Microfluidic Chip for Particle-Liquid Separation

2011 ◽  
Author(s):  
Priyank Bhardwaj ◽  
Piyush Bagdi ◽  
Ashish S. Sharma ◽  
Ashis K. Sen
Keyword(s):  
Theoretical Analysis ◽  
Separation Efficiency ◽  
Point Of Care ◽  
Solid Particles ◽  
Micro Milling ◽  
Group Model ◽  
Operational Parameters ◽  
Liquid Separation ◽  
Lab On Chip ◽  
Dimensional Group

This paper presents theoretical analysis, design, fabrication and test of a microfluidic device (‘Micro hydrocyclone’) for separation of micron and sub-micron size solid particles from liquid in a particle-liquid mixture. A theoretical analysis of the micro hydrocyclone is performed to understand the physics and develop suitable design models. The structure of the proposed device is designed based on Bradley model, as it offers lower cut-size thus making it suitable for microfluidics applications. The operational parameters are derived from the dimensional group model. The device is fabricated with SU-8 photoresist on PMMA substrate using a combination of photolithography and micro-milling. Experiments are performed to demonstrate particle-liquid separation using polystyrene microbeads suspended in PBS as the feed sample. The influence of inlet velocity and particle size on particle separation efficiency is investigated. The proposed device can be easily integrated with micro-environments thus is suitable for lab-on-chip and microsystems development. The device may have applications in chemical analysis, materials research, point-of-care, blood sample preparation and other biomedical applications.

Analysis and Simulation of a Micro Hydrocyclone Device for Particle Liquid Separation

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
P. Bagdi ◽  
P. Bhardwaj ◽  
A. K. Sen
Keyword(s):  
Stokes Equations ◽  
Separation Efficiency ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Group Model ◽  
Operational Parameters ◽  
Lab On Chip ◽  
Dimensional Group ◽  
Simulation Results ◽  
On Chip

This paper presents a three-dimensional simulation of a micro hydrocyclone for the separation of micron sized particles from liquid in a particulated sample. A theoretical analysis is performed to demonstrate the working principle of the micro hydrocyclone and develop design models. The geometry of the proposed device is designed based on the Bradley model, since it offers a lower cut-size, thus making it suitable for microfluidics applications. The operational parameters of the hydrocyclone are derived from a dimensional group model. The particle separation process inside the micro hydrocyclone is simulated by solving fluid flows using Navier-Stokes equations and particle dynamics using the Lagrangian approach in a Eulerean fluid. First, the numerical model is validated by comparing the simulation results with the experimental results for a macroscale hydrocyclone reported in the literature. Then, the micro hydrocyclone is simulated and the simulation results are presented and discussed in the context of the functioning of the micro hydrocyclone. Finally, the effects of inlet velocity, vortex finder diameter, particle size, and density on the separation efficiency are investigated. The proposed device can be easily integrated with micro-environments; thus, is suitable for lab-on-chip and microsystems development.

Flow Profiles and Gas/Liquid Separation in First and Second Generation Designs for Ebullated Reactors

2015 ◽  
Author(s):  
C. D. Lane ◽  
A. A. Donaldson
Keyword(s):  
Elevated Temperatures ◽  
Separation Efficiency ◽  
Oil And Gas Industry ◽  
Process Conditions ◽  
Foam Formation ◽  
Heavy Oils ◽  
Operational Parameters ◽  
Liquid Separation ◽  
Gas Recirculation ◽  
Operating Units

Ebullated bed reactor technology is found in the oil and gas industry as part of the hydrocracking process, within which heavy oils are cracked under elevated temperatures and pressures to produce increased fractions of refinable petroleum products. A unique feature of these types of reactors is the presence of an internal gas/liquid separation and liquid recycle line, through which 60 to 90% of the net liquid flow through the column is recycled to maintain fluidized conditions within the internal catalyst bed. The separation efficiency within these systems has a significant impact on overall unit profitability, whereby high levels of gas recirculation results in lower liquid throughput and increased potential of over-cracking of product gases and production of light ends [1]. These units typically operate at gas holdups above 30%, with even small reductions in gas entrainment potentially leading to significant increases in profitability. Due to the severe conditions present within operating units (several MPa pressures, >300°C), pilot-scale experimental systems exploring fluid flow phenomena have typically employed nitrogen and kerosene as analogous fluids[2]. Even within these systems, the ability to visualize flow patterns and parametrically evaluate the effects of separator modifications on gas recirculation has been limited. In an effort to provide strategic focus for future process improvements, Dalhousie University has been collaborating with Ottawa University and Syncrude Canada Ltd. to develop 3D CFD-based simulations of older generation designs to explore fundamental flow characteristics and sensitivity of gas-liquid separation efficiency to changes in geometry and process conditions. This work explores the sensitivity of gas separation efficiency to operational parameters (bubble size, processing rate, gas holdup), geometric design (two generations of separator designs), and computational model choices (drag correlations and packing limiters). Of particular note is the sensitivity of the predicted performance to drag models, for which there is limited empirical validation under the high gas fraction conditions present in this industrial unit, and the sensitivity to packing limiters, which reflect foam formation (an issue observed within operating units). The trends predicted within this work show significant similarities to current operational trends observed in commercial ebullated bed reactors, and provide a basis for predicting the effects of operational changes on the overall performance of these units.

