High-efficiency Separator Research Articles

Mechanism analysis of enhanced desulfurization of pulverized coal through high-gradient magnetic separation with microwave radiation

Dry high gradient magnetic separation technology is a low-carbon green technology. It can be embedded in a power plant to remove coal pyrite with a high-efficiency magnetic separator and remarkable magnetic properties difference between coal pyrite and coal matrix. This study selected the microwave radiation method to improve the magnetic properties difference and carried out a desulfurization experiment with a self-developed high-gradient permanent magnetic separator using the tapered iron auxiliary magnetic pole. The results demonstrate that the pyrite content and specific magnetic susceptibility increase with the decrease in particle size. The desulfurization rate did not change significantly at 25 °C. The coal sample began to appear in the thermal reaction at 450 °C, and the pyrite can become a strong magnetic property pyrrhotite. The desulfurization rate can achieve 58.70 % at 700 °C, and is equivalent to the wet washing index, due to the supply of high magnetic field force. The dynamic characteristic response of magnetic particles becomes more obvious with short time adsorption, and the probability of carrying non-magnetic particles is reduced. This study demonstrates that the high-gradient magnetic separation technology of pulverized coal enhanced by microwave irradiation is feasible.

Particulate filtration by cryogenic condensation using a high efficiency Stairmand cyclone separator

This paper describes the synergy of a high-efficiency Stairmand cyclonic separator and the phenomenon of condensation generated by the low temperatures of the mixture of liquid nitrogen and ethanol, to increase the separation efficiency on particles with diameters of 1 μm, 45 μm, 75 μm, 150 μm and 250 μm. The cyclone separator adds the phenomenon of condensation, generating a film of liquid water on its internal walls. The film of liquid water causes a loss of kinetic energy in the particles, reducing their speed and becoming stuck. Al2O3 particles and pozzolana rock particles are used to perform the particle separation experimental tests. A computational fluid dynamics analysis using the second order RSM model is incorporated to describe the fluid dynamic behavior of the particles within the separator cyclone. The results in computational fluid dynamics show the agglomeration of larger diameter particles near the internal walls. Using condensation as a phase change generated by cryogenic mixing results in an overall particle separation efficiency of 76.00 %, standing for an increment of 70.14 % in comparison to a conventional high-efficiency Stairmand separator cyclone.Technological innovation: Particles, filtration, separation, condensation, cryogenic.

High-Efficiency Separator Capacity-Compensation Strategy Applied to Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are expected to replace partial reliance on lithium-ion batteries (LIBs) in the field of large-scale energy storage as well as low-speed electric vehicles due to the abundance, wide distribution, and easy availability of sodium metal. Unfortunately, a certain amount of sodium ions are irreversibly trapped in the solid electrolyte interface (SEI) layer during the initial charging process, causing the initial capacity loss (ICL) of the SIBs. A separator capacity-compensation strategy is proposed, where the capacity compensator on the separator oxidizes below the high cut-off voltage of the cathode to provide additional sodium ions. This strategy shows attractive advantages, including adaptability to current production processes, no impairment of cell long-cycle life, controlled pre-sodiation degree, and strategy universality. The separator capacity-compensation strategy is applied in the NaNi1/3 Fe1/3 Mn1/3 O2 (NMFO)||HC full cell and achieve a compensated capacity ratio of 18.2%. In the Na3 V2 (PO4 )3 (NVP)||HC full cell, the initial reversible specific capacity is increased from 61.0 mAh g-1 to 83.1 mAh g-1 . The separator capacity-compensation strategy is proven to be universal and provides a new perspective to enhance the energy density of SIBs.

Wodyetia bifurcate structured carbon fabrics with durable superhydrophobicity for high-efficiency oil-water separation

The superhydrophobic fiber-based membranes with features of high separation efficiency and low energy consumption for oil-water separation remains a formidable challenge. In this paper, a robust and durable superhydrophobic cotton-derived carbon fabric (CDCF) with wodyetia bifurcate-like structure is fabricated via in situ cobalt-nickel basic carbonate (CNC) deposition and 1 H, 1 H, 2 H, 2 H-perfluorooctyltriethoxysilane (POTS) coating. The combined action of rough surface structure and low surface energy makes CDCF/CNC/POTS with superhydrophobicity/superoleophilicity, anti-wetting, and self-cleaning performance. Intriguingly, the CDCF/CNC/POTS can keep its superhydrophobicity under of the water droplet impact pressure of 781 Pa. In addition to its robust dynamic superhydrophobicity, CDCF/CNC/POTS can also maintain its non-wetting property under harsh environmental conditions such as mechanical abrasion treatment, acidic, alkaline and salt solutions, and ultraviolet radiation. Importantly, the CDCF/CNC/POTS can separate various oil-water mixtures and emulsions under gravity with ultrahigh oil-water mixtures permeate flux (∼19,126 L/m2h), high surfactant-stabilized emulsion permeate flux (∼821 L/m2h), and high separation efficiency (> 98.60 %). Moreover, remarkable recyclability endow the CDCF/CNC/POTS with promising application in treating oily wastewater. This work may benefit the low-cost mass production of cotton-based carbon fabrics for developing eco-friendly high-efficiency separators.

