The Experts below are selected from a list of 6081 Experts worldwide ranked by ideXlab platform
V Linek - One of the best experts on this subject based on the ideXlab platform.
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Gas Suction and mass transfer in Gas liquid up flow ejector loop reactors effect of nozzle and ejector geometry
Chemical Engineering Journal, 2018Co-Authors: M Opletal, V Linek, P Novotný, T Moucha, M KordacAbstract:Abstract The aim is to develop a method for the design of up-flow ejector loop reactors for coalescent systems respecting the different energy dissipation and mechanism of interfacial mass transfer in the ejector and in the holding vessel. Measurements and correlations of Gas entrainment rate (mG/mL) and of oxygen volumetric mass transfer coefficient (kLa) are reported describing their dependencies on operating conditions for various geometries of the ejector. The results show that the energy supplied into the ejector must be expressed as a two independent parts: one representing the energy of inner turbulence of the liquid jet leaving the nozzle and the one representing the kinetic energy of axial liquid flow entering the Suction chamber. Turbulent transverse motion generated in the nozzle characterized by its pressure loss coefficient ς, produces a surface roughness of the jet and plays a dominant role in its ability to entrain the surrounding Gas. The kinetic energy of the axial liquid flow characterized by liquid velocity in the nozzle vn, diminished for the energy spent on Gas compression is utilized in the mixing shock for dispersing of the entrained Gas into the liquid. The correlations formed for a prediction of mG/mL and of kLa in ejector based on the more of 700 individual ejector configurations have average deviation lower than 8%. Mass transfer and Gas hold-up in the holding vessel were modeled using the previously verified slip velocity concept, characterizing the mutual flow of phases in homogeneous bubble beds. An example of the application of the correlations for evaluation of mass transfer performance of Ejector Loop Reactor is shown.
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effect of the ejector configuration on the Gas Suction rate and Gas hold up in ejector loop reactors
Chemical Engineering Science, 1997Co-Authors: P Havelka, V Linek, J Sinkule, J Zahradnik, M FialovaAbstract:Abstract An experimental study has been aimed at examining the effect of ejector configuration on the rate and energy effectiveness of Gas Suction and on the values of Gas hold-up in ejector loop reactors. Experimental data showed that insertion of a swirl body into the ejector nozzle increased the Suction rate and dispersion efficiency of the ejector distributor and significantly improved its operating flexibility. In the absence of swirl elements, the Gas Suction rate increased slightly with the mixing tube length up to the length-to-diameter ratio equal to six. In the presence of swirls, however, the mixing tube length exhibited negative effect on the ejector performance and the highest values of Gas Suction rate and dispersion efficiency were observed for the configurations without the mixing tube. The ejector Suction efficiency increased sharply with increasing swirl number Swb (related to the swirl body parameters) in the region of its values 0.06–0.12 while the increase of Swb above 0.2 resulted in a decrease of the Gas Suction rate. For Swb = 0.12–0.20, the Gas Suction rate was significantly higher than that achieved in the absence of swirls even at the optimum mixing bube length. Comparison of the energy effectiveness of Gas Suction indicated superiority of the single-orifice nozzles with swirl inserts over the other tested variants. Good agreement of Gas holdup data from all experimental runs with values calculated from the relation u s = u oG ge G − u oL (1−ϵ G ) , for the slip velocity value us = 0.224 m s−1, proved adequacy of the slip velocity concept for description of Gas-liquid flow in ejector loop reactors.
M Kordac - One of the best experts on this subject based on the ideXlab platform.
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Gas Suction and mass transfer in Gas liquid up flow ejector loop reactors effect of nozzle and ejector geometry
Chemical Engineering Journal, 2018Co-Authors: M Opletal, V Linek, P Novotný, T Moucha, M KordacAbstract:Abstract The aim is to develop a method for the design of up-flow ejector loop reactors for coalescent systems respecting the different energy dissipation and mechanism of interfacial mass transfer in the ejector and in the holding vessel. Measurements and correlations of Gas entrainment rate (mG/mL) and of oxygen volumetric mass transfer coefficient (kLa) are reported describing their dependencies on operating conditions for various geometries of the ejector. The results show that the energy supplied into the ejector must be expressed as a two independent parts: one representing the energy of inner turbulence of the liquid jet leaving the nozzle and the one representing the kinetic energy of axial liquid flow entering the Suction chamber. Turbulent transverse motion generated in the nozzle characterized by its pressure loss coefficient ς, produces a surface roughness of the jet and plays a dominant role in its ability to entrain the surrounding Gas. The kinetic energy of the axial liquid flow characterized by liquid velocity in the nozzle vn, diminished for the energy spent on Gas compression is utilized in the mixing shock for dispersing of the entrained Gas into the liquid. The correlations formed for a prediction of mG/mL and of kLa in ejector based on the more of 700 individual ejector configurations have average deviation lower than 8%. Mass transfer and Gas hold-up in the holding vessel were modeled using the previously verified slip velocity concept, characterizing the mutual flow of phases in homogeneous bubble beds. An example of the application of the correlations for evaluation of mass transfer performance of Ejector Loop Reactor is shown.
