Localized Particle Concentration Measurement in Slurry Flows Using A-Scan Ultrasound Technique

2009 ◽  
Author(s):  
John M. Furlan ◽  
Venkat Mundla ◽  
Jaikrishnan Kadambi ◽  
Nathaniel Hoyt ◽  
Robert Visintainer ◽  
...  
Keyword(s):  
Solid Particle ◽  
Particle Concentration ◽  
Volume Fraction ◽  
Computational Study ◽  
Solid Particles ◽  
Acoustic Properties ◽  
Imaging Method ◽  
Concentration Profiles ◽  
Calibration Data ◽  
Slurry Flows

In the design of slurry transport equipment, the effects of solid particle concentration on hydraulic performance and wear have to be considered. This study involves examining the acoustic properties of slurry flows such as velocity, backscatter and attenuation as a function of volume fraction of solid particles. Ultrasound A-mode imaging method is developed to obtain particle concentration in a flow of soda lime glass particles (diameter of 200 micron) and water slurry in a 1″ diameter pipe. Based on the acoustic properties of the slurry a technique is developed to measure local solid particle concentrations. The technique is used to obtain concentration profiles in homogeneous (vertical flow) and non-homogeneous (horizontal flow) slurry flows with solid particle concentrations ranging from 1–10% by volume. The algorithm developed utilizes the power spectrum and attenuation measurements obtained from the homogeneous loop as calibration data in order to obtain concentration profiles in other (i.e. non-homogenous) flow regimes. A computational study using FLUENT was performed and a comparison is made with the experimental results. A reasonable agreement between the experimental and computational results is observed.

Ultrasonic Measurements of Local Particle Velocity and Concentration Within the Casing of a Centrifugal Pump

2015 ◽  
Author(s):  
John M. Furlan ◽  
Mohamed Garman ◽  
Jaikrishnan Kadambi ◽  
Robert J. Visintainer ◽  
Krishnan V. Pagalthivarthi
Keyword(s):  
Centrifugal Pump ◽  
Particle Velocity ◽  
Volume Fraction ◽  
Side Wall ◽  
Velocity Fields ◽  
Solid Particles ◽  
Acoustic Properties ◽  
Soda Lime Glass ◽  
Calibration Data ◽  
Slurry Flows

In the design of slurry transport equipment used in the mining and dredging industries, the effects of solid particle velocity and concentration on hydraulic performance and wear need to be considered. Two ultrasonic techniques have been used to investigate slurry flows through a centrifugal pump casing: a local particle concentration measurement technique (Furlan et al., 2012) and a pulsed ultrasonic Doppler Velocimetry (PUDV) technique (Hanjiang, 2003, Garman, 2015). Local particle velocities and concentrations have been obtained in a flow of soda lime glass particles (diameter of 195 μm) and water through the casing of a centrifugal slurry pump operating close to the best efficiency point using the two ultrasound techniques. For the concentration measurements, the acoustic properties of slurry flows such as sonic velocity, backscatter, and attenuation are correlated to the volume fraction of solid particles. The algorithm utilizes measurements obtained from homogeneous vertical pipe flow fields as calibration data in order to obtain experimental concentration profiles in the non-homogenous flow regimes which are encountered in the pump casing. The PUDV technique correlates the Doppler shift in frequency associated with the movement of particles towards or away from the transducer. A two measurement (angle) technique is applied within the pump casing in order to account for the components of particle velocity which are orthogonal to the casing side wall. The techniques are utilized to obtain concentration and velocity profiles within the pump casing for overall average loop particle concentrations ranging from 7–11 % by volume. The experimental results are compared with the concentration and velocity fields that are predicted by in-house finite element computational fluid dynamics (CFD) codes (Pagalthivarthi and Visintainer, 2009) which are used to predict wear in centrifugal slurry pump wet end components. Reasonable agreement is observed for both the concentration and velocity fields. Specifically, measurements indicate that there is a reduction of in-situ concentration and hence a corresponding radial acceleration of the particles with respect to the fluid occurring within the impeller which has also been predicted by computational predictions of flow through the impeller (Pagalthivarthi et al., 2013). Additionally, the prediction of the existence of secondary flow patterns by the casing computational code has been supported with the velocity measurements.

