scholarly journals Separation characteristics and structure optimization of double spherical tangent double-field coupling demulsifier

2021 ◽  
Author(s):  
Haifeng Gong ◽  
Zhi Qiu ◽  
Ye Peng ◽  
Bao Yu ◽  
Zhixiang Liao ◽  
...  
Keyword(s):  
Petrochemical Industry ◽  
Separation Efficiency ◽  
Structure Optimization ◽  
Internal Flow ◽  
Environmental Engineering ◽  
Balance Model ◽  
Field Coupling ◽  
Coupling Device ◽  
Conical Structure ◽  
Tangential Cone

AbstractThe demulsification and dewatering of the W/O emulsion are widely used in petrochemical industry, oilfield exploitation, and resource and environmental engineering. However, efficiently treating emulsion via traditional single methods. In this study, a new double-field coupling demulsification and dewatering device is proposed, where the conical structure of the device is double spherical tangential type. The numerical model for double-field coupling is established, especially, the population balance model (PBM) is used to simulate the coalescence and breakup of dispersed droplets under the double-field coupling action. And the effects of three conical structures on the internal flow and separation efficiency are analyzed. Results show that the conical structure has a significant effect on the coalescence of droplets, especially the double spherical tangential cone is more conducive for improving the coalescence ability of small droplets and improving the separation efficiency of the device. After optimization, the optimal R value of the double spherical tangential coupling device is 300 mm, and the separation efficiency can be up to 96.32%, which is 6.13% higher than the separation efficiency of the straight double-cone coupling device.

scholarly journals Strut-and-tie models for linear and nonlinear behavior of concrete based on topological evolutionary structure optimization (ESO)

2019 ◽  
Vol 12 (1) ◽  
pp. 87-100
Author(s):  
R. M. LANES ◽  
M. GRECO ◽  
M. B. B. F. GUERRA
Keyword(s):  
Nonlinear Behavior ◽  
Structure Optimization ◽  
Internal Flow ◽  
Optimization Method ◽  
Topological Optimization ◽  
Structural Elements ◽  
Stress Concentrations ◽  
Progressive Reduction ◽  
Strut And Tie ◽  
Safety And Reliability

Abstract The search for representative resistant systems for a concrete structure requires deep knowledge about its mechanical behavior. Strut-and-tie models are classic analysis procedures to the design of reinforced concrete regions where there are stress concentrations, the so-called discontinuous regions of the structure. However, this model is strongly dependent of designer’s experience regarding the compatibility between the internal flow of loads, the material’s behavior, the geometry and boundary conditions. In this context, the present work has the objective of presenting the application of the strut-and-tie method in linear and non-linear on some typical structural elements, using the Evolutionary Topological Optimization Method (ESO). This optimization method considers the progressive reduction of stiffness with the removal of elements with low values of stresses. The equivalent truss system resulting from the analysis may provide greater safety and reliability.

scholarly journals Modeling the Separation of Microorganisms in Bioprocesses by Flotation

2018 ◽  
Author(s):  
Stefan Schmideder ◽  
Christoph Kirse ◽  
Julia Hofinger ◽  
Sascha Rollié ◽  
Heiko Briesen
Keyword(s):  
Fluid Dynamics ◽  
Separation Efficiency ◽  
Algebraic Model ◽  
Balance Model ◽  
Separation Processes ◽  
Dissolved Air Flotation ◽  
Computational Fluid Dynamics Cfd ◽  
Cell Size Distributions ◽  
Fermentation Broths ◽  
The Impact

Bioprocesses for the production of renewable energies and materials lack efficient separation processes for the utilized microorganisms such as algae and yeasts. Dissolved air flotation (DAF) and microflotation are promising approaches to overcome this problem. The efficiency of these processes depends on the ability of microorganisms to aggregate with microbubbles in the flotation tank. In this study, different new or adapted aggregation models for microbubbles and microorganisms are compared and investigated for their range of suitability to predict the separation efficiency of microorganisms from fermentation broths. The complexity of the heteroaggregation models range from an algebraic model to a 2D population balance model (PBM) including the formation of clusters containing several bubbles and microorganisms. The effect of bubble and cell size distributions on the flotation efficiency is considered by applying PBMs, as well. To determine the impact of the model assumptions, the modeling approaches are compared and classified for their range of applicability. Evaluating computational fluid dynamics (CFD) of a DAF system shows the heterogeneity of the fluid dynamics in the flotation tank. Since analysis of the streamlines of the tank show negligible backmixing, the proposed aggregation models are coupled to the CFD data by applying a Lagrangian approach.

