Cyclone Separator Research Articles

Enhancing the efficiency of two‐stage cyclones without increasing pressure drop by optimizing inlet and outlet dimensions

AbstractEfforts to enhance cyclone separators aim to minimize gas energy consumption while improving separation efficiency. This study attempts to achieve this goal for cyclones arranged in series using straightforward methods. Experimental and numerical simulation analyses were performed to study the effect of matching inlet and outlet diameters on the performance of a two‐stage tandem cyclone separator. The results show that the matching method, in which the inlet gas velocities of both stages are higher than the outlet gas velocity, has a better separation efficiency. The efficiency and pressure drop models of the two‐stage cyclones in series were constructed using the response surface methodology (RSM) to obtain the optimal combination of inlet size and exhaust pipe diameter. Experimental tests showed that the accuracy of this model was reasonable. At different permitted pressure drops, the optimized structure revealed that: (1) The inlet area should be smaller than the outlet area for each cyclone stage. (2) The secondary inlet size (KA) should be as large as possible. (3) dr decreases while KA increases in each step.

Analysis on the gas-solid variation characteristics and dust spatial distribution in a return micro-cyclone with a tangential inlet

The cyclone separator is widely used for the dedusting process in industry to extend its application scope, a novel return micro-cyclone with a tangential inlet was constructed considering its small and convenient feature. The cyclone was constructed by 3D printing technology, and the experimental system was established. A 3D fluid dynamics (CFD) model was developed with RNG k–ε model and discrete random walk (DRW) model. Discrete Phase Model (DPM) was applied for dust particles of different sizes in the cyclone to investigate the swirl and separation flow. The transient flow field, the tail swinging phenomenon, the outer and inner swirling airflows can be detected vividly. The numerical method predicts the quantity percentage of dust well with the deviations of 0.92 %, 1.15 %, 0.88 %, 0.69 % and 4 % of the experimental data for PM10–20, PM20–30, PM30–40, PM40–50 and PM50–60 when the initial air velocity is 7.3 m/s. There are few dust particles in the exhaust pipe, which are mainly fine particles of PM10 with few particles of PM10–20 and PM20–30 when the initial air velocity is low. The phenomenon of the dust ring at the top region is significant and varies with the air velocity. Dust concentration in different sections can provide further references to optimize the cyclone structure.

Effect of Exhaust Pipe Size on Separation Efficiency of Cyclone Separator Used in Power Plant

In order to grasp the influence of exhaust pipe size on cyclone flow fields and improve the recovery and utilization rate of coal powder in power plant, the flow characteristics and the separation capacity of the fine coal powder separator in power plant were investigated through numerical simulation. The Reynolds stress model was employed to model the turbulent flow. The Eulerian-Lagrangian computational procedure was used to predict particles tracking in the cyclone. The particle trajectories were simulated using the discrete random walk. Five cyclone types with different insertion lengths of the exhaust pipe at the same other geometric dimensions were considered. It was found that tangential velocity played a dominant role in the radial distribution of particles, which was mainly represented by Rankine vortex. When the insertion length of the exhaust pipe was increased from 1638 mm to 5100 mm, the grade efficiency of 5–12 μm particles was increased by 19%, and the pressure drop reduced by 8%.

Hydrodynamic characteristics analysis of series hydraulic cyclone separators for pond aquaculture wastewater purification

This study introduces a series of hydraulic cyclone separators designed to efficiently remove sediments and other high-density particulate matter from pond aquaculture wastewater. A three-dimensional two-phase model of these hydraulic cyclone separators was developed using the discrete phase model (DPM) and Reynolds stress turbulence model (RSM) based on numerical simulation theory. The computational fluid dynamics (CFD) method was validated by comparing it with experimental data, and an analysis of the hydrodynamic characteristics of the hydraulic cyclone separators was conducted. Furthermore, the relationships between structural parameters and separation efficiency were examined using Pearson's correlation coefficient. The findings reveal that the length of the first-stage cyclone column significantly influences the tangential velocity distribution within the second-stage cyclone, while the length of the second-stage cyclone column predominantly affects the pressure distribution of the first-stage cyclone. Increasing the column length enhances the overall particulate separation efficiency of the system. Moreover, adjustments in the split ratio of the first-stage cyclone have a notable impact on the tangential velocity and pressure distribution within the second-stage cyclone. Increasing the split ratio proves beneficial in improving the separation efficiency of particulate matter. This study provides valuable insights into the design and optimization of hydraulic cyclone separators, offering a dependable computational model for predicting and understanding their flow behavior and separation performance effectively.

