Impact pressures on security industries associated with the processing of steam Nauch.org
The results, which show that the pressures observed during combustion of hydrogen-oxygen mixtures are shown also in the gas-vapor mixture, changing the potential dangers of tech-tech equipment, which present these systems.
Statement of the problem. One of the specific conditions ps5 of the process equipment in chemical industries is the presence of steps that use reduced pressure, not only in gas engines, but also in steam environments. ps5
Considering the features of the combustion gas at pressures up to 101 kPa, in [1, 2] have been established for the production of unsafe features. In particular, the model system H 2 O 2, at lower pressure, lower concentration limit distribution (ILC) flame initially decreases, then increases. The research model H 2 O 2-N 2 systems with [O 2] = Const> 4,8% showed that at low pressure ps5 limits combustion model system expands then narrows to closing the lower and upper limits. When [O 2] <4.8% no burning. The analysis indicates that there is uncertainty in the judgments of change KMP flame gas-vapor mixture with decreasing pressure. Parohazovi mix too common ps5 in production under reduced pressure. Therefore, the authors suggested that the above effect for hydrogen-oxygen mixtures can be expected ps5 also in the gas-vapor mixture and decided ps5 to investigate the dependence of the ILC pressure steam mixtures.
Analysis of recent research and publications. From the literature [1, 2] found that the majority of authors to carry out experimental work related to determining the effect of pressure on the ILC flame, installation and use different criteria for evaluating flammability, although existing experimental facilities fundamentally from one another not different. A laboratory ps5 setup to determine the ILC flame has the following drawbacks: different diameters and volumes of reaction vessels, various shape and material of the reaction vessel; different ps5 location ignition source (top, center and bottom of the reaction vessel), different sources of ignition ps5 - electric spark and spiral and others. There have been controversies about the most effective diameter of the reaction vessel in the study of combustion combined cycle systems in which simulated environment that occur in process equipment. If you determine the most appropriate pressure-diameter, you will be able to see more accurate results, to investigate the dependence ps5 of the ILC on the pressure.
Statement of the problem and its solution. Thus, to more accurately address the issue of pressure on flame KMP need to determine the influence of diameter reaction vessel to experiment. ps5 It is necessary to conduct ps5 experimental experiments flame propagation velocity for different diameters. If these experiments show the correct use of laboratory facility that is available, may conduct ps5 experiments on the effect of pressure on the ILC flame. This work was performed. Consider the problem of the diameter of the reaction vessel. ps5 Traditionally, research chamber is a cylindrical quartz vessel. When choosing the diameter of the chamber for gas and vapor-air mixtures at a pressure of 4 Pa 9,8-10 used sustainability criteria value on the brink of hell flame quenching ps5 [3]:
de Rais - criterion hell that according to [3], is about 65; R - gas constant (cm 3 kPa) / deg, T 0 - initial temperature of the mixture, K; λ cm - thermal conductivity of the gas mixture, cal / cm s hail; U N - normal flame speed for hydrogen content, m / s, C r.cm - heat the mixture, cal / mole-deg, P - pressure, kPa.
If the molecular weight of the mixture components do not differ greatly from one another, a linear relationship is used, which corresponds to an additive mixture thermal conductivity ps5 [3]: where λ 1 and λ 2 - Thermal conductivity, K 1 and K 2 - mole fraction of components.
From equation (1) it follows that the critical diameter increases with decreasing pressure, as in [5] shows that the normal rate may increase with decreasing pressure. Experiments were conducted by changing the apparent velocity of propagation of flame in mixtures of the fire area, close to the critical limits ps5 in the pressure range 1,25 April 10 6,4-10 4 Pa in cells with a diameter of 5 10 -2, 8 10 18 -2 and 10 -2 m, which showed similar results. The measurement results are apparent speed of propagation of flame in mixtures ps5 shown in Fig. 1. Rice. 1. The results of measurements of the apparent velocity of propagation of flame in mixtures of 1 - hydrogen-oxygen, 2 - isopropyl alcohol, 3 - acetone, 4 - methanol, 5 - P-xylene, 6 - toluene.
To determine A and B will take an array of experimental da-tion, ps5 which was used for plotting in Figure 1, where each of the studied compounds was constructed graph of the apparent velocity of flame propagation in mixtures with area fire close to critical limits.
