scholarly journals Explosion Characteristics of Propanol Isomer–Air Mixtures

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1574 ◽  
Author(s):  
Jan Skřínský ◽  
Tadeáš Ochodek
Keyword(s):  
Maximum Rate ◽  
Pressure Rise ◽  
Spherical Vessel ◽  
Explosion Pressure ◽  
Pressure Time ◽  
Vessel Volume ◽  
Deflagration Index ◽  
Pressure Maximum ◽  
Series Of Experiments ◽  
Effects Of Temperature

This paper describes a series of experiments performed to study the explosion characteristics of propanol isomer (1-propanol and 2-propanol)–air binary mixtures. The experiments were conducted in two different experimental arrangements—a 0.02 m3 oil-heated spherical vessel and a 1.00 m3 electro-heated spherical vessel—for different equivalence ratios between 0.3 and 1.7, and initial temperatures of 50, 100, and 150 °C. More than 150 pressure–time curves were recorded. The effects of temperature and test vessel volume on various explosion characteristics, such as the maximum explosion pressure, maximum rate of pressure rise, deflagration index, and the lower and upper explosion limits were investigated and the results were further compared with the results available in literature for other alcohols, namely methanol, ethanol, 1-butanol, and 1-pentanol. The most important results from evaluated experiments are the values of deflagration index 89–98 bar·m/s for 2-propanol and 105–108 bar·m/s for 1-propanol/2-propanol–air mixtures. These values are used to describe the effect of isomer blends on a deflagration process and to rate the effects of an explosion.

The Explosion Severity of Biogas(CH4-CO2)/Air Mixtures in a Closed Vessel

2019 ◽  
Vol 964 ◽  
pp. 33-39
Author(s):  
Nur Aqidah Muhammad Harinder Khan ◽  
Siti Zubaidah Sulaiman ◽  
Izirwan Izhab ◽  
Siti Kholijah Abdul Mudalip ◽  
Rohaida Che Man ◽  
...  
Keyword(s):  
Maximum Rate ◽  
Equivalence Ratio ◽  
Pressure Rise ◽  
Flammability Limit ◽  
Flammability Limits ◽  
Spherical Vessel ◽  
Suppression Effect ◽  
Explosion Overpressure ◽  
Deflagration Index ◽  
Lower Flammability Limit

Biogas which consists of methane (CH4) and carbon dioxide (CO2) could explode when diluted to a certain degree with air in the presence of ignition source. The maximum explosion overpressure (Pmax), the maximum rate of pressure rise (dP/dt)max, flammability limits, and deflagration index are the most important explosion severities parameters to characterize the risk of explosion. In this research paper, the effect of equivalence ratio (ER) of biogas/air mixtures and the effect of CO2 concentrations presence in biogas were studied in a 20 L spherical vessel. The values of Pmax and (dP/dt)max of biogas/air mixtures were more severe at ER 1.2. At various CO2 content, Pmax and (dP/dt)max of biogas/air mixtures were the least affected at 45% vol/vol of CO2. On the other hand, deflagration index (KG) of biogas/air mixtures trend was the most severe at 35% vol/vol of CO2 content despite the lowest Pmax and (dP/dt)max at 45% vol/vol of CO2 content. The lowest values in Pmax and (dP/dt)max were due to the diffusivity properties of CH4 that had surpassed the CO2 suppression effect. Furthermore, the presence of CO2 in biogas/air mixtures had increased the upper flammability limit and lower flammability limit of biogas.

scholarly journals Comparative study of the explosion pressure characteristics of micro- and nano-sized coal dust and methane–coal dust mixtures in a pipe

2020 ◽  
Vol 7 (1) ◽  
pp. 68-78 ◽  
Author(s):  
Bo Tan ◽  
Huilin Liu ◽  
Bin Xu ◽  
Tian Wang
Keyword(s):  
Coal Dust ◽  
Pressure Rise ◽  
Dust Explosion ◽  
Nano Particle ◽  
Explosion Pressure ◽  
Deflagration Index ◽  
Pressure Maximum ◽  
Explosion Accidents ◽  
The Impact ◽  
Pressure Characteristics

