Open Source Hydrocyclone Literature Review

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Open Source Hydrocyclone Literature Review[edit | edit source]

Background[edit | edit source]

This page is dedicated to the literature review of an Open Source Hydrocyclone.

Market Survey[edit | edit source]

Maker Community[edit | edit source]

OpenSCAD Dusty Cyclone made from wood[edit | edit source]

Notes:

  • Article is for a dust cyclone
  • Within the blog post it shows the process of designing the dust cyclone in OpenSCAD

Aquarium Cyclone Filter[edit | edit source]

Notes:

  • Partially 3D Printed design that utilizes what looks to be a clear PVC pipe for the cylinder body.
  • Filters out aquarium debris from water

Literature[edit | edit source]

Google scholar search: Hydrocyclone Design[edit | edit source]

Designing automated computational fluid dynamics modelling tools for hydrocyclone design[edit | edit source]

T. J. Olson and R. Van Ommen, “Optimizing hydrocyclone design using advanced CFD model,” Minerals Engineering, vol. 17, no. 5, pp. 713–720, May 2004, doi: 10.1016/j.mineng.2003.12.008.

Abstract: Resolution of the complex multiphase swirling flow field in a hydrocyclone using computational fluid modelling techniques is not a trivial task. CFD Modelling technology is not perfect and it is certainly still possible to improve our understanding of the fundamentals and the models needed to describe them. Nevertheless, computational modelling techniques are being used to compare and understand the workings of different hydrocyclone designs and modes of operation.

Until now, CFD has been the realm of the research analyst more than the plant or design engineer. The development of in house CFD expertise may be seen as prohibitive in terms of time and cost. These two factors have presented a barrier to the use of CFD by the hydrocyclone industry, in spite of improvements in modelling capability.

This paper describes how automated CFD tools have been developed based on documented best practices. The bespoke tool development described will enable a non-CFD analyst to carryout hydrocyclone simulations. The paper will also consider the advantages and limitations of different computational fluid dynamic techniques applicable to hydrocyclone modelling.

Notes:

  • Using CFD to optimize hydrocyclone design based on application. This allows for customized cyclones that are specific to the application.
  • For CFD analysis by using tetrahedral meshing around the inlet will provide a closer fitting mesh.
  • A CFD analysis of a particular design will help identify the fluid flow within the cyclone.
  • CFD allows for multiple design iterations without having to manufacture any prototypes.

A simple procedure for design and performance prediction of Bradley and Rietema hydrocyclones[edit | edit source]

L. R. Castilho and R. A. Medronho, “A simple procedure for design and performance prediction of Bradley and Rietema hydrocyclones,” Minerals Engineering, vol. 13, no. 2, pp. 183–191, Feb. 2000, doi: 10.1016/S0892-6875(99)00164-8.

Abstract Hydrocyclones were originally designed to promote solid-liquid separations but nowadays they are also used for solid-solid, liquid-liquid and gas-liquid separations. Although a hydrocyclone is a very simple equipment to build, the use of custom-made cyclones is not widely used. This is probably due to the lack of a simple procedure for hydrocyclone design. In the present work a procedure is presented, which allows the design and performance prediction of hydrocyclones that follow Bradley and Rietema recommended geometries, that are the only two well-known families of geometrically similar hydrocyclones. The procedure proposed here resulted in little error, when the results were compared with experimental data. Additionally, a comparison of both families of hydrocyclones revealed that, for a given hydrocyclone diameter and at the same operational conditions, Bradley hydrocyclones provide higher efficiencies, while Rietema hydrocyclones give higher capacities.

Notes:

  • Design of a hydrocyclone is made up of non-moving parts: The cylindrical top section with a tangential inlet connected bellow is a conical part that has a circular opening at the bottom. The top of the cyclone is closed off with a hole in the middle that has a pipe extruded downward from the top that is the vortex finder.
  • Paper provides relevant equations used in hydrocyclone design.
  • Bradley hydrocyclones = higher efficiencies while Rietema hydrocyclones = higher capacities

Optimizing small hydrocyclone design using 3D printing and CFD simulations[edit | edit source]

D. Vega-Garcia, P. R. Brito-Parada, and J. J. Cilliers, “Optimising small hydrocyclone design using 3D printing and CFD simulations,” Chemical Engineering Journal, vol. 350, pp. 653–659, Oct. 2018, doi: 10.1016/j.cej.2018.06.016.

Abstract The use of small hydrocyclones for the separation of particles in the micron range is of growing interest. However, these hydrocyclones are typically limited to conventional shapes or restricted to specific outlet sizes, which can lead to sub-optimal performance. The aim of this study is to present a method for the optimisation of small hydrocyclone design. This method consists of four steps that combine designing, Computational Fluid Dynamics (CFD) simulations, 3D printing and experimental testing. A 3D printed 10 mm hydrocyclone was shown first to match the performance of a ceramic equivalent, followed by factorial experiments with a set of printed hydrocyclones of different spigot and vortex finder diameters. A CFD model for small hydrocyclones was implemented and, following validation with the experimental data, used to simulate small hydrocyclone designs with parabolic walls. The model predicted improved separation performance compared to the conventional conic wall designs. In a novel development, a 10 mm hydrocyclone with parabolic walls was 3D printed and the prediction confirmed experimentally. The solids recovery and concentration ratio were increased by 10 percentage points and 0.2, respectively, for a 0.5 g/L yeast suspension and at an equivalent pressure drop. The use of 3D printing to manufacture small hydrocyclones of various designs has been proven in this study to be practical and to allow rapid prototyping design informed by CFD simulations. This is a significant improvement in the cost, time and versatility associated to hydrocyclone design and can lead to enhanced separation performance. Notes:

  • Different inlet configurations affect the recovery of solids
  • Vortex finder shape effects recovery of solids and separation efficiency
 	Possibly explore other more complex geometries that are not easily manufactured using traditional manufacturing techniques
  • Limited testing on small hydrocyclones due to only having a small selection of commercially available hydrocyclones.
  • Traditional manufacturing methods of hydrocyclones limit customization and experimental designs. 3D printing can eliminate this boundary.
  • Parabolic walled design had a higher solids recovery rate.

