scholarly journals The Numerical Modeling of Gas Movement in a Single Inlet New Generation Multi-Channel Cyclone Separator

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8092
Author(s):  
Aleksandras Chlebnikovas ◽  
Artūras Kilikevičius ◽  
Jaroslaw Selech ◽  
Jonas Matijošius ◽  
Kristina Kilikevičienė ◽  
...  
Keyword(s):  
Gas Flow ◽  
Numerical Models ◽  
Research Process ◽  
Solid Particles ◽  
Gas Flows ◽  
Cyclone Separator ◽  
Cleaning Efficiency ◽  
Gas Cleaning ◽  
Viscosity Models ◽  
New Generation

The work of traditional cyclones is based on the separation of solid particles using only the centrifugal forces. Therefore, they do not demonstrate high gas-cleaning efficiency, particularly in the cases where gas flows are polluted with fine solid particles (about 20 µm in diameter). The key feature of a new-generation multi-channel cyclone separator’s structure is that its symmetrical upgraded curved elements, with openings cut with their plates bent outwards, make channels for the continuous movement of the gas flows from the inflow opening to the central axis. The smoke flue of the vertical gas outflow is located near the cover of the separating chamber. The present work is aimed at studying the applicability of two various viscosity models and their modified versions to simulate aerodynamic processes in an innovative design for a multi-channel cyclone separator with a single inflow, using the computational fluid dynamics. The research results obtained in the numerical simulation are compared to the experimental results obtained using a physical model. The main purpose of this study is to provide information on how the new design for the multi-channel cyclone affects the distribution of gas flow in the cyclone’s channels. The modified viscosity models, k-ε and k-ω, and computational meshes with various levels of detailed elaboration were analyzed. The developed numerical models of a single-inlet multi-channel cyclone separator allow the researchers to describe its advantages and possible methods of improving its new structure. The developed models can be used for simulating the fluid cleaning phenomenon in the improved fourth-channel cyclone separator and to optimize the whole research process.

scholarly journals DAUGIAKANALIO CIKLONO PANAUDOJIMO DUJŲ SRAUTO DULKĖTUMUI MAŽINTI AGRESYVIOJE APLINKOJE TEORINIS VERTINIMAS

2016 ◽  
Vol 8 (4) ◽  
pp. 403-410
Author(s):  
Aleksandras Chlebnikovas ◽  
Pranas Baltrėnas
Keyword(s):  
Gas Flow ◽  
Flow Dynamics ◽  
Cleaning Efficiency ◽  
Theoretical Evaluation ◽  
Minimum Diameter ◽  
Gas Cleaning ◽  
Vapor Stream ◽  
Low Humidity ◽  
Pressure Resistance ◽  
New Generation

Contaminated gas cleaning from finely divided solids is carried out using a new generation of multi-channel design cyclones. The application of these devices are separated and precipitated particles with a minimum diameter up to 2 micrometers, reaching up to 95% cleaning efficiency. Cyclones of such constructions are usually used under usual conditions at elevated temperature and low humidity. Under aggressive conditions, these devices can be clogged, and their recovery is not possible. Further studies are research into the application of constructive solutions to adapt the cyclone gas cleaning of the particulate matter under aggressive conditions. This theoretical evaluation has described the characteristics change of gas flow and particulate matters at different aggressive environment. Such conditions were loudly describe the gas-flow high-temperature range of 50–200 °C and gas-vapor stream, the humidity reaches 70–100%. Estimated aggressive conditions on the gas flow dynamics forces – pressure, resistance and centrifugal, and particulate mechanical – gravitational and adhesion strength. All parameters are evaluated in comparison with the values under normal conditions. Naujos kartos daugiakanaliais ciklonais smulkiadispersės kietosios dalelės pašalinamos iš užterštų dujų. Naudojant šiuos įrenginius, yra atskiriamos ir nusodinamos kietosios dalelės, kurių minimalus skersmuo siekia 2 mikrometrus, taip gaunama iki 95 % valymo efektyvumo. Tokios konstrukcijos ciklonai dažniausiai yra naudojami įprastomis sąlygomis, esant padidintai temperatūrai ir nedideliam drėgniui. Esant agresyvioms aplinkos sąlygoms, šie įrenginiai užsikemša, o jų regeneruoti negalima. Tolesniuose ciklono veikimo parametrų tyrimuose numatoma analizuoti, kaip, taikant konstruktyvius sprendimus, pritaikyti cikloną ir šalinti kietąsias daleles iš dujų esant agresyvioms aplinkos sąlygoms. Šioje teorinėje analizėje yra aprašomas dujų srauto charakteristikų bei kietąsias daleles veikiančių jėgų pokytis esant skirtingai agresyviai aplinkai. Tokios sąlygos buvo apibrėžtos, nustačius 50–200 °C dujų srauto temperatūros intervalą ir tiriant dujų-garų srautą, kurio drėgnis siekė 70–100 %. Įvertinta agresyvių aplinkos sąlygų įtaka, daroma dujų srauto dinamikos jėgoms – slėgio, pasipriešinimo ir išcentrinei. – ir kietųjų dalelių mechaninėms jėgoms – gravitacijos ir adhezijos. Visi vertinami parametrai palyginti su vertėmis normaliomis sąlygomis.

