The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Satoru Ishizuka - One of the best experts on this subject based on the ideXlab platform.
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Reexamination on methane/oxygen Combustion in a rapidly mixed type tubular Flame burner
Combustion and Flame, 2014Co-Authors: Baolu Shi, Daisuke Shimokuri, Satoru IshizukaAbstract:Abstract To fundamentally elucidate the requirement for an inherently safe technique of rapidly mixed type tubular Flame Combustion, experiments have been made to investigate (1) the mixing process of fuel and oxidizer, and (2) the appearances of methane Flames under various oxygen mole fractions. Three optically accessible quartz burners of different slit widths were made for measuring the mixing layer thickness with a PIV system. Under various rates of flow of the oxidizer to the fuel, a boundary layer type flow is recognized to dominate the mixing of fuel and oxidizer around the exit of the injection slit, namely the mixing layer thickness is inversely proportional to the square root of mean injection velocity. Using two stainless steel burners, Combustion tests were conducted with the oxidizers of oxygen/air mixtures. To quantitatively investigate the requirement for tubular Flame establishment, the Damkohler number, which is the ratio of characteristic mixing time to characteristic chemical reaction time, has been discussed in detail. The mixing time was calculated according to estimated mixing layer thickness, while the chemical reaction time was computed with the Chemkin code. The Damkohler number has proved to be a useful measure for success/failure of tubular Flame Combustion. When the Damkohler number is larger than unity, chemical reaction starts before complete fuel/air mixing and the tubular Flame fails to be established; when the Damkohler number is much smaller than unity, the fuel and the oxidizer are completely mixed before the onset of reaction, resulting in successful tubular Flame Combustion. The results confirm our hypothesis in a previous study. Furthermore, based on the concept of Damkohler number, the minimum flow rate to achieve the tubular Flame Combustion could be estimated.
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Methane/oxygen Combustion in a rapidly mixed type tubular Flame burner
Proceedings of the Combustion Institute, 2013Co-Authors: Baolu Shi, Daisuke Shimokuri, Satoru IshizukaAbstract:Abstract An inherently safe technique of rapidly mixed type tubular Flame Combustion has been applied to pure oxygen Combustion. The Flame characteristics under various oxygen mole fractions are experimentally investigated with use of burners of different slit widths, and in addition, with optically accessible quartz burners. To fundamentally understand the requirements for rapidly mixed pure oxygen tubular Flame Combustion, the characteristic reaction times were calculated with Chemkin code, while the characteristic mixing times were estimated based on the width of mixing layer determined. Results show that the rapidly mixed type tubular Flame Combustion has been obtained under oxygen-enriched and even pure oxygen conditions. At high oxygen mole fraction, diffusion Flames are anchored at the exits of the fuel slits, which restrains mixing between fuel and oxidizer, resulting in a failure of tubular Flame Combustion. By reducing the slit width, however, the diffusion Flame is inhibited and a uniform tubular Flame can be obtained from 0.11 to 0.18 in overall equivalence ratio. To quantify the mixing process, the flow field was visualized, and it has been found that there exist two types of flows, a boundary layer type flow near the exits of the slits close to the wall and an axisymmetric potential flow around the axis of rotation. Based on the mixing layer width of the boundary layer type flow, the Damkohler numbers are obtained and it is clearly shown that when the Damkohler number is less than unity, the mixing is completed before the onset of reactions, resulting in establishment of tubular Flame Combustion.
Daisuke Shimokuri - One of the best experts on this subject based on the ideXlab platform.
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Tubular Flame Combustion for Nanoparticle Production
Industrial & Engineering Chemistry Research, 2019Co-Authors: Tomoyuki Hirano, Daisuke Shimokuri, Jun Kikkawa, Febrigia Ghana Rinaldi, Kenshi Kitawaki, Eishi Tanabe, Takashi OgiAbstract:Requirements for nanoparticle processing based on energy and cost-effective technologies have increased in recent years. Flame synthesis is widely used on an industrial scale and is superior to gas...