Performance experiments and pressure drop prediction modelling of an energy-saving cyclone separator

The study proposes a new type of axial-inlet cyclone separator with the smaller cylinder-cone ratio and an expansion tube at the particle exhaust, named energy-saving cyclone separator, which offers several advantages over the traditional tangential inlet cyclone in engineering units. Experimental results demonstrate that the separation efficiency exceeds 83 % for fine particles smaller than 10μm, while the pressure drop is significantly lower than that of the commonly used PV-type tangential inlet cyclone separator, at only 44 % of the PV cyclone separator’s pressure drop. Moreover, the flow fields of energy-saving cyclone separator are measured to analyze its characteristics. It is found that the lower tangential momentum ratio in both the inner and outer swirl zones of energy-saving cyclone separator reduces the dissipation of dynamic swirl pressure at the bottom of the cone section and outlet pipe, resulting in a lower pressure drop. The high proportion of downward axial momentum in the outer swirl section causes the separated large particles to discharge through the dust exhaust, improving the separation efficiency of coarse particles. Furthermore, a model to predict the pressure drop of energy-saving cyclone separator is developed.

Modification of Cyclone Separator Based on IOT Arduino Microcontroller with Activated Carbon from Cocoa Shell Waste as a Tool for Controlling Air Pollution

Modification of Cyclone Separator Based on IOT Arduino Microcontroller with Activated Carbon from Cocoa Shell Waste as a Tool for Controlling Air Pollution

Liquid–solid two-phase flow and separation behavior in a novel cyclone separator

In response to the prevalent issue of sand presence in liquid, particularly prominent in petroleum engineering, a novel cyclone separator has been meticulously engineered for fine-particle separation. Experiments and numerical simulation methods have provided a profound understanding of the flow-field characteristics and separation efficacy of this device. The internal architecture of the swirling flow inside the separator features a distinctive central vortex core, complemented by a turbulent secondary vortex formation in the lower section of the underflow. As the axial height increases, the secondary vortex gradually dissipates. An analysis of pressure and velocity distribution within the cyclone separator confirms the establishment of a stable cyclone field in the built-in cyclone and a tendency for the flow field within the tank to exhibit uniformity with increasing height. These flow-field characteristics show that the cyclone separator has a good separation effect on fine-rust particle impurities. Furthermore, the separation efficiency of the novel cyclone separator demonstrates a positive correlation with increasing particle size. Of the parameters studied, variation of the inlet velocity is the best method for obtaining optimum separation efficiency for a cyclone desander with a fixed particle size. Specifically, when the inlet velocity reaches 3 m/s, the desander attains an impressive separation efficiency of up to 70%.

Design of downhole oil-water separation device and study on separation mechanism based on rod pump heavy oil system

Abstract Downhole oil-water separation technology (DOWS) is a new type of separation technology, which can improve efficiency, reduce energy consumption, and can solve the problem of high water cut oilfield development. At present, there are only two separation methods in the same well injection-production separator, one is the swirl separation technology and the other is the gravity separation technology. Cyclone separation technology mainly relies on cyclone separators to separate oil and water, but it is affected by oil viscosity, water content, and temperature. The gravity separation technology mainly relies on the similar separation principle of a multi-cup equal-flow gas anchor to design a multi-cup equal-flow oil-water separator, but it requires the oil-water mixed production liquid to stay in the settling bowl for a long time. The centrifugal separator has the characteristics of a good separation effect, high efficiency, and low demand for oil. At present, the downhole centrifugal separator is not used in the same well injection-production technology, which mainly needs to solve the driving force problem of the centrifugal separator. The new injection-production device designed in this paper can better solve the driving problem of the centrifugal separator and meet the working requirements of the process.

