Droplet Coalescence in Liquid/Liquid Separation

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Weiwei E. ◽  
Kevin Pope ◽  
Xili Duan
Keyword(s):  
Relative Error ◽  
Volume Fraction ◽  
Force Balance ◽  
Water Volume ◽  
Droplet Coalescence ◽  
Liquid Separation ◽  
Water Separation ◽  
Numerical Predictions ◽  
New Correlation ◽  
Oil Water

Abstract In this paper, a new correlation is developed to predict liquid/liquid separation dynamics with a focus on a water/oil mixture. The correlation employs a force balance on the droplets to predict the rising velocity of the oil phase. The effect of droplet coalescence on the droplet's rising velocity is investigated, and the new correlation predicts the coalescence rate based on the oil/water volume fraction, as well as the initial droplet diameter. To develop the correlation for droplet coalescence, a series of new numerical simulations of a batch oil/water separation process were conducted. An equivalent experiment was conducted, the results of which agree well with the numerical predictions (relative error of 13.39%). The new correlation can predict the rate of separation with a relative error of 6.35% compared to numerical predictions.

Numerical Simulation of Oil- and Water-Sands Multiphase Flow in Gathered Pipes

2012 ◽  
Vol 557-559 ◽  
pp. 2294-2298
Author(s):  
Yi Xin Pan ◽  
Hong Bing Zhang ◽  
Rong Hua Xie ◽  
Xing Bin Liu
Keyword(s):  
Multiphase Flow ◽  
Volume Fraction ◽  
Low Flow ◽  
Governing Equations ◽  
Water Separation ◽  
Nonlinear Growth ◽  
Sediment Volume ◽  
Oil Water Separation ◽  
Oil Water ◽  
Logging Tool

In the oil mining process, we need to hold flow characteristic for oil- and water-sands, with low-middle volume fraction of the particles in gathered pipes, in order to design logging tool and build interpretation methods for the producing profile. We built governing equations and boundary conditions for the oil- and water-sands based on the three-D k-ε-kp model. The simulation results indicate the sand volume fraction affects the sedimentation quantity and rate obviously. Multiphase flow in the gathered pipe is compartmentalized three sections: oil-water separation section, transition section and full mixing section from entrance to exit and multiphase flow meter need to place in the full mixing section. Sediment mainly settles to the bottom of gathered pipes umbrella in the condition of low flow rate and content of sediment, which has little impact on the internal instrument, but need to clear timely. With the increase of sediment volume and reduce of flow race, the time which multiphase flow in the gathered pipe reached a steady state was nonlinear growth.

Investigation of Water Separation from Water-in-Oil Emulsion Using Centrifugal Field and Gravity with CFD Method

2014 ◽  
Vol 1081 ◽  
pp. 93-97
Author(s):  
Qing Li ◽  
Jia Qing Chen ◽  
Kui Sheng Wang
Keyword(s):  
Volume Fraction ◽  
Droplet Diameter ◽  
Reynolds Stress Model ◽  
Water Volume ◽  
Physical Parameters ◽  
Centrifugal Field ◽  
Water Separation ◽  
Oil Emulsion ◽  
Speed Increase ◽  
Water Volume Fraction

Numerical simulation has been carried out to investigate water separation from emulsion with new equipment designed by ourselves. Three rotate speed of 300r/min,1500r/min,3000r/min have been calculated using Reynolds stress model ,which is at the same water volume fraction, droplet diameter and other physical parameters .When the rotate speed increase, the velocity and pressure drop of fluid tends to increase. Due to the effect of centrifugal field, the water volume fraction of near the wall is larger than that of inner fluid. Because of the gravity, the water volume fraction of bottom is larger than that of upper.