M Fialova - One of the best experts on this subject based on the ideXlab platform.
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effect of the ejector configuration on the Gas Suction rate and Gas hold up in ejector loop reactors
Chemical Engineering Science, 1997Co-Authors: P Havelka, V Linek, J Sinkule, J Zahradnik, M FialovaAbstract:Abstract An experimental study has been aimed at examining the effect of ejector configuration on the rate and energy effectiveness of Gas Suction and on the values of Gas hold-up in ejector loop reactors. Experimental data showed that insertion of a swirl body into the ejector nozzle increased the Suction rate and dispersion efficiency of the ejector distributor and significantly improved its operating flexibility. In the absence of swirl elements, the Gas Suction rate increased slightly with the mixing tube length up to the length-to-diameter ratio equal to six. In the presence of swirls, however, the mixing tube length exhibited negative effect on the ejector performance and the highest values of Gas Suction rate and dispersion efficiency were observed for the configurations without the mixing tube. The ejector Suction efficiency increased sharply with increasing swirl number Swb (related to the swirl body parameters) in the region of its values 0.06–0.12 while the increase of Swb above 0.2 resulted in a decrease of the Gas Suction rate. For Swb = 0.12–0.20, the Gas Suction rate was significantly higher than that achieved in the absence of swirls even at the optimum mixing bube length. Comparison of the energy effectiveness of Gas Suction indicated superiority of the single-orifice nozzles with swirl inserts over the other tested variants. Good agreement of Gas holdup data from all experimental runs with values calculated from the relation u s = u oG ge G − u oL (1−ϵ G ) , for the slip velocity value us = 0.224 m s−1, proved adequacy of the slip velocity concept for description of Gas-liquid flow in ejector loop reactors.
M Opletal - One of the best experts on this subject based on the ideXlab platform.
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Gas Suction and mass transfer in Gas liquid up flow ejector loop reactors effect of nozzle and ejector geometry
Chemical Engineering Journal, 2018Co-Authors: M Opletal, V Linek, P Novotný, T Moucha, M KordacAbstract:Abstract The aim is to develop a method for the design of up-flow ejector loop reactors for coalescent systems respecting the different energy dissipation and mechanism of interfacial mass transfer in the ejector and in the holding vessel. Measurements and correlations of Gas entrainment rate (mG/mL) and of oxygen volumetric mass transfer coefficient (kLa) are reported describing their dependencies on operating conditions for various geometries of the ejector. The results show that the energy supplied into the ejector must be expressed as a two independent parts: one representing the energy of inner turbulence of the liquid jet leaving the nozzle and the one representing the kinetic energy of axial liquid flow entering the Suction chamber. Turbulent transverse motion generated in the nozzle characterized by its pressure loss coefficient ς, produces a surface roughness of the jet and plays a dominant role in its ability to entrain the surrounding Gas. The kinetic energy of the axial liquid flow characterized by liquid velocity in the nozzle vn, diminished for the energy spent on Gas compression is utilized in the mixing shock for dispersing of the entrained Gas into the liquid. The correlations formed for a prediction of mG/mL and of kLa in ejector based on the more of 700 individual ejector configurations have average deviation lower than 8%. Mass transfer and Gas hold-up in the holding vessel were modeled using the previously verified slip velocity concept, characterizing the mutual flow of phases in homogeneous bubble beds. An example of the application of the correlations for evaluation of mass transfer performance of Ejector Loop Reactor is shown.
P Havelka - One of the best experts on this subject based on the ideXlab platform.
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effect of the ejector configuration on the Gas Suction rate and Gas hold up in ejector loop reactors
Chemical Engineering Science, 1997Co-Authors: P Havelka, V Linek, J Sinkule, J Zahradnik, M FialovaAbstract:Abstract An experimental study has been aimed at examining the effect of ejector configuration on the rate and energy effectiveness of Gas Suction and on the values of Gas hold-up in ejector loop reactors. Experimental data showed that insertion of a swirl body into the ejector nozzle increased the Suction rate and dispersion efficiency of the ejector distributor and significantly improved its operating flexibility. In the absence of swirl elements, the Gas Suction rate increased slightly with the mixing tube length up to the length-to-diameter ratio equal to six. In the presence of swirls, however, the mixing tube length exhibited negative effect on the ejector performance and the highest values of Gas Suction rate and dispersion efficiency were observed for the configurations without the mixing tube. The ejector Suction efficiency increased sharply with increasing swirl number Swb (related to the swirl body parameters) in the region of its values 0.06–0.12 while the increase of Swb above 0.2 resulted in a decrease of the Gas Suction rate. For Swb = 0.12–0.20, the Gas Suction rate was significantly higher than that achieved in the absence of swirls even at the optimum mixing bube length. Comparison of the energy effectiveness of Gas Suction indicated superiority of the single-orifice nozzles with swirl inserts over the other tested variants. Good agreement of Gas holdup data from all experimental runs with values calculated from the relation u s = u oG ge G − u oL (1−ϵ G ) , for the slip velocity value us = 0.224 m s−1, proved adequacy of the slip velocity concept for description of Gas-liquid flow in ejector loop reactors.