A Model for the Effect of Velocity on Erosion of N80 Steel Tubing due to the Normal Impingement of Solid Particles

1992 ◽  
Vol 114 (1) ◽  
pp. 54-64 ◽  
Author(s):  
D. P. Chase ◽  
E. F. Rybicki ◽  
J. R. Shadley
Keyword(s):  
Solid Particle ◽  
Computational Study ◽  
Target Material ◽  
Target Surface ◽  
American Petroleum Institute ◽  
Solid Particles ◽  
Unknown Coefficient ◽  
Conservation Of Energy ◽  
Carrier Fluid ◽  
Erosion Behavior

As part of a combined experimental and computational study of erosion for gas and oil production conditions, a semi-empirical model has been developed to predict erosion ratio behaviors of metals due to solid particle impingement. One use of the model will be to reduce the total number of experiments needed to characterize erosion behavior. The model represents material property information associated with both the target material and the impinging particles, as well as impingement speed. Five different models are examined in terms of ability to predict erosion ratio behavior as a function of impingement speed. The model selected is based on a conservation of energy formulation and fracture mechanics considerations to predict the amount of material removed due to solid particle impingement. The resulting equation to predict the erosion ratio for a given particle size contains one unknown coefficient which is determined through comparison with experimental data. Illustrative examples are presented for data for two different sizes of glass bead solid particles in an oil carrier fluid impinging on an API (American Petroleum Institute) N80 grade steel target at an impingement angle 90 deg to the target surface. Using erosion data at one impingement speed to determine the unknown coefficient, the model was used to predict erosion behavior at a range of other speeds. Good agreement between the erosion ratio data and the values predicted by the model were found for two solid particle sizes. Recommendations for expanding the capabilities of the model are pointed out.

Computational Study of Slurry Flow in Pipes to Determine Profiles Sensed in Near Infrared Slurry Measurements

2011 ◽  
Author(s):  
V. Pasangulapati ◽  
N. R. Kesana ◽  
G. Sharma ◽  
F. W. Chambers ◽  
M. E. McNally ◽  
...  
Keyword(s):  
Near Infrared ◽  
Volume Fraction ◽  
Solid Phase ◽  
Computational Study ◽  
Solid Volume Fraction ◽  
Density Ratio ◽  
Optical Measurements ◽  
Concentration Profiles ◽  
Horizontal Pipe ◽  
Volume Fractions

It is desired to perform accurate Near Infrared sensor measurements of slurries flowing in pipes leaving large batch reactors. A concern with these measurements is the degree to which the slurry sensed is representative of the material in the reactor and flowing through the pipe. Computational Fluid Dynamics (CFD) has been applied to the flow in the pipe to determine the flow fields and the concentration profiles seen by the sensors. The slurry was comprised of a xylene liquid phase and an ADP (2-amino-4, 6-dimethylpyrimidine) solid phase with a density ratio of 1.7. Computations were performed for a horizontal pipe with diameter 50.8 mm, length 2.032 m, and 1.76 m/s and 3.26 m/s mixture velocities. The corresponding pipe Reynolds numbers were 1.19E+05 and 2.21E+05. The flow through a slotted cylindrical probe inserted radially in the pipe also was considered. Spherical slurry particles with diameters from 10 μm to 1000 μm were considered with solid volume fractions of 12%, 24%, and 35%. Computations were performed with ANSYS FLUENT 12 software using the Realizable k-ε turbulence model and the enhanced wall treatment function. Comparisons of computed vertical profiles of solid volume fraction to results in the literature showed good agreement. Symmetric, nearly flat solid volume fraction profiles were observed for 38 μm particles for all three initial solid volume fractions. Asymmetric solid volume fraction profiles with greater values toward the bottom were observed for the larger particles. Changes in the profiles of turbulent kinetic energy also were observed. These changes are important for optical measurements which depend upon the mean concentration profiles as well as the turbulent motion of the slurry particles.