Google Scholar Search: Novel Hydrocyclone Design[edit | edit source]

Novel conical section design for ultra-fine particles classification by a hydrocyclone[edit | edit source]

J. Ye, Y. Xu, X. Song, and J. Yu, “Novel conical section design for ultra-fine particles classification by a hydrocyclone,” Chemical Engineering Research and Design, vol. 144, pp. 135–149, Apr. 2019, doi: 10.1016/j.cherd.2019.02.006.

Abstract To overcome the limitation of the conventional hydrocyclone for the ultra-fine particles classification, the novel conical section design of the hydrocyclone is computationally investigated in this work. The electrolytic manganese dioxide (EMD, MnO2) powder, whose size is in the range from 0.2 μm to 70 μm, is took as a study case, and the feed solid concentration (SC) is up to 20%wt. The conical section with the modified cone design is proposed to enhance the performance of hydrocyclones. In addition, all the hydrocyclones are equipped with an arc inlet to obtain the pre-classification effect. The micron particles classification with the demarcation at 5 μm is accomplished in the novel hydrocyclone as the classification sharpness (Ss) is improved from 0.833 to 0.938 at the feed solid concentration of 5% wt. The combination of moderate conical length and modified cone with wide radial space near spigot is the outline of the high classification sharpness hydrocyclone. The dynamics analysis illustrates that the classification performance is attributed to the comprehensive effects of force, residence time, and separation space.

Notes:

  • Highest separation sharpness can be achieved by creating a balance between long cone section (high separation efficiency, fine particle in underflow) & short cone section (loss of coarse product in overflow).
  • Medium-length cone with moderately large radial space gives high level force field and sufficient separation space.
  • Wider cone design achieves improvement of classification sharpness at the cost of coarse product loss.
  • The effect of drag force is more significant on coarse particles


Effect of vortex finder diameter on the performance of a novel hydrocyclone separator[edit | edit source]

L. G. M. Vieira and M. A. S. Barrozo, “Effect of vortex finder diameter on the performance of a novel hydrocyclone separator,” Minerals Engineering, vol. 57, pp. 50–56, Mar. 2014, doi: 10.1016/j.mineng.2013.11.014.

Abstract Hydrocyclones are equipment widely used by the mineral industry, but it is possible to highlight its operation in de-sliming, selective classification, thickening and pre-concentration. Our research group designed a new hydrocyclone. In this novel device, the conical section of a conventional hydrocyclone was replaced by a conical filtering wall and the equipment was named filtering hydrocyclone. During the operation of this novel hydrocyclone, besides the underflow and overflow streams, there is another stream of liquid, resulting from the filtrate produced in the porous cone. In the present work, the influence of vortex finder diameter (Do) of a filtering hydrocyclone was analyzed by an experimental and CFD study. Data from a conventional hydrocyclone of the same configuration were also obtained. The results indicated that the performance of separation process was significantly improved with this new equipment. Depending on the specific functions of the separator (as a classifier or thickener) the best values of Do were also found for the filtering hydrocyclone.

Notes:

  • Increasing overflow diameter reduces separation efficiency for fine particles.
  • Reducing vortex finder diameter increased efficiency.
  • To separate fine particles use a smaller overflow diameter.
  • Hydrocyclones used in this work were made of brass.

Design of novel hydrocyclone for improving fine particle separation using computational fluid dynamics[edit | edit source]

K.-J. Hwang, Y.-W. Hwang, and H. Yoshida, “Design of novel hydrocyclone for improving fine particle separation using computational fluid dynamics,” Chemical Engineering Science, vol. 85, pp. 62–68, Jan. 2013, doi: 10.1016/j.ces.2011.12.046.

Abstract Several novel hydrocyclones are designed to improve fine particle separation using computational fluid dynamics. The effects of inlet size, number of inlets and top-plate types on the particle separation efficiency and cut-size sharpness are discussed based on the same feed flow rates. The fluid and particle flows are simulated using a segregated, steady-state, 3-dimensional implicit numerical solver supplied by FLUENT software. The governing equations are coupled using the SIMPLE algorithm, while the Reynolds stress model is employed for the hydrocyclone turbulent model due to its' anisotropic nature. Particle trajectories are simulated based on a Lagrangian frame considering the continuous phase interactions. The simulated particle separation efficiencies approximately agree with the available experimental data. The results show that increasing the inlet number and narrowing the inlet width are effective ways to improve the particle separation efficiency due to the increase in fluid velocity in the cylindrical parts of hydrocyclone. A cone-shaped top-plate reduces the fine particle circulation area near the outer surface of overflow conduit, significantly improving the separation efficiency of fine particles. However, increasing the cone angle has a contrary effect because of the decrease in particle residence time. Although installing an extra guide-channel from the inlet may also improve the fine particle separation efficiency, it is not effective for particle classification because of reduced particle cut-size sharpness.

