 2) the rapid use of CO2 spraying after fire does not damage the mechanical properties of Q235-B or 20#; and 3) the three pretreatments investigated have little effect on the bending properties of all the specimens.

Simulation Study on Temperature Control Performance of Lithium-Ion Battery Fires by Fine Water Mist in Energy Storage Stations.

The combustion of lithium-ion batteries is characterized by fast ignition, prolonged duration, high combustion temperature, release of significant energy, and generation of a large number of toxic gases. Fine water mist has characteristics such as a high fire extinguishing efficiency and environmental friendliness. In order to thoroughly investigate the temperature control effect of fine water mist on lithium-ion battery fires. This study employs numerical simulation methods, utilizing PyroSim software to simulate the fire process in lithium-ion battery energy storage compartments. First, we focus on the variation patterns of flame, changes in combustion temperature, and heat release rate over time at environmental temperatures of 10, 25, and 35 °C. Subsequently, the suppression of flame, reduction in temperature, and changes in heat release rate are simulated for water mist in lithium-ion battery fires. The simulation results indicate that the environmental temperature has a considerable impact on the flame but a lesser effect on the heat release rate. Fine water mist effectively impedes the spread of thermal runaway between internal battery core cells, leading to a reduction in the flame size and a significant decrease in the maximum temperature and heat release rate. The numerical simulation results can provide scientific guidance for the prevention and control of fires in lithium-ion battery energy storage compartments.

Feasibility assessment of a clean and efficient fire extinguishing system for pottery jar liquor warehouses

Clean fire extinguishing systems applicable to the pottery jar liquor warehouse are in demand. In this study, taking 53vol% liquor as the research subject, fire models of various clean fire extinguishing systems comprising water mist, liquid carbon dioxide (LCO2) and liquid nitrogen (LN2) were established using a fire dynamic simulator to determine their fire extinguishing effect. A feasibility assessment of systems was performed under different fire source types, fire source sizes, and ventilation conditions. The fire extinguishing efficiency was analyzed in terms of the fire extinguishing time, oxygen concentration, and space temperature. The results showed that the success rate of the LCO2 and LN2 fire extinguishing systems was 100%, whereas the success rate of the water mist fire extinguishing system was 95%. In terms of reducing the oxygen concentration at the bottom of the space and the temperature in the space, the LCO2 system exhibited the best performance, followed by the LN2 system, and lastly the water mist. Under different ventilation conditions and fire source types, the LCO2 fire extinguishing system was least affected, whereas the effectiveness of the water mist fire extinguishing system reduced under natural ventilation conditions, and the extinguishing efficiency of the LN2 fire extinguishing system was affected by the fire source type. Overall, the LCO2 system presented more advantages in extinguishing fires in pottery jar liquor warehouses and can provide a new idea for the development and application of clean and efficient fire extinguishing systems.

Comparative extinction of pine needle fires by gravity-fed release of inert cryogen or water

Dead needle debris accumulates in pine forest floors and poses wildfire hazards. This manuscript reports on laboratory-scale research, where gravity-fed liquid nitrogen (LN2) jets were used to suppress and extinguish pine needle fires. Minimum quantities of LN2 needed for fire extinction were determined, and similar quantities of gravity-fed water jets or water sprays were also used to illustrate differences in the underlying extinction mechanisms. LN2 snuffed the fires instantaneously, as its massive flash-vaporization and volumetric expansion displaced the surrounding air and starved the fires for oxygen. Concomitant cooling of the flame zone and the fuel bed also occurred by the vaporizing cryogen. To the contrary, water suppressed the fire by wetting and cooling accessible fuel surfaces. However, fuel bed surfaces which were not wetted continued to pyrolyze and smolder, and eventually reignited. In these experiments, a portion of the volatile LN2 jet vaporized in transit, a portion vaporized while traversing the hot gases of the flame, a portion vaporized in the pine needle pile, and some reached the ground and was absorbed therein. Application of LN2 to fires in confined spaces was most effective for fire extinction. Application of the cryogen to hot spots facilitated flash vaporization for maximum volumetric expansion.

