scholarly journals Experimental Analysis of Gas–Liquid–Solid Three-Phase Flows in Horizontal Pipelines

2020 ◽  
Vol 105 (4) ◽  
pp. 1035-1054
Author(s):  
Paolo Sassi ◽  
Youssef Stiriba ◽  
Julia Lobera ◽  
Virginia Palero ◽  
Jordi Pallarès
Keyword(s):  
Flow Visualization ◽  
Flow Regime ◽  
Solid Particles ◽  
High Complexity ◽  
Flow Conditions ◽  
Two Phase Flows ◽  
Two Phase ◽  
Three Phase ◽  
Inner Diameter ◽  
The Individual

AbstractThe dynamics of three-phase flows involves phenomena of high complexity whose characterization is of great interest for different sectors of the worldwide industry. In order to move forward in the fundamental knowledge of the behavior of three-phase flows, new experimental data has been obtained in a facility specially designed for flow visualization and for measuring key parameters. These are (1) the flow regime, (2) the superficial velocities or rates of the individual phases; and (3) the frictional pressure loss. Flow visualization and pressure measurements are performed for two and three-phase flows in horizontal 30 mm inner diameter and 4.5 m long transparent acrylic pipes. A total of 134 flow conditions are analyzed and presented, including plug and slug flows in air–water two-phase flows and air–water-polypropylene (pellets) three-phase flows. For two-phase flows the transition from plug to slug flow agrees with the flow regime maps available in the literature. However, for three phase flows, a progressive displacement towards higher gas superficial velocities is found as the solid concentration is increased. The performance of a modified Lockhart–Martinelli correlation is tested for predicting frictional pressure gradient of three-phase flows with solid particles less dense than the liquid.

Two-Phase Flow Regimes in Exchangers and Piping: Part 1

2015 ◽  
Author(s):  
Siddharth Talapatra ◽  
Kevin Farrell
Keyword(s):  
Flow Visualization ◽  
Flow Regime ◽  
Void Fraction ◽  
Heat Exchangers ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase Flows ◽  
Two Phase ◽  
Gas Phases ◽  
Shell And Tube

The ability to predict the liquid-gas two-phase flow regime and void fraction in exchangers and piping is a critical engineering requirement in the process industry. The distribution of the liquid and gas phases depend on many factors including flow conditions, physical properties of the two fluids, and geometry of the flow conduit. The problem of correctly predicting the two-phase distribution is of enormous complexity, and generalized correlations that adequately describe the flow regime and/or the void fraction have not been yet been developed even for the simplest of geometries. While Computational Fluid Dynamics codes that model two-phase flows exist, they are limited in their applicability and usually require a priori knowledge of the flow regime. In this part of a two paper series, we discuss the state-of-the-art in two-phase flow regime studies inside shell-and-tube heat exchangers, while in the second part, we will discuss two-phase flows inside piping. We have performed air-water tests inside a glass shell-and-tube exchanger at HTRI, and by systematically varying various geometrical parameters, compiled the largest flow visualization database inside such exchangers. We have evaluated the best available flow regime maps available in the open literature, and shown how our results help enhance understanding of liquid-gas distribution inside heat exchangers. We have shown how, for a given flow rate, increasing the baffle spacing and reducing baffle-cut enhances two-phase separation. While these results are expected, they have never been quantified before. However, the use of flow visualization limits the liquid and gas phases to water and air mixtures, which limits the range of applicability. Shellside studies using various industrially relevant fluids such as hydrocarbon mixtures, steam water are planned, where non-visual flow regime detection techniques need to be applied.