CFD Modeling of Gas Particle Flow Within a Solid Particle Solar Receiver

Solar Energy ◽  
2006 ◽  
Author(s):  
Huajun Chen ◽  
Yitung Chen ◽  
Hsuan-Tsung Hsieh ◽  
Nathan Siegel
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Solid Particle ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Operating Conditions ◽  
Solid Particles ◽  
Particle Flow ◽  
Cfd Modeling ◽  
Solar Receiver

A detailed three dimensional computational fluid dynamics (CFD) analysis on gas-particle flow and heat transfer inside a solid particle solar receiver, which utilizes free-falling particles for direct absorption of concentrated solar radiation, is presented. The two-way coupled Euler-Lagrange method is implemented and includes the exchange of heat and momentum between the gas phase and solid particles. A two band discrete ordinate method is included to investigate radiation heat transfer within the particle cloud and between the cloud and the internal surfaces of the receiver. The direct illumination energy source that results from incident solar radiation was predicted by a solar load model using a solar ray tracing algorithm. Two kinds of solid particle receivers, each having a different exit condition for the solid particles, are modeled to evaluate the thermal performance of the receiver. Parametric studies, where the particle size and mass flow rate are varied, are made to determine the optimal operating conditions. The results also include detailed information for the particle and gas velocity, temperature, particle solid volume fraction, and cavity efficiency.

An experimental study of the motion of concentrated suspensions in two-dimensional channel flow. Part 2. Bidisperse systems

1998 ◽  
Vol 363 ◽  
pp. 57-77 ◽  
Author(s):  
M. K. LYON ◽  
L. G. LEAL
Keyword(s):  
Large Particle ◽  
Particle Concentration ◽  
Volume Fraction ◽  
Balance Model ◽  
Concentration Profiles ◽  
Size Segregation ◽  
Small Particles ◽  
Concentrated Suspensions ◽  
Particle Volume ◽  
Large Particles

In this paper we report experimental velocity and concentration profiles for suspensions possessing a bidisperse distribution of particle size undergoing pressure-driven flow through a parallel-wall channel. In addition to the overall concentration distributions determined by implementing the modified laser Doppler velocimetry method described in Part 1 (Lyon & Leal 1998), concentration profiles for the particles of each size were measured by sampling the position of marked tracer particles across 60% of the channel gap. Non-uniform overall particle concentration distributions and blunted velocity profiles were found at bulk particle volume fractions of 0.30 and 0.40, which were equal to the monodisperse data of Part 1, within experimental uncertainty. The large-particle concentration profiles were non-uniform down to a large-particle bulk volume fraction of 0.075, while non-uniform distributions of the small particles were only found when the volume fraction of small particles in the bulk was greater than or equal to 0.20. Experiments in which at least half the suspended particulate volume was occupied by large particles revealed enrichment of the large particles in the centreline region of the channel. This size segregation was found to increase as the total number of suspended particles decreased. Finally, the data from experiments in which a uniform small-particle concentration profile was measured were compared with suspension balance model (McTigue & Jenkins 1992; Nott & Brady 1994) predictions for parameter values that corresponded only to the large particles. While close agreement with the large-particle concentration profiles was found, this comparison also reflected the fact that the small particles bring the suspension viscosity to a regime that is more sensitive to the particle concentration, rather than simply providing an increment in background viscosity to the suspending liquid.

