Study of the Particle Separation Performance of a Dust-settling Hopper

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Bofu Wu ◽  
Jinlai Men ◽  
Jie Chen
Keyword(s):  
Fluid Dynamics ◽  
Particle Concentration ◽  
Separation Efficiency ◽  
Simulation Analysis ◽  
Numerical Study ◽  
Particle Separation ◽  
Separation Performance ◽  
Particle Removal ◽  
Airflow Velocity ◽  
Calculation Results

This paper presents a numerical study to predict the particle separation performance of a dust-settling hopper using computational fluid dynamics. The Euler-Lagrange approach was employed to analyze the particle separation efficiency and the outflow particle concentration of the dust-settling hopper under different inlet airflow velocities. The calculation results obtained reveal that the overall particle separation efficiency and the outflow particle concentration decrease with the increase of the inlet airflow velocity, and the particle grade efficiency increases with particle size. Since there is a paradox between the particle separation performance and the particle removal performance for a street vacuum sweeper, it is necessary to counter-balance the effects of the inlet airflow velocity on them. According to the simulation analysis, an appropriate inlet airflow velocity is provided for the design of the dust-settling hopper.

Field testing CFD-based predictions of storage chamber gross solids separation efficiency

1999 ◽  
Vol 39 (9) ◽  
pp. 161-168 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul ◽  
Andrew Drinkwater ◽  
Ian Clifforde
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Settling Velocity ◽  
Separation Efficiency ◽  
Flow Patterns ◽  
Total Efficiency ◽  
Separation Performance ◽  
Storage Chamber ◽  
Solids Separation ◽  
Simulated Flow

The use of computational fluid dynamics-based techniques for predicting the gross solids and finely suspended solids separation performance of structures within urban drainage systems is becoming well established. This paper compares the result of simulated flow patterns and gross solids separation predictions with field measurements made in a full size storage chamber. The gross solids retention efficiency was measured for six different storage chambers in the field and simulations of these chambers were undertaken using the Fluent computational fluid dynamics software. Differences between the observed and simulated flow patterns are discussed. The simulated flow fields were used to estimate chamber efficiency using particle tracking. Efficiency results are presented as efficiency cusps, with efficiency plotted as a function of settling velocity. The cusp represents a range of efficiency values, and approaches to the estimation of an overall efficiency value from these cusps are briefly discussed. Estimates of total efficiency based on the observed settling velocity distribution differed from the measured values by an average of ±17%. However, estimates of steady flow efficiency were consistently higher than the observed values. The simulated efficiencies agreed with the field observations in identifying the most efficient configuration.

Cyclic Flow Experiments of a Fine Particle Separation Hydrocyclone

2007 ◽  
Author(s):  
Lixin Zhao ◽  
Minghu Jiang
Keyword(s):  
Flow Condition ◽  
Fine Particle ◽  
Fine Particles ◽  
Separation Efficiency ◽  
Amplitude Ratio ◽  
Particle Separation ◽  
Separation Performance ◽  
Period Ratio ◽  
Cyclic Flow ◽  
Signal Type

Basic separating principle of hydrocyclones and the cyclic experimental research facilities are introduced. The difficulty of separating fine particle is described. Based on a solid-liquid hydrocyclone used for separating fine particles, effect of cyclic flow condition on hydrocyclone’s performance is studied. Effects of cyclic period ratio, cyclic flowrate amplitude ratio, Reynolds number, gas liquid ratio, and the cyclical signal type on the hydrocyclone’s fine particle separation performance, especially on relative overflow purifying rate were studied in detail. The results show that the separation efficiency of the hydrocyclone operated under cyclic flow condition can be higher than that in steady condition, when the cyclic period ratio is about 0.68 and the cyclic flowrate amplitude ratio is about 2%. Rectangular wave seems to be the best cyclic signal for enhancing the hydrocyclone’s separation efficiency. The cyclical change of flowrate leads to the increasing of hydrocyclone’s energy consumption to some extent, while the increasing amount is very less, which is no more than 3% in general.

scholarly journals Numerical study of the effect of penstock slope on the increase in electric power of micro-hydro system using Computational Fluid Dynamics

