An experimental study of gas phase back mixing under the counter-current gas-liquid flow on a vertical expanded metal sheet packing by static tracer technique

1980 ◽  
Vol 45 (1) ◽  
pp. 214-221
Author(s):  
Jan Červenka ◽  
Mirko Endršt ◽  
Václav Kolář
Keyword(s):  
Gas Phase ◽  
Flow Model ◽  
Plug Flow ◽  
Packed Bed ◽  
Metal Sheet ◽  
Concentration Profiles ◽  
Expanded Metal ◽  
Gas Liquid Flow ◽  
Counter Current ◽  
Back Mixing

Gas phase back mixing has been measured in a column packed with vertical expanded metal sheet under the counter-current flow of gas and liquid by the static method using a tracer. The observed experimental concentration profiles has not confirmed our earlier proposed model of back mixing, based on the concentration profiles in absorption runs. These profiles do not even conform with the axially dispersed plug flow model currently used to describe axial mixing in packed bed columns. The concentration profiles may be described by a combination of the axially dispersed plug flow model with back flow.

Theoretical analysis of counter-current absorption of a poorly soluble gas based on the PDE-AD model

1986 ◽  
Vol 51 (6) ◽  
pp. 1222-1239 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk
Keyword(s):  
Experimental Data ◽  
Liquid Phase ◽  
Gas Phase ◽  
Transfer Functions ◽  
Packed Bed ◽  
Packed Bed Column ◽  
Interfacial Transport ◽  
Gaseous Component ◽  
Poorly Soluble ◽  
Counter Current

Expression have been derived in the paper for all four possible transfer functions between the inlet and the outlet gas and liquid steams under the counter-current absorption of a poorly soluble gas in a packed bed column. The transfer functions have been derived for the axially dispersed model with stagnant zone in the liquid phase and the axially dispersed model for the gas phase with interfacial transport of a gaseous component (PDE - AD). calculations with practical values of parameters suggest that only two of these transfer functions are applicable for experimental data evaluation.

scholarly journals Modeling Residence Time Distribution (RTD) Behavior in a Packed-Bed Electrochemical Reactor (PBER)

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Sananth H. Menon ◽  
G. Madhu ◽  
Jojo Mathew
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Model ◽  
Plug Flow ◽  
Flow Characteristics ◽  
Theoretical Models ◽  
Packed Bed ◽  
Electrochemical Reactor ◽  
Tracer Studies

This paper focuses on understanding the electrolyte flow characteristics in a typical packed-bed electrochemical reactor using Residence Time Distribution (RTD) studies. RTD behavior was critically analyzed using tracer studies at various flow rates, initially under nonelectrolyzing conditions. Validation of these results using available theoretical models was carried out. Significant disparity in RTD curves under electrolyzing conditions was examined and details are recorded. Finally, a suitable mathematical model (Modified Dispersed Plug Flow Model (MDPFM)) was developed for validating these results under electrolyzing conditions.

A one-dimensional plug-flow model of a counter-current spray drying tower

2014 ◽  
Vol 92 (5) ◽  
pp. 826-841 ◽  
Author(s):  
Muzammil Ali ◽  
Tariq Mahmud ◽  
Peter John Heggs ◽  
Mojtaba Ghadiri ◽  
Dusan Djurdjevic ◽  
...  
Keyword(s):  
Spray Drying ◽  
Flow Model ◽  
Plug Flow ◽  
One Dimensional ◽  
Counter Current

scholarly journals An in situ spatially resolved analytical technique to simultaneously probe gas phase reactions and temperature within the packed bed of a plug flow reactor

The Analyst ◽  
2013 ◽  
Vol 138 (10) ◽  
pp. 2858 ◽  
Author(s):  
Jamal Touitou ◽  
Robbie Burch ◽  
Christopher Hardacre ◽  
Colin McManus ◽  
Kevin Morgan ◽  
...  
Keyword(s):  
Gas Phase ◽  
Flow Reactor ◽  
Plug Flow ◽  
Packed Bed ◽  
Plug Flow Reactor ◽  
Gas Phase Reactions ◽  
Analytical Technique ◽  
Spatially Resolved

COMBUSTION BEHAVIOR OF LUMPY COKE IN PACKED BED IN A COUNTER CURRENT AIR FLOW

2018 ◽  
Author(s):  
Bassem Hallak ◽  
N. Linn ◽  
Eckehard Specht ◽  
Fabian Herz
Keyword(s):  
Air Flow ◽  
Packed Bed ◽  
Combustion Behavior ◽  
Counter Current