Oily Water Treatment Using Ceramic Membrane in Presence of Swirling Flow Induced by a Tangential Inlet via CFD

2014 ◽  
Vol 348 ◽  
pp. 51-57 ◽  
Author(s):  
Tássia Vieira Mota ◽  
Helton Gomes Alves ◽  
Severino Rodrigues Farias Neto ◽  
Antônio Gilson Barbosa de Lima
Keyword(s):  
Ceramic Membrane ◽  
Volume Fraction ◽  
Ceramic Membranes ◽  
Particle Model ◽  
Water Separation ◽  
Significant Difference ◽  
Oil Water Separation ◽  
Oily Water ◽  
Oil Water ◽  
Tangential Inlet

In recent years, attention has been given to the processes controlling the emission of oily effluents and their environmental impact. Many industrial processes generate large volumes of water contaminated with oil, called oily waters. The oily water must be treated before its discard in order to meet the criteria established by environmental agencies (for example in Brazil, 20 mg/L). In present days, the process of separating oil/water with ceramic membranes has attracted the attention of many researchers [1,2]. In this sense, the aim of this study is to evaluate the influence of the tangential inlet shape in the oil/water separation via ceramic membranes. We use a mathematical multiphase flow model to describe the oil-water separation, based on the particle model. Here oil is the dispersed phase while water the continuous phase. To model the turbulence effect we use the RNGk-εmodel. All simulations were carried out using the Ansys CFX ® commercial code. Results of streamlines and velocity, pressure and volume fraction of phase fields are present and analyzed. The numerical results indicate that no significant difference when using a circular or rectangular pipe with the same cross-sectional area.

Flow Pattern Transitions in Horizontal Pipelines Carrying Oil-Water Mixtures: Full-Scale Experiments

2000 ◽  
Vol 122 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Yuri V. Fairuzov ◽  
Pedro Arenas-Medina ◽  
Jorge Verdejo-Fierro ◽  
Ruben Gonzalez-Islas
Keyword(s):  
Crude Oil ◽  
Flow Pattern ◽  
Volume Fraction ◽  
Full Scale ◽  
Needle Valve ◽  
Water Volume ◽  
Special Device ◽  
Two Phase ◽  
Water Fraction ◽  
Oil Water

Full-scale experiments were conducted in order to investigate flow pattern transitions in horizontal pipelines carrying oil-water mixtures. In the experiments, a 16-in. pipeline conveying light crude oil was used. The line was connected to a freshwater network to control the input water volume fraction. A gate valve installed at the pipeline inlet controlled the oil flow rate. The transition from stratified flow to dispersed flow was determined by measuring the transversal water fraction profile. For this purpose, a special device, the multi-point sampling probe, was designed and installed into the pipeline. The probe has movable sampling tubes that allow taking samples simultaneously at six points along the diameter of the pipe. The rate of withdrawal of each sample was adjusted by a needle valve according to the mixture velocity in order to minimize the effect of the probe on the measured water fraction profile. The samples were analyzed for water content in a laboratory using a standard method for determining the water fraction in crude oils. Based on the data obtained, a flow pattern map was constructed. The experimental stratified/nonstratified transition boundary was compared with two theoretical criteria obtained in the linear stability analysis of stratified two-phase liquid-liquid flow. The results of this study can be useful for the design and operation of pipelines transporting crude oil, as well as for the validation of multifield multidimensional models of two-phase flow. [S0195-0738(00)00404-0]

Numerical Study of Drag Forces in Gravity-Induced Separation for Water Dominated Dispersed Oil-Water

2014 ◽  
Author(s):  
Elionora A. Caldera ◽  
Miguel Asuaje
Keyword(s):  
Water Flow ◽  
Volume Fraction ◽  
Separation Efficiency ◽  
Numerical Study ◽  
Phase Segregation ◽  
Continuous Phase ◽  
Water Volume ◽  
Dispersed Oil ◽  
Oil Water ◽  
Water Cut

