scholarly journals Dispersed phase hold-up and characteristic velocity in a pulsed packed extraction column

2012 ◽  
Vol 18 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Mehdi Asadollahzadeh ◽  
Jaber Safdari ◽  
Ali Haghighi-Asl ◽  
Meisam Torab-Mostaedi
Keyword(s):  
Physical Properties ◽  
Packed Column ◽  
Operating Conditions ◽  
Empirical Correlation ◽  
Extraction Column ◽  
Dispersed Phase ◽  
Characteristic Velocity ◽  
Operating Variables ◽  
Liquid Systems ◽  
Good Agreement

Dispersed phase hold-up has been measured in a 76.2 mm diameter pulsed packed column for four different liquid-liquid systems. The effects of pulsation intensity, phase ratio, and packing characteristic on the hold-up have been investigated under a variety of operating conditions. The dispersed phase axial hold-up shows a strong non-uniformity, depending on the operating conditions. The results indicated that the characteristic velocity approach is applicable to this type of extraction column for analysis of hold-up. An empirical correlation is derived for prediction of the hold-up in terms of operating variables, physical properties of the systems, and packing geometry. Good agreement between prediction and experiments was observed for all investigated operating conditions.

scholarly journals Slip velosity in pulsed disc and doughnut extraction columns

2011 ◽  
Vol 17 (3) ◽  
pp. 333-339 ◽  
Author(s):  
Meisam Torab-Mostaedi ◽  
Hossein Jalilvand ◽  
Mohammad Outokesh
Keyword(s):  
Slip Velocity ◽  
Energy Input ◽  
Continuous Phase ◽  
Operating Conditions ◽  
Extraction Column ◽  
Empirical Correlations ◽  
Flow Rates ◽  
Operating Variables ◽  
Liquid Systems ◽  
Good Agreement

In the present work, slip velocity has been measured in a 76 mm diameter pulsed disc and doughnut extraction column for four different liquid-liquid systems. The effects of operating variables including pulsation intensity and dispersed and continuous phase flow rates on slip velocity have been investigated. The existence of three different operational regimes, namely mixer-settler, transition, and emulsion regimes, was observed when the energy input was changed. Empirical correlations are derived for prediction of the slip velocity in terms of operating variables, physical properties of the liquid systems, and column geometry for different regimes. Good agreement between prediction and experiments was found for all operating conditions that were investigated.

scholarly journals A Newly Developed Empirical Predictive Model for the Dispersed Phase (DP) Holdup in Rotating Disc Contactors

2021 ◽  
Vol 5 (4) ◽  
pp. 79
Author(s):  
Ayham M. I. Al-Rahawi ◽  
Wallaa A. Noori ◽  
Amer A. Abdulrahman ◽  
Hasan Sh. Majdi ◽  
Issam K. Salih ◽  
...  
Keyword(s):  
Physical Properties ◽  
Flow Rate ◽  
Production Capacity ◽  
Hole Diameter ◽  
Operating Conditions ◽  
Percentage Error ◽  
Extraction Column ◽  
Dispersed Phase ◽  
Rotating Disc ◽  
Average Percentage

Newly novel developed correlations were derived to predict the dispersed phase (DP) holdup in a rotating disc contactor (RDC) extraction column. DP holdup is one of the significant parameters in the design of liquid–liquid contactors and for calculating their production capacity. Despite the availability of quite a large number of holdup prediction correlations for the RDC, most of these correlations are either general in nature or valid for a limited range of operating conditions. This study conducted an experimental and theoretical investigation of the RDC holdup under the influence of varying geometries, including variations in the dispersed phase distributor, speed of the disc, flow rate, and physical characteristics of the system. The analysis revealed that the holdup decreased with an increasing distributor hole diameter and increased with an increasing disc speed and total flow rate. The effect of the physical properties on the holdup was larger than the effect of the disc speed. Using the measurements of over 150 runs, two RDC column holdup predictive models were proposed and evaluated. The first correlation was derived in terms of the distributor hole diameter, operating parameters, system physical properties, and column geometry. The second correlation excluded the column geometry. These correlations, which consider the distributor hole inlet diameter in predicting the DP holdup for an RDC column, were presented for the first time in this study. The predictive capability of these correlations was evaluated via their standard deviation (SD) and mean average percentage error (MAPE). The respective SD and MAPE of the two correlations were 1.7 and 5.2% for the first correlation and 1.6 and 11.4% for the second.