Eulerian Three-Phase Flow Model Applied to Trickle-Bed Reactors

2014 ◽  
Vol 35 (1) ◽  
pp. 75-96 ◽  
Author(s):  
Andrzej Burghardt
Keyword(s):  
Fixed Bed ◽  
Solid Particles ◽  
Weighted Averaging ◽  
Phase Flow ◽  
Two Phase ◽  
Conservation Equations ◽  
Three Phase ◽  
Three Phase Flow ◽  
Reynolds Decomposition ◽  
Trickle Bed

Abstract The majority of publications and monographs present investigations which concern exclusively twophase flows and particulary dispersed flows. However, in the chemical and petrochemical industries as well as in refineries or bioengineering, besides the apparatuses of two-phase flows there is an extremely broad region of three-phase systems, where the third phase constitutes the catalyst in form of solid particles (Duduković et al., 2002; Martinez et al., 1999) in either fixed bed or slurry reactors. Therefore, the goal of this study is to develop macroscopic, averaged balances of mass, momentum and energy for systems with three-phase flow. Local instantaneous conservation equations are derived, which constitute the basis of the method applied, and are averaged by means of Euler’s volumetric averaging procedure. In order to obtain the final balance equations which define the averaged variables of the system, the weighted averaging connected with Reynolds decomposition is used. The derived conservation equations of the trickle-bed reactor (mass, momentum and energy balance) and especially the interphase effects appearing in these equations are discussed in detail.

A HIERARCHICAL MODEL FOR MULTI-PHASE FRACTAL MEDIA

Fractals ◽  
2010 ◽  
Vol 18 (01) ◽  
pp. 53-64 ◽  
Author(s):  
MAOFEI MEI ◽  
BOMING YU ◽  
JIANCHAO CAI ◽  
LIANG LUO
Keyword(s):  
Distribution Function ◽  
Pore Space ◽  
Fractal Dimensions ◽  
Solid Particles ◽  
Two Phase ◽  
Fractal Media ◽  
Proposed Model ◽  
Three Phase ◽  
Multi Phase ◽  
Good Agreement

The size distributions of solid particles and pores in porous media are approximately hierarchical and statistically fractals. In this paper, a model for single-phase fractal media is constructed, and the analytical expressions for area, fractal dimension and distribution function for solid particles are derived. The distribution function of solid particles obtained from the proposed model is in good agreement with available experimental data. Then, a model for approximate two-phase fractal media is developed. Good agreement is found between the predicted fractal dimensions for pore space from the two-phase fractal medium model and the existing measured data. A model for approximate three-phase fractal media is also presented by extending the obtained two-phase model.

Vibration and acoustic signal characteristics of solid particles carried in sand-water two-phase flows

2019 ◽  
Vol 345 ◽  
pp. 159-168 ◽  
Author(s):  
Kai Wang ◽  
Gang Liu ◽  
Yichen Li ◽  
Min Qin ◽  
Jinbang Wang ◽  
...  
Keyword(s):  
Acoustic Signal ◽  
Solid Particles ◽  
Two Phase Flows ◽  
Two Phase ◽  
Signal Characteristics

Determinant factors of olive oil stability, phenolic content and antioxidant capacity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jessica Maalouf ◽  
Jennifer C. Tomazou ◽  
Stephanie Azar ◽  
Christelle Bou-Mitri ◽  
Jacqueline Doumit ◽  
...  
Keyword(s):  
Prediction Model ◽  
Antioxidant Capacity ◽  
Olive Oil ◽  
Phenolic Content ◽  
Stability Index ◽  
Total Phenolic ◽  
Two Phase ◽  
Content Type ◽  
Three Phase ◽  
The Individual

Purpose This study aims to identify the effect of selected agro-industrial factors associated with the olive oil phenolic composition, total phenolic content (TPC), antioxidant capacity and oxidative stability index (OSI). The study also aims to assess the relationship between the quality indices and each of the individual phenol, TPC, antioxidant capacity and OSI. Design/methodology/approach Olive oil samples (n=108) were collected from Lebanese northern (Akkar and Zgharta-Koura) and southern (Hasbaya and Jezzine) regions, at three harvesting times (early, intermediate, late) and using different types of mills (traditional, sinolea, two- and three-phase decanters). The samples were analyzed using official standard methods. Findings The highest TPC, antioxidant capacity and OSI were obtained in early harvested olive oil, using two-phase decanters for TPC and three-phase decanters for antioxidant capacity and OSI. A prediction model, including the free acidity, K232, TPC, C18:2, C18:0, tyrosol and apigenin, was obtained; it allowed to predict very highly significantly the OSI (p < 0.001). Apigenin, tyrosol and C18:2 recorded the highest standardized coefficients (ß^+= 0.35) and thus had the highest influence on OSI. As per antioxidant capacity of olive oil, another very highly statistically significant prediction model was constructed (p < 0.001). It included only two predictors, oleacein and TPC, with the latter having the most influence (ß^+= 0.37). Originality/value The overall results highlighted the detrimental effects of agro-industrial factors on olive oil chemical composition, and this contributes significantly to improve olive oil’s quality and characteristics, which are important for the product economical and nutritional values.

