Cyclone Separator Research Articles

Performance enhancement of gas cyclone with streamlined ports using CFD simulations

Cyclones are extensively utilized as gas-solid separators in many industries such as pharmaceuticals, food processing, and powder handling often use mini cyclones for efficient dust collection, air filtration, and contaminant separation in compact systems. The impact of the cyclone vortex finder (VF) diameter, the VF inlet bell mouth shape, and the VF inlet curvature on both flow field distribution and performance has been analyzed through computational analysis employing the Reynolds stress turbulence model (RSM) for twelve cyclone separators. The results demonstrate that decreasing the diameter of the VF by 33% elevates the ultimate tangential velocity by 66%. The ultimate tangential velocity nearly reaches four times the inlet velocity. A reduction of 14% in the VF inlet curvature results in a 6% enlarging in the pressure loss.Enhancing the bell mouth configuration of the inlet VF by 25% decreases the maximum pressure by 3.7%. Increasing the diameter of the VF, the VF inlet curvature, and the VF inlet bell mouth shape will also lead to reduced x50. The cyclone with no curvature exhibits lower pressure and tangential velocity compared to the cyclones with curvature and radius of bell mouth shape of (DX/D) ratio equal 0.5. However, all the three cyclones have the same ratio. Cyclones A0 and C1 have the highest collection efficiency of all cyclone models.

Effects of Air Vortex Finder Length and Outlet Diameter Variations on Oil Palm Loose Fruit Collector

Oil palm is one of the largest economy sectors in Malaysia. Among the problems faced in the estates are oil palm loose fruits deposition which is currently being collected manually in the industry. Hence, an oil palm loose fruit collector is designed using cyclone separator mechanism and was studied using computational fluid dynamics (CFD). In the current study, Reynold’s stress model (RSM) and the Discrete phase model (DPM) was employed to navigate numerical simulations where the vortex finder of the cyclone separator was varied with two factors which are the vortex finder length and outlet diameter. Wall was set to a no slip condition with standard wall functions. Hydraulic diameter of the gas outlet is Bc=0.1 . Hydraulic diameters of the particle’s outlet are Jc=0.15 and 0.2 respectively. Turbulence intensity at the gas and particles outlet are specified at 5%. An injection with density 995.7 and 0.04 was set to simulate oil palm loose fruit collection into the system. Ultimately, effects of vortex finder and outlet variations on the pressure drop and collection efficiency were then analyzed. Results indicate that an outlet diameter of 0.18 m and vortex finder length of 0.405 m is favourable for the oil palm loose fruit machine with a collection efficiency of 88.71 % and pressure drop of 477.66 Pa.

Critical assessment of purification processes for the robust production of polymeric nanomedicine.

Polymeric nanoparticles are among the most widely used nanocarriers for delivering therapeutic molecules. However, their synthesis processes often generate undesirable impurities that could be toxic and challenging to eliminate. In this study, we compared three purification techniques - centrifugation, dialysis, and tangential flow filtration (TFF) - to evaluate their efficacy in removing residual drug, surfactant, and solvent while preserving the nanoparticles' physicochemical features (hydrodynamic size, zeta potential, polydispersity index). Centrifugation excels in eliminating unencapsulated drug and residual surfactant but significantly affects the nanoparticles' physicochemical properties, such as colloidal stability and size homogeneity. On the other hand, dialysis is a gentler technique effective in removing residual solvent but less so for residual surfactant and unencapsulated drug. TFF emerges as a balanced approach, offering a compromise between the two but none of these techniques achieves satisfactory purification at lab-scale alone. While each technique has its merits, none can meet all requirements independently. The optimal purification strategy often involves a combination of techniques, determined on a case-by-case basis considering factors like purity levels, time, costs, and the preservation of critical properties such as drug loading and colloidal stability. This study underscores the need for a nuanced approach in selecting purification strategies for polymeric nanoparticles in drug delivery applications.