2021 ◽  
Vol 927 (1) ◽  
pp. 012029
Author(s):  
Yoga Satria Putra ◽  
Evi Noviani ◽  
Muhardi ◽  
Azrul Azwar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Electric Power ◽  
Numerical Study ◽  
Electrical Power ◽  
Maximum Slope ◽  
The Public ◽  
Hydropower Plants ◽  
Calculation Results ◽  
Alternative Solutions

Abstract Micro-hydropower plants have become one of the alternative solutions to meet the electricity needs of people in remote villages that the public electricity company has not reached. However, the performance of a micro-hydro system has to be continuously developed. This research aims to improve the performance of a micro-hydro system by examining the effect of the slope of the penstock on the increase in electrical power. The penstock slope is varied with diverse angles, namely θ = 50 °, 60 °, 70 °, 80 °, and 90 °. Five simulations of water flow in the penstock for five slope angles were constructed using the open-source CFD software, i.e., OpenFOAM. We calculate the electric power for the five simulations aforementioned. The calculation results show that the variation of the penstock slope can affect the increase of the electric power of a micro-hydro system. The highest electric power occurs at a maximum slope, θ = 90 °.

Study of the Transitional Flow and Particle Separation With a Fishhook Effect in a Mini-Hydrocyclone

2012 ◽  
Author(s):  
Guofeng Zhu ◽  
Jong-Leng Liow ◽  
Andrew Neely
Keyword(s):  
Fine Particles ◽  
Separation Efficiency ◽  
Numerical Study ◽  
Particle Interaction ◽  
Particle Separation ◽  
Transitional Flow ◽  
Lagrangian Model ◽  
Correction Coefficient ◽  
Inlet Velocity ◽  
Les Model

The mini-hydrocyclone is being proposed as a micro-separator in complex micro-devices for in-line fine particle separation as it has a concise geometry and no moving parts,. In this work, we present a numerical study combined by experiments on a 5 mm minihydrocyclone to investigate the transitional flow and particle separation with the presence of a fishhook effect. The results showed that the simulation from the LES model gave good agreement with that from DNS at an inlet velocity of 0.4 m/s. The LES model was then used to study the higher inlet velocity cases of 1.0 and 1.8 m/s. The particle separation was predicted by a Lagrangian model with an added user defined function (UDF) in the Fluent code to account for the particle interaction. The modeling results for the three inlet velocities studied showed that small particle Reynolds number, ReP, resulted in a poorly developed wake behind the large particles, which did not entrain fine particles leading to a barely noticeable fishhook effect for the 0.4 m/s inlet velocity. In contrast, a large ReP gives rise to larger wakes, which are capable of entraining fine particles more efficiently causing the pronounced fishhook effect at higher inlet velocities. The results show the particle separation with the fishhook effect could be modeled based on the particle entrainment model, whereas the accurate simulation of the fishhook effect in future should include a correction coefficient that varies with Rep to improve the separation efficiency predictions.

Experimental Research on the Influence of Inlet Conditions of Corrugated Plate Dryer

2017 ◽  
Author(s):  
Mao Feng ◽  
Tian RuiFeng ◽  
Chen BoWen ◽  
He Wei
Keyword(s):  
Pressure Drop ◽  
Steam Generator ◽  
Experimental Research ◽  
Separation Efficiency ◽  
Experimental Studies ◽  
Separation Performance ◽  
Separation Mechanism ◽  
Airflow Velocity ◽  
Pressurized Water ◽  
Water Separation

