The performance of airlift pump for the solid particles lifting during the transportation of gas-liquid-solid three-phase flow: A comprehensive research review

2020 ◽  
pp. 095440892095172
Author(s):  
◽  
◽  
Keyword(s):  
Numerical Study ◽  
Solid Particles ◽  
Research Review ◽  
Operational Parameters ◽  
Pipe Length ◽  
Pump Performance ◽  
Study Section ◽  
The Future ◽  
Three Phase Flow ◽  
Airlift Pump

Research about the enhancement of the airlift pump performance by changing the geometry and operational parameters has drawn considerable attention in recent years. This paper presents a comprehensive review of some published research articles on the enhancement performance of the airlift pump and the future direction of the research. In the introductory section, the description, the application, and the performance of the airlift pump are described. The influencing parameters of the airlift pump performance are classified in the geometry and operational. The geometry parameters are including submergence ratio, pipe diameter, pipe length, design, and position of the injector. The operational parameters are including the testing fluid, diameter and density particles, and the superficial velocity of injected air. All of the involved parameters are detail explained in the experimental study section. The detailed derivation of equations of the airlift pump performance and also the modified equation was shown in the theoretical study section. The numerical study of airlift pump operating on two and three phases was also discussed. In the last section, the future directions of the airlift pump are noted, and some conclusions were summarized. It was found that only limited literature about flow patterns in terms of the dynamic interface of each phase and development bubble jet generator airlift pump. Therefore, experimental data are needed to support this effort. Additional work, both theoretical and experimental, needs to be conducted on the effects of type and position bubble jet generators on the flow characteristic and the airlift pump performance, with the hope that the better performance will be obtained.

A numerical study on combined baffles quick-separation device

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ehsan Dehdarinejad ◽  
Morteza Bayareh ◽  
Mahmud Ashrafizaadeh
Keyword(s):  
Turbulent Flows ◽  
Separation Efficiency ◽  
Numerical Study ◽  
Turbulence Models ◽  
Complete Separation ◽  
Solid Particles ◽  
Flow Rates ◽  
Separation Device ◽  
Coupling Technique ◽  
Laminar And Turbulent Flows

Abstract The transfer of particles in laminar and turbulent flows has many applications in combustion systems, biological, environmental, nanotechnology. In the present study, a Combined Baffles Quick-Separation Device (CBQSD) is simulated numerically using the Eulerian-Lagrangian method and different turbulence models of RNG k-ε, k-ω, and RSM for 1–140 μm particles. A two-way coupling technique is employed to solve the particles’ flow. The effect of inlet flow velocity, the diameter of the splitter plane, and solid particles’ flow rate on the separation efficiency of the device is examined. The results demonstrate that the RSM turbulence model provides more appropriate results compared to RNG k-ε and k-ω models. Four thousand two hundred particles with the size distribution of 1–140 µm enter the device and 3820 particles are trapped and 380 particles leave the device. The efficiency for particles with a diameter greater than 28 µm is 100%. The complete separation of 22–28 μm particles occurs for flow rates of 10–23.5 g/s, respectively. The results reveal that the separation efficiency increases by increasing the inlet velocity, the device diameter, and the diameter of the particles.

The Effect of the Thickness and Angle of the Inlet and Outlet Guide Vane on the Performance of Axial-Flow Pump

2016 ◽  
Author(s):  
Sang-Won Kim ◽  
Youn-Jea Kim
Keyword(s):  
Numerical Analysis ◽  
Numerical Study ◽  
Guide Vane ◽  
Axial Flow ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Pump Performance ◽  
Blade Thickness ◽  
Axial Flow Pump ◽  
Flow Pump

