Flow Field Test and Analysis of KYF Flotation Cell by PIV

2013 ◽  
Vol 331 ◽  
pp. 200-204 ◽  
Author(s):  
Shuai Xing Shi ◽  
Yue Yu ◽  
Wen Wang Yang ◽  
Hong Xi Zhou
Keyword(s):  
Flow Field ◽  
Large Scale ◽  
Test System ◽  
Tracer Particles ◽  
Flotation Cells ◽  
Image Velocimetry ◽  
Flotation Cell ◽  
Tank Bottom ◽  
Set Up ◽  
Ore Dressing

KYF flotation cell is one of the most widely used flotation cells in ore dressing in China. To optimize its structure parameters further, Particle Image Velocimetry (PIV) test system is set up to investigate the flow field in KYF flotation cell. The test is carried out under water condition, taking fluorescence sphere (51.7μm in diameter) as tracer particles of flow field, and three regions of flow field in KYF-0.2 flotation cell are determined as following: half of the whole tank, the region between the impeller and tank bottom, and the region in space between stator blades. Velocity vector diagrams of flow field in three regions are plotted. The results show that there are the upper and the lower flow circulations in flotation cell with dead area at the corner of tank bottom, and the smooth and steady flow in space between stator blades. All studies above strongly support the optimum design for large scale KYF flotation cell.

Nanoparticle Precipitation in a T-Mixer: Coupling Experimental and Numerical Investigations of the Fluid Dynamics With the Solid Formation Processes

2006 ◽  
Author(s):  
Johannes Gradl ◽  
Florian Schwertfirm ◽  
Hans-Christoph Schwarzer ◽  
Hans-Joachim Schmid ◽  
Michael Manhart ◽  
...  
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Concentration Field ◽  
Population Balance ◽  
Mixing Process ◽  
Image Velocimetry ◽  
Modeling Material ◽  
Field Information ◽  
Set Up ◽  
3D Information

Mixing and consequently fluid dynamic is a key parameter to tailor the particle size distribution (PSD) in nanoparticle precipitation. Due to fast and intensive mixing a static T-mixer configuration is capable for synthesizing continuously nanoparticles. The flow and concentration field of the applied mixer is investigated experimentally at different flow rates by Particle Image Velocimetry (PIV) and Laser Induced Fluorescence (LIF). Due to the PIV measurements the flow field in the mixer was characterized qualitatively and the mixing process itself is quantified by the subsequent LIF-measurements. A special feature of the LIF set up is to detect structures in the flow field, which are smaller than the Batchelor length. Thereby a detailed insight into the mixing process in a static T-Mixer is given. In this study a CFD-based approach using Direct Numerical Simulation (DNS) in combination with the solid formation kinetics solving population balance equations (PBE) is applied, using barium sulfate as modeling material. A Lagrangian Particle Tracking strategy is used to couple the flow field information with a micro mixing model and with the classical theory of nucleation. We found that the DNS-PBE approach including macro and micro mixing, combined with the population balance is capable of predicting the full PSD in nanoparticle precipitation for different operating parameters. Additionally to the resulting PSD, this approach delivers a 3D-information about all running subprocesses in the mixer, i.e. supersaturation built-up or nucleation, which is visualized for different process variables.

scholarly journals Hydrodynamic and Flotation Kinetic Analysis of a Large Scale Mechanical Agitated Flotation Cell with the Typical Impeller and the Arc Impeller

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 79 ◽  
Author(s):  
Zhengchang Shen ◽  
Ming Zhang ◽  
Xuesai Fan ◽  
Shuaixing Shi ◽  
Dengfeng Han
Keyword(s):  
Large Scale ◽  
Hydrodynamic Performance ◽  
Collision Probability ◽  
Collision Kernel ◽  
Low Grade ◽  
Performance Parameters ◽  
Effective Volume ◽  
Mineral Particles ◽  
Flotation Cells ◽  
Flotation Cell