Notes:

  • Hydro cyclones can have two different top Plate features. First is a cone that has varying angles which includes being completely flat. Second is a guide channel that vary on how much they wrap around.
  • Increasing the number of inlets with the same diameter as the single intake will result in a decrease in separation efficiency. However, if the diameter is reduced by half separation efficiency will increase for a second intake.
OpenSCAD file that is parametric and can add intakes, adjust cone angle, and add or remove guide channel.
Have top plate for initial prototype be separate so we can change out to different designs without having to reprint everything.

Google scholar search:Hydrocyclone Effect of Tangential Feed Inlet[edit | edit source]

Effects of curvature radius on separation behaviors of the hydrocyclone with a tangent-circle inlet[edit | edit source]

C. Zhang, D. Wei, B. Cui, T. Li, and N. Luo, “Effects of curvature radius on separation behaviors of the hydrocyclone with a tangent-circle inlet,” Powder Technology, vol. 305, pp. 156–165, Jan. 2017, doi: 10.1016/j.powtec.2016.10.002.

Abstract An appropriate design of the inlet type has been proved to be an effective approach to improve the performance of a hydrocyclone. Until now, there is still no detail analysis on the mechanism underlying the flow control by the inlet type. In this paper, numerical simulation was conducted to investigate effects of curvature radius on the separation performance of the hydrocyclone with a tangent-circle inlet. The validity of the approach was verified by the reasonably good agreement between the predicted and measured results in terms of water velocities and particle partition curves. The simulating results were further analyzed in aspects of the flow field, pressure drop and separation performance. Results showed that a smaller curvature radius could increase the tangential velocity and the pressure gradient. Besides, the turbulence kinetic energy in the inlet section and the annular section are reduced by decreasing the curvature radius. Meanwhile, the symmetry of the inner flow field was improved by reducing the curvature radius. All these factors enhanced the radial regular distribution of particles in the inlet section and reduced influences of the short circuit flow on relatively coarse particles. Therefore, the classification precision was improved when using a tangent-circle inlet with a smaller curvature radius compared with base hydrocyclone.

Notes:

  • Tangent curved inlet reduces the turbulence kinetic energy in the inlet section without significantly affecting turbulence within the vortex finder.
  • Curved inlets improve separation efficiency while the smaller the diameter of the curved section provides the best separation efficiency.
  • Decreased inlet curvature increases the pressure drop of the system.
  • Decreasing curvature radius will increase the tangential velocity of particles in the system. Resulting in a larger centrifugal force on the particles.

Google Scholar Search: hydrocyclone yeast cell separation concentration[edit | edit source]

The application of mini-hydrocyclones in the concentration of yeast suspensions[edit | edit source]

J.J. Cilliers a,1, S.T.L. Harrison, "The application of mini-hydrocyclones in the concentration of yeast suspensions," The Chemical Engineering Journal, vol 65, pp 21-26, 1997

Abstract Small diameter hydrocyclones have had an increasing use m performing difficult separations between phases, due to the large centrifugal forces generated in them. The potential use of hydrocyclones in the concentration of microbial suspensions is attractive as they are continuous, high capacity devices requiring low maintenance while having the additional benefit in that they can be readily sterilized. Results are reported on the de-watering of Bakers' yeast in a 10 mm diameter hydrocyclone to quantify the separation process. The form of the model equation for recovery has been derived based on the non-equilibrium residence time theory. This is shown to represent experimental data in that increasing pressure and temperature exhibit a positive effect on both the recovery and the concentrating effect whale an increase in the feed concentration exhibits a negative effect on these In addition, the influence of cyclone geometry on the recovery and concentration ratio has been illustrated. Increasing the vortex diameter results in an increasing concentration ratio and a decreasing recovery. Increasing the diameter of the spigot shows the opposing trends Typical results from a single stage separation combine a recovery of 60% with a concentration ratio of 1 25 and a recovery of 30% with a concentration ratio of 2.0. Concomitant improvement of the recovery and concentration ratio will be attainable through the use of multi-stage hydrocyclone circuits.

Notes:

  • Tangential forces pull particles out, radial forces pull particles in
  • Until high concentration temperature can help separation
  • Non-equilibrium residence time theory designed for 10mm hydrocyclone, changes drastically with cyclone geometry

Google Scholar Search: hydrocyclone microbial cell separation concentration[edit | edit source]

The Potential of Hydrocyclone Application for Mammalian Cell Separation in Perfusion Cultivation Bioreactors[edit | edit source]

Elsayed A. Elsayed1,2,* and Mohamad A. Wadaan, "The Potential of Hydrocyclone Application for Mammalian Cell Separation in Perfusion Cultivation Bioreactors," International Journal of Biotechnology for Wellness Industries, vol 2, pp 153-163, 2013

Abstract Hydrocyclones have been traditionally applied for long times in many industrial fields, such as in mineral processing and mining, chemical and petrochemical, and food industries. They have many characteristics that favor them as separation system in solid/liquid, gas/liquid and liquid/liquid processes. During the last two decades, they have been evaluated for their possible application in the separation of microbial and mammalian cells. Nowadays, mammalian cells are widely used for the production of a large number of valuable therapeutic proteins, antibodies, hormones and vaccines. This review highlights the potential of the application of hydrocyclones for mammalian cell separation in continuous perfusion bioreactors. The discussion will cover the structure of hydrocyclone, mechanism of separation inside hydrocyclones, different theories describing the separation process, as well as the effect of changing different geometrical variables on the efficiency and performance of the separation process. Furthermore, we will focus on the latest developments achieved in the field of separation of living cells in both laboratory and pilot plant cultivation scales.