Verification of the Solid–Liquid Separation of Waterlogged Reduced Soil via a Centrifugal Filtration Method

The efficient separation of solid and liquid phases of soil under reductive conditions is of the utmost importance to study soil chemistry and to predict the mobility and bioavailability of nutrients and toxic contaminants in waterlogged reduced soils (WRSs). However, there is no established method for efficiently separating the solid and liquid phases of WRS within a short time while maintaining its reductive conditions. This study aimed to verify the applicability of a simple centrifugal filtration method (CFM) for the efficient separation of solid and liquid phases of a WRS and examine the CFM-extracted soil solution to confirm that the reductive condition was maintained during the solid–liquid separation process. Incubation experiments were performed under reductive conditions with or without ethanol/molasses used as additional organic material (OM), while the soil solution was collected by both a suction method and CFM at different centrifugation speeds (700, 2760, and 11,000 rpm) and times (1–7 min). The results showed that the soil pH increased with time while the Eh decreased, indicating that its reducing state was enhanced during the incubation experiments. The addition of OM promoted the reductive conditions in the first days of the experiments. Centrifugation speed, rather than time, was found to be the key to extract the maximum amount of soil solution, while a higher centrifugation speed (11,000 rpm), which represents the permanent wilting point, was found to be most effective for extracting the maximum amount of soil solution. The results exhibited no significant difference in solute (As, Fe(II), and Mn) concentrations when varying amounts of CFM-extracted soil solution were measured. The statistical analysis also indicated no significant (p > 0.05) difference between the solute concentrations in the CFM-extracted soil solution and the solute concentrations in the soil solution extracted by the suction method, confirming that the reductive condition was maintained during solid–liquid separation by CFM. This study suggests that CFM operating at a higher centrifugation speed could potentially be employed as a simple and highly effective technique to efficiently separate the solid and liquid phases of WRS (sandy clay loam) within a short time while maintaining its reductive conditions.

Numerical analysis of cyclone separators with unique Dipleg structures at different Dipleg-to-dustbin ratios

This study investigates the influence of various configurations of dipleg and dustbin structures on cyclone separator performance. For comparative analysis, the inverted cone dipleg which reported has the highest collection efficiency was employed, and six models were developed with varying dipleg-to-dustbin ratios while maintaining a constant total height. Unsteady simulations were conducted using the RSM model and the Eulerian-Lagrangian approach to analyze the flow dynamics and particle migration behaviors in cyclone separators. The increase in dipleg length significantly influenced flow behavior in both the dipleg and dustbin regions, initially resulting in increased flow complexity before transitioning to smoother and more regular patterns. Analysis of vortex frequency indicated a weakening back-mixing effect with increased dipleg length, further underscoring the impact of this parameter on cyclone performance. Quality factors under different particle size ranges are proposed to compare the separation efficiency and pressure drop of different models, providing a reference for the selection of cyclone in different application scenarios.

Enhanced Simultaneous Nitrogen and Phosphorus Removal in a Continuous-Flow Granular Sludge System under Gradient-Controlled Hydraulic Loading

The feasibility of the aerobic granulation of activated sludge was investigated in a continuous-flow anaerobic–anoxic–oxic system under gradient-controlled hydraulic loading on the surface of a cyclone separator. Concentrated domestic sewage was used. After 80 days of operation, 80% of activated sludge in the system was in the form of granular sludge with an average particle size of 373 μm. High removal efficiency was achieved for chemical oxygen demand (94.40%), NH4+-N (99.93%), total nitrogen (89.44%), and total phosphorus (96.92%). A batch study revealed that Pseudomonas (1.34%) and Dechloromonas (1.05%) as the main denitrifying phosphorus-accumulating organisms could efficiently remove phosphorus using nitrate as an electron acceptor, which improved the utilization efficiency of carbon sources and achieved simultaneous denitrification and phosphorus removal. Overall, the study demonstrates the feasibility of enhanced denitrification and phosphorus removal in a continuous-flow granular sludge system. The sludge system enables simultaneous nitrogen and phosphorus removal under low carbon-to-nitrogen ratios.