Dual solution of thin film flow of fuzzified MHD pseudo-plastic fluid: numerical investigation in uncertain environment

The pseudoplastic fluids have wide range of applications in industrial areas including cyclone separation, bearings, paper fibre separation, heat exchangers and also in food industry. In this regard, the current manuscript investigates the impact of transverse magnetic field on thin pseudo-plastic film flow on a vertical wall in a fuzzy (uncertain) environment. The uncertainty in a model is characterized through triangular fuzzy numbers (TFNs) along with r -cut approach, which is computationally effective in capturing the uncertainties in physical phenomena. This results in the modelling of highly nonlinear fuzzified problem. For solution and analysis purposes, Runge–Kutta Fehlberg (RKF) is utilized. Also, RKF solutions are validated by comparing them to homotopy perturbation solutions in the current manuscript. The impact of r -cut, and fluid parameters including non-Newtonian parameter β, magnetic field M and Stoke's number S t on the upper and lower velocity profiles are captured and analysed numerically and graphically. Analysis reveals that velocity profile decreases with an increase in applied magnetic field at upper and lower bounds. Also, increase in S t and β increases the velocity profile at lower bound, while inverse behaviour is recorded in the case of upper bound. The results also indicate that as r goes from 0 to 1, the crisp solution always lies between upper and lower profiles, and becomes coherent at 1. Moreover, all fuzzy level set values of r ∈ [ 0 , 1 ] satisfy the fuzzy solution in the form of TFN.

Freeze-Induced Protein Assembly of α-Synuclein into Stable Microspheres to Fabricate Light-Induced Cargo Release Systems.

Stable hollow-type microspheres (MSs) have been fabricated using α-synuclein (αS), an amyloidogenic protein, via freeze-induced protein self-assembly. This assembly process involves three steps: rapid freezing to form spherical protein condensates from αS oligomers, frozen annealing to form a crust on the condensate and freeze-drying to create an interior lumen via the three-dimensional (3D) coffee-stain effect. The crust produced during the frozen-annealing step is a β-sheet-mediated protein structure that is presumed to be created at the quasi-liquid layer of the protein-ice interface and thus contributes to the stability of MSs in aqueous solutions at room temperature without any additional surface stabilization. MSs transform into amyloid fibril condensates when heated to 70 °C, and the drug is loaded via centrifugal membrane filtration. Additionally, the MSs were shielded with an iron-alginate layer embedded with gold nanoparticles (AuNPs) to prevent premature leakage and to control drug release. This takes advantage of the photothermal effect of AuNPs, resulting in combined cytotoxicity between the drug and heat. Therefore, drug-loaded MSs comprising αS and AuNPs can be suggested as light-controllable drug delivery systems that exhibit chemical and physical anticancer therapeutic effects.

Flow field and performance analysis of downhole pipe string in single-well injection-production technology

High water content is a critical issue that must be urgently addressed in the current oilfield development, and the single-well injection-production technology (SWIPT) is an effective approach for achieving economical extraction in high-water-content oilfields. To meet the 5.5-inch casing size requirements, further improve SWIPT performance, and minimize the impact of pump pressurization on the subsequent oil–water separation process, dual-pump suction-SWIPT is proposed and an axial-flow cyclone separation pipe string is designed. A theoretical fluid–solid interaction (FSI) model of the downhole pipe string (DHPS) applicable to SWIPT is established through vibration testing and data analysis. Based on the new FSI model-corrected numerical simulation method, single-factor experiments are performed to analyze the medium transport process and oil–water separation performance within the flow field under structural vibration disturbances. The results indicate that the separation of fluid media within the single-well injection-production DHPS is not significantly affected by structural interference. The simulation results closely matched the experimental data, with the average error of the axial velocity at different test points being within 0.041 m/s. In the transport pipe regions, minor variations in the velocity and pressure fields are observed under vibration conditions. Under an inlet flow rate of 4 m3/h, split ratio of 30%, and oil volume fraction of 1%, the optimal separation efficiency of 97.26% is achieved. This study provides new insights for the development and application of SWIPT.