Melt polymerization synthesis of a class of robust self-shaped olefin-linked COF foams as high-efficiency separators

Melt polymerization synthesis of a class of robust self-shaped olefin-linked COF foams as high-efficiency separators

Extraordinary Superhydrophobic Polycaprolactone-Based Composite Membrane with an Alternated Micro-Nano Hierarchical Structure as an Eco-friendly Oil/Water Separator.

Extraordinary superhydrophobic polycaprolactone (PCL) composite membranes with an alternated hierarchical micro-nano structure were designed by addition of SiO2 aerogel. The highest water contact angle (WCA) of 166.8 ± 1.5° was obtained when SiO2 aerogel content was 0.5% (PCL/SiO2-a0.5) in the PCL composite membrane, which was higher than other reported polymer-based membranes. SiO2 aerogel lowered PCL composite membrane's surface energy. The triple curvature structure composed of microspheres, nanospheres, and nanofibers produced on PCL/SiO2-a0.5 membranes endowed the excellent roughness of the surface. Also, the inner structure of the PCL/SiO2-a0.5 composite membrane composed of micro-nano spheres, nanofibers, and microfibers increased the porosity of the separation membrane, which would provide more adsorption space. The PCL/SiO2-a0.5 composite membrane as a separator for surfactant-stabilized emulsions of water-in-oil showed ultrahigh separation flux and efficiency. Meanwhile, the PCL/SiO2-a0.5 composite membrane had an outstanding chemical resistance, self-cleaning ability, and good reusability. The composite membranes reported in this work as eco-friendly separation materials possessed all these characters in oil/water separation. This research proposed a very simple method to design eco-friendly high-efficiency separators through the construction of the alternated micro-nano hierarchical structure.

Performance Improvement of Helical Downhole Gas-Oil Separator Using Experimental Approach

Summary Growing demand for a subsurface pump application to perform artificial lift in low-pressure wells increases the necessity of a high-efficiency downhole separator to prevent gas entrance in the pump. The purpose of this study is to empirically investigate the efficiency of a helical downhole separator and provide suggestions for improving its performance. To make the results more practical, dimensionless numbers governing the problem were specified using dimensional analysis and the Buckingham theorem, and a laboratory-scale separator was built. Oil and air were selected as the working fluids for this experiment. The results of the experiments showed that the separator performance was divided into three regions: inefficiency region, rapid-growth region, and nongrowth region. To increase the separator efficiency, the separator was modified by blocking the initial holes of the inner tube to provide a region for developing the prerotational effect. The modified separator showed an increase in efficiency as much as 7%. In the third step, the number of holes that were blocked at the entrance region in the first modification were distributed in the rest of the inner tube so that the total hole area remains constant. The separator efficiency, in this case, was significantly increased compared with the previous two cases by as much as twofold. It was found that the inlet design of the separator significantly affects its performance.

High-Efficiency Plasma Separator Based on Immunocapture and Filtration.

The shortcomings of standard plasma-separation methods limit the point-of-care application of microfluidics in clinical facilities and at the patient’s bedside. To overcome the limitations of this inconvenient, laborious, and costly technique, a new plasma-separation technique and device were developed. This new separation method relies on immunological capture and filtration to exclude cells from plasma, and is convenient, easy to use, and cost-effective. Most of the RBCs can be captured and immobilized by antibody which coated in separation matrix, and residue cells can be totally removed from the sample by a commercially plasma purification membranes. A 400 µL anti-coagulated whole blood sample with 65% hematocrit (Hct) can be separated by the device in 5 min with only one pipette. Up to 97% of the plasma can be recovered from the raw blood sample with a separation efficiency at 100%. The recovery rate of small molecule compounds, proteins, and nucleic acid biomarkers is evaluated; there are no obvious differences from the centrifuge method. The results demonstrate that this method is an excellent replacement for traditional plasma preparation protocols.

High-efficiency industrial cyclone separator: A CFD study

The flow within an industrial scroll-inlet high-efficiency cyclone separator has been studied using RSM and LES simulations. Of particular interest is the effect of the gas outlet configuration, i.e. outlet scroll and radial bend, on the flow pattern, pressure drop and cyclone efficiency. A surprising phenomenon is that the inner vortex splits into two vortices for the cyclone with a conventional outlet pipe while if the cyclone is equipped with an outlet scroll or radial bend there is no split. The outlet scroll and radial bend increase the pressure losses by 5.1% and 6.4%, respectively. These installations, moreover, significantly destabilize the pressure losses and the amplitude of instantaneous pressure drop oscillations increases from 0.65% to 16.2% and 33.96%, respectively. The investigated outlet scroll and radial bend have practically no effects on the cyclone efficiency since the flow in the main separation zone is not affected by the gas outlet configuration.