Preparation and Characterization of Chitosan/Hydroxypropyl Methylcellulose Temperature-Sensitive Hydrogel Containing Inorganic Salts for Forest Fire Suppression.

Effective forest fire suppression remains a critical challenge, necessitating innovative solutions. Temperature-sensitive hydrogels represent a promising avenue in this endeavor. Traditional firefighting methods often struggle to address forest fires efficiently while mitigating ecological harm and optimizing resource utilization. In this study, a novel intelligent temperature-sensitive hydrogel was prepared specially for forest fire extinguishment. Utilizing a one-pot synthesis approach, this material demonstrates exceptional fluidity at ambient temperatures, facilitating convenient application and transport. Upon exposure to elevated temperatures, it undergoes a phase transition to form a solid, barrier-like structure essential for containing forest fires. The incorporation of environmentally friendly phosphorus salts into the chitosan/hydroxypropyl methylcellulose gel system enhances the formation of temperature-sensitive hydrogels, thereby enhancing their structural integrity and firefighting efficacy. Morphological and thermal stability analyses elucidate the outstanding performance, with the hydrogel forming a dense carbonized layer that acts as a robust barrier against the spread of forest fires. Additionally, comprehensive evaluations employing rheological tests, cone calorimeter tests, a swelling test, and infrared thermography reveal the multifaceted roles of temperature-sensitive hydrogels in forest fire prevention and suppression strategies.

DETERMINATION OF THE CLASS B FIRE EXTINGUISHING PARAMETERS USING SPRAYED WATER

Sprayed water is a versatile tool for localising and extinguishing fires of various types. When water evaporates, its volume increases by 1700 times, resulting in the dilution of combustible components with non-combustible water vapour. The study aims to determine the parameters of extinguishing class B fires using sprayed water by obtaining analytical dependencies for these parameters. The paper derives an expression for the extinguishing temperature of class B fires when extinguished with sprayed water, using Semenov’s conditions. The process of liquid combustion is considered as diffusion. The study shows that the extinguishing temperature of this type of fire is a function of the activation energy of the burning liquid and the initial temperature (at the time of sprayed water supply) of the flame. A parameter of this function is the universal gas constant. The authors constructed a graph showing the area of change in the fire extinguishing temperature. The difference between the initial flame temperature and the fire extinguishing temperature belongs to the range of (80÷120) °C. Using the transition function of class B fire, the study derives an expression for its extinguishing time, which depends on the initial flame temperature, activation energy, and the multiplicative component in the form of a fire time constant. For the relative extinguishing time, the authors constructed the area of change in this parameter depending on the activation energy and the initial temperature. It shows that the value of the extinguishing time of such a fire is (0.28÷0.32) of the value of the constant fire time. The paper presents an expression for the minimum value of the intensity of the sprayed water supply, which ensures extinguishing a class B fire. This intensity of the supply of sprayed water, reduced to the value of the fire transmission coefficient, is determined by the initial temperature of the flame and the activation energy of the liquid that burns. The authors constructed the area of change of this fire extinguishing parameter. It shows that the minimum value of the intensity of the supply of sprayed water belongs to the range (3.8÷7.8) per unit of the fire transmission coefficient. Keywords: fire, fire parameters, sprayed water.

CALCULATING THE CARBON FOOTPRINT FOR ENVIRONMENTAL SUSTAINABILITY: THE CASE OF TED DİYARBAKIR COLLEGE (TÜRKİYE

It is crucial to promote awareness, particularly throughout society, regarding a topic that holds significant importance for our environment. This study was undertaken with the intention of making a contribution to research on carbon footprint, driven by this motive. In this study, the carbon footprint calculation of TED Diyarbakır (Türkiye) College was made using the IPCC Tier approach. The carbon footprint of 3 different capabilities, namely scope 1 (Natural gas, gasoline, diesel, fire extinguishers), scope 2 (electric) and scope 3 (Water consumption, services), were calculated. When Scope 1, Scope 2 and Scope 3 are evaluated together, it is seen that the amount of carbon footprint originating from Scope 1 is higher. Sources of emissions from Scope 1 include natural gas consumption, diesel and gasoline fuel consumption, as well as fire extinguishers. When the emission sources in the college were compared, it was determined that the highest carbon footprint was due to natural gas consumption within scope 1 (97.98%). Subsequently, it was determined that the carbon footprint was caused by existing vehicle shuttle within scope 3 (1.917%). Finally, it has been determined that the carbon footprint is caused by the existing electricity consumption within scope 2 (0.1%). It is stated that there are 2 reasons for the low carbon footprint caused by electricity consumption. The first is that the equipment used in lighting is LED, and the second is that there is no need for lighting fixtures due to the long lighting time of the day in our geography