Centrifugal filtration enhances the block freeze concentration and recovery of bioactive compounds from pomegranate juice

Centrifugal filtration enhances the block freeze concentration and recovery of bioactive compounds from pomegranate juice

Computationally efficient DEM simulation of a basket-type centrifugal filter using a novel switchable contact model

The discrete element method (DEM) offers enormous potential to gain a better understanding of cake formation in centrifugal filtration. However, the necessity to represent the highly porous filter mesh in these simulations incurs a significant computational cost. We propose replacing the porous mesh boundary that is conventionally used with a ‘switchable contact model’ (SCM) in which the contact model between a particle and a continuous cylindrical shell is selectively enabled or disabled depending on the particle's location at the periphery of the centrifuge basket. SCM is disabled whenever a particle is deemed to be in contact with a pore location, thus allowing its egress from the basket. There was a ∼ 36 % reduction in computation time compared to the conventional mesh-based representation of a bounding filter mesh, with similar particle retention and bulk cake formation behavior. This concept could in principle be applied to model any repetitive porous structure in DEM.

Comparison of three specimen collection techniques in tissue coagulum clot-based cell block preparation of endobronchial ultrasound-guided transbronchial needle aspiration

ObjectivesThe performance of cell blocks (CBs) can vary significantly depending on the specimen collection and processing techniques used. This study compared the efficiency of three distinct specimen collection methods for endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples. Materials and methodsFrom June 2021 to June 2023, the study involved 1450 patients who underwent EBUS-TBNA, resulting in the sampling of 1941 lesions. For these samples, three distinct specimen processing methods were employed to prepare tissue coagulum clot-based CBs. Specifically, the filter paper method was employed in 470 cases (yielding 626 samples), the centrifugation method in 500 cases (yielding 673 samples), and the funnel filtration method in 480 cases (yielding 642 samples). ResultsOut of these 1941 samples, the diagnostic yield for samples obtained using filter paper, centrifugation, and funnel filtration methods was 84.7 %, 87.7 %, and 92.5 %, respectively. In the subgroup of patients diagnosed with non-small cell lung cancer, the adequacy rate for molecular testing in samples processed through filter paper, centrifugation, and funnel filtration methods was 57.7 %, 82.0 %, and 88.3 %, respectively. In the centrifugation group, the combination of the CBs and cell pellet achieved an adequacy rate of 96.5 %. DiscussionThe cellular yield of CBs from EBUS-TBNA was significantly enhanced using centrifugation and funnel filtration methods. The funnel filtration method offered a more convenient and cost-effective approach, reducing cellular loss due to sample dispersion in the fixative medium. The use of the centrifugation method to prepare CBs, along with the retrieval of cell pellets from the residual fixative medium, can maximize the specimen adequacy rate for molecular testing.

Analysis of Pressure Drop in Gas–Solids Cyclone Separators: An Experimental Approach

In industrial operations, cyclone separators are essential for removing particles from gas streams. The performance and energy efficiency of these devices are greatly impacted by the pressure drop across them. Through experimental investigation, this paper examines the pressure decrease in gas-solids cyclone separators. The effect of many operational factors on the pressure drop was investigated, including gas velocity, particle size, and input design.The findings demonstrated that the pressure drop across the cyclone increases significantly with increasing inflow velocity and reduces with increasing cyclone size. Regardless of cyclone size, input velocity, or particle size, a strong direct correlation was found between the pressure drop for dusty air and that for clean air. Operating at moderate gas velocities was shown to significantly reduce pressure drop without compromising separation performance, whereas higher velocities necessitate advanced cyclone designs or secondary systems to mitigate the associated pressure increases

Insights into local wall erosion characteristics and prevention measures for cyclone separators