The processing of low grade mineral ores using large scale flotation cells is obviously more advantageous than smaller-scale processing. Large-scale flotation cells have become increasingly important for effective volume scale-up. In this study, the latest and largest flotation cell in China, with an effective volume of 680 m3, is considered. Hydrodynamics and flotation kinetics analyses are conducted using computational fluid dynamics (CFD) simulation. It is demonstrated that the flotation cell with a typical impeller produces suitable hydrodynamics for mineral particles based on analysis of the flow pattern, gas dispersion and solid suspension. The performance of the large-scale flotation cell is studied using hydrodynamic performance parameters. The variation of the performance parameters, such as the power number (Np), the Froude number (Fr), the air flow number (Na), and so on, with the flotation cell volumes, followed trends similar to that of previous cells of a different size, which were proven to be effective for engineering applications. To decrease the detachment of mineral particles, a new type of impeller, for which the impeller plate is a hyperbolic curve, viz. an arc impeller, was developed. Compared with the typical impeller, the arc impeller expands and lifts the low circulating flow, thereby shortening the transportation distance of the mineral particles. The data indicates that kinetic eddy dissipation plays a key role in determining the collision kernel and collision probability profile. The newly designed arc impeller leads to a higher collision probability than the typical impeller, resulting in better flotation performance. This research should aid in the optimization of the structure of the 680 m3 flotation cell.

Design of the Interval between Reaction Mass and Foundation in Vibration Test System

2013 ◽  
Vol 321-324 ◽  
pp. 17-22
Author(s):  
Lu Tao Yan ◽  
Zhi Peng Yang ◽  
Hong Li
Keyword(s):  
Large Scale ◽  
Maximum Amplitude ◽  
Fem Analysis ◽  
Test System ◽  
Reaction Mass ◽  
Vibration Test ◽  
The Finite Element Method ◽  
Mass System ◽  
Design And Optimization ◽  
Set Up

The dynamic model of the reaction mass system in the large-scale vibration test system is set up, and the crossover frequencies are calculated in order to determine the operation capability and the interval between reaction mass and foundation. On the basis of the finite element method (FEM) analysis and theory of analysis mechanics, the dynamic response of the reaction mass is studied. The results show that the maximum amplitude of the dynamical system is obtained at the natural frequency of the system. The results of theoretical and FEM calculations indicate that the maximum displacements responses are all much lower than the design of the interval, which means the design is satisfied and reasonable. This method can calculate the operation capability of the reaction mass effectively and can be used for vibration test system design and optimization.

Experimental Study of the Characteristics of Gas Impinging Streams Using PIV Technique

2013 ◽  
Author(s):  
Wei Wei ◽  
ZhiYi Li ◽  
Fengxia Liu ◽  
Zhijun Liu
Keyword(s):  
Mass Transfer ◽  
Experimental Study ◽  
Flow Field ◽  
Flow Rate ◽  
Particle Image ◽  
Velocity Fields ◽  
Experimental Equipment ◽  
Piv Technique ◽  
Tracer Particles ◽  
Image Velocimetry

Impinging streams technology has been widely used in many applications in recent years because of its enhancement to the heat and mass transfer between phases. In this paper, in order to investigate the influences of the impinging distance and flow rate on the characters of the flow field, gas-gas impinging streams flow fields are tested experimentally and analyze qualitatively with particle image velocimetry (PIV). The experimental equipment consists of two opposite nozzles which are the same axis. A PIV system is used to measure the characters of the 2-D flow field between two opposite nozzles. The gas is delivered by a compressor through two opposite jets which could be seeded with oil droplets as tracer particles. The effects of the flow rate and impinging distance on the velocity fields of impinging zone are investigated in detail. As the flow rate increases from 0.2 m3/h to 0.8 m3/h, the width of impinging zone increases from 0.25 to 0.5. However, the range of impinging zone does not change significantly as the impinging distance increases from 61mm to 94mm. The results indicate that the PIV technique is an effective method to measure and analyze the characters of impinging streams.

scholarly journals Design, Operation and Construction of a Large Rainfall Simulator for the Field Study on Acidic Barren Slope

2018 ◽  
Vol 4 (8) ◽  
pp. 1851 ◽  
Author(s):  
Siti Fazlina MD Isa ◽  
A T S Azhar ◽  
M Aziman
Keyword(s):  
Large Scale ◽  
Soft Soil ◽  
Test System ◽  
Rainfall Simulation ◽  
Rainfall Simulator ◽  
R And D ◽  
Subsequent Test ◽  
Pumping System ◽  
Artificial Rainfall ◽  
Set Up