Numerical Investigation on Optimal Design of Solid Particle Solar Receiver

2007 ◽  
Author(s):  
Huajun Chen ◽  
Yitung Chen ◽  
Hsuan-Tsung Hsieh ◽  
Greg Kolb ◽  
Nathan Siegel
Keyword(s):  
Solar Radiation ◽  
Solid Particle ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Solid Particles ◽  
Load Model ◽  
Concentrated Solar Radiation ◽  
Tracing Algorithm ◽  
Solar Receiver ◽  
And Storage

Solar thermo-chemical processes often require high temperatures that can be achieved by direct absorption of solar energy. The solid particle solar receiver can be used to heat ceramic particles that may serve as a heat transfer and storage medium or as a substrate on which chemical reaction may be performed directly. Using solid particles enclosed in a cavity to absorb concentrated solar radiation can provide efficient absorption of concentrated sunlight. In this work, different solid particle solar receiver designs have been investigated by using computation fluid dynamics (CFD) technique. The gas particle flow with the solid particle solar receiver was simulated by using two-way coupled Euler-Lagrange method. The direct illumination energy source that results from incident solar radiation was predicted by a solar load model using a solar ray tracing algorithm. The detailed information to guide the experiment, such as the particle and gas velocity, temperature, particle solid volume fraction, and cavity efficiency under different designs has been analyzed.

A Computational Analysis of Multiphase Flow Cyclonic Separator for Clean Combustion in Power Plants

2003 ◽  
Author(s):  
Fernando Z. Sierra ◽  
David Jua´rez ◽  
Juan C. Garci´a ◽  
Janusz Kubiak ◽  
Rube´n Nicola´s
Keyword(s):  
Power Plants ◽  
Particle Concentration ◽  
Volume Fraction ◽  
Solid Particles ◽  
Mixture Flow ◽  
Fuel Gas ◽  
Solid Mixture ◽  
High Particle Concentration ◽  
Aspect Ratios ◽  
Coal Particles

In this paper a numerical computation of the flow dynamics in a compact cyclonic separator (CCS) for multiphase mixtures is presented. The study is directed to power plants consumption requirements where fuel gas must be free of solid particulate. A finite volume approach has been employed with body-fitted coordinates in a 3-D solution of the CCS dynamics. The cylindrical geometry under study includes aspect ratios in the range 2.5<R<3.8 (where R = height/diameter). The CCS has three exits as follows: one on the top for gas; one on the bottom for low particle concentration liquid; and the last one tangentially located on the lower part of the CCS for high particle concentration liquid. The turbulence was resolved using a RNG model, while the interactions between each component of the flow were addressed using a mixture slip model. The three-phase liquid-gas-solid mixture considered was gasoil-propane-mineral coal particles with the composition in volume fraction of liquid to gas of 0.9 to 0.1 in addition to 109 kg/m3 of 40 microns coal particles as the disperse phase. The results indicate that reversible flow of liquid through the upper gas-outlet may be a function of the outlet pressure conditions. Also, velocity conditions of the income mixture flow at the inlet defined the residence time of the flow during the operation of the CCS, which affects the separation too. In this work density profiles are shown to indicate the regions of up flow for gas and liquid drag. The presence of a third phase in the form of solid particles affects the flow patterns in a CCS.

Numerical study of geometric parameters effects on the suspended solid particles in the oil transmission pipelines

2021 ◽  
pp. 095440622110454
Author(s):  
Seyed Mostafa Moafi Madani ◽  
Javad Alinejad ◽  
Yasser Rostamiyan ◽  
Keivan Fallah
Keyword(s):  
Fluid Flow ◽  
Solid Particle ◽  
Volume Fraction ◽  
Numerical Study ◽  
Suspended Solid ◽  
Geometric Parameters ◽  
Solid Particles ◽  
Bending Radius ◽  
Suspended Solid Particles ◽  
Transmission Pipelines

