Flash Fire Research Articles

Diagnosing electrostatic problems and hazards in industrial processes: Case studies

AbstractStatic electricity is a phenomenon commonly encountered yet often misunderstood and underestimated in terms of its hazard potential; it continues to challenge the safety and reliability of industrial processes, particularly those involving flammable substances. This paper delves into the critical issue of electrostatic hazards in industrial settings by presenting two flash fire/explosion case studies, one involving biphenyl dust and the other gasoline vapor; both linked to electrostatic discharges. The first case study examines an explosion in a flaker and pack‐out hopper during biphenyl flake manufacturing. The investigation reveals the role of electrostatic charges in the incident and how well‐intentioned equipment changes created warning signs of increased risk that were missed. The second case study discusses a gasoline vapor flash fire, highlighting the common yet overlooked hazard of static electricity during the transfer of flammable liquids. It underscores how common activities involving people can generate sufficient electrostatic charge to ignite flammable vapor–air mixtures in industry. The outcomes of these studies highlight the importance of acting on early warning signs of static electricity and the crucial role of data‐driven diagnostic techniques in addressing and controlling those hazards. By dissecting the intricacies of electrostatic phenomena, safety professionals can formulate actionable strategies to adapt plant operations and prevent hazards from static electricity. The paper advocates for a proactive approach to identifying and mitigating electrostatic risks in industrial settings beginning with process hazard analyses that incorporate static electricity hazards analysis and continues through employee training to ensure that early warning signs are identified, understood, and acted upon. It stresses the need for comprehensive safety measures, including proper grounding and bonding, use of static dissipative materials, and regular maintenance of safety equipment, to prevent incidents. Through these case studies, the paper contributes to understanding of electrostatic hazards in industrial processes and highlights the importance of integrating electrostatic safety measures into routine industrial operations.

Research on the dangerous scenarios of propylene oxide leakage from tank in a chemical plant in an industrial park of Tongling City, China

ABSTRACT Propylene oxide (PO) is toxic, flammable and explosive. Accidents from the release of PO from large-scale storage tanks can have disastrous consequences associated with meteorological conditions. Therefore, this study explores the dangerous scenarios of PO leakage from a 1000 m3 spherical tank in a chemical plant located in an industrial park during various seasons using the Aerial Location of Hazardous Atmospheres software. Our results show that the maximum hazard distance of poisoning, flash fire and vapour cloud explosion caused by leakage and diffusion from the PO storage tank occur in the summer season and the affected distances were 2900, 372, and 374 m, respectively. In regard the thermal radiation resulting from a pool fire scenario, the longest threat distance was 110 m in the summer. For the boiling liquid expanding vapour explosion (BLEVE), the maximum thermal effect was 2100 m in winter. The BLEVE scenario has the largest impact area and its toxic vapour cloud is the primary accident. Adequate safety management and technical measures should be put in place for the prevention and emergency response of accidental PO release in the factory.

Comparing the safety of bunkering LH2 and LNG using quantitative risk assessment with a focus on ignition hazards

Liquid hydrogen represents a potential candidate for a climate neutral fuel for shipping. The utilization of this fuel necessitates the implementation of safe and reliable bunkering operations. This paper employs a quantitative risk assessment to compare the safety of bunkering liquid hydrogen with the safety of bunkering LNG. Initially, a frequency analysis is conducted using an event tree. It can be demonstrated, that the occurrence of the hazardous events, pool fire, flash fire and explosion, is more frequent with liquid hydrogen than with LNG. In the second step, the consequence analysis determines necessary safety distances for the hazardous events under consideration. For the events of pool fire and explosion, LNG-bunkering requires higher safety distances. Liquid hydrogen-bunkering requires higher distances for flash fire event. Since the safety distances for flash fire events are largest, they define the distances for the system. However, the consequences of flash fire events are subject to greater uncertainties and require further investigation. Overall, hazardous events occur more often with liquid hydrogen-bunkering, but LNG-bunkering requires in two out of three cases larger safety distances.

