Performance Of Cyclone Separator Research Articles

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.

Investigating Dual Inlet Cyclone Separator Performance: Effects of Vortex Finder Diameter, Shape, and Particle Diameter on Separation Efficiency and Pressure Drop

The diameter and shape of the vortex finder of cyclone separator plays a significant role in separation efficiency and pressure drop. Currently, there have been many studies conducted on the shape and ratio of vortex finder of cyclone separator. This paper aims to compare numerical results of Raynold stress turbulence model RSM with K-ε RNG numerical analysis results and analyse the effect of further variation of the vortex finder diameter and shape of dual inlet cyclone separators. Five variation of vortex finder diameters namely 291mm, 310mm, 330mm, 348mm, and 366mm, four types of vortex finder shapes namely normal (cylindrical), spiral, divergent and spiral-divergent have been studied with different particle diameter and constant inlet velocity. The result obtained from this study suggests that increasing the vortex finder diameter have negative effect on separation efficiency. It also shows that increasing the vortex finder diameter consistently decrease the pressure drop. From the result, it is been found that the 291mm vortex finder has higher separation efficiency than the rest. Analysis with different vortex shapes, the spiral-divergent shape proved to be best in terms of separation efficiency.

Identifying the influence of inlet velocity changes to pressure drop and collecting efficiency in Stairmand and Lapple type cyclone separators

The object of this research is to compare the performance of Stairmand and Lapple type cyclone separators. The main problem to be solved in this research is determining which Stairmand or Lapple type cyclone separator is more suitable for integration into the pyrolysis system. The comparison is based on key performance indicators: pressure drop and collecting efficiency. The research findings indicate that both Stairmand and Lapple cyclone separators exhibit similar trends in pressure drop and collecting efficiency. As inlet velocity increases, the pressure drop also increases for both types. However, the collecting efficiency initially rises but then declines when inlet velocities exceed 13 m/s. The Lapple variant achieved a peak collecting efficiency of 98.94 % and pressure drop 16.26 mbar at an inlet velocity of 13 m/s, whereas the Stairmand design reached 97.33 % and pressure drop 12.16 mbar at 13 m/s inlet velocity. The Lapple type cyclone separator outperformed the Stairmand type in terms of both of pressure drop and collecting efficiency. This superiority is attributed to the specific design features and characteristics of the Lapple type. The superior performance of the Lapple type cyclone separator can be explained by its unique design elements that contribute to improved particulate matter separation and pressure drop. These elements may include differences in cylinder height and particulate matter outlet diameter. Based on the findings of this research, the Lapple type cyclone separator is recommended for integration into pyrolysis systems. However, it is important to consider the specific operating conditions of the pyrolysis process, such as temperature, the particulate matter size distribution, flow rate, and desired separation efficiency

Numerical Investigation of Inlet Height and Width Variations on Separation Performance and Pressure Drop of Multi-Inlet Cyclone Separators

Multi-inlet cyclone separators can play a vital role in industrial processes by enhancing particle separation efficiency and minimizing energy consumption. This numerical study investigates multi-inlet cyclone separators to enhance their performance using a constant flow rate with a varying inlet height and width. By systematically varying the inlet height and width, three-inlet and four-inlet cyclone separators are developed and evaluated, termed 3 inlet-a, 4 inlet-a, 3 inlet-b, and 4 inlet-b. The findings reveal that increasing the number of inlets without changing the total inlet area does not improve the separation performance. However, strategic modifications to the inlet height and width significantly enhance the separation efficiency. Notably, the 3 inlet-a and 4 inlet-a designs achieve higher separation efficiencies at a 1.22 m3/s flow rate without increasing the pressure drop. Meanwhile, the 3 inlet-b and 4 inlet-b models demonstrate superior performances, with a higher separation efficiency and a pressure drop only marginally higher than the two-inlet design. This study provides valuable insights into the impact of inlet variations on cyclone separator performance, guiding future efforts to enhance the separation efficiency in multi-inlet designs.

An experimental study on the effect of interstage inlet gas on separation performance of two-stage series cyclone separators

Cyclone separators generally operate in multi-stage series to improve gas-solid separation efficiency under high concentration condition. The two-stage series cyclone separators in Fluid Catalytic Cracking unit further require the interstage inlet gas. This paper experimentally studied the effect of the interstage inlet gas on separation performance of two-stage series cyclone separators. A ϕ130mm interstage inlet pipe was installed at the interstage connecting tube between industrial-sized two-stage series ϕ1000mm cyclone separators in the experimental setup. Experiments were conducted at inlet velocities of Vin = 10–20 m/s and concentration of Cin = 10 g/m3, with interstage inlet gas ratios of U = 0–20%. Silica powder with a median diameter of 10.1 μm was used. Results indicate that interstage inlet gas decreases separation efficiency and increases particle run-off loss due to the change of the optimized operation parameters, specifically inlet gas rate and inlet concentration. A prediction model was proposed to provide guidance for potential industrial applications.