Notes:

  • Mammalian cells are sensitive to shear stress and easily foul since by adhering to surfaces
  • Centrifugal and drag forces relate directly to particle size
  • Separation not affected by gravity
  • Equilibrium Orbit Theory particles separate by by relative radial forces acting on them
  • Residence Time Theory particle have different rates they settle toward the wall
  • Crowding Theory size distribution of feed dictate separation efficiency

Numerical Separation of Hydrocyclone for Cell Separation[edit | edit source]

R. A. Medronho, J. Schuetze, and W. -D. Deckwer, "Numerical Separation of Hydrocyclone for Cell Separation," Latin American Applied Research, vol 35, pp 1-8, 2005

Abstract Numerical simulation of hydrocyclone aiming at investigating the separation of microorganisms and mammalian cells was performed using Computational Fluid Dynamics (CFD). The turbulence model used in the 2d-axisymmetric calculations was the Reynolds Stress Model (RSM), in order to take into account the high swirl effects that occur in this type of equipment, which induce anisotropic turbulence. The Volume of Fluid Model (VOF) was used to account for the gas/liquid interface. In all calculations, a cylindrical air core, running the whole length of the cyclone, appeared naturally as a consequence of a low pressure region that developed along the central axis. The separation of Escherichia coli, Saccharomyces cervevisiae and mammalian cells (BHK-21) using Bradley hydrocyclones was studied. According to the present work, Bradley hydrocyclones with diameter down to 10 mm cannot efficiently separate microorganism, but the separation of mammalian cells with predicted efficiencies as high as 90% can be achieved.

Notes:

  • RSM model more accurate than other models but requires more robust hardware and memory per iteration
  • two-layered zonal model is a good model for wall interfaces
  • bulk properties are good in the VOF model

Google Scholar Search: hydrocyclone geometry optimization[edit | edit source]

Optimizing Geometric Parameters in Hydrocyclones for Enhanced Separations: A Review and Perspective[edit | edit source]

L. Ni, J. Tian, T. Song, Y. Jong, and J. Zhao, "Optimizing Geometric Parameters in Hydrocyclones for Enhanced Separations: A Review and Perspective," Separation and Purification Reviews, vol 48, pp 30-51, 2019.

Abstract Hydrocyclones have been extensively applied for solid–liquid or liquid–liquid separations in various industries. However, the exact mechanisms underlying the enhanced separation technologies based on the optimization of geometric parameters of hydrocyclones remain unclear, and a number of research teams have performed numerous studies to enlarge the application scope of hydrocyclones by optimizing geometric parameters. This review provides a comprehensive state-of-the-art review of hydrocyclone enhanced-separation technologies. The enhanced-separation technologies are categorized into ten groups: cylindrical section, inlet, vortex finder, underflow pipe, conical section, hydrocyclone inclination angle, hydrocyclone insertion, conical-section/apex water injection, reflux device, and multi-hydrocyclone arrangement. These enhanced-separation technologies were analyzed and summarized according to the key separation-performance parameters of hydrocyclones, such as separation efficiency, cut size, split ratio, energy consumption, and capacity. It is expected that both the reviewed contents and the proposed challenges and future methodologies and technologies may provide research fellows working in this field with an improved understanding of enhanced separation technologies of hydrocyclones.

Notes:

  • bulk properties change with cyclone size, to get higher capacity increase number of hydrocyclones
  • bigger cyclones have low energy loss and large capacity
  • cylindrical section length dictates residence time
  • problems with separation and energy happen at junction of cylindrical and conical sections
  • there is an optimum inlet size
  • different size particles are effected greatly by different aspects of cyclone design

Performance of Hydrocyclones with Different Geometries by Vieira, Silverio, Damasceno, and Barrozo[edit | edit source]

L. G. M. Vieira,* B. C. Silverio, J. J. R. Damasceno and M. A. S. Barrozo, "Performance of Hydrocyclones with Different Geometeries," Canadian Journal of Chemical Engineering, vol 89, pp. 655-662, Aug 2011.

Abstract Hydrocyclones belong to an important group of equipment designed to solid–liquid or liquid–liquid separation in a centrifugal field. It is possible to adapt a hydrocyclone to the accomplishment of several industrial activities depending on the geometrical relations among its main dimensions. The operation and design of these devices are relatively simple; however, the flow inside them is very complex and its prediction is very difficult. For that reason, most models that are used to predict hydrocyclone performance are empirical ones. The objective of this work was to study the influence of geometric variables in the performance of hydrocyclones, using CFD and response surface techniques. The obtained results show that it was possible to find an optimum hydrocyclone design, that is, geometric relationships that lead to Euler number and cut size in minimum levels.

Notes:

  • Set equation hasn't been made because hydrocyclone has turbulent flow, vortex breakdown, flow inversions, and an air core
  • Empirical formulas mostly used, do not work outside of test parameters
  • To maximize efficiency minimize cut size
  • Minimum energy is Euler Number
  • Euler Number relates local pressure drop and kinetic energy

Google Scholar Search: hydrocyclone industrial cell separation[edit | edit source]

Advantages of Hydrodynamic Cell Separation in Industrial Cell Culture Processes[edit | edit source]

Bernd Schröder, Elsayed Ahmed Elsayed, Johanna Olownia, and Roland Wagner, "Advantages of Hydrodynamic Cell Separation in Industrial Cell Culture Processes," Cells and Culture, 2010, DOI 10.1007/978-90-481-3419-9_113

Abstract The Cell Culture Hydrocyclone Perfusion System separates cells by hydrodynamic-driven centrifugal forces. Cells are only exposed for a very short period of time of less than 0.2 s during the process of separation. The small 10 cm – high Cell Culture Hydrocyclone has a maximum process-specific perfusion performance of 450–720 liters of cell culture harvest per day while operating at a flow rate of 0.3–0.5 L min–1. Its special properties – characterized by its small dimensions, in situ sterilizability, robustness, reusability, and simple adjustment for higher process volumes – emphasize the advantages that distinguish the Cell Culture Hydrocyclone from other cell separation systems.