Study on Characteristics and Operating Parameters of Axial Rotating Hydrocyclone

2009 ◽  
Author(s):  
Yan Xu ◽  
Zunce Wang ◽  
Fengxia Lv ◽  
Sen Li
Keyword(s):  
Pressure Drop ◽  
Laboratory Experiments ◽  
Separation Efficiency ◽  
Rotation Speed ◽  
Tangential Velocity ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Axial Rotation ◽  
Rotating Wall ◽  
Simulation Results

The axial rotation of the hydrocyclone affects its internal flow characteristics and separating effect directly, as some local applications require the static hydrocyclone rotates about its own axis. Based on CFD, velocity distribution in the axial rotating hydrocyclone is studied. It is shown that as the rotation speed increasing, the tangential velocity improves and its gradient reduces in free vortex region observably, while the radial velocity has an incremental trend in the section of the small cone. The laboratory experiments are carried out for the static hydrocyclone of disposal capacity of 4 m3/h at 100r/min ∼ 300r/min. The relationships among rotation speed, flowrate, pressure drop and separated efficiency are achieved, which agree well with the numerical simulation results. The results indicate that the disposal capacity of hydrocyclone subjected to the rotation wall can be more flexible than that with no-rotating wall, the scope of best disposal capacity gradually enlarges with the increase of rotation speed of wall. Appropriate rise of the rotation speed is favor of the separation efficiency at the steady flowrate, however the increase of the flowrate and rotation speed induces the growth of the hydrocyclone’s pressure drop correspondingly to some extent.

scholarly journals Numerical Simulation on Flow Field of Oilfield Three-Phase Separator

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yong-tu Liang ◽  
Sheng-qiu Zhao ◽  
Xia-xue Jiang ◽  
Xian-qi Jia ◽  
Wang Li
Keyword(s):  
Flow Field ◽  
Water Content ◽  
Production Management ◽  
Separation Efficiency ◽  
Internal Flow ◽  
Accuracy Requirement ◽  
Operation Conditions ◽  
Three Phase ◽  
Phase Separator ◽  
The Impact

The conventional measurement method can no longer guarantee the accuracy requirement after the oilfield development entering high water cut stage, due to the water content and gas phase in the flow. In order to overcome the impact of measurement deviation the oilfield production management, the flow field of three-phase separator is studied numerically in this paper using Fluent 6.3.26. Taking into consideration the production situation of PetroChina Huabei Oilfield and the characteristics of three-phase separator, the effect of internal flow status as well as other factors such as varying flow rate, gas fraction, and water content on the separation efficiency is analyzed. The results show that the separation efficiencies under all operation conditions are larger than 95%, which satisfy the accuracy requirement and also provide the theoretical foundation for the application of three-phase separators at oilfields.

scholarly journals Recent advances in facilitated transport membranes for olefin/paraffin separation

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Long Cheng ◽  
Gongping Liu ◽  
Wanqin Jin
Keyword(s):  
Energy Consumption ◽  
Future Development ◽  
Petrochemical Industry ◽  
Separation Efficiency ◽  
Facilitated Transport ◽  
Membrane Technology ◽  
Light Olefins ◽  
Separation Mechanism ◽  
Save Energy ◽  
The Stability

AbstractWith the development of the petrochemical industry, the demand for light olefins is rapidly increasing. The separation of olefin/paraffin by membrane technology can save energy consumption and improve separation efficiency. This article reviews the latest progress in facilitated transport membranes for olefin/paraffin separation. The separation mechanism and common types of facilitated transport membranes are briefly introduced. Meanwhile, the mechanism of carrier deactivation and the corresponding strategies to improve the stability of the membranes are summarized. In concluding, current developments regarding facilitated transport membranes are summarized and directions for future development are proposed.