Risk Analysis of Jet A-1 Tank Filling and Storage Processes at the Shorebase

Coastal Logistics Centers (CLS) provide logistics support to deep-sea drilling operations. Jet A-1 (helifuel), required for helicopters that transfer personnel to drilling ships, is filled into tanks from the tanker arriving at CLS and stored in open areas. Jet A-1 is a hazardous chemical with flammable and toxic effects and can also explode when exposed to flame. Risk analysis of this hazardous chemical is essential for CLS. This study aimed to determine the process hazards and risk analysis in the filling and storage operation of Jet A-1 from tankers to tanks. For this purpose, the Preliminary Hazard List (PHL) and Preliminary Hazard Analysis (PHA) were performed. Then, a Hazard and Operability (HAZOP) study was carried out based on these analysis results. The HAZOP study identified Jet A-1 overflow from the tank as a high-risk event. Afterward, Event Tree Analysis (ETA) was performed on the initial event of Jet A-1 spilling due to tank overflow. In ETA analysis, immediate ignition, delayed ignition, and explosion probabilities resulting from delayed ignition were calculated with the CCPS (Center for Chemical Process Safety) Module. The probability and frequency values of accident scenarios were calculated as P=0.0028, f=1.736 x10-4 year-1 for jet fire, P=0.0225, f=1.395x10-3 year-1 for vapor cloud explosion, P=0.127, f=7.874x10-3 year-1 for flash fire, P=0.847, f = 0.0525 year-1 for toxic release, respectively. It was determined that all accident scenario frequency values were above the legislation threshold value (10-4 year-1). Design solutions and preventive measures have been proposed to reduce risks. The combination of risk analysis methods is effective in risk assessment studies.

Thermal performance of protective clothing (firefighter) under extreme ambient conditions

Protective clothing is made up of multiple layers of textile, which include thermal barrier, moisture barrier, chemical protection and heat radiation protection layers etc. This clothing is commonly used by workers working in the chemical industry, blast furnaces, glass industry, industrial boilers and many more. The ambient conditions for these workplaces are humid and hot in which the clothing is designed for the external protection of heat and fluids but the neglected issue is the internal heat and moisture accumulation. This makes the clothing extremely uncomfortable and significantly reduces the workability of the wearer. The multi-layered structure of this clothing causes the body moisture and heat to trap in between layers, which in extreme ambient conditions like working near the furnace or flash fire causes body burns, these “steam burns” are common and considered to be caused by the condensed moisture trapped in the layers of protective garment. This research aims to firstly investigate the moisture flow through hybrid textile layers and its effect on heat transfer and then secondly to see the impact of extreme radiation flux on the moisture flow inside the textile layers and improvement by using Aerogels.

A comparative assessment of open flame flares and enclosed ground flares for cleaner and safer hydrocarbon production in Mexico

Hydrocarbon industry flaring practices emit large amounts of unburned hydrocarbons and climate forcers, creating environmental and social impacts. The objective of this study is to thoroughly compare different flaring technologies in situations where the industry is unable to avoid flaring. An integrated methodology for assessing two flare technologies in terms of Health-Environment-Safety (HES) impacts, economic performance, and safety benefits is proposed. The methodology includes stoichiometric calculations of combustion reactions, pollutants emission estimation, flare dimensioning for an equivalent inflow stream to be flared, and economic scenarios for assessing Enclosed Ground Flares (EGFs) versus Open Flame Flares (OFFs). The methodology was applied to a Mexican hydrocarbon installation that currently operates OFFs with a historical record of low combustion efficiency. If an EGF were to replace the existing OFF, there would be a significant emissions abatement that depends on their realistic operating efficiencies. Furthermore, the EGF has the potential to utilize 1.55thermal GW for energy applications, which is currently being wasted as the OFF releases it into the environment by flaring 3.75 Mm3/d. The safety radius required for the OFF is 9.3 times that required for the EGF of equivalent capacity. Over a 30-year period for the case study, the cumulative investment and O&M costs for EGF are about 23% less than for OFF. The consequence analysis with the PHAST software found that various failure conditions can be contained within the EGF combustion chamber without causing significant damage to the facility. However, the impacts of disturbances in the OFF such as gas clouds, flash fires, and explosions are around the torch. All these findings indicate that replacing OFF with EGF would be a safer and more economical solution in the future, as it also helps reduce pollutant emissions.