scholarly journals Holdup and characteristic velocity in a pulsed packed extraction column

2020 ◽  
Vol 9 (8) ◽  
pp. e674982543
Author(s):  
Jarlon Conceição da Costa ◽  
Luiz Mário Nelson de Góis ◽  
Silvana Mattedi e Silva
Keyword(s):  
Flow Rate ◽  
Water System ◽  
Continuous Phase ◽  
Liquid System ◽  
Operating Conditions ◽  
Extraction Column ◽  
Dispersed Phase ◽  
Internal Diameter ◽  
Phase Flow ◽  
Characteristic Velocity

The present work aims to evaluate the hydrodynamics of a pulsed packed extractor, with an internal diameter of 0.026m and a length of 1.0m, using the liquid butanol-water system. Thus, the basic parameters obtained for the hydrodynamic study of the extraction column in question as dispersed phase, slip velocity, characteristic velocity and flooding point. The methodology used in the work consisted of determining the holdup fraction of the dispersed phase, obtained through tests of simultaneous interruptions in the column feedings. The effects of frequency pulsation, dispersed phase flow rate and continuous phase flow rate investigated in the analysis of these parameters. New empirical correlations derived from the predictions of the parameters studied obtained in terms of operating variables and physical properties of the liquid system involved. The average absolute value of the relative error (AARE) was always below 5.6%. Good agreement between calculated and experimental results observed for all investigated operating conditions.

scholarly journals Visualisation of flow pattern and measurement of liquid distribution in a random packed column using electrical resistance tomography (ERT)

2021 ◽  
Author(s):  
Nazar Aoda
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
Electrical Resistance ◽  
Packed Column ◽  
Operating Conditions ◽  
Flow Mode ◽  
Electrical Resistance Tomography ◽  
Liquid Distribution ◽  
Flow Rates ◽  
Good Agreement

The aim of this research is to use Electrical Resistance Tomography technique (ERT) to measure factors that affect local mass transfer at various axial locations in a random packed column with diameter 0.3m and bed height 150cm filled with 2 cm plastic spheres. These factors are: liquid maldistribution, velocity profiles, and flow pattern. The system was designed to run in a trickling down-flow mode and a full liquid up-flow mode. Experiments were performed at flow rates of 3, 6, and 9 gpm (or 0.27 x 10⁻², 0.54 x 10⁻² and 0.8 x 10⁻² m³/m² s) and under normal operating conditions of 25C° and atmospheric pressure. The liquid maldistribution factors were measured via ERT technique and the conventional liquid collection method. Both measurements were conducted at various fluid flow rates at different bed heights. The results of ERT were in very good agreement with the conventional method. The standard deviation values were 17% and 21% at flow rates 3 and 6 gpm respectively. The numerical values of velocity for full liquid up flow at 3 gpm were 0.83cm/s, 1.2cm/s, 1.2 cm/s and 1.11 cm/s for different heights of 30, 60 and 90 cm respectively and the numerical values of velocity for trickle down flow at 3 gpm were 16.5 cm/s, 22.5 cm/s and 24 cm/ for different heights of 30, 60 and 90 cm respectively. The values of the liquid maldistribution factor for flow rate 3 gpm were 0.43 (30cm), 0.33(60cm) and 0.30 (90cm) and for flow rate 6 gpm were 0.33(30cm), 0.27(60cm) and 0.22 (90cm). By comparison with findings of many studies conducted on liquid distribution in packed bed column, a good agreement was observed on the relation of Mf and flow rates and bed heights.

scholarly journals Visualisation of flow pattern and measurement of liquid distribution in a random packed column using electrical resistance tomography (ERT)

2021 ◽  
Author(s):  
Nazar Aoda
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
Electrical Resistance ◽  
Packed Column ◽  
Operating Conditions ◽  
Flow Mode ◽  
Electrical Resistance Tomography ◽  
Liquid Distribution ◽  
Flow Rates ◽  
Good Agreement