Cyclone separators are separation devices that use the principle of inertia to remove particulate matter from flue gases. The present study mainly focuses on wall erosion in cyclone separators and associated research. The main locations of erosion in gas–solid cyclone separators, including the entrance impact section, cyclone roof corner, vortex finder outer surface, spiral-type erosion strip, and lower cone section, are examined in detail. The main factors influencing wall erosion are discussed, including inlet flow velocity, solid particle properties and loading, geometrical structure, and manufacturing quality. Finally, several practically preventive measures against wall erosion are presented, including adjustment of operating conditions, the use of erosion-resistant materials, optimization of geometrical structures, and the addition of auxiliary devices, all of which are essential for ensuring operational efficiency, equipment reliability, safety, and environmental protection in various industrial applications. This paper aims to provide a basis for further research into erosion in cyclone separators as well as guidance for engineers involved in their industrial applications.

A Review of the Experimental Analysis of Gas–Solid Cyclone Separators

AbstractGas–solid cyclones are broadly employed in the industrial sector. Even though numerical methods are currently a strong tool for predicting the characteristics of flow patterns inside cyclone separators, they should be validated using experimental data. On the other hand, several practical aspects must be considered to analyze the operating circumstances of cyclones and their design optimization. This paper summarizes cyclone working principles and measurement techniques utilized in experimental analysis. Besides, experimental aspects, including various geometries, surface roughness, erosion rate, external electric field, particle properties, etc., are discussed. Eventually, research gaps and future directions are introduced.

Comparative Analyses of Dynamic Characteristics of Gas Phase Flow Field Within Different Structural Cyclone Separators

The gas phase flow field inside a cyclone separator is crucial to the particle separation process. Previous studies have paid attention to the steady-state characteristics of the gas phase flow field, while research on its dynamic characteristics remains insufficient. Meanwhile, cyclone separators often adopt different structural forms according to the process requirements, the evolution laws of the dynamic characteristics flow field within them are still not well understood. Therefore, in this study, a hot-wire anemometer (HWA) was employed to measure the instantaneous tangential velocity of the gas phase flow fields within different structural cyclone separators (cylinder type, cylinder–cone (no hopper), and cylinder–cone (with hopper)). Comparative analyses and discussions were conducted regarding the dynamic characteristic distribution rules of the flow field in the time domain and the frequency domain. The results revealed that the dimensionless tangential velocity distributions of different types of cyclone separators all conformed to the Rankine vortex structure. The instantaneous tangential velocity fluctuated with low frequency and high amplitude, and the low-frequency velocity fluctuation exhibited a transfer behavior along the radial direction. Compared with the cylinder–cone-type cyclone separator, the tangential velocity in the cylinder-type cyclone separator fluctuated more greatly, and its quasi-periodic behavior was also more obvious. The time-averaged tangential velocity, the tangential velocity fluctuation intensity (Sd), and the dominant fluctuation frequency all had obvious attenuation along the axial direction in the cylinder-type cyclone separator, while the above-mentioned parameters had no attenuation along the axial direction in cylinder–cone-type cyclone separators. Additionally, the backflow from the hopper of the cylinder–cone-type cyclone separator (with hopper) led to an increase in the instantaneous tangential velocity fluctuation intensity of the local flow field near the dust outlet, as well as the occurrence of the “double dominant frequencies” phenomenon.

Impact of the Draft Plate on the Wall Erosion and Flow Field Stability of a Cyclone Separator

Cyclone separators are commonly employed in the mining, metallurgy and chemical industries due to their simple structure, easy maintenance and high recovery efficiency. However, with the wide application of cyclone separators, many problems have become exposed in their practical operation, restricting their development. Among these, wall erosion is becoming a significant problem. In this study, to resolve the problem of severe erosion on the walls, the Eulerian–Lagrangian framework was employed to investigate a cyclone separator with a draft plate at the inlet and to evaluate the effect of a draft plate with angles of 0°, 45° and 90° on the degree of erosion and the stabilization of flow fields. Moreover, after verifying the reliability of the numerical model via data from experiments, the characteristics of gas–solid flow were analyzed and the effects of the new structure on the degree of wear were investigated. The results demonstrated that unfavorable phenomena such as secondary flow and wall erosion generated during the operation could be mitigated by the draft plate. When the plate angle was 90°, the wall erosion was the lightest and the range of influence of the secondary flow was the smallest. When the plate angle was 45°, the comprehensive performance was the best, and there was a better balance between the energy loss and the degree of wall erosion. Therefore, the presence of the draft plate has a significant impact on the interaction of gas–solid phases in a cyclone separator.