Experimental Determination of Flash Points and Fire Points of Alcoholic Beverages

Experimental Determination of Flash Points and Fire Points of Alcoholic Beverages

Optimization of fire safety measures at the agribusiness protection facility with a mass stay of people

Studies have shown that when assessing safety conditions, it is possible to use methods for calculating the consequences of exposure to damaging factors of fire and explosion: thermal radiation of a strait fire; thermal effects of combustion products of a vapor-air cloud in the event of a flash fire; shock wave during combustion of a vapor-air cloud; thermal radiation of a fireball. At the same time, additional research is required in order to adjust the regulatory framework in the field of fire safety.

Consequences modeling and determining of safe distance in the natural gas pressure reduction station using PHAST software (Case study: Borumi station in Ahvaz)

Introduction: Gas pressure reduction stations are one of the most important parts of natural gas distribution networks. Risk assessment in operational units is a suitable method to assess risks, and their results can be used for management and decision-making regarding control and reduction of its consequences without critical concern. In other words, risk assessment is a process that identifies risks, assesses losses and determines risk characteristics. The present study aimed to model possible accidents, the subsequent evaluation of the consequences, and determination of safe boundaries in the suburban natural gas pressure reduction station located in the Bromi area of Ahvaz city using PHAST software.
 Materials and Methods: In this study, possible scenarios based on the investigated background and utilizing the process data of the studied gas pressure reduction station, such as temperature, gas pressure, gas analysis, and meteorological data, and also using Pasquil's classification of atmospheric conditions the safe boundaries in the suburban natural gas pressure reduction station was investigated using PHAST software version 22.8 and. For this purpose, 6 possible scenarios were investigated in the selected atmospheric classes as well as the worst possible conditions. The consequences were evaluated based on different states of gas discharge, gas release, flash fire, sudden fire, and explosion.
 Results: Based on the obtained results, the areas with high-risk potential were related to gas release and explosion, respectively. Also, the highest risk range belonging to scenario number five was reported for a gas explosion with atmospheric class F and wave intensity of 0.02068 bars and equivalent to 358.5 meters. In this range, according to the damage caused by the explosion, with a probability of 95%, without serious damage, 50% of the windows will be broken, and therefore it can cause human injuries. Based on this, the safe distance in this station was determined to be 358.5 meters.
 Conclusion: Based on concerns about the lack of risk assessment studies over the initial phases and during the operation of the station, the study shows that determining the safe boundaries and high-risk areas along with the priority of risk reduction is very necessary. It can be concluded that the modeling of accidents and the evaluation of the resulting consequences along with the determination of safe boundaries is one of the basic factors in the health of the working environment of personnel and the general public.

Consequence analysis of CNG leakage at joint refueling and charging stations

AbstractThe number of new‐energy vehicles is steadily increasing worldwide, and joint refueling and charging stations will be increasingly constructed and developed in China. A CNG leakage at joint stations can lead to superimposed consequences, including fire (flash fire, pool fire, jet fire), explosion, and release of toxic and hazardous gases. Based on FLACS and SAFETI, the impact of leakage aperture and wind direction on CNG leakage diffusion are analyzed by modeling a joint refueling and charging station in Shaanxi, China. The safe distance between charging piles and leakage points is investigated in the worst case scenario. The superimposed consequences of leakage in joint stations under different scenarios are analyzed, and the individual risk is analyzed at stations. This study shows that the larger the leakage aperture, the larger the CNG leakage dispersion range under the same wind directions and wind speeds, and the higher the wind speed, the more volatile the gas under the same leakage apertures. The safety distance of the charging pile should reach at least 37 and 40 m considering leaks in the tanker and gas storage well, respectively. The impact range of superimposed consequences shows the descending order of jet fire > flash fire > pool fire.