Notes:

  • Hydrocyclones have the advantage of no moving parts
    • Moving parts often clog or damage cells
  • Dead cells often leave the overflow which helps viability
  • High pressure needed to start damaging cells

A 3D-printed mini-hydrocyclone for high throughput particle separation: application toprimary harvesting of microalgae†[edit | edit source]

Maira Shakeel Syed, Mehdi Rafeie, Rita Henderson, Dries Vandamme, Mohsen Asadniad and Majid Ebrahimi Warkiani, "A 3D-printed mini-hydrocyclone for high throughput particle separation: application toprimary harvesting of microalgae†," Royal Society of Chemistry, Lab Chip vol 17, pp 2459–2469, 2017, DOI: 10.1039/c7lc00294g

Abstract The separation of micro-sized particles in a continuous flow is crucial part of many industrial processes, from biopharmaceutical manufacturing to water treatment. Conventional separation techniques such as centrifugation and membrane filtration are largely limited by factors such as clogging, processing time and operation efficiency. Microfluidic based techniques have been gaining great attention in recent years as efficient and powerful approaches for particle–liquid separation. Yet the production of such systems using standard micro-fabrication techniques is proven to be tedious, costly and have cumbersome user interfaces, which all render commercialization difficult. Here, we demonstrate the design, fabrication and evaluation based on CFD simulation as well as experimentation of 3D-printed miniaturized hydrocyclones with smaller cut-size for high-throughput particle/cell sorting. The characteristics of the mini-cyclones were numerically investigated using computational fluid dynamics (CFD) techniques previously revealing that reduction in the size of the cyclone results in smaller cut-size of the particles. To showcase its utility, high-throughput algae harvesting from the medium with low energy input is demonstrated for the marine microalgae Tetraselmis suecica. Final microalgal biomass concentration was increased by 7.13 times in 11 minutes of operation time using our designed hydrocyclone (HC-1). We expect that this elegant approach can surmount the shortcomings of other microfluidic technologies such as clogging, low-throughput, cost and difficulty in operation. By moving away from production of planar microfluidic systems using conventional microfabrication techniques and embracing 3D-printing technology for construction of discrete elements, we envision 3D-printed mini-cyclones can be part of a library of standardized active and passive microfluidic components, suitable for particle–liquid separation.

Notes:

  • looks at hydrocyclones for microfluid applications instead of macro
  • Simulation on micro-scale overestimated size separation
    • probably because Brownian motion and no slip were unaccounted for
  • for micro pressure drop has much more impact

Google scholar search: Hydrocyclone Design Parameters[edit | edit source]

Evaluation of hydrocyclone models for practical applications[edit | edit source]

W. Chen, N. Zydek, and F. Parma, “Evaluation of hydrocyclone models for practical applications,” Chemical Engineering Journal, vol. 80, no. 1, pp. 295–303, Dec. 2000, doi: 10.1016/S1383-5866(00)00105-2.

Abstract Hydrocyclone is an important industrial solids–liquid separation equipment. Although widely used nowadays, the selection and design of hydrocyclones are still empirical and experience based. Although quite a few hydrocyclone models had been developed over the years, the validity of these models for practical applications was still not clear to all users. In this work, seven hydrocyclone models were evaluated. They are the more theoretically oriented models by Bohnet, Braun, and Mueller, semi-empirical models by Schubert/Neese and Svarovsky, plus the empirical models by Plitt and Krebs Engineers. Plant operation data from the Dow Chemical Company were used to compare with the predictions from these models. It was found that most of the models studied work well for certain cases but none of the models can predict all applications. The best results are obtained by using more than one model for predictions. Some experimental data are very important in choosing the models.

Notes:

  • Krebs' and Plitt's models are best for predicting pressure drop.
  • To calculate what size particles that cannot be separated by using Bonnet's model.
  • For any model Predictions it is best to have experimental data.
  • Multiple model's for predicting performance of a hydro cyclone should be used.

Optimizing Geometric Parameters in Hydrocyclones for Enhanced Separations: A Review and Perspective[edit | edit source]

L. Ni, J. Tian, T. Song, Y. Jong, and J. Zhao, “Optimizing Geometric Parameters in Hydrocyclones for Enhanced Separations: A Review and Perspective,” Separation & Purification Reviews, vol. 48, no. 1, pp. 30–51, Jan. 2019, doi: 10.1080/15422119.2017.1421558.

Abstract Hydrocyclones have been extensively applied for solid-liquid or liquid-liquid separations in various industries. However, the exact mechanisms underlying the enhanced separation technologies based on the optimization of geometric parameters of hydrocyclones remain unclear, and a number of research teams have performed numerous studies to enlarge the application scope of hydrocyclones by optimizing geometric parameters. This review provides a comprehensive state-of-the-art review of hydrocyclone enhanced-separation technologies. The enhanced-separation technologies are categorized into ten groups: cylindrical section, inlet, vortex finder, underflow pipe, conical section, hydrocyclone inclination angle, hydrocyclone insertion, conical-section/apex water injection, reflux device, and multi-hydrocyclone arrangement. These enhanced-separation technologies were analyzed and summarized according to the key separation-performance parameters of hydrocyclones, such as separation efficiency, cut size, split ratio, energy consumption, and capacity. It is expected that both the reviewed contents and the proposed challenges and future methodologies and technologies may provide research fellows working in this field with an improved understanding of enhanced separation technologies of hydrocyclones.