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Reexamination on methane/oxygen Combustion in a rapidly mixed type tubular Flame burner
Combustion and Flame, 2014Co-Authors: Baolu Shi, Daisuke Shimokuri, Satoru IshizukaAbstract:Abstract To fundamentally elucidate the requirement for an inherently safe technique of rapidly mixed type tubular Flame Combustion, experiments have been made to investigate (1) the mixing process of fuel and oxidizer, and (2) the appearances of methane Flames under various oxygen mole fractions. Three optically accessible quartz burners of different slit widths were made for measuring the mixing layer thickness with a PIV system. Under various rates of flow of the oxidizer to the fuel, a boundary layer type flow is recognized to dominate the mixing of fuel and oxidizer around the exit of the injection slit, namely the mixing layer thickness is inversely proportional to the square root of mean injection velocity. Using two stainless steel burners, Combustion tests were conducted with the oxidizers of oxygen/air mixtures. To quantitatively investigate the requirement for tubular Flame establishment, the Damkohler number, which is the ratio of characteristic mixing time to characteristic chemical reaction time, has been discussed in detail. The mixing time was calculated according to estimated mixing layer thickness, while the chemical reaction time was computed with the Chemkin code. The Damkohler number has proved to be a useful measure for success/failure of tubular Flame Combustion. When the Damkohler number is larger than unity, chemical reaction starts before complete fuel/air mixing and the tubular Flame fails to be established; when the Damkohler number is much smaller than unity, the fuel and the oxidizer are completely mixed before the onset of reaction, resulting in successful tubular Flame Combustion. The results confirm our hypothesis in a previous study. Furthermore, based on the concept of Damkohler number, the minimum flow rate to achieve the tubular Flame Combustion could be estimated.
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Methane/oxygen Combustion in a rapidly mixed type tubular Flame burner
Proceedings of the Combustion Institute, 2013Co-Authors: Baolu Shi, Daisuke Shimokuri, Satoru IshizukaAbstract:Abstract An inherently safe technique of rapidly mixed type tubular Flame Combustion has been applied to pure oxygen Combustion. The Flame characteristics under various oxygen mole fractions are experimentally investigated with use of burners of different slit widths, and in addition, with optically accessible quartz burners. To fundamentally understand the requirements for rapidly mixed pure oxygen tubular Flame Combustion, the characteristic reaction times were calculated with Chemkin code, while the characteristic mixing times were estimated based on the width of mixing layer determined. Results show that the rapidly mixed type tubular Flame Combustion has been obtained under oxygen-enriched and even pure oxygen conditions. At high oxygen mole fraction, diffusion Flames are anchored at the exits of the fuel slits, which restrains mixing between fuel and oxidizer, resulting in a failure of tubular Flame Combustion. By reducing the slit width, however, the diffusion Flame is inhibited and a uniform tubular Flame can be obtained from 0.11 to 0.18 in overall equivalence ratio. To quantify the mixing process, the flow field was visualized, and it has been found that there exist two types of flows, a boundary layer type flow near the exits of the slits close to the wall and an axisymmetric potential flow around the axis of rotation. Based on the mixing layer width of the boundary layer type flow, the Damkohler numbers are obtained and it is clearly shown that when the Damkohler number is less than unity, the mixing is completed before the onset of reactions, resulting in establishment of tubular Flame Combustion.
Baolu Shi - One of the best experts on this subject based on the ideXlab platform.
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Reexamination on methane/oxygen Combustion in a rapidly mixed type tubular Flame burner
Combustion and Flame, 2014Co-Authors: Baolu Shi, Daisuke Shimokuri, Satoru IshizukaAbstract:Abstract To fundamentally elucidate the requirement for an inherently safe technique of rapidly mixed type tubular Flame Combustion, experiments have been made to investigate (1) the mixing process of fuel and oxidizer, and (2) the appearances of methane Flames under various oxygen mole fractions. Three optically accessible quartz burners of different slit widths were made for measuring the mixing layer thickness with a PIV system. Under various rates of flow of the oxidizer to the fuel, a boundary layer type flow is recognized to dominate the mixing of fuel and oxidizer around the exit of the injection slit, namely the mixing layer thickness is inversely proportional to the square root of mean injection velocity. Using two stainless steel burners, Combustion tests were conducted with the oxidizers of oxygen/air mixtures. To quantitatively investigate the requirement for tubular Flame establishment, the Damkohler number, which is the ratio of characteristic mixing time to characteristic chemical reaction time, has been discussed in detail. The mixing time was calculated according to estimated mixing layer thickness, while the chemical reaction time was computed with the Chemkin code. The Damkohler number has proved to be a useful measure for success/failure of tubular Flame Combustion. When the Damkohler number is larger than unity, chemical reaction starts before complete fuel/air mixing and the tubular Flame fails to be established; when the Damkohler number is much smaller than unity, the fuel and the oxidizer are completely mixed before the onset of reaction, resulting in successful tubular Flame Combustion. The results confirm our hypothesis in a previous study. Furthermore, based on the concept of Damkohler number, the minimum flow rate to achieve the tubular Flame Combustion could be estimated.