Recognizing jet trajectories of fire monitor extinguishing agent based on digital images

Recognizing jet trajectories of fire monitor extinguishing agent based on digital images

Identifying Effect of Car Fire Blankets on Chosen Fire Parameter Using Large-Scale Fire Tests of Internal Combustion Engine Vehicle and High-Voltage Traction Battery—Comparative Slovak Case Study

Firefighting units in the Slovak Republic are well prepared for extinguishing fires of vehicles with internal combustion engines. However, the expansion of electromobility is also coming to Slovakia. It is essential to pay attention to this topic from the point of view of repression. This article deals with car fire blankets. The main objective is to verify and compare the effectiveness of extinguishing internal combustion engine vehicle (ICEV) fires and high-voltage traction battery (HTB) fires using car fire blankets. The effectiveness of a car fire blanket was determined based on the analysis of temperature drops during large-scale fire tests of ICEVs and HTBs. The temperature was recorded by four thermocouples. Two thermocouples were placed at 0.7 m from the ICEV and HTB; one thermocouple was placed in the interior of the ICEV and inside the HTB; one thermocouple was placed on the roof of the ICEV and the surface of the HTB. Subsequently, the results were compared based on temperature–time curves obtained from experimental measurements. Applying the car fire blanket to the ICEV fire caused a drop in temperature on all thermocouples. The most significant temperature drop was recorded in the interior of the vehicle. Specifically, the temperature dropped from 724 °C to 140 °C. However, the application of the car fire blanket had a different effect on the HTB fire. There was a minimal temperature change in the thermocouple on the right side at a 0.7 distance. The other thermocouples identified a slight increase in temperature.

Assessing teachers' fire security knowledge, training effectiveness and attitudinal changes: a cross‐sectional study in Turkey

AbstractThe purpose of this study was to determine the knowledge level of teachers about basic fire and extinguishing and the effectiveness of the fire training received. This is a cross‐sectional study. The research population comprises teachers employed in educational institutions affiliated with the Ministry of National Education (MNE) in Konya, Turkey, during the year 2021. The sample of this research consisted of 2649 participants who voluntarily agreed to participate in the research and answered all questions completely. Data were collected from the questionnaire forms prepared by the researchers by examining the literature in the electronic environment via Google Forms. Of the participants, 53.7% were women, 39.8% were between the ages of 35 and 44 and 93.0% were working as teachers. The fire safety knowledge score is higher for those who attended the fire training. While the fire knowledge score increased as the end‐of‐training attainment score increased in those receiving fire training, no significant relationship was found between the education environment and content score, the educator effectiveness score, the status of having a fire extinguishing task and having encountered a fire and this score. Teachers' fire safety knowledge score is higher and at a moderate level compared to the attitude score. Participating in fire education positively affects both knowledge and attitude toward fire.

Experimental study on suppression of thermal runaway propagation of lithium-ion battery by salt hydrate based dry powder extinguishants

To develop the high cooling effect, high fire extinguishing performance, non-conductive and low cost extinguishant for fighting lithium-ion battery (LIB) fire, seven salt hydrates with different amounts of crystal water were systematically studied as the dry powder extinguishants in this work. The results of the differential scanning calorimeter (DSC) measurement demonstrate that the highest endothermic enthalpies of the salt hydrates below 150 °C is larger than 800 kJ kg−1, which can effectively suppress the thermal runaway (TR) propagation between LIBs. Moreover, the heat absorption capacity of the salt hydrate can be enhanced by increasing the reaction entropy, which can be achieved by increasing the crystal water content. The electric breakdown voltages of the salt hydrates were ranged from 4 kV to 60 kV, which are mainly determined by the crystal water content and the melting point. Furthermore, the fire extinguishing performances of the salt hydrates have no obvious relationship with their heat absorption capacities, but are related to their chemical component. This work systematically studied the factors that affect the cooling effect, the fire extinguishing performance and the conductivity of the salt hydrates, which provides an essential basis for developing high performance salt hydrate based dry powder extinguishants in fighting LIB fire.