Notes:

Vortex finder optimum length in hydrocyclone separation[edit | edit source]

L. F. Martínez, A. G. Lavín, M. M. Mahamud, and J. L. Bueno, “Vortex finder optimum length in hydrocyclone separation,” Chemical Engineering and Processing: Process Intensification, vol. 47, no. 2, pp. 192–199, Feb. 2008, doi: 10.1016/j.cep.2007.03.003.

Abstract Effectiveness of hydrocyclone separations is highly dependent on their geometrical characteristics such as: chamber dimensions, aperture diameters or feed inlet geometry, for instance. Moreover, slight modifications of any of these features might severely affect separation efficiency. This work highlights the fundamental significance of the position of the vortex finder, showing how small changes in its length have meaningful effects on mass recovery and particle size distribution in overflow and underflow streams. This parameter has been scarcely considered in design studies. In order to establish the importance of the vortex finder length different and complementary methodologies were used such as mass balance, granulometric analysis and efficiency evaluation. Results obtained using theses methodologies were in agreement, showing that the highest efficient length of the vortex finder is 10% of the total length of the cyclone (0.1 Lt). This result was found for two hydrocyclones of different sizes, giving a more consistent conclusion.

Notes:

  • Having no vortex finder results in no separation. While too long of a vortex finder will have a reduced efficiency because the vortex is still developing at the bottom.
  • Near the region where the cylindrical and conical bodies join there is high turbulence it is best to avoid having the opening of the vortex finder in this zone.
  • Having the vortex finder below the inlet and above the transition from cylindrical to conical sections should provide the best separation.
  • Vortex finder length to total length ratio of 0.1 was determined to be the optimum length.

Google scholar search: Hydrocyclone equations[edit | edit source]

Influence of geometry on separation efficiency in a hydrocyclone[edit | edit source]

S. M. Mousavian and A. F. Najafi, “Influence of geometry on separation efficiency in a hydrocyclone,” Arch Appl Mech, vol. 79, no. 11, pp. 1033–1050, Nov. 2009, doi: 10.1007/s00419-008-0268-8.

Abstract A numerical study of the gas–liquid–solid multiphase flow in hydrocyclones is presented. Three models of turbulence, the RNG k–ε model, the Reynolds stress model and Large eddy simulation with the volume of fluid model (VOF) multiphase model for simulating air core are compared in order to predict axial and tangential velocity distributions. This presentation is mainly aimed at identifying an optimal method, used to study effective parameters, based on which, eventually, effect of inlet flow rate variations and body dimension variations such as underflow diameter, overflow diameter and cone angle on the separation performance and pressure drop are investigated. The results are then used in the simulation of particle flow described by the stochastic Lagrangian model. The results suggest that the predicted size classifications are approximately similar to those of RSM and LES methods. Predictions using the RSM model are found in agreement with experimental results with a marginal error within the range of 4 to 8%. Proceeding model validation, parametric studies have been carried out concerning the influence of velocity inlet, particle size and body dimension such as underflow and overflow diameter and cone angle. The predictions demonstrate that the flow fields in the hydrocyclones with different sizes and lengths are different, which yields different performances.

Notes:

Google scholar search: Cyclone Cylindrical and Conical Heights[edit | edit source]

Effects of cylindrical and conical heights on pressure and velocity fields in cyclones[edit | edit source]

S. Demir, A. Karadeniz, and M. Aksel, “Effects of cylindrical and conical heights on pressure and velocity fields in cyclones,” Powder Technology, vol. 295, pp. 209–217, Jul. 2016, doi: 10.1016/j.powtec.2016.03.049.

Abstract Nine modifications of Stairmand high-efficiency type cyclone with various cylindrical and conical heights were used to investigate their effects on pressure drop and flow field within cyclones. An experimental setup was built and experiments were conducted on various cyclone geometries at inlet velocities ranging from 10 to 18.5 m/s. The body heights ranged from D to 2D (D being the diameter of the cyclone body), while the conical heights were between 2D and 3D. The experimental results were used to calibrate CFD (Computational Fluid Dynamics) model. Experimental results showed that the pressure drop ranged from 191 to 235 Pa and 690 to 920 Pa at the lowest and highest inlet velocities, respectively, and that pressure drop is a function of both cylindrical and conical heights with reduced pressure drops as cylindrical and/or conical heights increase. Maps showing the change in pressure drop with respect to cylindrical and conical heights were prepared and interpreted to determine optimum ratio of conical-to-cylindrical height for reduced pressure drop. Optimum ratio was found experimentally as between 1.67 and 2.5. CFD results agreed well with the experimental data and the results helped gain insights into complicated phenomena taking place in cyclones. CFD results showed that increased axial velocities at the lip of vortex finder disturb radial velocity profiles and that tangential velocities in the stabilized vortex can be as high 1.4 times the mean inlet velocity. Both findings indicate that collection efficiency of the cyclone may be influenced by the height of the cyclone.