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Methane/oxygen Combustion in a rapidly mixed type tubular Flame burner
Proceedings of the Combustion Institute, 2013Co-Authors: Baolu Shi, Daisuke Shimokuri, Satoru IshizukaAbstract:Abstract An inherently safe technique of rapidly mixed type tubular Flame Combustion has been applied to pure oxygen Combustion. The Flame characteristics under various oxygen mole fractions are experimentally investigated with use of burners of different slit widths, and in addition, with optically accessible quartz burners. To fundamentally understand the requirements for rapidly mixed pure oxygen tubular Flame Combustion, the characteristic reaction times were calculated with Chemkin code, while the characteristic mixing times were estimated based on the width of mixing layer determined. Results show that the rapidly mixed type tubular Flame Combustion has been obtained under oxygen-enriched and even pure oxygen conditions. At high oxygen mole fraction, diffusion Flames are anchored at the exits of the fuel slits, which restrains mixing between fuel and oxidizer, resulting in a failure of tubular Flame Combustion. By reducing the slit width, however, the diffusion Flame is inhibited and a uniform tubular Flame can be obtained from 0.11 to 0.18 in overall equivalence ratio. To quantify the mixing process, the flow field was visualized, and it has been found that there exist two types of flows, a boundary layer type flow near the exits of the slits close to the wall and an axisymmetric potential flow around the axis of rotation. Based on the mixing layer width of the boundary layer type flow, the Damkohler numbers are obtained and it is clearly shown that when the Damkohler number is less than unity, the mixing is completed before the onset of reactions, resulting in establishment of tubular Flame Combustion.
Cristian Focsa - One of the best experts on this subject based on the ideXlab platform.
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A comprehensive protocol for chemical analysis of Flame Combustion emissions by secondary ion mass spectrometry
Rapid communications in mass spectrometry : RCM, 2018Co-Authors: Cornelia Irimiea, Alessandro Faccinetto, Yvain Carpentier, Ismael-kenneth Ortega, Nicolas Nuns, Eric Therssen, Pascale Desgroux, Cristian FocsaAbstract:RATIONALE Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is used to provide detailed information on the surface chemical composition of soot. An analytical protocol is proposed and tested on a laboratory Flame, and the results are compared with our previous measurements provided by two-step laser mass spectrometry (L2MS). METHODS This work details: (1) the development of a dedicated apparatus to sample Combustion products from atmospheric Flames and deposit them on substrates suitable for TOF-SIMS analysis; (2) the choice of the deposition substrate and the material of the sampling line, and their effect on the mass spectra; (3) a method to separate the contributions of soot and condensable gas based on impact deposition; and finally (4) post-acquisition data processing. RESULTS Compounds produced during Flame Combustion are detected on the surface of different deposition substrates and attributed a molecular formula based on mass defect analysis. Silicon and titanium wafers perform similarly, while the surface roughness of glass microfiber filters results in a reduced mass resolution. The mass spectra obtained from the analysis of different locations of the deposits obtained by impaction show characteristic patterns that are attributed to soot/condensable gas. CONCLUSIONS A working method for the analysis of soot samples and the extraction of useful data from mass spectra is proposed. This protocol should help to avoid common experimental issues like sample contamination, while optimizing the setup performance by maximizing the achievable mass resolution.