The critical mass for the unconfined vapour cloud explosion of compressed and liquid hydrogen

AbstractThe (unconfined) vapour cloud explosion (VCE) is a dramatic phenomenon that generates a severe pressure wave with a high potential to damage assets and produce injuries in the far field. This definition applies also to hydrogen. Nevertheless, no clear tools and methodology have been so far developed and tested for this highly reactive gas, and even advanced numerical simulations lack validation and suffer from large uncertainties. In this view, the comprehension of the physic which subtends this dramatic phenomenon for the specific case of hydrogen is still a central issue. This paper revises some of the most adopted theories on VCE based on classical acoustic theory and models for pressure wave propagation and provides a consequence‐based, threshold (minimum) value for the critical mass of hydrogen which is needed—at a stoichiometric concentration in air—for a vapour cloud to behave as a VCE. To this regard, any non‐stoichiometric hydrogen concentration in air or lower amount of hydrogen would decrease either the flame Mach number or the total energy, thus resulting in negligible overpressure. In this sense, the effects of buoyancy, diffusivity, and weather conditions on the dispersion of hydrogen should be taken into account. The results are valid either for compressed or cryogenic liquid tanks and can be adopted for the sake of distinction between hydrogen flash fire and VCE; for the hazard analysis of hydrogen production and storage; and more in general for the risk assessment of hydrogen systems.

Effect of fabric properties and glove structure on thermal protective performance of fire gloves under flash fire exposure

The purpose of this study was to analyze the influence of fabric properties and glove structure on the thermal protective performance of fire glove when exposed to a flash fire. Ten types of firefighting glove fabrics were selected, and nine types of gloves with four-layer fabrics were obtained for an orthogonal experiment. Different structures and sizes of gloves were also designed. The burn area and absorbed energy were tested using a flame hand system. Pearson correlations were established to analyze the relationships of fabric properties and absorbed energy, and of shrinkage rate and absorbed energy. The statistical analysis from these obtained data indicated that the thickness of fabric systems had no significant correlation for total absorbed energy ( p > 0.05), while the flame retardancy, air permeability, and shrinkage rate of the outer shell fabric exhibited a strong relation ( p = 0.033, 0.012, and 0.013, respectively). With the increase in glove looseness, the absorbed energy and burn area first decreased and then increased. The thermal protective performance was best at a looseness of 10 mm (by the largest absorbed energy reduction of 24%). It has been found that long gloves provide better thermal protection than short gloves. For short gloves, adding an elastic belt to the wrist can reduce the absorbed energy, while adding an elastic belt to the cuff for long gloves has a negative effect on the thermal protective performance.

CFD simulations of instantaneously released liquefied gas in urban areas: A case study of LPG tank truck accident in Wenling, China

The accidental release and ignition of flammable liquefied gas can cause catastrophic events, such as flash fires, vapor cloud explosions, and boiling liquid expanding vapor explosion, which severely endanger urban residents and the environment. In the current study, a method for simulating liquefied gas instantaneous release accidents was established to explore the vapor cloud diffusion behavior in urban areas. The rare liquefied petroleum gas instantaneous release accident in Wenling, China is considered as a test case. To this end, an instantaneous release source model that considers the gas phase, liquid pool, and droplets was developed. The CFD model was validated using the damage distribution at the accident site. The simulation results revealed that droplets in the release source, terrains, and large obstacles significantly affected the dispersion behavior and extension distance of the vapor cloud. The evaporation of droplets resulted in a mushroom-shaped cloud. In addition, when the cloud was ignited, the area covered by the LFL was 1.94 and 2.07 times larger in the cases with droplets than those without. The method developed in this study is applicable to developing hazardous chemical transportation and emergency response measures in urban environments to maintain the sustainable cities development.

