On the modeling of gas-phase mass-transfer in metal sheet structured packings

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

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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

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19800214 ◽

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.

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Effective Mass-Transfer Area in a Pilot Plant Column Equipped with Structured Packings and with Ceramic Rings

Industrial & Engineering Chemistry Research ◽

10.1021/ie00027a023 ◽

1994 ◽

Vol 33 (3) ◽

pp. 647-656 ◽

Cited By ~ 87

Author(s):

M. Henriques de Brito ◽

U. von Stockar ◽

A. Menendez Bangerter ◽

P. Bomio ◽

M. Laso

Keyword(s):

Mass Transfer ◽

Effective Mass ◽

Pilot Plant ◽

Structured Packings

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Performance of packed columns: V. Effect of solute concentration on gas-phase mass transfer rates

AIChE Journal ◽

10.1002/aic.690050308 ◽

1959 ◽

Vol 5 (3) ◽

pp. 290-294 ◽

Cited By ~ 9

Author(s):

H. L. Shulman ◽

L. J. Delaney

Keyword(s):

Mass Transfer ◽

Gas Phase ◽

Solute Concentration ◽

Packed Columns ◽

Transfer Rates

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Analysis of Heat and Mass Transfer Between a Desiccant-Air System in a Packed Tower

Journal of Solar Energy Engineering ◽

10.1115/1.3268198 ◽

1987 ◽

Vol 109 (2) ◽

pp. 89-93 ◽

Cited By ~ 59

Author(s):

P. Gandhidasan ◽

M. Rifat Ullah ◽

C. F. Kettleborough

Keyword(s):

Mass Transfer ◽

Gas Phase ◽

Heat And Mass Transfer ◽

Packing Material ◽

Mass Transfer Resistance ◽

Liquid Desiccant ◽

Governing Equations ◽

Packed Tower ◽

Transfer Resistance ◽

Steady State Model

Heat and mass transfer analysis between a desiccant-air contact system in a packed tower has been studied in application to air dehumidification employing liquid desiccant, namely calcium chloride. Ceramic 2 in. Raschig rings are used as the packing material. To predict the tower performance, a steady-state model which considers the heat and mass transfer resistances of the gas phase and the mass transfer resistance of the liquid phase is developed. The governing equations are solved on a digital computer to simulate the performance of the tower. The various parameters such as the effect of liquid concentration and temperature, air temperature and humidity and the rates of flow of air and liquid affecting the tower performance have been discussed.

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