AbstractCoal dust explosion accidents often cause substantial property damage and casualties and frequently involve nano-sized coal dust. In order to study the impact of nano-sized coal on coal dust and methane–coal dust explosions, a pipe test apparatus was used to analyze the explosion pressure characteristics of five types of micro-nano particle dusts (800 nm, 1200 nm, 45 μm, 60 μm, and 75 μm) at five concentrations (100 g/m3, 250 g/m3, 500 g/m3, 750 g/m3, and 1000 g/m3). The explosion pressure characteristics were closely related to the coal dust particle size and concentration. The maximum explosion pressure, maximum rate of pressure rise, and deflagration index for nano-sized coal dust were larger than for its micro-sized counterpart, indicating that a nano-sized coal dust explosion is more dangerous. The highest deflagration index Kst for coal dust was 13.97 MPa/(m·s), indicating weak explosibility. When 7% methane was added to the air, the maximum deflagration index Kst for methane–coal dust was 42.62  MPa/(m·s), indicating very strong explosibility. This indicates that adding methane to the coal dust mixture substantially increased the hazard grade.

scholarly journals NUMERICAL SIMULATION ON THE EFFECT OF CONCENTRATION ON PREMIXED CH4/CO2/AIR EXPLOSION CHARACTERISTICS

2019 ◽  
Vol 5 (1) ◽  
pp. 39-47
Author(s):  
Nur Aqidah Muhammad Harinder Khan ◽  
Siti Zubaidah Sulaiman ◽  
Izirwan Izhab ◽  
Siti Kholijah Abdul Mudalip ◽  
Rohaida Che Man ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Maximum Rate ◽  
Pressure Rise ◽  
Spherical Vessel ◽  
Explosion Pressure ◽  
Flame Acceleration ◽  
Explosion Overpressure ◽  
Pressure Development ◽  
Air Explosion ◽  
Rich Mixtures

In this study, a numerical simulation on the premixed CH4/CO2/Air (methane/carbon dioxide/air) mixture explosion characteristics was conducted by using the Flame Acceleration Simulator (FLACs) software. The domain used in the 20 L spherical vessel with 0.808 m diameter. The effect of various equivalence ratios on the explosion characteristics such as the explosion pressure, Pex, maximum explosion overpressure, Pmax, the maximum rate of the pressure rise, (dP/dt)max and gas deflagration index, KG, were studied. For this purpose, the mixture concentrations range from equivalence ratio (ER) 0.8 to 1.5 (9.6 to 18% vol/vol) were considered. From this study, the explosion pressure, Pex, maximum explosion overpressure, Pmax, and the maximum rate of pressure rise, (dP/dt)max, at various ER was the maximum at a slightly rich concentration (ER=1.2). At lean and rich mixtures, the Pex, Pmax, (dP/dt)max and KG decreases. It can be said that, at ER=1.2, the role of thermal-diffusive instability and its effect on the flame speed during the pressure development process had causes the diffused methane, CH4, to react further into the flame front, which significantly increases the mixture mass burning rate and flame was also found to propagates the fastest at ER=1.2 due to the incompletecombustion process caused by the insufficient and excess CH4 present in the lean and rich mixtures. The CH4/CO2/air mixtures studied in this study were also found to have the highest level of hazard potential when exploded.

scholarly journals Maximizing the Safety Production of Energo Gas - Determination of Explosion Characteristics

2020 ◽  
Vol 328 ◽  
pp. 03015
Author(s):  
Jan Skřínský ◽  
Jan Koloničný
Keyword(s):  
Maximum Rate ◽  
Pressure Rise ◽  
Optimum Concentration ◽  
Gas Explosion ◽  
Real Gas ◽  
Explosion Pressure ◽  
Pressure Method ◽  
Deflagration Index ◽  
Safety Production

The article is focused on the determination of explosion characteristics of energo gas produced from an industrial scale, biomass gasifier. The results underline that the composition of energo gas from industrial technology has a significant impact on the gas explosion characteristics. The gas explosion experiments were carried out in the spherical 20-L explosion vessel. The Real gas was sampled into the 50-L Tedlar bags, introduced into the vessel and mixed with air by a partial-pressure method. Absolute explosion pressure for energo gas air mixture was higher than 6 bar for the energo gas optimum concentration close to 30 vol. % of fuel. The maximum rate of pressure rise and the deflagration index have been determined. Obtained explosion characteristics could be used to describe the explosion process and to rate the effects of an explosion.