scholarly journals A Review of Design Considerations of Centrifugal Pump Capability for Handling Inlet Gas-Liquid Two-Phase Flows

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1078 ◽  
Author(s):  
Qifeng Jiang ◽  
Yaguang Heng ◽  
Xiaobing Liu ◽  
Weibin Zhang ◽  
Gérard Bois ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Experimental Studies ◽  
Petroleum Industry ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Atmospheric Conditions ◽  
Centrifugal Pumps ◽  
Flow Conditions ◽  
Two Phase Flows ◽  
Two Phase

Most of the pumps working under two phase flows conditions are used in petroleum industry applications, like electrical submersible pumps (ESP) for hydrocarbon fluids, in chemistry, nuclear industries and in agriculture for irrigation purposes as well. Two-phase flows always deteriorate overall pump performances compared with single flow conditions. Several papers have been published aiming to understand flow physics and to model all the main mechanisms that govern gas pocket formation and surging phenomena. These mechanisms depend on the pump type, the impeller geometry, the rotational speed, design and off-design liquid flow rate conditions, the volumetric gas fraction, the fluid properties and the inlet pressure. In the present paper, a review on two phase performances from various centrifugal pumps designs is presented, mainly based on experimental results. The main focus is devoted to detect the significant geometrical parameters that: (1) Modify the pump head degradation level under bubbly flow regime assumption; (2) Allow single stage centrifugal pumps keep working under two-phase flow conditions with high inlet void fraction values before pump shut down, whatever the pump performance degradations and liquid production rates should be. Because most of the published experimental studies are performed on dedicated laboratory centrifugal pump models, most of the present review is based on air-water mixtures as the working fluid with inlet pressures close to atmospheric conditions. The following review supposes that gas phase is considered as a non-condensable perfect gas, while the liquid phase is incompressible. Both phases are isolated from external conditions: neither mass nor heat transfer take place between the phases.

scholarly journals Prospects for the application of radiometric methods in the measurement of two-phase flows

2018 ◽  
Vol 180 ◽  
pp. 01001
Author(s):  
Marcin Zych
Keyword(s):  
Environmental Protection ◽  
Solid Phase ◽  
Life Sciences ◽  
Solid Particles ◽  
Gas Mixture ◽  
Gas Flows ◽  
Mathematical Methods ◽  
Two Phase Flows ◽  
Two Phase ◽  
Phase Mixture

The article constitutes an overview of the application of radiometric methods in the research of two-phase flows: liquid-solid particles and liquid-gas flows. The methods which were used were described on the basis of the experiments which were conducted in the Water Laboratory of the Wrocław University of Environmental and Life Sciences and in the Sedimentological Laboratory of the Faculty of Geology, Geophysics and Environmental Protection, AGH-UST in Kraków. The advanced mathematical methods for the analysis of signals from scintillation probes that were applied enable the acquisition of a number of parameters associated with the flowing two-phase mixture, such as: average velocities of the particular phases, concentration of the solid phase, and void fraction for a liquid-gas mixture. Despite the fact that the application of radioactive sources requires considerable carefulness and a number of state permits, in many cases these sources become useful in the experiments which are presented.

scholarly journals Precise Void Fraction Measurement in Two-phase Flows Independent of the Flow Regime Using Gamma-ray Attenuation

2016 ◽  
Vol 48 (1) ◽  
pp. 64-71 ◽  
Author(s):  
E. Nazemi ◽  
S.A.H. Feghhi ◽  
G.H. Roshani ◽  
R. Gholipour Peyvandi ◽  
S. Setayeshi
Keyword(s):  
Flow Regime ◽  
Void Fraction ◽  
Gamma Ray ◽  
Two Phase Flows ◽  
Two Phase ◽  
Gamma Ray Attenuation ◽  
Fraction Measurement
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