scholarly journals INLET TEMPERATURE INFLUENCE ON ISOTHERMAL GAS CLEANING FROM MONO-IMPURITIES BY FIXED LAYER OF ADSORBENT

2020 ◽  
Vol 63 (9) ◽  
pp. 88-92
Author(s):  
Olga N. Filimonova ◽  
Andrey S. Vikulin ◽  
Marina V. Enyutina ◽  
Alexey V. Ivanov
Keyword(s):  
Gas Flow ◽  
Physical Adsorption ◽  
Plug Flow ◽  
Fixed Bed ◽  
Initial Boundary ◽  
Gas Production ◽  
Solid Particles ◽  
Inlet Temperature ◽  
Isothermal Adsorption ◽  
Gas Cleaning

The influence of the temperature of the inlet gas containing mono-impurity was evaluated for the process of physical adsorption purification in a porous fixed bed of granular adsorbent. The theoretical analysis is based on the classical mathematical model of the isothermal adsorption dynamics in a porous stationary medium structurally made-up of the dispersed phase of solid particles, under the assumptions made: the gas to be purified contains a low-concentration mono-impurity, its motion in the adsorber is unidirectional, and the levelling effect of the velocity profile in the porous cross section environment allowed to adopt the hydrodynamic regime of plug flow; axial mixing in the gas flow  is negligible; the adsorption heat is negligible; the layer porosity is uniform; adsorption rate is determined by the sorption kinetics equation with an isotherm, obeying Henry's law. An initial-boundary-value problem is formulated for a system of first-order partial differential equations, which solution with respect to mono-impurity concentrations in the gas stream and adsorbent is obtained in an explicit analytical form using the one-sided integral Laplace transform. A comparative analysis of the computational experiment results with known experimental data showed that the proposed model with an assumptions system is quite adequate qualitatively and quantitatively describes the adsorption separation process. Using the example of an industrial adsorber functioning in the ZB-120/120 complex purification unit in a mobile gas production system, it is shown that the temperature increase by 10 K of inlet dried air after compression containing carbon dioxide reduces the working time in the adsorption stage by 45%. It has been established that the temperature change in the gas inlet flow has a significant effect on the adsorber efficiency and should be taken into account when identifying the overall characteristics of the complex cleaning unit.