Numerical calculation on the short-circuit flow rate in a gas cyclone

Short-circuit flow rate is a crucial indicator in assessing the separation performance of cyclone separators. The existing literature lacks a comprehensive exploration of how both structural and operating parameters affect this rate. Previous studies produced inconsistent conclusions, and a calculation formula for short-circuit flow rate is absent. Therefore, this paper proposes a novel method for calculating short-circuit flow rate and analyzes it within cyclone separators under different inlet area coefficients KA, dimensionless vortex finder diameters Der, and inlet velocities Vi using response surface methodology. The findings reveal a significant negative correlation between short-circuit flow rate and KA, while positive correlations with Der and Vi are observed. The calculation formula is derived using response surface methodology. The paper concludes by analyzing the influence mechanisms of KA, Der, and Vi on short-circuit flow rate in the separator, aiming to provide valuable insights for the structural optimization of cyclones in engineering applications.

Hybrid copper-polyelectrolyte nanoaggregates obtained with smart block copolymers based on 4-[(hydroxyimino)aldehyde]butyl methacrylate (HIABMA) in water and acetonitrile

The AB multi-stimuli-responsive block copolymer pTEGMA-b-pHIABMA (TEGMA: tetra(ethyleneglycol) methyl ether methacrylate; HIABMA: 4-[(hydroxyimino)aldehyde]butyl methacrylate) comprises a hydrophilic and thermoresponsive PTEGMA block linked to the hydrophobic PHIABMA chain. The latter is endowed with slightly acidic oxime groups that potentially form complexes with metal ions. Here we investigate the formation of hybrid Cu(II)-polymer nanoaggregates both in water and in acetonitrile. Cu(II) ions are quantitatively and rapidly incorporated, in the presence of a base, into pre-formed polymeric core-shell micelles (30 nm diameter by DLS) in water up to 1:2 metal-to-ligand stoichiometry. The pKa of the polymer is decreased from ≅11.2 to 4.65 due to interaction with Cu(II) and the complex is shown to involve oximate ions. The thermoresponsivity of the polymeric micelles remains unchanged with Cu(II) complexation and allows an easy separation by flocculation of the hybrid complex. Moreover, nanoaggregates (D = 20 nm) form in acetonitrile from the fully solubilized copolymer interacting with Cu(OAc)2. The 1:2 Cu(II)/ligand stoichiometry is confirmed with the Job graphical method. Characterization of the hybrid micelles was carried out by UV–Vis spectrometry, DLS, TEM, STEM and SAXS. Quantitative release of Cu(II) in acidic conditions is demonstrated both in water and in acetonitrile. Full recovery of the free metal ions and of intact polymeric micelles is achieved through centrifugal filtration of the aqueous preparation, as a proof-of-concept for a recyclable system for metal uptake and release. Furthermore, Cu0 nanoparticles of 5–10 nm are obtained through reduction of Cu(II) within the micelles with ascorbic acid in aqueous solution.

Effect of concave‐wall jets with circumferential multi‐inlet on liquid–solid separation