Corrugated plate dryer is one of the key components of natural circulation steam generator in the pressurized water reactor nuclear power plant. It play a decisive role in the water separation system to making steam become a good quality after steam flow out of a vertical steam generator. With the increase of the reactor power in the future design, it requires that the performance of corrugated plate dryer must be increased in the characteristics of steam load, separating efficiency, volume and resistance to make sure that steam generators still produce qualified steam at higher steam loads and higher cycle magnitudes. In this paper, we have done some experimental studies on the corrugated plate dryer. And we concentrated on airflow parameters on the separation performance and resistance performance of dryer. (1) First of all, we have determined the experimental research program about this study, after this, we finished the design works of the test bench, and then we have completed the construction work based on the design works. (2) Afterwards, the flow and separation mechanism of the wave plate dryer was experimentally studied by means of parameter measurement and analysis combined with observation and recording. The effects of different inlet humidities and inlet velocity on separation efficiency, pressure drop and re-entrainment were studied. The above study shows that: (1) The separation efficiency of corrugated plate dryer is related to inlet humidity and inlet airflow velocity. The separation efficiency of corrugated plate dryer is increase with inlet humidity goes higher, and increased to reach a highest point then goes down when inlet airflow velocity increased. (2) The re-entrainment is related to inlet humidity. When inlet humidity increased, the inlet airflow critical velocity which lead to re-entrain would decrease. (3) The pressure drop of dryer is related to the inlet airflow velocity. When the inlet wind velocity increases, the pressure drop increases.

scholarly journals Prediction of Particle-Collection Efficiency for Vacuum-Blowing Cleaning System Based on Operational Conditions

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 809 ◽  
Author(s):  
Yuan Xi ◽  
Yan Dai ◽  
Xi–long Zhang ◽  
Xing Zhang
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Separation Efficiency ◽  
Collection Efficiency ◽  
Particle Separation ◽  
Separation Performance ◽  
Dust Collection ◽  
Operational Conditions ◽  
Dust Collection Efficiency ◽  
Traveling Speed

The dust-collection system, as the core of a sweeper vehicle, directly inhales dust particles on the pavement. The influence of variable operational conditions on particle-separation performance was investigated using computational fluid dynamics (CFD) Euler–Lagrange multiphase model. The particle-separation performance efficiency and retention time were used to evaluate the dust-collection efficiency. The uniform design (UD) and multiple regression analysis (MRA) methods were employed to predict and optimize the effects of reverse-blowing flow rate, pressure drop, and traveling speed on separation efficiency. The results indicated that the dust-collection performance initially increased and then decreased with increasing reverse-blowing flow rate. As the pressure drop increased, there was an increase in total dust-collection efficiency. However, the efficiency decreased with increasing traveling speed. The regression model showed that the proposed approach was able to predict the particle collection efficiency accurately. In addition, the optimum operational conditions were obtained, namely a reverse-blowing flow rate of 2100 m3/h, a traveling speed of 5 km/h, and a pressure drop of 2400 Pa. The maximum particle-separation efficiency was 99.10%, which showed good agreement with the experimental results.

scholarly journals Feasibility Evaluation on Single-Collector Collision Model to Separate Microplastics in Micro Bubble Flotation Process

2021 ◽  
Vol 43 (1) ◽  
pp. 10-19
Author(s):  
Min-Ho Jang ◽  
Yong-Ho Choi ◽  
Heung-Joe Jung ◽  
Yong-Hoon Jeong ◽  
Dong-Heui Kwak
Keyword(s):  
Separation Efficiency ◽  
Particle Separation ◽  
Particle Removal ◽  
Collision Efficiency ◽  
Flotation Process ◽  
Adhesion Coefficient ◽  
Feasibility Evaluation ◽  
Micro Bubble ◽  
Adhesion Efficiency ◽  
The Impact

Objectives:The single collector collision (SCC) model is a model that predicts the separation efficiency of particles based on the collision efficiency between microbubbles and particles in the particle separation process. In order to remove micro-plastics (MPs) particles, which have recently been known to be harmful, we tried to analyze the impact and separation efficiency of MPs based on the SCC model and evaluate its application feasibility.Methods:Based on the SCC model, the collision efficiency prediction for MPs particle removal was simulated and the separation efficiency was evaluated. In addition, a series of flotation experiments were conducted using a flotation device that injects microbubbles to remove MPs particles suspended in water, and the experimental results and predicted values were compared.Results and Discussion:Using the SCC model, the collision efficiency according to the size distribution of MPs particles was not significantly different from that of typical particles (clay, kaolin) in water. Based on this collision efficiency, the maximum removal efficiency of MPs particles separated from the water body is predicted to reach about 90%. On the other hand, the initial collision-adhesion coefficient () of the MPs particles based on the SCC model was 0.03 to 0.1, showing a slight difference from the clay particles having the range of 0.3 to 0.4. The flotation separation efficiency of the MPs particles evaluated and predicted by applying this initial collision-adhesion coefficient showed a range similar to the measured value. In addition, the particle separation efficiency according to the increase of the measured bubble volume concentration to improve the particle separation efficiency also showed a pattern similar to the predicted value.Conclusions:In the flotation process, the initial collision-adhesion efficiency of the MPs particles predicted by the SCC model was lower than that of the kaolin particles. Based on the simple and simple model SCC theory, it was confirmed that it can be applied to the flotation separation analysis of MPs particles.