Frequency-Response Approach to Modelling Continuous Reactors

1971 ◽  
Vol 6 (1) ◽  
pp. 249-272
Author(s):  
P.B. Melynk ◽  
J.D. Norman ◽  
A.W. Wilson
Keyword(s):  
Frequency Response ◽  
Flow Model ◽  
Plug Flow ◽  
Order Reaction ◽  
Parameter Estimates ◽  
Second Order Reaction ◽  
Mixing Conditions ◽  
Bode Plot ◽  
Flow Through ◽  
Search Routine

Abstract It is postulated that the mixing conditions in a flow-through reactor can be characterized as having either completely mixed, completely plug flow, or some network of completely mixed and plug flow component vessels. A frequency-response technique is used to obtain an experimental Bodé plot for arbitrarily mixed vessels. The interpretation of the Bodé plot is discussed, and , in light of this interpretation, a network of plug flow and completely mixed components is specified as a flow model. A Rosenbrock search routine is used to improve the parameter estimates of the model. To verify the model, a second order reaction was run through the vessel and the experimentally measured conversion was compared to that predicted by the model. It is shown that the modeling technique, in addition to describing the mixing in the system, will indicate inactive volume, as well as measure the extent of any channeling or short circuiting in the reactor.

Numerical modeling of the influence of bubbles on flow and heat transfer in the descending gas-liquid flow in a pipe

2012 ◽  
Vol 9 (1) ◽  
pp. 131-135
Author(s):  
M.A. Pakhomov
Keyword(s):  
Heat Transfer ◽  
Gas Phase ◽  
Liquid Flow ◽  
Bubble Diameter ◽  
Gas Content ◽  
Two Phase ◽  
Eulerian Description ◽  
Flow And Heat Transfer ◽  
Gas Liquid Flow ◽  
The Mathematical Model

The paper presents the results of modeling the dynamics of flow, friction and heat transfer in a descending gas-liquid flow in the pipe. The mathematical model is based on the use of the Eulerian description for both phases. The effect of a change in the degree of dispersion of the gas phase at the input, flow rate, initial liquid temperature and its friction and heat transfer rate in a two-phase flow. Addition of the gas phase causes an increase in heat transfer and friction on the wall, and these effects become more noticeable with increasing gas content and bubble diameter.

Analysis of observability of model parameters for physical absorption of poorly soluble gases in packed beds

1982 ◽  
Vol 47 (10) ◽  
pp. 2639-2653 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk
Keyword(s):  
Transfer Functions ◽  
Plug Flow ◽  
Packed Bed ◽  
Model Parameters ◽  
Packed Bed Column ◽  
Interfacial Transport ◽  
Complex Arithmetic ◽  
Physical Absorption ◽  
Poorly Soluble ◽  
Phase Lags

Expressions have been derived for four possible transfer functions of a model of physical absorption of a poorly soluble gas in a packed bed column. The model has been based on axially dispersed flow of gas, plug flow of liquid through stagnant and dynamic regions and interfacial transport of the absorbed component. The obtained transfer functions have been transformed into the frequency domain and their amplitude ratios and phase lags have been evaluated using the complex arithmetic feature of the EC-1033 computer. Two of the derived transfer functions have been found directly applicable for processing of experimental data. Of the remaining two one is useable with the limitations to absorption on a shallow layer of packing, the other is entirely worthless for the case of poorly soluble gases.

An experimental dynamic method of investigation of counter-current absorption of oxygen in water in a packed bed column

1987 ◽  
Vol 52 (7) ◽  
pp. 1715-1729 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk
Keyword(s):  
Transfer Functions ◽  
Simultaneous Detection ◽  
Harmonic Component ◽  
Packed Bed ◽  
Packed Bed Column ◽  
Oxygen Electrodes ◽  
Simultaneous Evaluation ◽  
Physical Absorption ◽  
On Line ◽  
Counter Current

An experimental method and technique are described in the paper of simultaneous detection of the transfer functions outlet-gas-stream-to-inlet-gas-stream and outlet-liquid-stream-to-inlet-gas-stream for the absorption of oxygen into water in a counter-current packed bed column. Both transfer functions were simultaneously monitored by means of three oxygen electrodes operating on the polarographic principle. The signals of these electrodes were processed in three steps to yield parameters of the model of physical absorption of gas. The first step was on-line evaluation of the Fourier coefficients of the principal harmonic component in all three monitored streams. The second step was the calculation of the frequency characteristics of both transfer functions while the third step yielded parameters of the model by optimization in the frequency domain. The method permits simultaneous evaluation of the parameters of the flow of both phases in the column and the interfacial transfer of oxygen.

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