Coloured powder potential dust explosions

The use of Coloured powder (Holi powder orcolour dust) has been largely used in India for their festivities. Due to their popularity is extensive around the world since the popularity of the parties and events with this kind of show is increasing considerably. Despite the fact of its extensive use, its highly flammable nature is poorly known. Currently, some serious accidents related to the Coloured powder have been registered. Coloured powder organic nature implies a significant increase in the probability to form an explosive atmosphere as their use includes dust dispersion, leading to explosion hazards as has been previously reported. Moreover, it is important to take into account the effects on the flammability of the additives and the colorings existing in the Coloured powder as they might increase the hazard. To properly understand Coloured powder potential for producing an explosive atmosphere, and the attached risk of dust explosions, several samples were tested. Coloured powder from 6 different manufacturers were gathered. Each manufacturer provided several colours (between 5 and 8) which were characterized through moisture content and particle size determination. Once each sample was characterized, screening tests were performed on each sample determining whether ignition was produced or not. Those screening tests were carried out under certain conditions using the equipment for minimum ignition temperature on cloud determination (0.5 g set at 500 °C and 0.5 bar), and minimum ignition energy determination (using 100 and 300 mJ energies and 900 and 1200 mg). From those test results, important differences were seen between manufacturers, but most important, differences between colours of the same manufacturer were observed. The screening tests allowed the selection of 11 samples that were fully characterized through thermogravimetric analysis, maximum pressure of explosion, Kst, minimum ignition temperature on cloud, and minimum ignition energy. When carrying out thermogravimetric analysis, some samples increased mass at temperatures close to 300 °C and unexpectedly absorbed energy, followed by the expected combustion reaction at higher temperatures. From the obtained results it was noticed that the colour powders that included talcum in its composition did not produce explosion. Flammability and explosion tests, again, showed important differences between manufacturers and colours, and so it was possible to determine the relative flash fire and explosion risks of the various tested powders.

Forensic Investigations of Propane-Related Food Truck Incidents

The proliferation of propane-fueled food trucks and concession trailers over the last decade has led to a fast-growing industry. As with many nascent industries, accidents accompany the surge in growth, and the food truck industry is no exception. Numerous propane-related fires, flash fires, and explosions have resulted in property damage, business interruption, injury, and death. Conducting a proper investigation of a food truck incident is essential in determining the origin/cause and ultimately assigning liability and preventing recurrences. This paper discusses the food truck industry as well as the design, construction, and layout of the trucks. It provides an overview of the gas systems installed in the vehicles — from the cylinder or tank to the appliances, properties of propane, and relevant codes and standards applicable to food trucks that utilize propane. Finally, an outline of the proper methodology to use when investigating a food truck incident is pro-vided, and a food truck explosion case study is presented.

Experimental Investigation on performance and emission of Mosambi peel pyro oil bending with Orange oil

Pyrolysis method of thermal degradation of carbonaceous of waste material extracts the pyro oil from the waste bio-mass like Mosambi peel pyro oil (MPO) in the without oxygen. In this procedure, the temperature at 750°C. The pyro oil obtained from Mosambi peel bio-mass can then blended with orange oil Diesel in three dissimilar ratios. Bio-oil blend DMO10 (80%Diesel oil +10%MPO+10%Orange oil), DMO20 (70%Diesel oil +20%MPO+10%Orange oil), and DMO30 (60%Diesel oil +30%MPO+10%Orange oil) they can prepare with the given volume. The blended of oil is mixed from a Mechanical Agitator rapidity of 950 rpm for 30 min. The properties of all the blends they can investigated as the Flash point, Fire point, Density, Viscosity, Calorific value, and FTIR analysis all these blends. Among these three samples, the best sample DMO10 was close to the properties of Diesel fuel. The results show that Brake Thermal efficiency is increased to DMO10 Bio-fuels and reduced Specific fuel consumptions and lesser the exhaust gas temperature. Emission shows that the considerable reduction for the Smoke, UHC, and CO emission and Nox they slightly increased when compared to Diesel fuel. The usage of Diesel fuel DMO10 blends of pyro oil can be used without any modification in the Diesel fuel Engine.

Hazard Identification of Liquefied Natural Gas (LNG) Transportation and Storage in DKI Jakarta Province

LNG is an alternative fuel to replace diesel and gasoline. The use of LNG as a fuel has many advantages from various aspects. Besides having advantages, LNG also has disadvantages because it contains dangers in it. LNG is a volatile material that is easily flammable, which causes fires and explosions. Environmental Risk Assessment (ERA) is a systematic method used to measure the magnitude of the risk of a process and product that is a hazard to human health and ecology. By conducting an ERA, the risks and hazards of LNG are known. In carrying out the research, describing the LNG delivery system, identifying hazards in the event of LNG released from the carrier, making accident scenarios along with the outcome events that will occur, collecting data, calculating the frequency of accidents and their consequences, determining existing risks, and providing preventive actions, and mitigation. Hazard evaluation was determined using fault tree analysis (FTA) and event tree analysis (ETA). Based on identifying hazards to the storage and transportation of LNG, it is classified into category four and server (severe). Scenarios of releasing LNG into the environment in the process of transporting and storing LNG can be caused by several things, including external factors, failure in filling, and failure due to excess pressure so that it can cause fire pools/BLEVE events, cloud vapor explosions, flash fires, and cloud vapors. Based on the level of risk entered into, not tolerable action at the next opportunity.