The utilization of rainfall simulators has turned out to be more far reaching with the automated instrumentation and control systems. This paper portrays a rainfall simulator designed for analysis of erosion on steep (2.5H: 1V). A rainfall simulator designed to perform experiments in slope is introduced. The large scale of the apparatus allows the researcher to work in remote areas and on steep slopes. This simulator was designed to be effortlessly set up and kept up as well as able and additionally ready to create a variety of rainfall regimes. The nozzle performance tests and lateral spacing tests were performed at Research Center for Soft Soil (RECESS), which is another Research and Development (R and D) activity by Universiti Tun Hussein Onn Malaysia. This test system is the standard for research involving simulated rainfall. The rainfall simulator is a pressurized nozzle type simulator. It discharges uniform rainfall on a square plot 6 m wide by 6 m (19.685 ft) long. The fundamental parts of a sprinkler rainfall simulator are a nozzle, a structure in which installs the nozzle, and the connections with the water supply and the pumping system. The structure of the test system was manufactured created with four fixed hollow rectangular galvanised on which a header with 25 nozzles attached to it. The nozzles are spaced 1 m apart. Flow meters control the inflow of water from the storage tank, ensuring each nozzle has a similar release rate, regardless of the introduction of the test system. The tank that was utilized has the 200 gallons of water which is 757.08 Lit and the full with water in tank can run the artificial rainfall simulation roughly around 50 to 60 minutes. The support system is collapsible, easy to set up and maintain. The subsequent test system is conservative (under RM9,000 to build), made with industrially accessible parts, simple to set-up and maintain and highly accurate.

scholarly journals Large-scale volumetric flow visualization of the unsteady wake of a flapping-wing micro air vehicle

2019 ◽  
Vol 61 (1) ◽  
Author(s):  
B. Martínez Gallar ◽  
B. W. van Oudheusden ◽  
A. Sciacchitano ◽  
M. Karásek
Keyword(s):  
Large Scale ◽  
Flow Speed ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Body Angle ◽  
Reduced Frequency ◽  
Tracer Particles ◽  
Unsteady Wake ◽  
Image Velocimetry ◽  
Air Vehicle

Abstract The objective of this experimental investigation is the volumetric visualization of the near wake topology of the vortex structures generated by a flapping-wing micro air vehicle. To achieve the required visualization domain (which in the present experiments amounts to a size of 60,000 cm3), use is made of robotic particle image velocimetry, which implements coaxial illumination and imaging in combination with the use of helium-filled soap bubbles as tracer particles. Particle trajectories are determined via Lagrangian particle tracking and information of different phases throughout the flapping cycle is obtained by means of a phase-averaging procedure applied to the particle tracks. Experiments have been performed at different settings (flow speed, flapping frequency, and body angle) that are representative of actual flight conditions, and the effect of reduced frequency on the wake topology is investigated. Furthermore, experiments have been carried out in both tethered and free-flight conditions, allowing an unprecedented comparison between the aerodynamics of the two conditions. Graphic abstract

Stereoscopic Particle Shadow Velocimetry

2018 ◽  
Author(s):  
Jeff R. Harris ◽  
Michael McPhail ◽  
Christine Truong ◽  
Arnold Fontaine
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Particle Image ◽  
Scattered Light ◽  
Stereoscopic Particle Image Velocimetry ◽  
Two Dimensional ◽  
Tracer Particles ◽  
Image Velocimetry ◽  
Out Of Plane ◽  
Led Backlight

Stereoscopic particle image velocimetry (SPIV) is a variant of particle image velocimetry (PIV) that allows for the measurement of three components of velocity along a plane in a flow field. In PIV, particles in the flow field are tracked by reflecting laser light from tracer particles into two angled cameras, allowing for the velocity field to be determined. Particle shadow velocimetry (PSV) is an inherently less expensive velocity measurement method since the method images shadows cast by particles from an LED backlight instead of scattered light from a laser. Previous studies have shown that PSV is an adequate substitute for PIV for many two-dimensional, two-component velocimetry measurements. In this work, the viability of the two-dimensional, three-component stereoscopic particle shadow velocimetry (SPSV) is demonstrated by using SPSV to examine a simple jet flow. Results obtained using SPIV are also used to provide benchmark comparison for SPSV measurements. Results show that in-plane and out-of-plane velocities measured using SPSV are comparable to those measured using SPIV.