An experimental modeling of cyclone separator efficiency with PCA-PSO-SVR algorithm

Accurate prediction of the complicated nonlinear relationship among the grade efficiency, geometrical dimensions, and operating parameters based on limited experimental data is the most effective way to design a high-efficiency cyclone separator. Herein, a hybrid PCA-PSO-SVR model is proposed to predict the grade efficiency of cyclone separators with the operating parameters based on 217 sets of experimental data provided in the literature. The experimental data are preprocessed using the random sampling technique together with the normalization method and principal component analysis (PCA) at first; subsequently, the particle swarm optimization (PSO) algorithm is incorporated to optimize the parameters for the support vector regression (SVR), including the penalty factor C, kernel function parameter g, and insensitive loss ε. Finally, the SVR model with the optimized parameters is trained with 80% pretreatment data, and the generalization ability of the model is tested with the remaining 20% data. The mean squared error of the test sets is 6.948 × 10−4 with a correlation coefficient of 0.982. The comparison results show that the PCA-PSO-SVR model has higher accuracy, better generalization ability, and stronger robustness than the existing models for predicting the cyclone separator efficiency in the case with only a few experimental data.

Design of a novel high-efficiency water separator for proton exchange membrane fuel cell system

In the fuel cell system, hydrogen recirculation subsystem is usually used to increase efficiency of hydrogen usage. While the hydrogen recirculation subsystem is a closed circuit that the water might be accumulated, water separator is used necessarily to separate the water and gas at the anode side. As the poor swirling effect caused by the guide vane in commercial separator, a novel water separator for proton exchange membrane fuel cell system is designed and the flow field characteristics of the separator are gained by computational fluid dynamics. The structure of volute inlet and overflow pipe in the novel separator can enhance the swirling flow and increase the tangential velocity. Based on the results, the separation efficiency and steady performance throughout the flow-rate range can be improved by the novel water separator.

An improved design method for compact vertical separator combined with the theoretical method and numerical simulation

Hydrocyclone is mostly used in high efficiency and compact separators to simplify the process flow, and reduce the occupied area and weight of separation equipments. However, the separation outer cylinder size is determined by the traditional Stokes law and the size of traditional droplets, the calculation result would be bigger than expected. So, a new improved design method is put forward in this paper. Firstly, the theoretical calculation is conducted on the effective diameter of the dispersed phase oil droplets according to the droplet coalescence principle and the population balance equation (PBE), and then the numerical simulation verification of multiple load cases is conducted on the two possible maximum particle sizes of the oil droplets by means of the VOF multiphase flow model. Then the floating velocity of oil droplets can be obtained by the droplet sedimentation velocity calculation model, and finally, the size of the outer cylinder of the compact vertical separator can be determined. This method can greatly reduce the size of the outer cylinder of the separator and realize the compactness of the overall structure of the separator. The feasibility of the structure and the reliability of the separation effect have also been verified by field tests.

A High-Efficiency Separator Upgrade: Threading a Separator Through the Eye of a Needle

Since 2007, the Nebraska Cement Market has been seeing increasing strength requirements. As a result, the blaine fineness of cement produced by first-generation separator finish mill systems has been slowly progressing beyond the capability of these units. Previously, at 3,800 blaine, the mills could easily outgrind the kilns and satisfy a highly seasonal market. However, the drive to produce Type I/II cement at 4,700 blaine to meet market demands reduced productivity such that finish mill capacity was quickly becoming a bottleneck to cement production.

Development of a novel high-efficiency dynamic hydrocyclone for oil–water separation

A dynamic hydrocyclone (DH) is a high-efficiency separator, but the oil core dispersion phenomenon was observed when the split ratio was small in the experiment. The separated oil mixed with water again and the separation failed in that case. To overcome these deficiencies and improve the performance, a novel reverse-flow DH (RDH) was designed by the inspiration of conventional hydrocyclones. The performances of the DH and RDH were investigated both experimentally and numerically. The results showed that in RDH, air bubbles and oil droplets were discharged quickly from the oil outlet, and the influence of the interferences was diminished. Thus the oil core dispersion phenomenon was avoided, and separation performance was improved. The results of numerical simulations were largely consistent with the experimental results. Furthermore, the flow field analyses indicated that the residence times of the oil droplets in two DHs are similar, while the tangential velocity in the RDH was larger than that in the DH, which leads to a higher separation efficiency.