The aim of this research is to use Electrical Resistance Tomography technique (ERT) to measure factors that affect local mass transfer at various axial locations in a random packed column with diameter 0.3m and bed height 150cm filled with 2 cm plastic spheres. These factors are: liquid maldistribution, velocity profiles, and flow pattern. The system was designed to run in a trickling down-flow mode and a full liquid up-flow mode. Experiments were performed at flow rates of 3, 6, and 9 gpm (or 0.27 x 10⁻², 0.54 x 10⁻² and 0.8 x 10⁻² m³/m² s) and under normal operating conditions of 25C° and atmospheric pressure. The liquid maldistribution factors were measured via ERT technique and the conventional liquid collection method. Both measurements were conducted at various fluid flow rates at different bed heights. The results of ERT were in very good agreement with the conventional method. The standard deviation values were 17% and 21% at flow rates 3 and 6 gpm respectively. The numerical values of velocity for full liquid up flow at 3 gpm were 0.83cm/s, 1.2cm/s, 1.2 cm/s and 1.11 cm/s for different heights of 30, 60 and 90 cm respectively and the numerical values of velocity for trickle down flow at 3 gpm were 16.5 cm/s, 22.5 cm/s and 24 cm/ for different heights of 30, 60 and 90 cm respectively. The values of the liquid maldistribution factor for flow rate 3 gpm were 0.43 (30cm), 0.33(60cm) and 0.30 (90cm) and for flow rate 6 gpm were 0.33(30cm), 0.27(60cm) and 0.22 (90cm). By comparison with findings of many studies conducted on liquid distribution in packed bed column, a good agreement was observed on the relation of Mf and flow rates and bed heights.

Dispersed-Phase Holdup and Characteristic Velocity in a Pulsed and Nonpulsed Disk-and-Doughnut Solvent Extraction Column

2016 ◽  
Vol 55 (3) ◽  
pp. 714-721 ◽  
Author(s):  
Yong Wang ◽  
Kathryn A. Mumford ◽  
Kathryn H. Smith ◽  
Zheng Li ◽  
Geoffrey W. Stevens
Keyword(s):  
Solvent Extraction ◽  
Extraction Column ◽  
Dispersed Phase ◽  
Characteristic Velocity

scholarly journals Boiling in volume of low temperature droplets of dispersed phase of liquid emulsions

2017 ◽  
Vol 21 (6 Part B) ◽  
pp. 2981-2992 ◽  
Author(s):  
Alexander Rozentsvaig ◽  
Cheslav Strashinskii
Keyword(s):  
Low Temperature ◽  
Solid Wall ◽  
Experimental Studies ◽  
Nucleate Boiling ◽  
Similarity Criteria ◽  
Dispersed Phase ◽  
Homogeneous Fluid ◽  
Liquid Systems ◽  
Physical Phenomena ◽  
Good Agreement

Mechanisms of droplets boiling in dispersed liquid-liquid systems differ significantly from more commonly studied and better understood mechanisms of vaporization in homogeneous fluids. For the analysis of boiling of liquid emulsions with low-temperature dispersed phase the theory of Labuntsov has been used, which was developed for boiling of homogeneous fluid near a solid wall. Model representations of more complex physical phenomena were substantiated using the similarity criteria, corresponding to the character of the heat exchange mechanisms with the dispersed droplets in the analogous conditions. A modified calculated dependence has been obtained for liquid emulsions with the low boiling dispersed phase. The results of the calculations are compared with the data of visual observations and experimental studies from the literature. It turned out that depending on the concentration of dis-persed phase heat transfer in emulsions is characterized by two regimes with different nucleate boiling mechanisms. Good agreement was indicated with measured data of heat flux at boiling of emulsions of water-in-oil type.

UNITEMP HX

Alloy Digest ◽  
1964 ◽  
Vol 13 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Base Material ◽  
Heat Treating ◽  
Operating Conditions ◽  
High Temperature Strength ◽  
Temperature Performance ◽  
Nickel Base

Abstract Unitemp-HX is a nickel-base material recommended for high temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-91. Producer or source: Universal Cyclops Steel Corporation.

HASTELLOY ALLOY X

Alloy Digest ◽  
1954 ◽  
Vol 3 (12) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Heat Treating ◽  
Operating Conditions ◽  
Molybdenum Alloy ◽  
High Temperature Strength ◽  
Nickel Chromium

Abstract HASTELLOY Alloy X is a nickel-chromium-iron-molybdenum alloy recommended for high-temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on forming, heat treating, and machining. Filing Code: Ni-14. Producer or source: Haynes Stellite Company.

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