An axial-flow pump has a relatively high discharge flow rate and specific speed at a relatively low head and it consists of an inlet guide vane, impeller, and outlet guide vane. The interaction of the flow through the inlet guide vane, impeller, and outlet guide vane of the axial-flow pump has a significant effect on its performance. Of those components, the guide vanes especially can improve the head and efficiency of the pump by transforming the kinetic energy of the rotating flow, which has a tangential velocity component, into pressure energy. Accordingly, the geometric configurations of the guide vanes such as blade thickness and angle are crucial design factors for determining the performance of the axial-flow pump. As the reliability of Computational Fluid Dynamics (CFD) has been elevated together with the advance in computer technology, numerical analysis using CFD has recently become an alternative to empirical experiment due to its high reliability to measure the flow field. Thus, in this study, 1,200mm axial-flow pump having an inlet guide vane and impeller with 4 blades and an outlet guide vane with 6 blades was numerically investigated. Numerical study was conducted using the commercial CFD code, ANSYS CFX ver. 16.1, in order to elucidate the effect of the thickness and angle of the guide vanes on the performance of 1,200mm axial-flow pump. The stage condition, which averages the fluxes between interfaces and is accordingly appropriate for the evaluation of pump performance, was adopted as the interface condition between the guide vanes and the impeller. The rotational periodicity condition was used in order to enable a simplified geometry to be used since the guide vanes feature multiple identical regions. The shear stress transport (SST) k-ω model, predicting the turbulence within the flow in good agreement, was also employed in the CFD calculation. With regard to the numerical simulation results, the characteristics of the pressure distribution were discussed in detail. The pump performance, which will determine how well an axial-flow pump will work in terms of its efficiency and head, was also discussed in detail, leading to the conclusion on the optimal blade thickness and angle for the improvement of the performance. In addition, the total pressure loss coefficient was considered in order to investigate the loss within the flow paths depending on the thickness and angle variations. The results presented in this study may give guidelines to the numerical analysis of the axial-flow pump and the investigation of the performance for further optimal design of the axial-flow pump.

A numerical study of the nucleation, growth and settling of crystals from a turbulent convecting fluid

2021 ◽  
Author(s):  
Vojtech Patocka ◽  
Nicola Tosi ◽  
Enrico Calzavarini
Keyword(s):  
Magma Chamber ◽  
Solid Fraction ◽  
Large Scale ◽  
Solid Phase ◽  
Numerical Study ◽  
Equilibrium Concentration ◽  
Solid Particles ◽  
Settling Rate ◽  
Carrier Fluid ◽  
Nucleation Growth

<p>We evaluate the equilibrium concentration of a thermally convecting suspension that is cooled from above and in which<br>solid crystals are self-consistently generated in the thermal boundary layer near the top. In a previous study (Patočka et<br>al., 2020), we investigated the settling rate of solid particles suspended in a highly vigorous (Ra = 10<sup>8</sup> , 10<sup>10</sup>, and 10<sup>12</sup> ),<br>finite Prandtl number (Pr = 10, 50) convection. In this follow-up study we additionally employ the model of crystal<br>generation and growth of Jarvis and Woods (1994), instead of using particles with a predefined size and density that are<br>uniformly injected into the carrier fluid.</p><p>We perform a series of numerical experiments of particle-laden thermal convection in 2D and 3D Cartesian geometry<br>using the freely available code CH4 (Calzavarini, 2019). Starting from a purely liquid phase, the solid fraction gradually<br>grows until an equilibrium is reached in which the generation of the solid phase balances the loss of crystals due to<br>sedimentation at the bottom of the fluid. For a range of predefined density contrasts of the solid phase with respect to<br>the density of the fluid (ρ<sub>p</sub> /ρ<sub>f</sub> = [0, 2]), we measure the time it takes to reach such equilibrium. Both this time and<br>the equilibrium concentration depend on the average settling rate of the particles and are thus non-trival to compute for<br>particle types that interact with the large-scale circulation of the fluid (see Patočka et al., 2020).</p><p>We apply our results to the cooling of a large volume of magma, spanning from a large magma chamber up to a<br>global magma ocean. Preliminary results indicate that, as long as particle re-entrainment is not a dominant process, the<br>separation of crystals from the fluid is an efficient process. Fractional crystallization is thus expected and the suspended<br>solid fraction is typically small, prohibiting phenomena in which the feedback of crystals on the fluid begins to govern the<br>physics of the system (e.g. Sparks et al, 1993).</p><p>References<br>Patočka V., Calzavarini E., and Tosi N.(2020). Settling of inertial particles in turbulent Rayleigh-Bénard convection.<br>Physical Review Fluids, 26(4) 883-889.</p><p>Jarvis, R. A. and Woods, A. W.(1994). The nucleation, growth and settling of crystals from a turbulently convecting<br>fluid. J. Fluid. Mech, 273 83-107.</p><p>Sparks, R., Huppert, H., Koyaguchi, T. et al (1993). Origin of modal and rhythmic igneous layering by sedimentation in<br>a convecting magma chamber. Nature, 361, 246-249.</p><p>Calzavarini, E (2019). Eulerian–Lagrangian fluid dynamics platform: The ch4-project. Software Impacts, 1, 100002.</p>