Inert Gas Influence on Propagation Velocity of Methane-air Laminar Flames

2018 ◽  
Vol 69 (1) ◽  
pp. 196-200 ◽  
Author(s):  
Maria Mitu ◽  
Venera Giurcan ◽  
Domnina Razus ◽  
Dumitru Oancea
Keyword(s):  
Experimental Data ◽  
Kinetic Modeling ◽  
Early Stage ◽  
Pressure Rise ◽  
Laminar Flames ◽  
Inert Gas ◽  
Spherical Vessel ◽  
Pressure Time ◽  
Expansion Coefficients ◽  
Propagation Velocities

The flame propagation in methane-air mixtures diluted by inert additives (He, Ar, N2, CO2) was studied by means of pressure-time records of laminar deflagrations occurring in a spherical vessel with central ignition. Experiments were made using mixtures with various equivalence ratios between 0.610 and 1.310 and various inert concentrations between 5 and 25 vol%, at various initial pressures between 50 and 200 kPa. Examination of pressure-time records in the early stage of explosions delivered the normal burning velocities Su via the coefficients of the cubic law of pressure rise, using a previously described procedure. The propagation velocities (or the flame speed) were calculated from the normal burning velocities using the expansion coefficients of the unburnt gas during the isobaric combustion. The propagation velocities of examined systems obtained from experimental data were examined against the propagation velocities obtained from kinetic modeling of methane-air-inert combustion by means of 1D COSILAB package using the GRI 3.0 mechanism.

scholarly journals Determination of the Explosion Characteristics of Wheat Flour

2017 ◽  
Vol 25 (40) ◽  
pp. 9-16
Author(s):  
Richard Kuracina ◽  
Zuzana Szabová ◽  
Denisa Pangrácová ◽  
Karol Balog
Keyword(s):  
Wheat Flour ◽  
Maximum Rate ◽  
Pressure Rise ◽  
Explosion Pressure ◽  
Maximum Explosion Pressure ◽  
Dust Clouds ◽  
Maximum Value ◽  
Flour Dust ◽  
Explosion Limit

Abstract The article deals with the measurement of explosion characteristics of wheat flour. The measurements were carried out according to STN EN 14034-1+A1:2011 Determination of explosion characteristics of dust clouds. Part 1: Determination of the maximum explosion pressure pmax of dust clouds, the maximum rate of explosion pressure rise according to STN EN 14034-2+A1:2012 Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds and LEL according to STN EN 14034-3+A1:2011 Determination of explosion characteristics of dust clouds: Determination of the lower explosion limit LEL of dust clouds. The testing of explosions of wheat flour dust clouds showed that the maximum value of the pressure was reached at the concentrations of 600 g/m3 and its value is 8.32 bar/s. The fastest increase of pressure was observed at the concentration of 750 g/m3 and its value was 54.2 bar/s.

scholarly journals Explosion prevention and mitigation in plants which process, generate and store combustible dusts

2022 ◽  
Vol 354 ◽  
pp. 00041
Author(s):  
Adrian Marius Jurca ◽  
Mihaela Părăian ◽  
Niculina Vătavu
Keyword(s):  
Pressure Rise ◽  
Process Equipment ◽  
Process Industries ◽  
Explosion Pressure ◽  
Dust Clouds ◽  
Large Numbers ◽  
Burning Rates ◽  
Explosion Protection ◽  
Pressure Maximum ◽  
Protective Systems

Combustible dusts which are present in workplaces are a significant hazard which cannot be ignored by the plant owners, managers and workers. Combustible dust deflagrations and explosions have caused large numbers of deaths and catastrophic property damages in various industries, ranging from pharmaceutical plants to sugar factories. One may say that dust explosions in process industries always start inside process equipment such as mills, dryers, filters. Such events may occur in any process in which a combustible dust is handled, produced or stored, and can be triggered by any energy source, including static electricity, friction and hot surfaces. For any combustible dust type, several important parameters have to be taken into account when designing and using protective systems: i.e. the ease with which dust clouds ignite and their burning rates, maximum explosion pressure, maximum rate of explosion pressure rise. These parameters vary considerably depending on the dust type, their knowledge being a first step for carrying out a proper explosion risk assessment in installations which circulate combustible dusts. The paper presents the main aspects concerning explosion protection which have to be taken into account when designing protective systems intended to be used in explosive atmospheres generated by combustible dusts and the importance of selecting the proper explosion protection technique.

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