The results, which show that the pressures observed during combustion of hydrogen-oxygen mixtures are shown also in the gas-vapor mixture, changing the potential dangers of tech-tech equipment, which present these systems.
Statement of the problem. One of the specific conditions ps5 of the process equipment in chemical industries is the presence of steps that use reduced pressure, not only in gas engines, but also in steam environments. ps5
Considering the features of the combustion gas at pressures up to 101 kPa, in [1, 2] have been established for the production of unsafe features. In particular, the model system H 2 O 2, at lower pressure, lower concentration limit distribution (ILC) flame initially decreases, then increases. The research model H 2 O 2-N 2 systems with [O 2] = Const> 4,8% showed that at low pressure ps5 limits combustion model system expands then narrows to closing the lower and upper limits. When [O 2] <4.8% no burning. The analysis indicates that there is uncertainty in the judgments of change KMP flame gas-vapor mixture with decreasing pressure. Parohazovi mix too common ps5 in production under reduced pressure. Therefore, the authors suggested that the above effect for hydrogen-oxygen mixtures can be expected ps5 also in the gas-vapor mixture and decided ps5 to investigate the dependence of the ILC pressure steam mixtures.
Analysis of recent research and publications. From the literature [1, 2] found that the majority of authors to carry out experimental work related to determining the effect of pressure on the ILC flame, installation and use different criteria for evaluating flammability, although existing experimental facilities fundamentally from one another not different. A laboratory ps5 setup to determine the ILC flame has the following drawbacks: different diameters and volumes of reaction vessels, various shape and material of the reaction vessel; different ps5 location ignition source (top, center and bottom of the reaction vessel), different sources of ignition ps5 - electric spark and spiral and others. There have been controversies about the most effective diameter of the reaction vessel in the study of combustion combined cycle systems in which simulated environment that occur in process equipment. If you determine the most appropriate pressure-diameter, you will be able to see more accurate results, to investigate the dependence ps5 of the ILC on the pressure.
Statement of the problem and its solution. Thus, to more accurately address the issue of pressure on flame KMP need to determine the influence of diameter reaction vessel to experiment. ps5 It is necessary to conduct ps5 experimental experiments flame propagation velocity for different diameters. If these experiments show the correct use of laboratory facility that is available, may conduct ps5 experiments on the effect of pressure on the ILC flame. This work was performed. Consider the problem of the diameter of the reaction vessel. ps5 Traditionally, research chamber is a cylindrical quartz vessel. When choosing the diameter of the chamber for gas and vapor-air mixtures at a pressure of 4 Pa 9,8-10 used sustainability criteria value on the brink of hell flame quenching ps5 [3]:
de Rais - criterion hell that according to [3], is about 65; R - gas constant (cm 3 kPa) / deg, T 0 - initial temperature of the mixture, K; λ cm - thermal conductivity of the gas mixture, cal / cm s hail; U N - normal flame speed for hydrogen content, m / s, C r.cm - heat the mixture, cal / mole-deg, P - pressure, kPa.
If the molecular weight of the mixture components do not differ greatly from one another, a linear relationship is used, which corresponds to an additive mixture thermal conductivity ps5 [3]: where λ 1 and λ 2 - Thermal conductivity, K 1 and K 2 - mole fraction of components.
From equation (1) it follows that the critical diameter increases with decreasing pressure, as in [5] shows that the normal rate may increase with decreasing pressure. Experiments were conducted by changing the apparent velocity of propagation of flame in mixtures of the fire area, close to the critical limits ps5 in the pressure range 1,25 April 10 6,4-10 4 Pa in cells with a diameter of 5 10 -2, 8 10 18 -2 and 10 -2 m, which showed similar results. The measurement results are apparent speed of propagation of flame in mixtures ps5 shown in Fig. 1. Rice. 1. The results of measurements of the apparent velocity of propagation of flame in mixtures of 1 - hydrogen-oxygen, 2 - isopropyl alcohol, 3 - acetone, 4 - methanol, 5 - P-xylene, 6 - toluene.
To determine A and B will take an array of experimental da-tion, ps5 which was used for plotting in Figure 1, where each of the studied compounds was constructed graph of the apparent velocity of flame propagation in mixtures with area fire close to critical limits.
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