Numerical Simulation of Internal Flow Field on Diesel Centrifugal Gas-Oil Separator Based on CFD

2013 ◽  
Vol 373-375 ◽  
pp. 409-412
Author(s):  
Zhi Guo Zhao ◽  
Wen Ming Yu
Keyword(s):  
Flow Field ◽  
Separation Efficiency ◽  
Vertical Direction ◽  
Internal Flow ◽  
Gas Oil ◽  
Discrete Phase Model ◽  
Fluid Field ◽  
Discrete Phase ◽  
Import And Export ◽  
Low Efficiency

Aiming at the low efficiency problem of the traditional gas-oil separator, this paper put forward a centrifugal gas-oil separator. In order to identify out the interior fluid field character of centrifugal gas-oil separator, RANS equation, RNG k-ε model and discrete phase model was applied to simulate the interior fluid field character and separation efficiency of centrifugal gas-oil separator. The simulation results showed that the flow field in the disc clearance was mainly laminar flow, and the flow field at the import and export of the disc was turbulence. Meanwhile, the velocity and pressure of the interior fluid field were equably distributed, the velocity and pressure in the disc clearance fluctuate in a tight range along vertical direction, and decrease along horizontal direction, and the particles in the disc clearance were distributed uniformly. The separation efficiency was 96.6% and the results met the design requirements.

scholarly journals Experimental Study on Downhole Oil-water Separation Hydrocyclone

2015 ◽  
Vol 8 (1) ◽  
pp. 257-261 ◽  
Author(s):  
Xu Yan ◽  
Yuan Lin ◽  
Wang Zunce ◽  
Li Sen ◽  
Zhang Jinglong ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Orthogonal Experiment ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Practical Application ◽  
Water Separation ◽  
Rotating Speed ◽  
Split Ratio ◽  
Oil Water Separation ◽  
Oil Water

In the process of downhole oil-water separation, the traditional liquid-liquid separation hydrocyclone (LLSH) is used in conjunction with screw pumps, which makes the hydrocyclone rotating around its own axis. The rotation of wall of hydrocyclone affects its internal flow characteristics and separation properties directly. The orthogonal experiment of the downhole oil-water separation hydrocyclone (DOWSH) is designed to analyze the effect of flowrate, rotating speed and split ratio on separation efficiency and pressure drop, The primary and secondary factors of operation parameters have been studied, and the optimum condition and reasonable working range of DOWSH have been obtained. It provides reliable basis for process of practical application of DOWSH􀀁so as to guide the production.

Numerical Simulation on Steam-Water Separator Performance Based on Population Balance Model

2017 ◽  
Author(s):  
Yang Xuelong ◽  
Gan Guohua ◽  
Feng Jing ◽  
Zhang Qian ◽  
Xu Xuhui
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Separation Efficiency ◽  
Fluid Model ◽  
Resistance Coefficient ◽  
Drop Size Distribution ◽  
Balance Model ◽  
Single Drop ◽  
Two Fluid Model ◽  
Two Fluid

The performance of the moisture separator is simulated and analyzed by the Euler two fluid model with population balance model (PBM), and compared with the traditional single drop size calculation method. The traditional Euler two fluid model based on single drop size was used to calculate the drop size effects on the separator performance, and the drop size range of significant effect on the separator was determined. The PBM model was used to calculate the separation performance in the case of multiple drop sizes, and the drop size was divided into five groups with different drop diameters. The percentage of each group was given at the separator inlet. The results show : (1) With increasing drop size, the pressure drop of the separator first increases and then decreases, and the separation efficiency gradually increases and when the drop size is larger than 150 μm, the separation efficiency is close to 100%, therefore, when the PBM model is used, its drop size range can be calculated by single drop size method; (2) With the drop size distribution moving to the direction of large diameter, the resistance coefficient decreases, the separation efficiency increases, the PBM model is consistent with the mass weighting performance from the single drop size method, but the separation efficiency and resistance coefficient are larger. (3) Steady-state PBM model can realize simultaneous calculation with different drop sizes, calculation cost is slightly larger than the single drop size method, but can quickly get the separator performance under a drop size distribution; (4) The unsteady PBM model can automatically obtain a drop size distribution before entering the separator rotating vane, and solve the problem of drop size setting at the inlet of the separator.

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