AbstractThis study combined numerical simulation and experiment to explore the influence of the concave‐wall jets with uniformly distributed tangential inlets in the cyclone separator on the liquid–solid separation characteristics and equipment. The results show that as the number of tangential inlets increases, the superposition effect of particle trajectories and flow fields becomes more significant. The superimposed flow field enhances the circumferential flow velocity of the fluid, causing the distribution of the jet along the radial and spanwise directions to shrink, greatly improving the uniformity of particle distribution and turbulent kinetic energy along the circumference, and effectively reducing the impact of particles on local areas near the jet inlet. Since the superposition of circumferential multi‐inlet jets enhances the swirling flow, the local disturbance and wall erosion effects near the jet inlet were reduced. Compared with double inlets, the flow rates of three inlets and four inlets were increased by 50% and 100%, respectively, the maximum turbulent kinetic energy increased by 14.5% and 56.2%, and the maximum escape time of particles was shortened by 3.2 and 3.3 s, respectively, the maximum erosion rates were reduced by 38.4% and 23.6%, respectively, and the separation efficiency and material handling capacity were significantly improved. This study supplemented the theory of concave‐wall jets' superposition characteristics and provided a theoretical basis for applying circumferential multi‐inlet devices in liquid–solid separation equipment.

Determination of an axial gas cyclone separator cut-off point by CFD numerical modeling

Determination of an axial gas cyclone separator cut-off point by CFD numerical modeling

Production of High-Yield Adeno Associated Vector Batches Using HEK293 Suspension Cells.

Adeno-associated viral vectors (AAVs) are a remarkable tool for investigating the central nervous system (CNS). Innovative capsids, such as AAV.PHP.eB, demonstrate extensive transduction of the CNS by intravenous injection in mice. To achieve comparable transduction, a 100-fold higher titer (minimally 1 x 1011 genome copies/mouse) is needed compared to direct injection in the CNS parenchyma. In our group, AAV production, including AAV.PHP.eB relies on adherent HEK293T cells and the triple transfection method. Achieving high yields of AAV with adherent cells entails a labor- and material-intensive process. This constraint prompted the development of a protocol for suspension-based cell culture in conical tubes. AAVs generated in adherent cells were compared to the suspension production method. Culture in suspension using transfection reagents Polyethylenimine or TransIt were compared. AAV vectors were purified by iodixanol gradient ultracentrifugation followed by buffer exchange and concentration using a centrifugal filter. With the adherent method, we achieved an average of 2.6 x 1012 genome copies (GC) total, whereas the suspension method and Polyethylenimine yielded 7.7 x 1012 GC in total, and TransIt yielded 2.4 x 1013 GC in total. There is no difference in in vivo transduction efficiency between vectors produced with adherent compared to the suspension cell system. In summary, a suspension HEK293 cell based AAV production protocol is introduced, resulting in a reduced amount of time and labor needed for vector production while achieving 3 to 9 times higher yields using components available from commercial vendors for research purposes.

Performance and techno-economic evaluation of a high-efficiency electrospray cyclone

"Nowadays, because of the global air pollution issue caused by fine dust, fine dust collection and removal technologies are crucial for enhancing living environments and human health. This research proposes a new pilot-scale electrospray cyclone (ESC) designed for the collection of submicron dust particles. The experimental apparatuses comprised a cyclone dust collector and an insulating tank. Initially, laboratory-scale single-nozzle visualization tests were conducted to investigate the droplets’ number and size under various operating conditions. Subsequently, based on the visualization research outcomes, electrospray module was inserted to the industrial cyclone, which was designated by ESC. Performance assessments of the pilot-scale ESC were conducted under diverse water flowrates, applied voltages and nozzle sizes. The capture efficiencies for PM10, PM2.5, and PM1.0 were measured up to 98.2%, 95.4%, and 90.3%, respectively. Both the environmental and economic viabilities of the newly-proposed ESC in this study were evaluated based on three aspects: 1) capacitive particle collection efficiency; 2) capacitive installation cost; and 3) rated power and operational cost. This evaluation method has been defined as the Levelized Cost of Precipitator (LCOP), and it is intended to assess the environmental and economic performance of 5-convenstional dust collectors. In these results, the ESC shows relatively high performance in terms of the environmental and economic aspects. Based on these indices, we assess that the ESC has one of the promising alternatives of commercial precipitators."

