scholarly journals Conditions of gas–solid two-phase flow formed in a vertical screw conveyor

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879776
Author(s):  
Sun Xiaoxia ◽  
Meng Wenjun ◽  
Yuan Yuan

This study investigates the velocity and pressure distributions of gas flow field in a vertical screw conveyor through EDEM simulation. Results show that the vertical velocity of gas is the highest and that the minimum pressure is negative, which is at the exit, thereby aiding in the upward transportation of particles. The particle state in the vertical screw conveyor is obtained without considering gas (EDEM simulation) and by considering gas (EDEM + FLUENT simulation), respectively. Investigation of the relationship among the screw critical speed, screw diameter, and particle size shows that the conditions of gas–solid two-phase flow form in the vertical screw conveyor. A test is designed to verify the correctness of the conclusions. The results of this study lay a foundation for the development of design methods based on gas–solid two-phase flow in a vertical screw conveyor.

2011 ◽  
Vol 291-294 ◽  
pp. 2403-2406
Author(s):  
Yan Min Li ◽  
Fei Ma

Taking a nozzle jet for gas-fluid phase flow as a research object, the influences of the main structural parameters on the vacuum in the internal suction volume are analyzed. Utilizing the software FLUENT to simulate the gas-liquid two-phase flow in nozzle jet with different structural parameters, the pressure distributions are obtained and the relationship between the structural parameters and the vacuum in the suction volume is concerned. The results show that the vacuum in the suction volume of jet reaches the maximum when these structural parameters are some certain values. The research is helpful for the optimal design and performance testing of nozzle jets.


Author(s):  
Yu Li ◽  
Yongzhi Li ◽  
Dingfang Chen

Among the whole ship unloading process, how to effectively and conveniently put the bulk into the ship-unloader is often a big and key problem. This article advance a new equipment to solve the problem—Screw-gas Bulk Sucking and Taking Equipment, which applies both the theory of vertical screw conveyor and the theory of pneumatic handling. The author describes the constitution of the equipment and explains the working principles in detail, by thus pointing out the superiorities of the equipment, such as low clearing-up, little dust removal, simple construction and convenient maintenance. The article also brings tentative data for proof. The article gives a good solution by providing with a brand-new equipment—Screw-gas Bulk Sucking and Taking Equipment, which applies both the theory of vertical screw conveyor and the theory of pneumatic handling. It constitutes of 3 parts; respectively from bottom to above they are: Centrifugal force Separating Part, Screw Lifting Part and Pneumatic Conveying Part. Granular material is drawn into the equipment in the form of gas-solid two-phase flow by the Atmospheric pressure, and then helically rises in the Centrifugal Force Separating Part which is an inverted cone. The material would be separated from the two-phase flow by the effect of centrifugal force and then be lifted in the Screw Lifting Part. The gas flow with the very little remained material would be drawn into the blower. By thus Screw-gas Bulk Sucking and Taking Equipment could take the material and put it to the next conveying process conveniently and efficiently with the superiorities of low clearing-up, little dust removal, simple construction and convenient maintenance.


2011 ◽  
Vol 127 ◽  
pp. 374-378
Author(s):  
Yu Li ◽  
Yong Zhi Li ◽  
Ding Fang Chen

Among all the bulk conveying processes, how to effectively and conveniently put the bulk into the conveying process is regarded as one of the most important problems. This article brings out a brand-new equipment—Screw-gas Bulk Sucking and Taking Equipment for the solution, which applies both the theory of vertical screw conveyor and the theory of pneumatic handling. It constitutes of 3 parts; respectively from bottom to above they are: Centrifugal force Separating Part, Screw Lifting Part and Pneumatic Conveying Part. Particle material is drawn into the equipment in the form of gas-solid two-phase flow by the Atmospheric pressure, and then helically rises in the Centrifugal Force Separating Part which is an inverted cone. The material would be separated from the two-phase flow by the effect of centrifugal force and then be lifted in the Screw Lifting Part. The gas flow with the very little remained material would be drawn into the blower. By thus Screw-gas Bulk Sucking and Taking Equipment could take the material and put it to the next conveying process conveniently and efficiently with the superiorities of low clearing-up, little dust removal, simple construction and convenient maintenance. The article provides the feasibility of the new equipment by experiments on 3 kinds of identical particle.


2003 ◽  
Vol 3 ◽  
pp. 266-270
Author(s):  
B.H. Khudjuyerov ◽  
I.A. Chuliev

The problem of the stability of a two-phase flow is considered. The solution of the stability equations is performed by the spectral method using polynomials of Chebyshev. A decrease in the stability region gas flow with the addition of particles of the solid phase. The analysis influence on the stability characteristic of Stokes and Archimedes forces.