Effects of Particle Exit Diameter on the Performance of a Gas-Solid Cyclone Separator of High Solid Loading Designed for a Circulating Fluidized Adsorption Refrigeration System

In applications such as in chemical, pharmaceutical, nanotechnology and food industries where cyclones are used for product separation and recovery, the gases carry a product rather than a waste in which the solid loadings (Co) can be much higher. Ensuring efficient products separation and recovery from the air stream without damaging their characteristics becomes so crucial. It is therefore highly imperative to consider the effects of the particle (product) exit design on the cyclone performance for optimization purposes. The effects of particle exit diameter (

Vortex core eccentricity and passive control for separation performance enhancement of a novel circumfluent cyclone separator

We have proposed a circumfluent cyclone separator (CCS) that features a concentric internal cylinder and a gas–solid inlet located at the bottom of the separator shell, as opposed to the conventional cyclone design with the inlet at the upper part. The objective of this study is to investigate the eccentricity of the vortex core within CCSs, its impact on separation performance, and to propose a vortex control method for enhancement of separation efficiency. Our research findings indicate that the eccentricity of the vortex core varies with the vertical position, with the maximum eccentricity observed at the bottom of the cone. Increasing the inlet gas velocity (Uin) results in an elongation of the vortex length and a decrease in the eccentricity of the vortex core. These observations suggest that a high level of vortex core eccentricity negatively affects the separation performance of the CCS. To address this issue, we propose a passive control method to reduce vortex oscillations and enhance collection efficiency. By incorporating a central tube within the CCS, we effectively reduce the eccentricity of the vortex core and alter the characteristics of the power spectral density plot of the instantaneous velocity. Importantly, the addition of a 4–5 mm diameter tube enables the CCS to achieve similar separation efficiency for small particles at a Uin of 18 m/s, compared to the CCS without a central tube operating at a Uin of 24 m/s. Furthermore, the central tube configuration reduces the associated pressure drop by 50%. These findings highlight the effectiveness of vortex control mechanisms in enhancing the separation performance of CCS and other cyclone designs.

Modified throughput ninhydrin method for the qualitative assessment of dietary protein absorption in pig plasma.

Protein maldigestion and malabsorption lead to malnutrition and are a feature of exocrine pancreatic insufficiency (EPI). Although it is the current standard, measurement of nitrogen in stool to assess protease activity is indirect. Up to 80% of hydrolysed proteins appear in blood in the form of peptides, so we developed a method to measure peptide-derived amino acids in plasma as a relevant measure of proteolysis, verified its accuracy, precision, and linearity, and validated it in a porcine model. We modified a ninhydrin method. Large proteins were eliminated from plasma with 10 kDa-cut-off centrifugal filters. Free and total amino acids were measured in permeate before and after its hydrolysis. Peptide-derived amino acids were quantified by subtracting free amino acids from total amino acids. We verified the method in vitro and by comparing results in healthy and EPI pigs. The accuracy of the analysis was close to 100%, with excellent precision (mean relative standard deviation for low, medium, and high amino acid levels = 0.88%) and with stringent linearity (r2 = 0.986, %RE = 5.23). The high-throughput ninhydrin method detected levels of peptide-derived amino acids in vivo with maximal changes seen approximately 2 hours postprandially in young pigs. The AUC and Cmax were significantly higher in healthy compared to EPI pigs (P = .0026 and P = .0037, respectively). The high-throughput ninhydrin method is a sensitive, reliable, and practical method for the estimation of dietary peptide-derived amino acids. This assay endpoint could serve as a direct biomarker of protein digestion and absorption.