Addition of Heated Solid Particles to a Gas Flowing in a Pipe

1972 ◽  
Vol 94 (1) ◽  
pp. 81-87 ◽  
Author(s):  
G. Rudinger
Keyword(s):  
Gas Flow ◽  
Constant Pressure ◽  
Volume Fraction ◽  
High Heat ◽  
Solid Particles ◽  
Gas Flows ◽  
Particle Loading ◽  
Flow Equations ◽  
High Particle ◽  
Loading Ratio

A number of processes, such as pneumatic conveying of powdered materials through ducts, feed lines for powdered rocket fuels, or certain flow processes in air-augmented solid-propellant rockets, involve addition of a stream of solid particles to a gas flow. The present study deals with the analysis of gas flows from a constant-pressure and temperature reservoir through a pipe into which the particles are injected at some point, and the pipe is assumed long enough to allow equilibrium between the gas and the particles to be established. Ultimately, the mixture is discharged into another reservoir of constant pressure. The temperature of the injected particles may be different from the reservoir temperature of the gas, so that the effects of simultaneous particle and heat addition must be considered. Allowance is made in the flow equations for the volume fraction occupied by the particles, and the analysis may therefore be applied to arbitrarily high particle loadings. To demonstrate the influence of the various parameters involved, the flow equations are solved numerically with the aid of a digital computer. With increasing particle loading the gas flow is markedly reduced, and the temperature of the discharge closely approaches that of the injected particles as a result of the high heat capacity of the particle stream. If this temperature behavior is assumed to hold, simple relationships can be derived which yield results in good agreement with data obtained from the complete equations if the loading ratio equals about ten or more for typical gas-particle mixtures. Of special interest is the finding that the gas flow needed to transport particles at a prescribed rate can be significantly reduced by heating of the particles before injection. It is demonstrated that equivalent direct heating of the gas would not be practicable unless the particle loading is quite low.

Multidimensional Measurements of Turbulent Boundary Layer Including Scattered Particles Using PIV Technique

2015 ◽  
Author(s):  
Yoshiki Sugawara ◽  
Takahiro Tsukahara ◽  
Yasuo Kawaguchi
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Gas Flow ◽  
Solid Particles ◽  
Gas Flows ◽  
Stress Distributions ◽  
Dominant Term ◽  
Piv Technique ◽  
Image Velocimetry ◽  
Experimental Researches

Although many experimental researches on solid-gas flows have been conducted, the involved stress balance problem has not been elucidated. To have a deep investigation of the stress balance in gas flow with entrained solid particles, this study conducts particle image velocimetry (PIV) experiment on a horizontal turbulent boundary layer. In the experiment, air and micro-scale glass beads are chosen as the gas phase and solid particles, respectively. The velocities of both air and solid particles are obtained simultaneously based on the acquired images and by image processing; each term of the stress balance equation is calculated and the influences of solid particles are analyzed. Based on the experiment results, the dominant term of the stress in the solid-gas flow as well as the influence of the solid particles on the stress distributions are identified.

scholarly journals RESEARCH INTO THE CLEANING EFFICIENCY OF 300 M3/H MAINTAINED BY THE SPIRAL MULTI-CHANNEL CYCLONE IN THE PROCESS OF REMOVING SOLID PARTICLES OF <20 ΜM / 300 M3/H NAŠUMO SPIRALINIO DAUGIAKANALIO CIKLONO VALYMO EFEKTYVUMO TYRIMAS, ŠALINANT < 20 ΜM KIETĄSIAS

2014 ◽  
Vol 6 (4) ◽  
pp. 373-378
Author(s):  
Pranas Baltrėnas ◽  
Diana Platova
Keyword(s):  
Particulate Matter ◽  
Gas Flow ◽  
Experimental Studies ◽  
Flow Distribution ◽  
Experimental Tests ◽  
Solid Particles ◽  
Treatment Efficiency ◽  
Cleaning Efficiency ◽  
Ultrafine Particulate Matter ◽  
Spiral Casing