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.

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.

Numerical Study of the Gas–Solid Separation Performance of Axial Flow Cyclone Separators

Cyclone separators, which have a high separation performance, play a crucial role in mitigating the occurrence of dust explosion incidents. This study aims to improve the performance of an axial cyclone separator using the results of simulations employing the RNG k-ε model together with a user-defined function to simulate the wall collision process. The effectiveness of various structural modifications to the vortex tube has been addressed. Specifically, we found that increasing the number of blades, reducing the blade exit angle, and adopting L-shaped blades increase separation efficiency. Additionally, enlarging the guide vane and exhaust pipe diameters, as well as increasing the exhaust pipe inclination angle, contribute to an improved separation performance due to the developed tangential velocity and vortex cores. However, it also increases the pressure drop losses due to the increase in the turbulence pulsation entropy and the wall entropy, while the time-averaged entropy is found to be less significant. As a result, our study sheds light on the flow characteristics, the gas–solid separation process, and the energy loss mechanism in the cyclone separator.

Study of the performance and flow field of a new spiral-roof cyclone separator

This paper addresses deficiencies in the separating efficiency of conventional spiral-roof cyclone separators compared to flat-roof cyclone separators. A novel design is proposed, adding spiral guide vanes into the spiral-roof cyclone separator's annular space. The performance of the new spiral-roof cyclone separator is evaluated through cold-model experiments and numerical simulations and compared with conventional flat-roof and spiral-roof counterparts. The results demonstrate a more than 20% reduction in pressure drop compared to the flat-roof cyclone. The new design exhibits 3%–5% higher efficiency than the conventional spiral-roof cyclone and surpasses the flat-roof cyclone by 2%–3%. The numerical simulations investigate tangential velocity distribution, airflow residence time, short-circuit flow air volume, particles carried away by short-circuit flow, and vortex core stability. The findings confirm the new spiral-roof cyclone as a low-pressure and highly efficient separator with promising practical applications in diverse gas-solid separation operations.

Experimental and computational fluid dynamics study on the effects of erosion spiral angle of the cone on cyclone separator performance

In order to improve the cyclone anti-erosion design and performance, the research on the influences of erosion spiral angle on cyclone flow field and separation performance was conducted by numerical simulations using computational fluid dynamics technique with the aid of the Ansys-Fluent 19.2 software and experiments. Based on numerical simulations, Reynolds stress model was used to describe the variation of airflow field, and Oka erosion model was utilized to make predictions about the cyclone wall erosion. The models were verified by the experimental data, ensuring the accuracy of results in this work. The results reveal that the erosion of fine particles on the cyclone wall is caused by the random interaction, and as the particle size increases, the location of collision between the particle and cyclone wall is closer to the air inlet. The cyclone cylinder in inlet channel front and the bottom of the cone is prone to the structural size deformation by the cyclone wall erosion. The cyclone wall erosion enhances the synergistic effect of the secondary flow inside the cyclone separation space, and the cyclone flow field stability further decreases as the increase in the erosion spiral angle at the cone bottom, resulting in a sharp decline in the cyclone performance. Compared with the cyclone without erosion, as the erosion spiral angle is 30°, the size of completely separated particles increases from 4 to 8 μm, the cut size increases from 1.33 to 1.6 μm, and the pressure drop is 420.73 Pa with a decrease in about 35.44%.

Performance analysis of multi-inlet cyclone separators considering different shapes and locations of the inlet ducts

The present study analyzes the performance of multi-inlet cyclone separators with different shapes and axial locations of the inlet ducts. The cyclone model having a single inlet has been considered as the reference model. The two inlets are incorporated such that the total cross-sectional area equals the original (single inlet) section – this ensures no change in the inlet velocity. Three cases for the shape of the cross-section have been considered. In the RA variant, the two inlet areas have been halved ensuring the same aspect ratio. In the RH variant, the height of the two inlets is half of the original duct. In the last case of the RW variant, the width of the two inlets is reduced by half of the original area. The impact of relative axial displacement between the two inlets is also analyzed. The advanced closure LES has been used to investigate the flow field as well as the performance. Conclusive results indicate that both pressure losses and collection efficiencies are the lowest in the RH variant and the highest in the RW variant. Furthermore, using continuous wavelet transformation, it has been revealed that the precessing frequency of the vortex core is time-dependent.