Accuracy Verification of 2-Dimensional Velocity Field Derived From Optical Flow With Respect to PIV Flow Field Measurement

2020 ◽  
Author(s):  
Mingli Cui ◽  
Zhe Sun ◽  
Min Xu ◽  
David Hung ◽  
Xuesong Li
Keyword(s):  
Flow Field ◽  
Optical Flow ◽  
Field Measurement ◽  
Ambient Air ◽  
Fuel Spray ◽  
Measurement Technology ◽  
Air Velocity ◽  
Tracer Particles ◽  
Image Velocimetry ◽  
Flow Field Measurement

Abstract As a mature flow field measurement technology, particle image velocimetry (PIV) has been widely used to calculate the instantaneous motion of particles by identifying and comparing the positions of tracer particles between successive image frames. For example, the ambient air velocity distributions around fuel spray can be measured using LIF-PIV However, due to the need to accurately identify the tracer particles, PIV is limited in its applications, such as measuring the flow field in turbid media. Optical flow calculates apparent velocities of movement of brightness patterns in an image. Different from PIV, optical flow segments images into regions that corresponds to different objects without requirement of tracer particles. Since it is based on brightness patterns, optical flow may be widely used in measuring flow field in the area of fuel spray and in-cylinder combustion. To check the accuracy and robustness of optical flow, this study will calculate the 2-dimensional velocity fields of the same PIV image sequences using iterative optical flow and PIV respectively. Using PIV results as criterions, precision and accuracy of optical flow are studied.

scholarly journals Large Scale Infrared-Based Remote Sensing of Turbulence Metrics in Surface Waters: Going Beyond Mean Flow

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Seth Avram Schweitzer ◽  
Edwin Alfred Cowen
Keyword(s):  
Large Scale ◽  
Surface Velocity ◽  
Seeding Density ◽  
Mean Flow ◽  
Tracer Particles ◽  
Image Velocimetry ◽  
Temporal Averaging ◽  
Spatio Temporal ◽  
Scale Particle ◽  
Image Collection

In recent years field-scale applications of image-based velocimetry methods, often referred to as large scale particle image velocimetry (LSPIV), have been increasingly deployed. These velocimetry measurements have several advantages—they allow high resolution, non-contact measurement of surface velocity over a large two dimensional area, from which the bulk flow can be inferred. However, visiblelight LSPIV methods can have significant limitations. The water surface often lacks natural features that can be tracked in the visible and generally requires seeding with tracer particles, which creates concerns regarding the fidelity with which tracer particles track the flow, and introduces challenges in achieving sufficient and uniform seeding density, in particular in regions with appreciable velocity accelerations such as turbulence. In LSPIV, image collection is generally limited to daylight hours, and can suffer from non-uniformity of illumination across the camera’s field of view. Due to these issues LSPIV often requires spatio-temporal averaging, and as a result is generally able to extracting the mean, but not the instantaneous, velocity field, and hence is often not a suitable tool for calculating turbulence metrics of the flow.

scholarly journals Evidence of preferential sweeping during snow settling in atmospheric turbulence

2021 ◽  
Vol 928 ◽  
Author(s):  
Jiaqi Li ◽  
Aliza Abraham ◽  
Michele Guala ◽  
Jiarong Hong
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Particle Tracking ◽  
Particle Tracking Velocimetry ◽  
Large Scale ◽  
Particle Image ◽  
Atmospheric Flow ◽  
Image Velocimetry ◽  
Snow Particle ◽  
Scale Particle

We present a field study of snow settling dynamics based on simultaneous measurements of the atmospheric flow field and snow particle trajectories. Specifically, a super-large-scale particle image velocimetry (SLPIV) system using natural snow particles as tracers is deployed to quantify the velocity field and identify vortex structures in a 22 m  $\times$  39 m field of view centred 18 m above the ground. Simultaneously, we track individual snow particles in a 3 m  $\times$  5 m sample area within the SLPIV using particle tracking velocimetry. The results reveal the direct linkage among vortex structures in atmospheric turbulence, the spatial distribution of snow particle concentration and their settling dynamics. In particular, with snow turbulence interaction at near-critical Stokes number, the settling velocity enhancement of snow particles is multifold, and larger than what has been observed in previous field studies. Super-large-scale particle image velocimetry measurements show a higher concentration of snow particles preferentially located on the downward side of the vortices identified in the atmospheric flow field. Particle tracking velocimetry, performed on high resolution images around the reconstructed vortices, confirms the latter trend and provides statistical evidence of the acceleration of snow particles, as they move toward the downward side of vortices. Overall, the simultaneous multi-scale particle imaging presented here enables us to directly quantify the salient features of preferential sweeping, supporting it as an underlying mechanism of snow settling enhancement in the atmospheric surface layer.

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