Temperature Prediction Model Based on Low Temperature Release Method of Fire Extinguishing Bottle for Civil Aircraft Flight Test

Temperature Prediction Model Based on Low Temperature Release Method of Fire Extinguishing Bottle for Civil Aircraft Flight Test

Containment and suppression of compartment fires using specialized liquid compositions

Experimental research findings are reported on the characteristics of physicochemical processes at different stages of fire development and suppression. Fires involving solid materials like wood, cardboard and linoleum were investigated. The minimum necessary and sufficient volumes of firefighting liquid (water with different additives, e.g., a foaming agent, bentonite, bischofite, etc.) and their spraying times were identified. Differences in spraying characteristics (droplet velocities, sizes and concentration) were recorded. A relationship between the spraying characteristics of fire extinguishing agents and efficiency of fire suppression was established. Correlations were identified between the operational characteristics of fire detectors during fire suppression involving several fire extinguishing agents. The most efficient compositions in terms of fire suppression time and extinguishing agent consumption were found for typical indoor combustible materials. Mathematical equations were derived to predict the key characteristics of fire suppression.

Preparation and Experimental Research of Temperature Sensitive Expansion Gel Material for Fire Prevention and Extinguishing in Coal Mines

ABSTRACT In order to solve the problems of high viscosity at room temperature, easy dehydration and shrinkage of phase change gel, and poor plugging effect of traditional mine gel, a new type of temperature-sensitive expansion gel was developed by using hydroxypropyl methyl cellulose, chitosan, guar gum and sodium bicarbonate as raw materials, using orthogonal test and response surface analysis. The structural characterization, characteristics, fire prevention, and extinguishing performance of the temperature-sensitive expansion gel were tested. The experimental results show that the optimal ratio of temperature-sensitive swelling gel is 0.75 wt % chitosan, 0.5 wt % acetic acid, 2.5 wt % hydroxypropyl methyl cellulose, 0.4 wt % sodium bicarbonate, and 0.15 wt % guar gum. The phase transition temperature (LCST) of this ratio is 67°C. After standing at room temperature for 6 h, the gel viscosity is 5852 mpa·s, the expansion ratio is 0.846, and the strength is 319.525 N/m2. During the heating process of the coal sample after adding the temperature-sensitive expansion gel, the gel will undergo phase change and expansion in the high-temperature area of the coal, and the viscosity will increase. It can stay in the high-temperature area, wrap the coal block, and isolate the oxygen from entering, thus effectively inhibiting the coal spontaneous combustion process. In addition, the gel also produces inert gas carbon dioxide, which effectively suffocates the flame. Therefore, compared with the conventional inhibitor solution, the temperature-sensitive expansion gel has better fire extinguishing effect.

Fire emergency response system at PT X based on International Safety Rating System (ISRS)

Fire is the unwanted occurrence of fire. Preparedness in the face of catastrophic fire events is part of the Occupational Safety and Health (K3) standards that must be implemented in the company. PT X is a company engaged in concrete manufacturing. In the production process, many potential hazards, such as fires, can cause losses. This research aims to study the fire emergency response system at PT X. The method used is descriptive research, with data collection done cross-sectionally. The analysis was carried out descriptively by clearly and thoroughly describing the condition of the object of study and comparing it with the applicable regulatory standards. The results showed that PT X had implemented a fire emergency response system and efforts to prevent and overcome fire hazards. PT X's efforts include forming a firefighting team providing fire hazard management facilities such as fire extinguishers, fire blankets, first aid kits, evacuation stretchers, and other infrastructure facilities. PT X has conducted fire emergency response and first-aider training for employees and workers. This research concludes that PT X has implemented an emergency response system well and refers to the International Safety Rating System.