Effect of internally mounted helical fins on the separation performance of a cylindrical gas-solid cyclone separator

In this study, an innovation was made by adding helical fins on the vortex finder of a cylindrical gas-solid cyclone separator, and the effect of this structural improvement on the separation performance was analyzed based on the flow field characteristics. The results show that both cyclones with and without helical fins exhibit a separation efficiency of almost 100% for particles larger than 5 ?m. As the inlet velocity increases, the effect of adding helical fins on the overall separation efficiency decreases, with a relative deviation of only 0.16% at an inlet velocity of 27 m/s, while it becomes increasingly effective in reducing energy consumption, with a pressure drop of 25.33%. The mechanism of the overall performance improvement lies in the fact that the helical fins change the flow field distribution in the cyclone, where the turbulence intensity in the vortex finder is significantly reduced, the tangential velocity of the external vortex is decreased, and the pressure gradient is reduced. The purpose of this paper is to provide new ideas for the optimal design of the internal components of the cyclone separator.

Study of the short-circuit flow and circulation flow’s impact on separation performance of cyclone separator with volute-helical inlet

Short-circuit flow and circulation flow are important secondary flows in a cyclone, which have a negative impact on separation performance. This work proposed new cyclones (VH cyclone), incorporating volute-helical inlets with five tilt angles based on the characteristics of short-circuit flow and circulation flow, in order to enhance separation efficiency without a significant pressure drop compared to a Lapple-type cyclone with a tangential inlet (TI cyclone). The separation performance and Euler number of six cyclones are obtained by experiments and analytical models. The simulation is utilized to explore characteristics of short-circuit flow and circulation flow, with a focus on the impact of these flow patterns on particle motion. The result shows that proportion of short-circuit flow increases initially and then decreases with the increase of the tilt angle, while circulation flow is continually weakened. The cutoff diameter increases first and then decreases while the trend of Euler number is opposite for new cyclones. By considering both separation performance and Euler number, VH4 cyclone (Tilt angle of volute-helical inlet is 6.5°) exhibits optimal performance, with a cutoff diameter 20.41% lower than that of TI cyclone, while their Euler numbers are similar.

A Preliminary Numerical Study on the Performance of Cyclone Separators in Supercritical CO2 Solar Power Plants

A combined approach of computational fluid dynamics, the discrete phase model, and the wall erosion model was used to numerically investigate the hydrodynamics, separation efficiency, and erosion rate in cyclone separators for s-CO2 solar power plants. Moreover, the results were compared with those for air and CO2 as carrier phases. The experimental data from the literature were used to validate the numerical model, and it was observed that the simulated gas velocities and wall erosion rate accurately aligned with the experimental measurements. The numerical results reveal that s-CO2 had the largest tangential velocity compared to the other two media; its area-weighted axial velocity of upward flow was the lowest in the middle part of the cyclone body, and varied considerably in the bottom region of the conical section. The particles were all collected at the bottom surface of air and CO2, but the separation efficiency of s-CO2 was 81.51%, due to the poor distribution of the vortex and short circuit. Finally, the erosion rate distribution and averaged surface erosion rate were also analyzed for the three carrier phases.

Numerical Investigation on the Performance of Cyclone Separators

Cyclone separators are commonly employed in the solid particle separation process due to their simplicity and low-cost manufacture. Collection efficiency and pressure drop are two of the most important factors. Small-size cyclone separator has outperformed collection efficiency. However, due to its small size, it’s hard to detailed flow investigation experimentally. So, the target of this work is to perform a numerical investigation of the flow characteristics as well as the collection efficiency and pressure drop of small cyclone separators, using Ansys Fluent software. Discrete Phase Model is included to simulate the particle-flow interaction. Different values of velocity inlet and particle size are considered. Typical flow characteristics of cyclone separators with a strong vortex are revealed. Results also show that the larger particle size or the stronger inlet velocity provides higher collection efficiency. Particularly, for a typical particle diameter of 2.96 micrometers, the collection efficiency of the cyclone separator is always higher than 91% when the inlet velocity surpasses 15 m/s. All these results provide a valuable framework for the operation of cyclone separators.

Predicting the performance of aero-type cyclone separators with different spiral inlets under macroscopic bio-granular flow using CFD–DEM modelling

Predicting the performance of aero-type cyclone separators with different spiral inlets under macroscopic bio-granular flow using CFD–DEM modelling

Numerical modeling of body shape effect on the performance of a square cyclone separator

This study aims to determine the effect of a square cyclone body shape on the performance of a square cyclone separator. To achieve this goal, four square cyclone separators with square lengths 0, 1, 2, and 3 times the hydraulic diameter of the cyclone body were considered. The simulation of the gas-solid flow was carried out using the Euler-Lagrange approach, while the gas flow was modeled by Navier–Stokes equations and the Reynolds stress turbulent model (RSTM), and the injected solid particle was solved using the Newton equation. The pressure drop, separation efficiency, and flow pattern were investigated to evaluate the performance of square cyclone separators. The results revealed that the pressure drop and separation efficiency decreased as the relative square length increased. In the case with a lower relative square length, the vortex core penetration is less than that in the other cases, which leads to a decrease in the entrainment phenomena and separation efficiency enhancement. At an inlet velocity of 16 m/s, an increase in the relative square length from 0 to 3 reduced the pressure drop by approximately 35%. At an inlet velocity of 24 m/s and a particle diameter of 8 µm, with an increase in the relative square length from 0 to 3, the efficiency decreased from 88.7 to 77.4%.