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.

Computational and Experimental Investigation of the Vertical Flash Tank Separator Part 1: Effect of Parameters on Separation Efficiency

2019 ◽  
Vol 27 (01) ◽  
pp. 1950005 ◽  
Author(s):  
Raid Ahmed Mahmood ◽  
David Buttsworth ◽  
Ray Malpress
Keyword(s):  
Separation Efficiency ◽  
Fluid Dynamic ◽  
Effective Area ◽  
Working Fluid ◽  
Cfd Simulations ◽  
Liquid Separation ◽  
Two Phase ◽  
Flash Tank ◽  
Tank Design ◽  
The Heat Transfer Coefficient

The flash tank separator is one of the most important components that can be used to improve the performance of a refrigeration cycle by separating the liquid from the gas–liquid two-phase flow and providing the evaporator with only liquid refrigerant. This technique increases the effective area and enhances the heat transfer coefficient in the evaporator. To optimize the size of the vertical flash tank separator for obtaining high separation efficiency, the effect of the size of the vertical flash tank separator needs to be considered. This paper investigates the effect of the size on the liquid separation efficiency of the vertical flash tank separator. This paper also assesses the usefulness of Computational Fluid Dynamic (CFD) in flash tank design, and this is achieved through experiments and simulations on a range of relevant configurations using water as the working fluid. The results revealed that the size has a significant effect on the liquid separation efficiency, as the highest value was achieved by the largest size (VFT-V5). The CFD simulations give a good agreement with the experiments; all the simulations underestimated the liquid separation efficiency by approximately 0.02 over the range of conditions tested.

Point-of-Care Systems for Rapid DNA Quantification in Oncology

2008 ◽  
Vol 94 (2) ◽  
pp. 216-225 ◽  
Author(s):  
Marco Bianchessi ◽  
Sarah Burgarella ◽  
Marco Cereda
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Semiconductor Industry ◽  
Point Of Care Testing ◽  
Lab On Chip ◽  
Diagnostic Assays ◽  
Care Systems ◽  
Point Of Care Systems ◽  
The Common ◽  
On Chip

The development of new powerful applications and the improvement in fabrication techniques are promising an explosive growth in lab-on-chip use in the upcoming future. As the demand reaches significant levels, the semiconductor industry may enter in the field, bringing its capability to produce complex devices in large volumes, high quality and low cost. The lab-on-chip concept, when applied to medicine, leads to the point-of-care concept, where simple, compact and cheap instruments allow diagnostic assays to be performed quickly by untrained personnel directly at the patient's side. In this paper, some practical and economical considerations are made to support the advantages of point-of-care testing. A series of promising technologies developed by STMicroelectronics on lab-on-chips is also presented, mature enough to enter in the common medical practice. The possible use of these techniques for cancer research, diagnosis and treatment are illustrated together with the benefits offered by their implementation in point-of-care testing.

scholarly journals Rainbow on a Chip: Experimental Observation of the Trapped Rainbow Effect Using Tapered Hollow Bragg Waveguides

Eureka ◽  
2014 ◽  
Vol 4 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Aaron Melnyk
Keyword(s):  
Theoretical Analysis ◽  
Experimental Observation ◽  
Entire Length ◽  
Lab On Chip ◽  
Out Of Plane ◽  
Frequency Components ◽  
Input Spectrum ◽  
Bragg Waveguides ◽  
On Chip ◽  
Future Work

Experimental observation of the ‘trapped rainbow’ in the visible is demonstrated using tapered hollow Bragg waveguides. These waveguides spatially disperse an input spectrum into its various frequency components and vertical out of plane radiation was observed at wavelength dependant positions along the entire length of the waveguide. The experimental observation is corroborated by a brief theoretical analysis and simulation. These devices form the foundation for future work involving integration into a micro-spectrometer for eventual lab-on-chip use. 