Drone-Assisted Particulate Matter Measurement in Air Monitoring: A Patent Review

Air pollution is caused by the presence of polluting elements. Ozone (O3), carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter (PM) are the most controlled gasses because they can be released into the atmosphere naturally or as a result of human activity, which affects air quality and causes disease and premature death in exposed people. Depending on the substance being measured, ambient air monitors have different types of air quality sensors. In recent years, there has been a growing interest in designing drones as mobile sensors for monitoring air pollution. Therefore, the objective of this paper is to provide a comprehensive patent review to gain insight into the proprietary technologies currently used in drones used to monitor outdoor air pollution. Patent searches were conducted using three different patent search engines: Google Patents, WIPO’s Patentscope, and the United States Patent and Trademark Office (USPTO). The analysis of each patent consists of extracting data that supply information regarding the type of drone, sensor, or equipment for measuring PM, the lack or presence of a cyclone separator, and the ability to process the turbulence generated by the drone’s propellers. A total of 1473 patent documents were retrieved using the search engine. However, only 13 met the inclusion criteria, including patent documents reporting drone designs for outdoor air pollution monitoring. Therefore, was found that most patents fall under class G01N (measurement; testing) according to the International Patents Classification, where the most common sensors and devices are infrared or visible light cameras, cleaning devices, and GPS tracking devices. The most common tasks performed by drones are air pollution monitoring, assessment, and control. These categories cover different aspects of the air pollution management cycle and are essential to effectively address this environmental problem.

Effect of Different Outlet Structure of Axial Flow Cyclone Separator in Drying Tower

The axial flow cyclone separator used in drying tower is characterized by the diameter of the dust outlet at the tail is larger than that of the cylinder, and the dust removal efficiency is increased by a series dust outlet. The numerical analysis of its separation characteristics is carried out by using the RSM model of CFD. The results show that the separation efficiency can be increased by appropriately increasing the diameter of the dust outlet, and the separation efficiency will not change when the diameter of the dust outlet increases to a certain value. When the insertion depth of the air outlet is reduced from 150mm to 100mm, the average separation efficiency of particles with a diameter of 15-30um is reduced by 4.5%. When the insertion depth of the air outlet is greater than the width of the dust outlet, the insertion depth has no effect on the dust removal efficiency. The tandem dust outlet and parallel dust outlet have the same separation effect on small particles, and the gas flow rate is equivalent to twice the gas flow rate of a single dust outlet. The average particle separation efficiency of 1 - 30um is increased by 16.5% compared with that of a single dust outlet. The flow velocity of the tandem dust outlet is higher than that of the parallel dust outlet.

Designing Centrifugal Membrane Filters with uniform-pressure for UF/NF/RO separations

A novel Ortho-Centrifugal Membrane Filter (O-CMF) was designed and assessed to tackle common issues in conventional laboratory centrifugal membrane filters, e.g. non-uniform transmembrane pressure and concentration polarization, and to ease membrane replacement. The O-CMF, manufactured by additive 3D printing in acrylonitrile butadiene styrene, with membrane area of 0.95 cm2, was designed to process a maximum liquid sample of 9 mL. It was tested with nanofiltration of aqueous solutions of NaCl, MgSO4, and lactose (concentrations of 1–20 g/L) at transmembrane pressures of 6–24 bar. Complementary Computational Fluid Dynamics (CFD) simulations, employing a custom solver from the open-source OpenFOAM-2306 c++ toolbox, were also run to seek insight of the O-CMF main features.The permeation experiments displayed minimal impact of concentration polarization. CFD simulations showed that concentration polarization is nearly uniform and that concentrate chamber is homogenized by centrifugal convection. The CFD permeate flux predictions, based on the osmotic pressure model, closely matched experimental data, and a correlation for predicting concentration polarization was also developed.The O-CMF device represents a substantial breakthrough in the technology of centrifugal membrane filters, consistently maintaining uniform transmembrane pressure and effectively minimizing concentration polarization. The device was evaluated using nanofiltration, but its pressure range is versatile enough to cover conditions suitable for both ultrafiltration and reverse osmosis operations. This adaptability extends its application across a variety of laboratory experiments, including sample concentration, hydraulic permeability tests, and membrane screening.