Tests on the cleaning efficiency of an experimental spiral cyclone have been conducted to determine the removal efficiency of the solid particles the dispersion of which makes &lt;20 µm in the streamlined multi-channel cyclone. The introduced device is adapted to removing ultrafine particulate matter from contaminated air (gas) flow. A multi-channel cyclone with spiral casing has been designed at the Department of Environmental Protection (DEP) of Vilnius Gediminas Technical University. Experimental studies have disclosed that air (gas) flow cleaning efficiency of the spiral multi-cyclone (capacity 300 m3) depend on the internal structure of the device, i.e. on the number of channels and air (gas) flow distribution ratio of transit and peripheral channels. Also, the treatment efficiency of the applied equipment has been evaluated removing solid particles of different nature. AFA-VP-20 filters have been employed for conducting experimental tests. The obtained results have disclosed that solid granite particles – 95.1%, glass – 91.4% and wood – 92.2% are removed most effectively. Eksperimentiniai spiralinio ciklono valymo efektyvumo tyrimai atliekami siekiant nustatyti kietųjų dalelių, kurių dispersija x &lt; 20 μm, pašalinimo efektyvumą patobulintame daugiakanaliame ciklone. Minėtas įrenginys pritaikytas itin smulkioms kietosioms dalelėms iš užteršto oro (dujų) srauto pašalinti. Daugiakanalis ciklonas, turintis spiralinį korpusą, sukurtas Vilniaus Gedimino technikos universiteto (VGTU) Aplinkos apsaugos katedroje (AAK). Eksperimentinių tyrimų metu nustatytas spiralinio daugiakanalio ciklono (našumas 300 m3/h) oro (dujų) srauto valymo efektyvumas priklausomai nuo vidinės įrenginio konstrukcijos, t. y. nuo kanalų skaičiaus ir oro (dujų) srauto pasiskirstymo į tranzitinį ir periferinį kanalus santykio. Taip pat įvertintas įrenginio valymo efektyvumas, šalinant skirtingos prigimties kietąsias daleles. Eksperimentiniams bandymams atlikti naudoti AFA-VP-20 filtrai. Remiantis bandymų rezultatais, nustatyta, kad efektyviausiai šalinamos granito kietosios dalelės – 95,1 %, stiklas – 91,4 %, mediena – 92,2 %.

Researches of Aggressive Gas Flow Cleaning from Wood Ash Particu-late Matter in the Multi-Channel Cyclone

2017 ◽  
Author(s):  
Aleksandras Chlebnikovas ◽  
Pranas Baltrėnas
Keyword(s):  
Flow Velocity ◽  
Gas Flow ◽  
Aerodynamic Resistance ◽  
Experimental Tests ◽  
Wood Ash ◽  
Cleaning Efficiency ◽  
Gas Cleaning ◽  
Place Studies ◽  
Aerodynamic Parameters ◽  
Gas Flow Velocity

The studies examined the gas flow aerodynamic parameters and treatment efficiency from the wood ash particulate matter, also an adhesion dependencies in multi-channel cyclone using aggressive gas flow – temperature up to 75 °C and relative humidity more than 95%. Researches of gas flow velocity and cyclone aerodynamic resistance in case of different average gas flow velocity in the cyclone and particle adhesion analysis inside the cyclone. Cyclones work is based on centrifugal forces and additionally resulting filtration process operation. Due to the interaction between inlet flow from the (peripheral) channel coming next and the flow following the direction towards the axis of the cyclone along the channel (transit), additional filtration takes place. Studies was carried out the prototype of multi-channel cy-clone, which is used with curvilinear quarter-rings with opening slot folded at an angle, so that the peripheral and transit flows are equal to each other. The aim – to determine the multi-channel cyclone aerodynamic parameters, and their dependencies, to make aggressive gas flow and to analyse the wood ash particles adhesion and its impact to multi-channel cyclone operation by occluding device's internal design. The average velocity of gas flow was equal to 8, 12 and 16 m/s, the highest aerodynamic resistance was equal to 410 Pa, which was determined in the case at 16 m/s. Based on experimental tests, PM which the diameter up to 20 microns, the gas cleaning efficiency is above 85% when inlet concentration was 5 g/m3.

scholarly journals MODELING OF A DUSTED GAS FLOW CLEANING PROCESS USING A KINEMATIC MODEL OF THE INTERACTION OF DISPERSED PARTICLES WITH DROPLETS IN A WET SCRUBBER