CFD Assessment and Experimental Investigation of the Liquid Separation Efficiency Enhancements in a Vertical Gravity Separator

2020 ◽  
Vol 28 (03) ◽  
pp. 2050021
Author(s):  
Raid Ahmed Mahmood
Keyword(s):  
Separation Efficiency ◽  
Flow Direction ◽  
Fluid Dynamic ◽  
Working Fluid ◽  
Cfd Simulations ◽  
Liquid Separation ◽  
Flash Tank ◽  
Tank Design ◽  
Vertical Gravity ◽  
Design Options

Three design enhancement options for a vertical gravitational flash tank separator were proposed and investigated in this work. Computational Fluid Dynamic (CFD) was used to assess the optimum configurations of the vertical gravitational flash tank separator. A series of experiments were performed to test the CFD proposed configurations of the enhancement design options. This paper also assessed the usefulness of CFD in flash tank design, and this is achieved through experiments and simulations on a range of relevant configurations using water as the working fluid. The results revealed that the combination of the inlet flow direction and extractor had a significant effect on the performance of the vertical flash tank separator which increased by 2%. The results also revealed that there was a good agreement between the CFD simulations and experiments; the CFD simulations underestimated the liquid separation efficiency by approximately 0.02 over the range of conditions tested.

scholarly journals Scaling Electrowetting with Printed Circuit Boards for Large Area Droplet Manipulation

MRS Advances ◽  
2018 ◽  
Vol 3 (26) ◽  
pp. 1475-1483 ◽  
Author(s):  
Udayan Umapathi ◽  
Samantha Chin ◽  
Patrick Shin ◽  
Dimitris Koutentakis ◽  
Hiroshi Ishii
Keyword(s):  
Printed Circuit Boards ◽  
Dielectric Material ◽  
Point Of Care ◽  
Digital Microfluidics ◽  
Microfluidic Devices ◽  
Electrode Arrays ◽  
Large Area ◽  
Lab On Chip ◽  
Electrowetting On Dielectric ◽  
Droplet Manipulation

ABSTRACTDroplet based microfluidics (digital microfluidics) with Electrowetting on dielectric (EWOD) has gained popularity with the promise of being technology for a true lab-on-chip device with applications spanning across assays/library prep, next-gen sequencing and point-of-care diagnostics. Most electrowetting device architecture are linear electrode arrays with a shared path for droplets, imposing serious limitations -- cross contamination and limited number of parallel operations. Our work is in addressing these issues through large 2D grid arrays with direct addressability providing flexible programmability.Scaling electrowetting to larger arrays still remains a challenge due to complex and expensive cleanroom fabrication of microfluidic devices. We take the approach of using inexpensive PCB manufacturing, investigate challenges and solutions for scaling electrowetting to large area droplet manipulation. PCB manufactured electrowetting arrays impose many challenges due to the irregularities from process and materials used. These challenges generally relate to preparing the surface that interfaces with droplets -- a dielectric material on the electrodes and the top most hydrophobic coating that interfaces with the droplets. A requirement for robust droplet manipulation with EWOD is thin (<10um) hydrophobic dielectric material which does not break down at droplet actuation voltages (AC/DC, 60V to 200V) and has a no droplet pinning. For this, we engineered materials specifically for large area PCBs.Traditionally, digital microfluidic devices sandwich droplets between two plates and have focussed on sub-microliter droplet volumes. In our approach, droplets are on an open surface with which we are able to manipulate droplets in microliter and milliliter volumes. With milliliter droplet manipulation ability on our electrowetting device, we demonstrate “digital millifluidics”. Finally, we report the performance of our device and to motivate the need for large open arrays we show an example of running multiple parallel biological experiments.

Experimental Study and Analysis of Different Air-Injecting Segment on the Separation Performance of Air-Injected De-Oiling Hydrocyclone

2008 ◽  
Author(s):  
Minghu Jiang ◽  
Dehai Chen ◽  
Lixin Zhao ◽  
Liying Sun
Keyword(s):  
Experimental Study ◽  
Theoretical Analysis ◽  
Separation Efficiency ◽  
State Of The Art ◽  
Experimental Studies ◽  
Separation Performance ◽  
Research Results ◽  
Compound Body ◽  
Oil Gas

Developing state-of-the-art and separating principle of deoiling hydrocyclones are introduced. By theoretical analysis, the ways to enhance hydrocyclone’s separation efficiency are described. One way is to inject air into the hydrocyclones so as to combine with oil to form oil-gas compound body, and then increase de-oiling efficiency. By means of injecting air into large cone segment, or fine cone segment of the hydrocyclone, experiments were carried out. It is found that the best injecting part is fine cone segment. Further experimental studies were continued for confirming detail part in fine cone segment, which includes one-third segment and two-thirds segment for the sake of research. Results show that the best air-injecting part is the first one-third segment of fine cone segment. This conclusion would be useful for understanding of air-injected de-oiling hydrocyclone’s separating process, and for its design and applications.

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.

Sign in / Sign up

Export Citation Format

Share Document