Blade Outlet Angle Effect on Two-Phase Flow in Chemical Pump With Crystallization Phenomenon

2012 ◽  
Author(s):  
Dong Liu ◽  
Zhong Li ◽  
Chun-lin Wang ◽  
Min-guan Yang
Keyword(s):  
Delay Period ◽  
Solid Particles ◽  
Two Phase ◽  
Pressure Surface ◽  
Outlet Angle ◽  
Tail Part ◽  
Image Velocimetry ◽  
Angle Effect ◽  
Crystal Particle ◽  
Chemical Pump

Particle Image Velocimetry combined with image processing method is used to measure the liquid-solid two phase flows with crystallization phenomenon in three different impellers. The experimental results indicate that: there is not any crystal particle during the delay period, and the performance of pump is not affected. After the delay period, the crystal nuclei are born from the supersaturating solution and growing larger with temperature decreasing. And it was found solid particles tend to move towards blade pressure surface. It is also observed that collision between solid particles with tail part of blade pressure surface is more intensive in impeller with large blade outlet angle.

scholarly journals PIV test of the flow field of a centrifugal pump with four types of impeller blades

2021 ◽  
Vol 37 ◽  
pp. 192-204
Author(s):  
Baocheng Shi ◽  
Kaili Zhou ◽  
Jianpeng Pan ◽  
XingKai Zhang ◽  
Ruomeng Ying ◽  
...  
Keyword(s):  
Flow Field ◽  
Relative Velocity ◽  
Solid Particles ◽  
Particle Image Velocimetry System ◽  
Pump Efficiency ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Solid Mixture ◽  
Pressure Surface ◽  
Single Arc

Abstract Flow fields for various impellers were measured using water and a two-phase liquid–solid mixture with a particle image velocimetry system in a centrifugal rotating frame in controlled conditions. After measuring absolute velocity vectors in impeller passages, the vectors were decomposed based on the triangle speed principle and the distribution of relative velocity vectors within the impeller was obtained. Then, the distribution of particles and their influence on the performance of different impellers were analyzed. The following conclusions were made from the comparison of relative velocity vector field: first, the wear on the outlet of blades can be mitigated effectively by reducing the outlet angle of impeller blades; second, the pump with a double-arc-shaped profile had a more uniform and stable flow field distribution and higher performance than that with a single-arc profile; and finally, the “jet–wake” structure can be improved significantly by using impellers with long and short blades, resulting in a remarkable reduction in energy loss and improvement in pump efficiency. We also found that solid particles were mainly distributed at the outlet of the impeller and volute wall, while the concentration distribution of large particles tended to match the pressure surface. This research can provide some theoretical guidance for the design and optimization of two-phase flow centrifugal pumps.

scholarly journals Liquid/solid flow field in a centrifugal pump with different impeller blade types by PIV

2021 ◽  
pp. 002029402110223
Author(s):  
Baocheng Shi ◽  
Kun Xue ◽  
Jianpeng Pan ◽  
XingKai Zhang ◽  
Ruomeng Ying ◽  
...  
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Vector Fields ◽  
Solid Particles ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Impeller Blade ◽  
Rotating Speed ◽  
Pressure Surface ◽  
Solid Liquid

In this study, a non-stirred Particle Image Velocimetry (PIV) testing device is developed to measure the flow field in a solid–liquid two-phase centrifugal pump. The pump casing and impeller are made of an organic glass material. Two types of impellers are designed considering different structure parameters. The performance curves of the pump are obtained for the different impellers at a rotating speed of 900 rpm with particle concentrations of 0%, 3%, 5%, and 10%. The flow fields for water and a solid–liquid two-phase mixture for the two impellers are measured utilizing the PIV system in a centrifugal rotating frame at the designed condition. The distribution of the particles, together with its influence on the performance of the different impellers, is analyzed. From a comparison of the relative velocity vector fields, the following can be concluded. First, the pump with a double arc-shaped profile demonstrated a more uniform and stable flow field distribution and higher performance than that with a single arc profile. Secondly, the solid particles were distributed mainly at the outlet of the impeller and volute wall, whereas the concentration distribution of the larger particles tended to match the pressure surface. This research can provide theoretical guidance for the design and optimization of two-phase flow centrifugal pumps.

Experimental Determination of Statistical Properties of Two-Phase Turbulent Motion

1960 ◽  
Vol 82 (3) ◽  
pp. 609-621 ◽  
Author(s):  
S. L. Soo ◽  
H. K. Ihrig ◽  
A. F. El Kouh
Keyword(s):  
Gas Phase ◽  
Tracer Diffusion ◽  
Statistical Properties ◽  
Solid Particles ◽  
Turbulent Motion ◽  
Two Phase ◽  
Gaseous State ◽  
Diffusion Technique ◽  
And Diffusion

Experimental methods for the determination of certain statistical properties of turbulent conveyance and diffusion of solid particles in a gaseous state are presented. Methods include a tracer-diffusion technique for the determination of gas-phase turbulent motion and a photo-optical technique for the determination of motion of solid particles. Results are discussed and compared with previous analytical results.

scholarly journals Two-Phase Dusty Fluid Flow Along a Rotating Axisymmetric Round-Nosed Body

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Sadia Siddiqa ◽  
Naheed Begum ◽  
M. A. Hossain ◽  
Rama Subba Reddy Gorla
Keyword(s):  
Boundary Layer ◽  
Flow Characteristics ◽  
Leading Edge ◽  
Solid Particles ◽  
Dust Particles ◽  
Computational Domain ◽  
Two Phase ◽  
Carrier Fluid ◽  
Boundary Layer Equations ◽  
Implicit Finite Difference