2021 ◽  
pp. 84-98
Author(s):  
I.A. Volchyn ◽  
V.A. Raschepkin
Keyword(s):  
Mathematical Model ◽  
Gas Flow ◽  
Kinematic Model ◽  
Significant Proportion ◽  
Solid Particles ◽  
Venturi Tube ◽  
Gas Cleaning ◽  
Dispersed Particles ◽  
Spray Density ◽  
Wet Scrubber

A mathematical model is proposed for the scavenging process of the dispersed particles by droplets in a wet scrubber under excess spray density in Venturi tube within kinematic approach of the interaction of particles in countercurrent gas-dispersed flows, which refines the existing engineering model, taking into account the spatial size variation of the droplets, due to their coagulation with wet slurry droplets and uncaptured particles entering a wet scrubber from the Venturi tube. The results of calculations with the adopted mathematical model showed that in case of possibility to organize the spraying of a gas flow in a scrubber with 300–500 micron droplets aerosol at a specific spray density of about 1 liter/m3, a 1–2 meters wide layer of droplets ensures effective absorption of both uncaptured PM2.5 solid particles, and the slurry droplets from the Venturi tube. The ejection of the slurry droplets into a wet scrubber from the Venturi tube, and the associated increase in the size of the scrubber droplets due to coagulation with slurry droplets, does not noticeably affect the efficiency of the dusted gas stream cleaning. An adopted mathematical model was applied to calculate the capture of particles by droplets in cylindrical and conical scrubbers. Due to the increase in a residence time of the droplets upon increased velocity of the countercurrent gas flow, the efficiency of gas cleaning from dispersed particles in a conical scrubber appears to be higher than in a cylindrical scrubber. However, with an increase in the spray density above 2 liter/m3 and with droplet diameters greater than 1000 microns, the efficiency of the conical scrubber decreases, which is associated to an increase in the escape of a significant proportion of massive drops to the walls with a reduction in the scrubber reactor cross-section.  Bibl. 21, Fig. 4.

INVERSE PROBLEMS METHOD FOR STUDY OF HEAT TRANSFER IN SOLIDS INTERACTED WITH GAS FLOWS LOADED BY SOLID PARTICLES

Equipment ◽  
2006 ◽  
Author(s):  
Aleksey V. Nenarokomov ◽  
O. M. Alifanov ◽  
E. A. Artioukhine ◽  
I. V. Repin
Keyword(s):  
Heat Transfer ◽  
Inverse Problems ◽  
Solid Particles ◽  
Gas Flows

Investigation of the different particle size dust releases from rigid filter candles during pulse-jet cleaning

2021 ◽  
pp. 095440622110179
Author(s):  
Xin Luan ◽  
Zhongli Ji ◽  
Longfei Liu ◽  
Ruifeng Wang
Keyword(s):  
Particle Size ◽  
Critical Role ◽  
Operating Conditions ◽  
Solid Particles ◽  
Dust Particles ◽  
Cleaning Efficiency ◽  
Term Operation ◽  
Cleaning Performance ◽  
Experimental Apparatus ◽  
Pulse Jet

Rigid filters made of ceramic or metal are widely used to remove solid particles from hot gases at temperature above 260 °C in the petrochemical and coal industries. Pulse-jet cleaning of fine dust from rigid filter candles plays a critical role in the long-term operation of these filters. In this study, an experimental apparatus was fabricated to investigate the behavior of a 2050 mm filter candle, which included monitoring the variation of pressure dynamic characteristics over time and observing the release of dust layers that allowed an analysis of the cleaning performance of ISO 12103-1 test dusts with different particle size distributions. These results showed the release behavior of these dusts could be divided into five stages: radial expansion, axial crack, flaky release, irregular disruption and secondary deposition. The cleaning performance of smaller sized dust particles was less efficient as compared with larger sized dust particles under the same operating conditions primarily because large, flaky-shaped dust aggregates formed during the first three stages were easily broken into smaller, dispersed fragments during irregular disruption that forced more particles back to the filter surface during secondary deposition. Also, a “low-pressure and long-pulse width” cleaning method improved the cleaning efficiency of the A1 ultrafine test dust from 81.4% to 95.9%.

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