Eulerian–Lagrangian fluid dynamics study on the effects of inlet radial angle on the performance and flow pattern of multi-inlet cyclone separator

This paper presents a study on the influence of inlet radial angle in a multi-inlet cyclone separator using Eulerian-Lagrangian (EL) fluid dynamics approach. The investigation focuses on the behavior of air and solid particles within the cyclone. Air circulation was simulated at velocities ranging from 2 to 6 m/s, with inlet radial angles of 15°, 32°, 45°, 61°, and 72°. To model the turbulent flow, the Reynolds stress model (RSM) and renormalization group k-model (RNG) were employed, while the particle trajectories were simulated using the discrete phase model (DPM) in ANSYS Fluent. The purpose of this study was to determine how the inlet radial angle impacts various parameters: collection efficiency, pressure drop, cut-off diameter, axial velocity, and tangential velocity. The numerical data obtained from the simulations were validated and found to be consistent with the existing literature. The results revealed interesting findings. In the case of an inlet velocity of 6 m/s, the highest pressure drop of 84.5 Pa was observed for the 15° inlet radial angle, while the lowest pressure drop of 77.42 Pa was observed for the 32° inlet radial angle. It was found that the collection efficiency varied according to the radial angle of the inlet, with values of 89.00%, 91.70%, 92.50%, 94.77%, and 94.83% for 32°, 45°, 15°, 72°, and 61°, respectively. Additionally, at an inlet velocity of 2 m/s and a radial angle of 72°, 61°, 15°, 45°, and 32°, the corresponding cut-off sizes were determined to be 1.17 μm, 1.19 μm, 1.25 μm, 1.33 μm, and 1.38 μm, respectively. At an inlet velocity of 6 m/s, the peak tangential velocities were found to be approximately 1.48, 1.44, 1.44, 1.39, and 1.34 times the inlet velocity for the 15°, 72°, 61°, 45°, and 32° radial angles, respectively, within the axial location range of z = 1.5D to z = 3.4D. The peak axial velocity values for the 32°, 72°, 45°, 15°, and 61° radial angles, were reported as 0.85, 0.89, 0.92, 0.94, and 0.96 times the inlet velocity respectively.

Performance analysis of the cyclone separator with a novel clean air inlet installed on the roof surface

The study investigated the impact of implementing a new method of injecting clean air axially through the roof of the cylindrical section on the performance of cyclone separators. This secondary inlet was confined to a region common to both the vortex finder tube and the cylindrical section. The Stairmand high-efficiency cyclone was used as a reference model for comparison against the proposed design. For analysis, we made the potential use of CFD methods (based on LES and DPM models), along with the experimental and stereo-PIV research. Comparative analysis was carried out based on performance parameters (viz. the collection efficiency and pressure losses) and exploring flow physics inside the separator. Furthermore, six different values of clean gas inlet velocities were also considered to measure the relative performance. Conclusive results indicate that the new model increased the separation efficiency for all inlet velocities of the clean gas.

CFD Investigation on the Performance of Cyclone Separators with Divergent or Convergent Insertion Pipes

For multi-phase separation, developing high-performance cyclone separators is highly demanded. In this study, different divergent or convergent insertion pipes bFelow the vortex finder are employed to improve the separation performance. The impacts of insertion pipe geometrical configurations on the flow characteristics, pressure drop, and separation efficiency are systematically analyzed. The results reveal that the employed insertion pipe can significantly affect the static pressure distribution inside the cyclone. A longer insertion pipe length and larger tilt angle result in a wider central low-pressure area and smaller overall static pressure. The divergent insertion pipes increase pressure loss, while the convergent insertion pipes augment pressure loss. A larger insertion pipe length significantly impacts the axial velocity distribution. For divergent insertion pipes, the maximum central axial velocity increases with increasing tilt angles and then decreases. For small particles (dp ≤ 5 μm), a convergent insertion pipe exhibits a better separation performance. When the particle diameter dp ≥ 5 μm, divergent insertion pipes with larger angles and lengths can significantly decrease the pressure drop while guaranteeing satisfied collection efficiency. When L = 75 mm and θ = 60°, the pressure drop is reduced by 7.8%. This study may contribute to rationally designing high performance cyclone separators and also paves ways for improving the existing cyclone separators.