Notes:

  • Generally collection efficiency increases when the pressure drop increases.
  • When the body height is 1.5D and conical height is 2.5D where D is the body diameter pressure drop behaves as a linear function. When body height is less than 1.5D and the conical height is greater than 2.5D The pressure drop is only changed by the body height. Increasing both dimensions will lower the pressure drop while increasing the cost to manufacture.
  • Tangential velocity is reduced as the conical height increases. Overall having taller body and conical heists will result in lower tangential velocities.
  • A conical-to-body height ratio greater than 1.67 while not exceeding 2.5 will provide a lower pressure drop while being the most cost-effective design

Google scholar search: 3D Printing Filament Material Compatible with Biomass[edit | edit source]

Revealing interactions of layered polymeric materials at solid-liquid interface for building solvent compatibility charts for 3D printing applications[edit | edit source]

Erokhin, K.S., Gordeev, E.G. & Ananikov, V.P. Revealing interactions of layered polymeric materials at solid-liquid interface for building solvent compatibility charts for 3D printing applications. Sci Rep 9, 20177 (2019). doi.org/10.1038/s41598-019-56350-w

Abstract Poor stability of 3D printed plastic objects in a number of solvents limits several important applications in engineering, chemistry and biology. Due to layered type of assembling, 3D-printed surfaces possess rather different properties as compared to bulk surfaces made by other methods. Here we study fundamental interactions at the solid-liquid interface and evaluate polymeric materials towards advanced additive manufacturing. A simple and universal stability test was developed for 3D printed parts and applied to a variety of thermoplastics. Specific modes of resistance/destruction were described for different plastics and their compatibility to a representative scope of solvents (aqueous and organic) was evaluated. Classification and characterization of destruction modes for a wide range of conditions (including geometry and 3D printing parameters) were carried out. Key factors of tolerance to solvent media were investigated by electron microscopy. We show that the overall stability and the mode of destruction depend on chemical properties of the polymer and the nature of interactions at the solid-liquid interface. Importantly, stability also depends on the layered microstructure of the sample, which is defined by 3D printing parameters. Developed solvent compatibility charts for a wide range of polymeric materials (ABS, PLA, PLA-Cu, PETG, SBS, Ceramo, HIPS, Primalloy, Photoresin, Nylon, Nylon-C, POM, PE, PP) and solvents represent an important benchmark for practical applications.

Notes:

  • Printed object stability depends on chemical properties of the polymer, nature of interactions at the solid-liquid interface and layered microstructure(which depends on printing parameters.
  • Porosity, defects and layer by layer construction increases surface area for solid-liquid interaction, reducing chemical resistance.
  • PLA, PLA-Cu, ABS, SBS, Ceramo, Primalloy and HIPS are stable in gentle aqueous media and susceptible to most organic solvents (suitable for biotech applications).
  • Photopolymers and PETG are resistant to water-miscible organic solvents (suitable for application in medicine)
  • PP, PE, POM, Nylon and Nylon-C are resistant to majority of organic solvents (suitable for building chemical reactors, fittings and medical tools).
  • Parts printed at k=1.1 - 1.3 are most stable, increase in k results in increase in wall thickness and wall density (same stability as an extruded part).


Custom fabrication of biomass containment devices using 3-D printing enables bacterial growth analyses with complex insoluble substrates[edit | edit source]

C.Nelson, N.Beri, J.Gardner, Custom fabrication of biomass containment devices using 3-D printing enables bacterial growth analyses with complex insoluble substrates. Journal of Microbiological Methods, Vol. 130, pp 136-143 (2016). doi.org/10.1016/j.mimet.2016.09.013

Abstract Physiological studies of recalcitrant polysaccharide degradation are challenging for several reasons, one of which is the difficulty in obtaining a reproducibly accurate real-time measurement of bacterial growth using insoluble substrates. Current methods suffer from several problems including (i) high background noise due to the insoluble material interspersed with cells, (ii) high consumable and reagent cost and (iii) significant time delay between sampling and data acquisition. A customizable substrate and cell separation device would provide an option to study bacterial growth using optical density measurements. To test this hypothesis we used 3-D printing to create biomass containment devices that allow interaction between insoluble substrates and microbial cells but do not interfere with spectrophotometer measurements. Evaluation of materials available for 3-D printing indicated that UV-cured acrylic plastic was the best material, being superior to nylon or stainless steel when examined for heat tolerance, reactivity, and ability to be sterilized. Cost analysis of the 3-D printed devices indicated they are a competitive way to quantitate bacterial growth compared to viable cell counting or protein measurements, and experimental conditions were scalable over a 100-fold range. The presence of the devices did not alter growth phenotypes when using either soluble substrates or insoluble substrates. We applied biomass containment to characterize growth of Cellvibrio japonicus on authentic lignocellulose (non-pretreated corn stover), and found physiological evidence that xylan is a significant nutritional source despite an abundance of cellulose present.

Notes:

  • For biocontainment device, UV-cured acrylic plastic is superior to nylon or SS as a 3D printing material in terms of reactivity, heat tolerance and sterilization.
  • Sterilization compatibility makes it reusable. 3 materials are tested: nylo(Alumide), acrylic(UV cured) and stainless steel(60% steel,40% bronze).
  • Price range for one BCD (top to bottom pieces): $4.76(nylon; Mk 2.1), $12.24(acrylic;Mk2.1), and $15.21(steel; Mk2.1).
  • Sterilization options: UV exposure, surface sterilization with bleach and ethanol, or autoclaving.


