Influence of added packing on the volumetric efficiency in a Karr column
TL;DR: In this article, a reciprocating plate column with high porosity packing in interplate spaces of the column was compared with the column without packing, showing substantial increase in the dispersed phase holdup and in the interfacial area to give an enhancement of 4 to 5 times in the volumetric efficiency.
Abstract: Dispersed phase holdup and volumetric mass transfer coefficient were measured in a reciprocating plate column with high porosity packing in interplate spaces of the column and the performance was compared with that of the column without packing The data and its analysis show substantial increase in the dispersed phase holdup and in the interfacial area to give an enhancement of 4 to 5 times in the volumetric efficiency of the column with the added packing
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TL;DR: In this article, drop size distributions, mean drop diameter and slip velocity are experimentally studied in a reciprocating plate column and correlations for the above are presented in terms of plate geometry, flow rates of phases and physical properties of the system covering a wide range in experimental conditions.
Abstract: Drop size distributions, mean drop diameter and slip velocity are experimentally studied in a reciprocating plate column The correlations for the above are presented in terms of plate geometry, flow rates of phases and physical properties of the system covering a wide range in experimental conditions
8 citations
Cites methods from "Influence of added packing on the v..."
...Experiments were conducted in a reciprocating plate column [ 5 ] with kerosene (dispersed phase) fed at the bottom and water (continuous phase) fed at the top of the column....
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TL;DR: In this paper, continuous biodiesel production from a waste pig-roasting lard, methanol and KOH was carried out in a reciprocating plate reactor (RPR) using a factorial design containing three process factors.
8 citations
TL;DR: In this article, a comprehensive study of the influence of plate geometry and the added packing on the holdup and slip velocity in reciprocating plate columns is presented, and the use of packing in the interplate spaces of the column is of interest as packing alters the character of dispersion and also provides contact area for the phases.
Abstract: A comprehensive study of the influence of plate geometry and the added packing on the holdup and slip velocity in reciprocating plate columns is presented. The use of packing in the interplate spaces of the column is of interest as packing alters the character of dispersion and also provides contact area for the phases.
1 citations
Cites background or methods from "Influence of added packing on the v..."
...The column was sectioned into number of stages using horizontal perforated plates or wire mesh plates, mounted on a central rod which was given the reciprocating motion using slider crank mechanism ( 10 )....
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...However, an estimation of the latter shows that the power dissipation due to the flow of phases through high porosity packing such as Rasching rings or pall rings is very small compared to that required for pulsing the contents of the column ( 10 )....
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References
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Journal Article•
01 Jun 1978TL;DR: In this paper, the authors evaluated the applicability of the standard κ-ϵ equations and other turbulence models with respect to their applicability in swirling, recirculating flows.
Abstract: The standard κ-ϵ equations and other turbulence models are evaluated with respect to their applicability in swirling, recirculating flows. The turbulence models are formulated on the basis of two separate viewpoints. The first perspective assumes that an isotropic eddy viscosity and the modified Boussinesq hypothesis adequately describe the stress distributions, and that the source of predictive error is a consequence of the modeled terms in the κ-ϵ equations. Both stabilizing and destabilizing Richardson number corrections are incorporated to investigate this line of reasoning. A second viewpoint proposes that the eddy viscosity approach is inherently inadequate and that a redistribution of the stress magnitudes is necessary. Investigation of higher-order closure is pursued on the level of an algebraic stress closure. Various turbulence model predictions are compared with experimental data from a variety of isothermal, confined studies. Supportive swirl comparisons are also performed for a laminar flow case, as well as reacting flow cases. Parallel predictions or contributions from other sources are also consulted where appropriate. Predictive accuracy was found to be a partial function of inlet boundary conditions and numerical diffusion. Despite prediction sensitivity to inlet conditions and numerics, the data comparisons delineate the relative advantages and disadvantages of the various modifications. Possible research avenues in the area of computational modeling of strongly swirling, recirculating flows are reviewed and discussed.