A Numerical Study on the Ultimate Strength of Damaged Tubular Bracing Members Under Axial Compression

2018 ◽  
Author(s):  
Ling Zhu ◽  
Jieling Kong ◽  
Qingyang Liu ◽  
Han Yang ◽  
Bin Wang
Keyword(s):  
Ultimate Strength ◽  
Axial Compression ◽  
Numerical Study ◽  
Load Capacity ◽  
Approximate Equation ◽  
Offshore Structures ◽  
Experimental Investigations ◽  
Pipe Length ◽  
Axial Load Capacity ◽  
Parametric Studies

The tubular bracing members of offshore structures may sustain collision damages from the supply ships, which lead to the deterioration of the load carrying capacity of tubular bracing members. This paper presents a numerical simulation of the ultimate strength of damaged tubular bracing members under axial compression with the nonlinear finite element code ABAQUS, based on previous experimental investigations. Parametric studies are conducted to investigate the load capacity of damaged tubular bracing members, by considering the effects of diameter (D), wall thickness (H), pipe length (L) and the damage positions on the ultimate strength of tubular members. It is found that lateral damage can cause great reduction of the axial load capacity of tubular members. In addition, an approximate equation to predict the ultimate strength of tubular members based on the given damage depth is proposed.

Numerical study of a crown fire spreading toward a fuel break using a multiphase physical model

2005 ◽  
Vol 14 (2) ◽  
pp. 141 ◽  
Author(s):  
Jean-Luc Dupuy ◽  
Dominique Morvan
Keyword(s):  
Physical Model ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Vertical Plane ◽  
Solid Particles ◽  
Crown Fire ◽  
Fire Behaviour ◽  
Canopy Layer ◽  
Mediterranean Pine ◽  
Fire Spreading

The propagation of a wildfire through a Mediterranean pine stand was simulated using a multiphase physical model of fire behaviour. The heterogeneous character of the vegetation was taken into account using families of solid particles, i.e. the solid phases (foliage, twigs, grass). The thermal decomposition of the solid fuel by drying and pyrolysis, and the combustion of chars were considered, as well as the radiative and convective heat transfer between the gas and the vegetation. In the gaseous phase, turbulence was modelled using a two transport equations model (RNG k–ϵ) and the rate of combustion, which was assumed to be controlled by the turbulent mixing of fuel and oxygen, was calculated using an eddy dissipation concept. The radiation transfer equation, which includes absorption and emission of both the gas–soot mixture and the vegetation, was solved to calculate the contribution of radiation to the energy balance equations. Numerical solutions were calculated in a two-dimensional domain (vertical plane). Results showed the ability of this approach to simulate the propagation of a crown fire and to test the efficiency of a fuel break with success. The effects of the terrain slope were also tested. Some effects on fire behaviour of vortices resulting from the interaction of the wind flow with the canopy layer are shown.

Numerical Study of Thermochemical Storage Using Ca(OH)2/CaO: High Temperature Applications

2016 ◽  
Author(s):  
Qasim A. Ranjha ◽  
Nasser Vahedi ◽  
Alparslan Oztekin
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Numerical Study ◽  
Storage System ◽  
Packed Bed ◽  
Heat Transfer Fluid ◽  
Operational Parameters ◽  
Storage And Retrieval

Thermal energy storage by reversible gas-solid reaction has been selected as a thermochemical energy storage system. Simulations are conducted to investigate the dehydration of Ca(OH)2 and the hydration of CaO for thermal energy storage and retrieval, respectively. The rectangular packed bed is heated indirectly by air used as a heat transfer fluid (HTF) while the steam is transferred through the upper side of the bed. Transient mass transport and heat transfer equations coupled with chemical kinetics equations for a two dimensional geometry have been solved using finite element method. Numerical results have been validated by comparing against results of previous measurements and simulations. The effect of geometrical and operational parameters including the material properties on overall storage and retrieval process has been investigated. The co-current and counter-current flow arrangements for steam and heat transfer fluid have been considered.

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.

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