2021 ◽  
Author(s):  
Ekhwaiter Abobaker ◽  
Abadelhalim Elsanoose ◽  
Mohammad Azizur Rahman ◽  
Faisal Khan ◽  
Amer Aborig ◽  
...  

Abstract Perforation is the final stage in well completion that helps to connect reservoir formations to wellbores during hydrocarbon production. The drilling perforation technique maximizes the reservoir productivity index by minimizing damage. This can be best accomplished by attaining a better understanding of fluid flows that occur in the near-wellbore region during oil and gas operations. The present work aims to enhance oil recovery by modelling a two-phase flow through the near-wellbore region, thereby expanding industry knowledge about well performance. An experimental procedure was conducted to investigate the behavior of two-phase flow through a cylindrical perforation tunnel. Statistical analysis was coupled with numerical simulation to expand the investigation of fluid flow in the near-wellbore region that cannot be obtained experimentally. The statistical analysis investigated the effect of several parameters, including the liquid and gas flow rate, liquid viscosity, permeability, and porosity, on the injection build-up pressure and the time needed to reach a steady-state flow condition. Design-Expert® Design of Experiments (DoE) software was used to determine the numerical simulation runs using the ANOVA analysis with a Box-Behnken Design (BBD) model and ANSYS-FLUENT was used to analyses the numerical simulation of the porous media tunnel by applying the volume of fluid method (VOF). The experimental data were validated to the numerical results, and the comparison of results was in good agreement. The numerical and statistical analysis demonstrated each investigated parameter’s effect. The permeability, flow rate, and viscosity of the liquid significantly affect the injection pressure build-up profile, and porosity and gas flow rate substantially affect the time required to attain steady-state conditions. In addition, two correlations obtained from the statistical analysis can be used to predict the injection build-up pressure and the required time to reach steady state for different scenarios. This work will contribute to the clarification and understanding of the behavior of multiphase flow in the near-wellbore region.


2011 ◽  
Vol 383-390 ◽  
pp. 4922-4927
Author(s):  
Peng Xia Xu ◽  
Yan Feng Geng

Wet gas flow is a typical two-phase flow with low liquid fractions. As differential pressure signal contains rich information of flow parameters in two-phase flow metering, a new method is proposed for wet gas flow metering based on differential pressure (DP) and blind source separation (BSS) techniques. DP signals are from a couple of slotted orifices and the BSS method is based on time-frequency analysis. A good relationship between the liquid flow rate and the characteristic quantity of the separated signal is established, and a differential pressure correlation for slotted orifice is applied to calculate the gas flow rate. The calculation results are good with 90% relative errors less than ±10%. The results also show that BSS is an effective method to extract liquid flow rate from DP signals of wet gas flow, and to analysis different interactions among the total DP readings.


2017 ◽  
Vol 27 (12) ◽  
pp. 2799-2815
Author(s):  
Ewa Kolczyk ◽  
Zdzisław Miczkowski ◽  
Józef Czernecki

Purpose The purpose of this study is application of a numerical simulation for determination of the influence of geometric parameters of a furnace and hydrodynamics of the gas introduced by a vertical submerged lance on the process of feed mixing and temperature distribution. Design/methodology/approach A numerical simulation with Phoenics software was applied for modeling of liquid phase movement and heat exchange between the gas supplied through a lance and the slag feed in a top submerged lance (TSL) furnace. The simulation of a two-phase flow of a slag–gas mixture based on the inter phase slip algorithm module was conducted. The influence of selected parameters, such as depth of lance submergence, gas flow rate and change of furnace geometry, on the phenomena of movement was studied. Findings Growth of dynamics of mixing with the depth of lance submergence and with increase of gas velocity in the lance was observed. Formation of a recirculation zone in the liquid slag was registered. Movement of the slag caused by the gas flow brought homogenization of the temperature field. Originality/value The study applied the simulation of a two-phase flow in the liquid slag–gas system in steady state, taking into account heat transfer between phases. It provides possibilities for optimization and selection of process parameters within the scope of the developed new technology using a TSL furnace.


2013 ◽  
Vol 712-715 ◽  
pp. 1253-1258
Author(s):  
Hai Feng Xue ◽  
Xiong Chen ◽  
Yong Ping Wang ◽  
Ya Zheng

The two-dimension axisymmetric and two-phase flow in a full-size solid rocket motor with submerged nozzle under high acceleration condition has been simulated with Euler-Lagrange model. Without acceleration and under high axial acceleration on particle trajectories, the influences of different particle diameters were analyzed. The difference between gas flow field and two-phase flow field is significant. The particle accumulation zone above the inner wall of chamber and nozzle is mainly concentrated in two regions. The axial acceleration will intensify the impaction to the end of the chamber. The accretion of the particle phase diameter will increase the inertia of the particle phase, which may cause the following property worse, and the particles can easily form a highly-concentrated aggregation flow.


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