This article is concerned with the class of solutions of gas boundary layer containing uniform, spherical solid particles over the surface of rotating axisymmetric round-nosed body. By using the method of transformed coordinates, the boundary layer equations for two-phase flow are mapped into a regular and stationary computational domain and then solved numerically by using implicit finite difference method. In this study, a rotating hemisphere is used as a particular example to elucidate the heat transfer mechanism near the surface of round-nosed bodies. We will investigate whether the presence of dust particles in carrier fluid disturbs the flow characteristics associated with rotating hemisphere or not. A comprehensive parametric analysis is presented to show the influence of the particle loading, the buoyancy ratio parameter, and the surface of rotating hemisphere on the numerical findings. In the absence of dust particles, the results are graphically compared with existing data in the open literature, and an excellent agreement has been found. It is noted that the concentration of dust particles’ parameter, Dρ, strongly influences the heat transport rate near the leading edge.

PIV Measurements Within the Waves of Wavy and Wavy-Annular Horizontal Two-Phase Flow

2005 ◽  
Author(s):  
R. E. Foster ◽  
T. A. Shedd
Keyword(s):  
Particle Image ◽  
Image Processing Algorithm ◽  
Two Phase ◽  
Piv Measurements ◽  
Post Process ◽  
Image Velocimetry ◽  
Processed Form ◽  
Image Pairs ◽  
Particle Images ◽  
The Waves

A novel technique of microscopic Particle Image Velocimetry (PIV) is presented for two-phase annular, wavy-annular and stratified flow. Seeding of opaque particles in a water/dye flow allows the acquisition of instantaneous film velocity data in the film cross-section at the center of the tube in the form of digital image pairs. An image processing algorithm is also described that allows numerical velocities to be distilled from particle images by commercial PIV software. The approach yields promising results for stratified and wavy-annular flows, however highly bubbly flows remain difficult to image and post-process. Initial data images are presented in raw and processed form.

scholarly journals Experimental and Numerical Analysis on Two-Phase Induced Low-Speed Pre-Ignition

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5063
Author(s):  
Norbert Zöbinger ◽  
Thorsten Schweizer ◽  
Thomas Lauer ◽  
Heiko Kubach ◽  
Thomas Koch
Keyword(s):  
Gas Phase ◽  
Cfd Simulation ◽  
Particle Temperature ◽  
Solid Particles ◽  
Two Phase ◽  
Engine Operation ◽  
Oil Droplet ◽  
Low Speed ◽  
Detailed Reaction Mechanism ◽  
Oil Fuel

The root cause of the initial low-speed pre-ignition (LSPI) is not yet clarified. The literature data suggest that a two-phase phenomenon is most likely triggering the unpredictable premature ignitions in highly boosted spark-ignition engines. However, there are different hypotheses regarding the actual initiator, whether it is a detached liquid oil-fuel droplet or a solid-like particle from deposits. Therefore, the present work investigates the possibility of oil droplet-induced pre-ignitions using a modern downsized engine with minimally invasive endoscopic optical accessibility incorporating in-cylinder lubrication oil detection via light-induced fluorescence. This setup enables the differentiation between liquid and solid particles. Furthermore, the potential of hot solid particles to initiate an ignition under engine-relevant conditions is analyzed numerically. To do so, the particle is generalized as a hot surface transferring heat to the reactive ambient gas phase. The gas-phase reactivity is represented as a TRF/air mixture based on RON/MON specifications of the investigated fuel. The chemical processes are predicted using a semi-detailed reaction mechanism, including 137 species and 633 reactions in a 2D CFD simulation framework. In the optical experiments, no evidence of a liquid oil droplet-induced pre-ignition could be found. Nevertheless, all observed pre-ignitions had a history of flying light-emitting objects. There are strong hints towards solid-like deposit LSPI initiation. The application of the numerical methodology to mean in-cylinder conditions of an LSPI prone engine operation point reveals that particles below 1000 K are not able to initiate a pre-ignition. A sensitivity analysis of the thermodynamic boundary conditions showed that the particle temperature is the most decisive parameter on the calculated ignition delay time.

scholarly journals Simulation Analysis of Erosion–Corrosion Behaviors of Elbow under Gas-Solid Two-Phase Flow Conditions

Lubricants ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 92
Author(s):  
Qunfeng Zeng ◽  
Wenchuang Qi
Keyword(s):  
Chemical Reaction ◽  
Simulation Analysis ◽  
Electrochemical Corrosion ◽  
Simulation Software ◽  
Solid Particles ◽  
Two Phase ◽  
Particle Count ◽  
Coal Gas ◽  
Erosion Corrosion ◽  
Corrosion Behaviors

In the production and gathering process of coal gas, the complex composition of the coal gas, harsh environments, the complex medium, and high content of solid particles in slurry cause the equipment malfunctions and even failure because of erosion and corrosion. In the present study, COMSOL multi-physics finite element simulation software is used to simulate the erosion–corrosion behaviors of elbow in key chemical equipments. The electrochemical corrosion, solid particle erosion, chemical reaction, and turbulent flow are coupled together. The particle count method is proposed to clarify the erosion phenomenon. The simulation results show that particles with high turbulent intensity hit the wall of elbow directly, which forms a slanted elliptical erosion zone on the extrados surface at 40°–50°. The chemical reaction in turbulence has a difference in the concentration distribution of substances, and this phenomenon leads to different magnitudes of the corrosion current densities in the tube. Moreover, 1/6 released particles hit the extrados surface of the elbow. These findings are beneficial to understand the erosion–corrosion phenomena and design the elbow in key chemical equipment.

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