The innovation of this paper is geometric parameters effects of the oil transmission pipelines on the suspended solid particles. This geometry has been simulated with the Lattice Boltzmann Method based on D2Q9 model for analyzing solid particle tracing, streamlines, solid particle volume fraction, and nondimensional velocity field of fluid flow. These parameters have been investigated in 9 cases of the oil transmission pipelines at two different intensity of fluid flow. The results signified that maximum and minimum ranges of fluid velocity at [Formula: see text] were in case 3 that the oil transmission pipelines with diameter of the pipeline and bending radius, D and 2D, respectively. Also, maximum volume fraction of solid particles at bending radius at [Formula: see text] was in case 3 with diameter of the pipeline and bending radius, D and 2D, respectively. Also, in case 9, solid particles in the oil transmission pipelines were almost symmetrical. Finally, with comparison between figures of solid particles tracing and volume fraction of solid particles, by increasing of the diameter of oil transmission pipelines, the sediment of solid particles was decreased, also, by increasing of the bending radius of oil transmission pipelines, the sediment of solid particles was increased.

scholarly journals Flow Modulation by Finite-Size Neutrally Buoyant Particles in a Turbulent Channel Flow

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Lian-Ping Wang ◽  
Cheng Peng ◽  
Zhaoli Guo ◽  
Zhaosheng Yu
Keyword(s):  
Particle Size ◽  
Solid Particle ◽  
Channel Flow ◽  
Volume Fraction ◽  
Finite Size ◽  
Turbulent Channel Flow ◽  
Solid Particles ◽  
Momentum Exchange ◽  
Flow Modulation ◽  
Neutrally Buoyant

A fully mesoscopic, multiple-relaxation-time (MRT) lattice Boltzmann method (LBM) is developed to perform particle-resolved direct numerical simulation (DNS) of wall-bounded turbulent particle-laden flows. The fluid–solid particle interfaces are treated as sharp interfaces with no-slip and no-penetration conditions. The force and torque acting on a solid particle are computed by a local Galilean-invariant momentum exchange method. The first objective of the paper is to demonstrate that the approach yields accurate results for both single-phase and particle-laden turbulent channel flows, by comparing the LBM results to the published benchmark results and a full-macroscopic finite-difference direct-forcing (FDDF) approach. The second objective is to study turbulence modulations by finite-size solid particles in a turbulent channel flow and to demonstrate the effects of particle size. Neutrally buoyant particles with diameters 10% and 5% the channel width and a volume fraction of about 7% are considered. We found that the mean flow speed was reduced due to the presence of the solid particles, but the local phase-averaged flow dissipation was increased. The effects of finite particle size are reflected in the level and location of flow modulation, as well as in the volume fraction distribution and particle slip velocity near the wall.

scholarly journals A computational study of a multi-solid liquid fluidized bed incorporating inclined channels

2020 ◽  
pp. 41-41
Author(s):  
Naveedul Syed ◽  
Naseer Khan ◽  
Iftikhar Ahmad
Keyword(s):  
Internal State ◽  
Computational Study ◽  
Terminal Velocity ◽  
Solid Particles ◽  
Concentration Profiles ◽  
Particle Species ◽  
Bed Height ◽  
Inclined Channels ◽  
Solid Liquid ◽  
Solid System

Simulations were performed under continuous processing conditions using the 2D continuum model to describe the internal state of a multi-solid system comprising solid particles of different sizes and densities at the same time. The feed consisted of 35 types of solid particle species with five different sizes, 1.70, 1.20, 0.85, 0.60 and 0.35 mm and seven different densities ranging 1400 to 2000 kg/m3. The simulations results have been used to plot the concentration profiles of solid particles along the bed height. The concentration profiles of the solid particles depicted that the fine dense particles, 0.60 mm, having density equal to 1900 kg/m3 and terminal velocity 0.058 m/s moved downwards and discharged into the underflow. However, the low-density coarse particles, 1.20 mm, having density equal to 1400 kg/m3 and terminal velocity 0.068 m/s moved upwards and conveyed to the overflow, hence, showing a separation process based on the density difference. Furthermore, simulation results showed that the particle species having densities close to the value of the separation relative density exhibited higher concentrations along the system height and the suspension within the system was mainly composed of these species.

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