3D‐printed individual labware in biosciences by rapid prototyping: A proof of principle[edit | edit source]

T.Lücking ,F.Sambale, S.Beutel and T.Scheper, 3D‐printed individual labware in biosciences by rapid prototyping: A proof of principle. Engineering in Life Sciences, Vol. 15 Issue 1 (2014). doi.org/10.1002/elsc.201400093


Abstract The fabrication of individual labware is a sophisticated task that requires dedicated machines and skills. Three‐dimensional (3D) printing has the great potential to simplify this procedure drastically. In the near future, scientists will design labware digitally and then print them three dimensionally directly in the laboratory. With the available rapid prototyping printer systems, it is possible to achieve this. The materials accessible meet the needs of biotechnological laboratories that include biocompatibility and withstanding sterilization conditions. This will lead to a completely new approach of adapting the labware to the experiment or even tailor‐made it to the organism it is being used for, not adapting the experiment to a certain standard labware. Thus, it will encourage the creativity of scientists and enrich the future laboratory work. We present different examples illustrating the potential and possibilities of using 3D printing for individualizing labware. This includes a well plate with different baffle geometries, shake flask cap with built‐in luer connections, and filter holder for an in‐house developed membrane reactor system.

Notes:

  • Bioscience applications of 3-D printing include 3D scaffolds, build reaction ware and labware.
  • Low cost FDM printers currently reach a resolution as low as 100 microns (sufficient for most applications)
  • Most affordable printer filaments include acrylonitrile butadiene styrene(ABS) and polylactic acid, recent addition is Nylon(PA 6.6).
  • Material compatibility requirements for bioscience applications include acceptable chemical resistance and tolerance for steam sterilization (121 Celsius for 20 min. at 2 bar).

Google scholar search: 3D Printing Material for hydrocyclones[edit | edit source]

Influence of Design Parameters on Biomass Separation in Mini-hydrocyclones[edit | edit source]

P.Parada, R.Dewes, D.Garcia, J.Cilliers, "Influence of Design Parameters on Biomass Separation in Mini-hydrocyclones" Chemical Engineering & Technology, Vol.41, Issue 12 (2018),doi.org/10.1002/ceat.201800290

Abstract Small hydrocyclones are an attractive technology for biomass separation from fermentation processes. The interactive effect of design parameters on the performance of mini‐hydrocyclones is, however, not fully explored and studies are often limited by the challenges in manufacturing such small units. Here, 10‐mm mini‐hydrocyclones are produced by 3D printing and the impact of spigot diameter, vortex finder diameter and height on separation performance is studied. A central composite rotatable design was adopted to obtain information on the relation between the variables and their influence on concentration ratio and recovery of yeast from a highly diluted system. A Pareto front for separation performance was generated and shown to be suitable to select an optimal design for a set of process constraints.

Notes:

  • Bioproducts of interest are mostly present in highly diluted aqueous systems which needs to be concentrated.
  • Since cut size is directly proportional to diameter, mini-hydrocyclones with 10mm in diameter are suitable for bio-separation. Separation efficiency can be increased at high flow rates, low yeast feed concentration, high operating pressure and high temperature.
  • Mini-hydrocyclone is printed in transparent acrylic (VeroClear) using Objet30 Pro printer. Variables studied are vortex finder diameter, spigot diameter and vortex finder height.
  • Diluted suspension of yeast, Saccharomyces cerevisiae is used with a concentration of 0.5gL-1 and yeast density is 1100kgm-3. Hydrocyclone feed flow rate is set to 65mLs-1.
  • Vortex finder height is related to reducing percentage of solids in the underflow. At higher values of spigot diameter, effect of low vortex finder diameter on recovery values is nonlinear.
  • Vortex finder can be varied to improve recovery without affecting concentration ratio. Concentration ratio can be increased by decreasing spigot diameter.
  • Performance is a trade-off between recovery and concentration ratio.

Google scholar search: Polymers for 3D Printing[edit | edit source]

Mechanical characterization of 3D-printed polymers[edit | edit source]

J.Dizon, A.Espera Jr., Q.Chen and R.Advincula, “Mechanical characterization of 3D-printed polymers,” Additive Manufacturing, vol. 20, pp. 44-67, Mar. 2018, doi.org/10.1016/j.addma.2017.12.002.

Abstract 3D printing, more formally known as Additive Manufacturing (AM), is already being adopted for rapid prototyping and soon rapid manufacturing. This review provides a brief discussion about AM and also the most employed AM technologies for polymers. The commonly-used ASTM and ISO mechanical test standards which have been used by various research groups to test the strength of the 3D-printed parts have been reported. Also, a summary of an exhaustive amount of literature regarding the mechanical properties of 3D-printed parts is included, specifically, properties under different loading types such as tensile, bending, compressive, fatigue, impact and others. Properties at low temperatures have also been discussed. Further, the effects of fillers as well as post-processing on the mechanical properties have also been discussed. Lastly, several important questions to consider in the standardization of mechanical test methods have been raised.

Notes:

  • Mechanical property analysis of AM manufactured parts based on ASTM and ISO standards. No standard tests for Additive Manufactured(AM) products yet. Review of tension, compression, bending, cyclic/fatigue loading, impact loading, and creep of material.
  • AM methods for polymers: Fused deposition modeling (FDM), Stereolithography (SLA), Digital light processing (DLP), Selective layer sintering (SLS), Three-dimensional printing (3DP), Laminated object manufacturing (LOM) and PolyJet technology.
  • ASTM standards for testing plastics: ASTM D638, ASTM D412, ASTM D882, ASTM D790, ASTM D1938 and ASTM D3039. ISO standards: ISO 527, ISO 34-2:2015, ISO 34-1:2010 and ISO 37.
  • Materials with supplier are listed, including property values of density, tensile strength, tensile modulus, elongation to failure and HDT(heat deflection temperature).