scholarly journals Design of Cyclone Separator Critical Diameter Model Based on Machine Learning and CFD

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1521
Author(s):  
Donggeun Park ◽  
Jeung Sang Go
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Network Model ◽  
Separation Efficiency ◽  
Critical Diameter ◽  
Particle Separation ◽  
Separation Performance ◽  
Cyclone Separator ◽  
Model Based ◽  
Design Variables

In this paper, the characteristics of the cyclone separator was analyzed from the Lagrangian perspective for designing the important dependent variables. The neural network network model was developed for predicting the separation performance parameter. Further, the predictive performances were compared between the traditional surrogate model and the developed neural network model. In order to design the important parameters of the cyclone separator based on the particle separation theory, the force acting until the particles are separated was calculated using the Lagrangian-based computational fluid dynamics (CFD) methodology. As a result, it was proved that the centrifugal force and drag acting on the critical diameter having a separation efficiency of 50% were similar, and the particle separation phenomenon in the cyclone occurred from the critical diameter, and it was set as an important dependent variable. For developing a critical diameter prediction model based on machine learning and multiple regression methods, unsteady-Reynolds averaged Navier-Stokes analyzes according to shape dimensions were performed. The input design variables for predicting the critical diameter were selected as four geometry parameters that affect the turbulent flow inside the cyclone. As a result of comparing the model prediction performances, the machine learning (ML) model, which takes into account the critical diameter and the nonlinear relationship of cyclone design variables, showed a 32.5% improvement in R-square compared to multi linear regression (MLR). The proposed techniques have proven to be fast and practical tools for cyclone design.

Miscible blend polyethersulfone/polyimide asymmetric membrane crosslinked with 1,3-diaminopropane for hydrogen separation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nur’ Adilah Abdul Nasir ◽  
Ameen Gabr Ahmed Alshaghdari ◽  
Mohd Usman Mohd Junaidi ◽  
Nur Awanis Hashim ◽  
Mohamad Fairus Rabuni ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Chemical Characterization ◽  
Gas Permeation ◽  
Separation Performance ◽  
Membrane Composition ◽  
Asymmetric Membrane ◽  
Wet Phase Inversion ◽  
Pair Performance ◽  
Improved Performance ◽  
Physical And Chemical

Abstract Efficient purification technology is crucial to fully utilize hydrogen (H2) as the next generation fuel source. Polyimide (PI) membranes have been intensively applied for H2 purification but its current separation performance of neat PI membranes is insufficient to fulfill industrial demand. This study employs blending and crosslinking modification simultaneously to enhance the separation efficiency of a membrane. Polyethersulfone (PES) and Co-PI (P84) blend asymmetric membranes have been prepared via dry–wet phase inversion with three different ratios. Pure H2 and carbon dioxide (CO2) gas permeation are conducted on the polymer blends to find the best formulation for membrane composition for effective H2 purification. Next, the membrane with the best blending ratio is chemically modified using 1,3-diaminopropane (PDA) with variable reaction time. Physical and chemical characterization of all membranes was evaluated using field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR). Upon 15 min modification, the polymer membrane achieved an improvement on H2/CO2 selectivity by 88.9%. Moreover, similar membrane has demonstrated the best performance as it has surpassed Robeson’s upper bound curve for H2/CO2 gas pair performance. Therefore, this finding is significant towards the development of H2-selective membranes with improved performance.

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