5,396 citations
TL;DR: An open type of reciprocating-plate extraction column was developed, and it was proposed that the scaling up of such a column should be straightforward; that is, the height of an equivalent theoretical stage (H.E.S.) and the throughput per unit area should be independent of the diameter of the column.
Abstract: An open type of reciprocating-plate extraction column was developed, and it is proposed that the scaling up of such a column should be straightforward; that is, the height of an equivalent theoretical stage (H.E.T.S.) and the throughput per unit area should be independent of the diameter of the column.
Plates having 5/8-in.–diameter holes and 62.8% free space were selected to minimize the resistance to countercurrent flow in the column. With this design low H.E.T.S. values were achieved at throughputs much higher than those reported for other columns. Thus for two systems the present column was shown to require the lowest volume of column to accomplish a given extraction job. Data were obtained in a 3-in.–diameter column on two systems, methyl isobutyl ketone-acetic acid-water and o-xylene-acetic acid-water. Throughputs studied on the first system ranged from 547 to 1,837 gal./hr./sq. ft., and the corresponding minimum H.E.T.S. values achieved were 4.3 and 7.5 in. respectively. For the second system minimum H.E.T.S. values of 7.7 and 9.1 in. were attained at throughputs of 424 and 804 gal./hr./sq. ft. respectively.
Extraction column design procedures are discussed. The fabrication of the reciprocating-plate column is relatively simple, and this should encourage its use first in pilot-scale sizes and ultimately in large-scale columns.
105 citations
"Influence of added packing on the v..." refers background in this paper
...Reciprocating plate columns find wide application in liquid-liquid extraction ( 2 ), in extraction of fermentation broths (3), for the production of exocellular poly-saccharide by yeast Aureobasidium poly-saccharide (4), for growth of fungi and bacteria (5) and for biological waste water treatment (6)....
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...The rapid increase in Koa with U d in ( 2 ) 3-phase operation compared to 2-phase operation is due to the preferential breaking of drops as they pass through the packing....
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TL;DR: The reciprocating-jet-bioreactor showed excellent properties as fermenter, especially when the biosuspension is highly viscous and non-Newtonian by nature.
Abstract: In a comprehensive study the properties of the reciprocating-jet-bioreactor have been investigated. Fermentations have been carried out with two fungi and one bacterium. The fungi were Cyathus striatus for the production of antibiotics and Aspergillus niger for the production of citric acid. The bacterium Zymomonas mobilis was used in an anaerobic fermentation for the production of ethanol. The reciprocating-jet-bioreactor showed excellent properties as fermenter, especially when the biosuspension is highly viscous and non-Newtonian by nature.
32 citations
"Influence of added packing on the v..." refers background in this paper
...Figure 7 compares experimental Koa24 ~ and Koa34 ~ with the predictions using equations ( 5 ) to (8)....
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...Reciprocating plate columns find wide application in liquid-liquid extraction (2), in extraction of fermentation broths (3), for the production of exocellular poly-saccharide by yeast Aureobasidium poly-saccharide (4), for growth of fungi and bacteria ( 5 ) and for biological waste water treatment (6)....
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TL;DR: The performance of reciprocating plate bioreactors for the production of an exocellular polysaccharide (pullulan) by yeast Aureobasidium pullulans is analyzed and results clearly show that a more efficient substrate utilisation is achieved with reciprocating plates.
Abstract: The environment in which live microorganisms has a major impact on their productivity. One important factor is the mechanical mixing that is used to promote good heat and mass transfer in bioreactors. In this paper, the performance of reciprocating plate bioreactors is first evaluated for their ability to produce high oxygen transfer coefficients. Pure water and a glycerol water (50∶50 wt%) solution are used for this evaluation. Then, the performance of reciprocating plate bioreactors for the production of an exocellular polysaccharide (pullulan) by yeast Aureobasidium pullulans is analyzed in terms of quantity and quality of the polysaccharide. Results clearly show that a more efficient substrate utilisation is achieved with reciprocating plate bioreactors.
22 citations