A novel pneumatic separator for separating diode and CD capacitance of waste printed circuit boards

Abstract Waste printed circuit boards (WPCBs) contain abundant metals. Recovering WPCBs is significant in energy conservation, sustainable development, and environmental protection, which save the energy and environment cost of searching and melting of metals. Many reports were related to environment-friendly disposal of basal boards of WPCBs. Little information was reported about the recovery technology of electronic components. In this paper, a novel and pollution-free pneumatic separator was invented to separate diode (Ti enriched components) and CD capacitance (Sn enriched components). Trajectory models of diode and CD capacitance in pneumatic separation were established. Then, optimized parameters of airflow velocity (0.77 m/s) and position (0.16 m) of separation plate of pneumatic separation were obtained. Separation rates of diode and CD capacitances in pneumatic separation reached up to 96.7 wt% and 97.3 wt%. This paper provided an environment-friendly and high-efficiency separator for separating electronic components of WPCBs. The trajectory models also can guide pneumatic separation of other electronic components.

Numerical Investigation on the Effects of Pipe Rotation on a Dynamic Hydrocyclone

Dynamic hydrocyclone and compound hydrocyclone are both new high efficiency separators whose difference is whether the pipe wall (wall of separation chamber) is rotating when working, but the influences of rotating pipe on hydrodynamics and performance of dynamic hydrocyclone has not been well studied. In this paper, a three dimensional numerical simulation applying Reynolds Stress Model (RSM) coupled with Multiple Reference Frame (MRF) model and algebraic slip mixture model was conducted to analyze flow field of dynamic hydrocyclone with and without pipe rotation. The results show that, pipe rotation can accelerate the flow around the wall leading to an increase of tangential velocity as well as avoidance of large velocity gradient around the wall. On the other hand, pipe rotation has little impact on axial velocity. And investigation on the turbulence shows that pipe rotation may effectively attenuate turbulent transport. What’s more, pipe rotation significantly improves aggregation effect of oil droplet, which leads to an increase of separation performance.

A high-efficiency superhydrophobic plasma separator.

To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device's superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a "blood in-plasma out" capability, consistently extracting 65 ± 21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of >84.5 ± 25.8%. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method.

CFD modeling and analysis of the fish-hook effect on the rotor separator's efficiency

This paper presents a three-dimensional numerical simulation of the gas–solid flow in the third generation dynamic separator. The industrial CFD code (Fluent) is used to model the high turbulent fluid flow and the separation efficiency inside this separator. The Reynolds Stress Model (RSM) and the Discrete Phase Model (DPM) are used respectively to predict the velocity field and pressure drop and to estimate the selectivity curve inside the high efficiency separator. While the DPM model is used to estimate the selectivity curve. Some factors which affect the performance of dynamic separator were identified. The fish-hook effect is the most marked mechanism for selecting finer cement powder. The CFD simulation results are analyzed in order to understand the fish-hook effect and the separation mechanism in the dynamic separator. It is found that the RSM model better captures the phenomenon in the dynamic separator when compared with industrial results made by the Enfidha Cement plant “CE” and that the fish-hook effect was a result of the bubble-type vortex breakdown in the separating chamber. But much difficulty has been reached to achieve convergence.

Development of high-efficiency hydraulic separators

Hydraulic separators are commonly used for particle size classification and gravity concentration of minerals and coal. Unfortunately, the efficiency of these processes can be quite low due to poor equipment design and variations in feed consistency. To help alleviate these problems, an industry-driven R&D program was undertaken to develop a new generation of hydraulic separators that are more efficient and less costly to operate and maintain. Two of the most promising technologies, the CrossFlow and HydroFloat separators, have now been tested at industrial sites. The data obtained from these sites have been used to illustrate the potential performance improvements that can be realized through the application of these high-efficiency separators.

Confined and Agitated Swirling Flows with Applications in Chemical Engineering

Turbulent, swirling flows are encountered frequently in chemical engineering practice. In this article, experiments and simulations on two classes of swirling flows, viz. agitated flows (stirred tanks), and confined swirling flows are discussed. Results of large-eddy simulations of stirred tank flow are compared with experimental data, mainly phase-resolved LDA data of the flow in the vicinity of the impeller. Next to the average velocity field, also the turbulent kinetic energy, and the anisotropy of the Reynolds stress tensor have been assessed. An important application of confined swirling flow is the cyclone separator (hydrocyclones for the separation of liquids, gas cyclones for gas-solid separation). The flow in a swirl tube geometry exhibiting many of the typical features of swirl flows (e.g. vortex breakdown) is discussed. Furthermore, a large-eddy simulation of the gas flow in a high-efficiency Stairmand cyclone separator is presented. Two examples of process modeling based on flow simulations are briefly treated: orthokinetic agglomeration of crystals in a stirred tank, and particle separation in a cyclone.