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 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.

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 Gas flow dynamics in the conduit of Strombolian explosions inferred from seismo-acoustic observations at Aso volcano, Japan

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Kyoka Ishii ◽  
Akihiko Yokoo ◽  
Tsuneomi Kagiyama ◽  
Takahiro Ohkura ◽  
Shin Yoshikawa ◽  
...  
Keyword(s):  
Gas Flow ◽  
Flow Dynamics ◽  
Aso Volcano ◽  
Strombolian Explosions

The Theoretical and Experimental Evaluation of Gas-Particle Flow in Laser Cladding Repairing of Three Dimensions

Materials ◽  
2004 ◽  
Author(s):  
Hui-Shan Li ◽  
Xi-Chen Yang ◽  
Chun-Xian Wang
Keyword(s):  
Mass Flow Rate ◽  
Laser Cladding ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Flow ◽  
Ccd Camera ◽  
Longitudinal Axis ◽  
Three Dimensions ◽  
Theoretical Evaluation ◽  
Transportation Equipment

In this paper, the powders transportation in laser cladding repairing during the coaxial powder-feeding was evaluated. The theoretical evaluation is based on a two-fluid approach in which both the gas and particulate phase is treated each phase separately, and the only link between the phases is through the drag force in the momentum equations. The particles velocities are calculated with changes of the gas flow and mass flow rate. This is important for the coaxial nozzle and the carrier-gas powder transportation equipment characteristics determined. An experimentally of the influence of carrying gas on the powder stream was set up. The gas-particles flowing from the nozzle was illuminated by a 2D sheet of light. A typical image from the CCD camera is captured. The axial velocity and cross section were described. According to the results, it was found that: (1) Different mass flow rate Mp=0.5g/s, 0.67g/s, 0.83g/s, 1g/s, the powder stream luminance intensity and distribution will change. (2) The distribution of powder concentration at longitudinal axis from the nozzle exit is shown. The faster particulates stream has the less density per unit volume for a given mass flow rate. (3) The gas velocity for transportation is the most important parameter.

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