In recent years, the oil sector has been struggling with the amount of water produced associated with the total volume of oil production. This quantity is known as water cut and could be over 90% in oil extraction. Handling of this water generates additional costs, affecting the sector’s revenues. In order to solve this problem, several techniques to reduce water cut in the wellbore have been applied. This paper evaluates CFD (computational fluid dynamics) models to predict phase segregation in dispersed oil in water flows. This evaluation has been conducted in an attempt to use CFD models to improve the design methodology of an inline separator of oil-water flow for petroleum production systems [1]. In this 3D study, three cases simulating water dominated dispersed oil-water flow in an inclined pipe 45° from horizontal, were evaluated numerically using a CFD model The oil was considered as the disperse phase and the water as the continuous phase, using Ansys®CFX. Mono size droplet dispersion was employed to represent the dispersed phase. The equations for the forces considered in this study are: drag and buoyancy. The simulated results are compared with the experimental data, which includes water volume fraction, drop pressure and separation efficiency. The result shows an improvement of over 50% in the experimental values, which match the values of the total flow rate (Q), water holdup (Hw) and pressure drop (ΔP), deviating by less than 4%.

Hydrodynamics Study of Oil–Water Flow in Coiled Flow Inverter

2020 ◽  
Vol 12 (2) ◽  
pp. 173-180
Author(s):  
Anshumaan Dey ◽  
Monisha M. Mandal
Keyword(s):  
Pressure Drop ◽  
Water Flow ◽  
Viscosity Ratio ◽  
Volume Fraction ◽  
Phase Distribution ◽  
Numerical Study ◽  
Chemical Reactor ◽  
Interval Length ◽  
Water Volume ◽  
Oil Water

The present numerical study is an effort to examine the hydrodynamics characteristics of two immiscible liquids (oil and water) flowing in different tubes. i.e., straight, coiled and Coiled Flow Inverter (CFI) tube of equal dimensions. CFI is a novel device in which fluid flow inversion takes place at uniform interval length of tube. The effect of oil-water viscosity ratio (µoil/µwater = 1.6 and 30) on velocity contours, phase distribution and pressure drop in the different tubes were investigated. The present work show that flow pattern of oil–water flows was changed from stratified to annular flows at higher water volume fraction for µoil/µwater = 1.6 in CFI. Phase inversion of oil–water flow was observed in CFI at higher viscosity ratio (µoil/µwater = 30). There was remarkable reduction in pressure drop with the increment in volume fraction of water flowing in coiled as well as CFI. CFI being more compact can be efficiently used in industries as chemical reactor, heat exchanger, mixer, etc.

On the Development of Deadleg Criterion

2005 ◽  
Vol 127 (1) ◽  
pp. 124-135 ◽  
Author(s):  
M. A. Habib ◽  
H. M. Badr ◽  
S. A. M. Said ◽  
I. Hussaini ◽  
J. J. Al-Bagawi
Keyword(s):  
Volume Fraction ◽  
Argon Laser ◽  
Secondary Phase ◽  
Momentum Conservation ◽  
Low Flow ◽  
Water Mixture ◽  
Fluid Mixture ◽  
Water Separation ◽  
Oil Water ◽  
Stagnant Fluid

Corrosion in deadlegs occurs as a result of water separation due to the very low flow velocity. This work aims to investigate the effect of geometry and orientation on flow field and oil/water separation in deadlegs in an attempt for the development of a deadleg criterion. The investigation is based on the solution of the mass and momentum conservation equations of an oil/water mixture together with the volume fraction equation for the secondary phase. Results are obtained for two main deadleg orientations and for different lengths of the deadleg in each orientation. The considered fluid mixture contains 90% oil and 10% water (by volume). The deadleg length to diameter ratio (L/D) ranges from 1 to 9. The results show that the size of the stagnant fluid region increases with the increase of L/D. For the case of a vertical deadleg, it is found that the region of the deadleg close to the header is characterized by circulating vortical motions for a length l≈3 D while the remaining part of the deadleg occupied by a stagnant fluid. In the case of a horizontal deadleg, the region of circulating flow extends to 3–5 D. The results also indicated that the water volumetric concentration increases with the increase of L/D and is influenced by the deadleg orientation. The streamline patterns for a number of cases were obtained from flow visualization experiments (using 200 mW Argon laser) with the objective of validating the computational model.

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