Enhanced performance of cyclone separator through coupling of centrifugal force, electrostatic force and particle pre-charge

The electrostatic enhancement can effectively improve the performance of cyclone separator at low load or high-temperature, but its application is limited owing to the reduction of spark voltage in high-temperature. Aiming at this question, a new technology coupling centrifugal force, electrostatic force and particle pre-charge was proposed. The characteristics of particles charging and agglomeration were analyzed, and the influence of different factors on the change of particle partition number concentration and total removal efficiency of cyclone separator were studied. The results showed that, increasing the charge generator voltage and decreasing the main pipe gas velocity can increase the particles charge quantity and improve agglomeration, which is benefit for the efficiency improvement of either cyclone separator or electrostatic cyclone separator, especially at low inlet gas velocity. Higher charge generator voltage and lower inlet gas velocity, more obvious efficiency improvement. The total removal efficiency can be increased by up to 10 % and 9 % respectively for the cyclone separator and electrostatic cyclone separator because of particle pre-charge at 10 m/s of inlet gas velocity, and the removal efficiency of fine particles can also be effectively improved. Comparing with the electrostatic cyclone separator, achieving the same total removal efficiency, the internal voltage can be reduced 16 kV through particle pre-charge. The electrostatic force and centrifugal force were the main factor of the small particles and big particles removal, respectively.

Development and Validation of an Improved HPLC-MS/MS Method for Quantifying Total and Unbound Lenalidomide in Human Plasma.

This study aimed to develop a fully validated HPLC-MS/MS method for quantifying total and unbound lenalidomide concentrations in human plasma. Unbound concentrations were measured using plasma ultrafiltrate prepared with Amicon® Centrifugal Filters. Lenalidomide and lenalidomide-d5 (internal standard) were extracted from 50 μL of human plasma using liquid-liquid extraction. Chromatography was conducted with a Halo® C18 column using 0.1% formic acid and methanol (20:80, v/v) as the mobile phase. The mass spectrometer was operated in a positive ion mode with an electrospray ionization interface and multiple reaction monitoring modes. Calibration curves were linear over the range of 5 to 1000 ng/mL (r2 > 0.996) for both the total and unbound lenalidomide. For total lenalidomide concentrations, between-run precision (coefficients of variation) and accuracy were 1.70-7.65% and 94.45-101.10%, respectively. For unbound concentrations, inter-day precision and accuracy were 1.98-10.55% and 93.95-98.48%, respectively. We developed a highly reproducible, sensitive, and efficient bioanalytical method using a smaller volume of plasma sample (50 μL) with a relatively short run time (2.5 min). The proposed analytical method was successfully applied to measure total and unbound lenalidomide concentrations at various time points in multiple myeloma patients with renal impairment.

Experimental and numerical study of maximum efficiency vortex finder insertion depth of a Stairmand cyclone

The vortex finder is essential in cyclone separators, significantly affecting separation performance via its diameter and insertion depth. The current study shows that as the insertion depth of the vortex finder increases, the separation efficiency initially increases and then decreases, and there exists a maximum point with which the corresponding insertion depth is the maximum efficiency insertion depth (SMEID). However, there are inconsistent conclusions in the existing literature regarding the maximum efficiency insertion depth and a lack of explanation for the flow field mechanism at the maximum efficiency insertion depth. This study examines the Stairmand type cyclone using 13 μm silicon micro-powder, employing numerical simulation and cold mold experiments to explore the effects of the vortex finder's insertion depth and diameter on separation performance and flow field. The results indicate that the insertion depth has minimal impact on pressure drop. The maximum efficiency insertion depth of the vortex finder decreases as the diameter decreases and is independent of this insertion depth with respect to the inlet velocity. Analysis of the flow field reveals that the maximum efficiency insertion depth is essentially the result of a "competitive and synergistic" mechanism between the annular space separation capability and the separation space separation capability.