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A comprehensive protocol for chemical analysis of Flame Combustion emissions by secondary ion mass spectrometry
Rapid Communications in Mass Spectrometry, 2018Co-Authors: Cornelia Irimiea, Alessandro Faccinetto, Yvain Carpentier, Ismael-kenneth Ortega, Nicolas Nuns, Eric Therssen, Pascale Desgroux, Cristian FocsaAbstract:RATIONALE. Time of flight secondary ion mass spectrometry (ToF-SIMS) is used to provide detailed information on the surface chemical composition of soot. An analytical protocol is proposed and tested on a laboratory Flame, and the results are compared with our previous measurements provided by two-step laser mass spectrometry (L2MS). METHODS. This work details: (1) the development of a dedicated apparatus to sample Combustion products from atmospheric Flames and deposit them on substrates suitable for ToF-SIMS analysis; (2) the choice of the deposition substrate and the material of the sampling line, and their effect on the mass spectra; (3) a method to separate the contributions of soot and condensable gas based on impact deposition, and finally (4) the post-acquisition data processing. RESULTS. Compounds produced during Flame Combustion are detected on the surface of different deposition substrates and attributed a molecular formula based on mass defect analysis. Silicon and titanium wafers perform similarly, while the surface roughness of glass microfiber filters results in a reduced mass resolution. The mass spectra obtained from the analysis of different locations of the deposits obtained by impaction show characteristic patterns that are attributed to soot/condensable gas. CONCLUSIONS. A working method for the analysis of soot samples and the extraction of useful data from mass spectra is proposed. This protocol should help avoiding common experimental issues like sample contamination, while optimizing the setup performance by maximizing the achievable mass resolution.
Cornelia Irimiea - One of the best experts on this subject based on the ideXlab platform.
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A comprehensive protocol for chemical analysis of Flame Combustion emissions by secondary ion mass spectrometry
Rapid communications in mass spectrometry : RCM, 2018Co-Authors: Cornelia Irimiea, Alessandro Faccinetto, Yvain Carpentier, Ismael-kenneth Ortega, Nicolas Nuns, Eric Therssen, Pascale Desgroux, Cristian FocsaAbstract:RATIONALE Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is used to provide detailed information on the surface chemical composition of soot. An analytical protocol is proposed and tested on a laboratory Flame, and the results are compared with our previous measurements provided by two-step laser mass spectrometry (L2MS). METHODS This work details: (1) the development of a dedicated apparatus to sample Combustion products from atmospheric Flames and deposit them on substrates suitable for TOF-SIMS analysis; (2) the choice of the deposition substrate and the material of the sampling line, and their effect on the mass spectra; (3) a method to separate the contributions of soot and condensable gas based on impact deposition; and finally (4) post-acquisition data processing. RESULTS Compounds produced during Flame Combustion are detected on the surface of different deposition substrates and attributed a molecular formula based on mass defect analysis. Silicon and titanium wafers perform similarly, while the surface roughness of glass microfiber filters results in a reduced mass resolution. The mass spectra obtained from the analysis of different locations of the deposits obtained by impaction show characteristic patterns that are attributed to soot/condensable gas. CONCLUSIONS A working method for the analysis of soot samples and the extraction of useful data from mass spectra is proposed. This protocol should help to avoid common experimental issues like sample contamination, while optimizing the setup performance by maximizing the achievable mass resolution.
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A comprehensive protocol for chemical analysis of Flame Combustion emissions by secondary ion mass spectrometry
Rapid Communications in Mass Spectrometry, 2018Co-Authors: Cornelia Irimiea, Alessandro Faccinetto, Yvain Carpentier, Ismael-kenneth Ortega, Nicolas Nuns, Eric Therssen, Pascale Desgroux, Cristian FocsaAbstract:RATIONALE. Time of flight secondary ion mass spectrometry (ToF-SIMS) is used to provide detailed information on the surface chemical composition of soot. An analytical protocol is proposed and tested on a laboratory Flame, and the results are compared with our previous measurements provided by two-step laser mass spectrometry (L2MS). METHODS. This work details: (1) the development of a dedicated apparatus to sample Combustion products from atmospheric Flames and deposit them on substrates suitable for ToF-SIMS analysis; (2) the choice of the deposition substrate and the material of the sampling line, and their effect on the mass spectra; (3) a method to separate the contributions of soot and condensable gas based on impact deposition, and finally (4) the post-acquisition data processing. RESULTS. Compounds produced during Flame Combustion are detected on the surface of different deposition substrates and attributed a molecular formula based on mass defect analysis. Silicon and titanium wafers perform similarly, while the surface roughness of glass microfiber filters results in a reduced mass resolution. The mass spectra obtained from the analysis of different locations of the deposits obtained by impaction show characteristic patterns that are attributed to soot/condensable gas. CONCLUSIONS. A working method for the analysis of soot samples and the extraction of useful data from mass spectra is proposed. This protocol should help avoiding common experimental issues like sample contamination, while optimizing the setup performance by maximizing the achievable mass resolution.