A new thermal protective clothing design with silica aerogel filled acrylic nanofibers

PurposeFirefighters are exposed to high outdoor temperature and heat stress caused by metabolic activities during firefighting and should wear protective clothing to ensure their safety and health. Traditional firefighter protective suits are bulky and heavy garments with reduced thermal comfort properties since the fabric thickness and moisture barrier layers prevent heat transfer of the garment and cause additional heat stress. The aim of this study is to reduce heat stress by creating a new fabric design with silica aerogel membrane as a moisture barrier for three-layer fabric system.Design/methodology/approachPolyacrylonitrile (PAN) nanofibers were produced with three different silica aerogel contents and used for three-layered clothing system as a moisture barrier for giving desired protectiveness and thermal comfort to firefighters. Different fabric combinations were designed using two types of outer shell fabrics, two types of moisture barrier fabrics, two types of thermal barrier fabrics and PAN/silica aerogel membranes.FindingsThe results show that a lighter fabric system with improved wearer’s mobility and thermal comfort properties (thermal resistance and moisture permeability) is achieved with the use of PAN/silica aerogel membrane as an intermediate layer compared to commercial thermal protective fabric systems.Originality/valueDifferently from traditional thermal protective clothing, which may not provide adequate protection in long-term heat conditions or when exposed to flash fire, a new thermal protective clothing has been developed to be used in extremely hot environments, providing desired technical and performance properties, ease to wear comfort.

Comparison of FLACS and BASiL Model for Ro-Pax Ferry LNG Bunkering Leak Analysis

Performing liquefied natural gas (LNG) bunkering involves the risk of accidental leakage. When released from containment, LNG rapidly vaporizes into flammable natural gas and could lead to flash fire and explosion. Hence, LNG bunkering needs to take place in an area without an ignition source called a safety zone. This study compares the safety zone estimated by the Bunkering Area Safety Information for LNG (BASiL) model with that of the computational fluid dynamic (CFD) software FLACS, for Ro-Pax ferry bunkering. Horizontal leaks covering different wind speeds in eight wind directions were compared between the two models. Additionally, a grid refinement study was performed systematically to quantify the discretization error uncertainty in the CFD. Of 24 leak cases, FLACS and the BASiL model results agreed on 18 cases. In three cases validation was inconclusive due to the CFD error uncertainty. The BASiL model underestimated the safety zone distance in three cases compared with FLACS. Future work would be to perform a higher grid refinement study to confirm inconclusive comparison and examine ways to reduce gas dispersion spread for the worst result.

Методы расчета дрейфа тяжелых облаков с учетом движения среды

Peculiarities are considered related to the numerical integration of the diffusion equations for describing the formation and motion (drift) of explosive clouds formed on the territories of industrial facilities as a result of the accidental releases of combustible substances. The relevance of the study is associated with the fact that when the contents of an emergency release are mixed with an air, an explosive and flammable mixture is formed. The process of its combustion is determined by the volumetric concentration of the combustible substance. At concentrations below the lower concentration limit of ignition, combustion or explosion of the mixture is completely excluded. If the concentration of the mixture is between the lower and upper concentration limits of ignition, then there is an explosion. When the concentration of the mixture is above the upper concentration limit of ignition, a flash fire or a fireball occurs. Thus, the information is required on the parameters of the explosive mixture that may form due to the accidental release. Accidental releases can occur under the most adverse atmospheric environment and weather conditions. As a result, the focus of the article is on determining the parameters of an explosive cloud in the conditions of drift under the influence of a slight movement of the atmosphere (the most unfavorable scenario for the development of an accident). The results of numerical calculations of the diffusion equation with allowance for the mobility of the atmosphere are presented. The presence of a weak wind is the most unfavorable situation in terms of the drift of an explosive cloud. The methods and criteria are substantiated that allow obtaining the most correct results of calculating its motion.