Науковий вісник НГУ

Analytical studies on constrained particle settling velocity in a water suspension of fly ash from thermal power plants

• 
• 

User Rating:  / 1

PoorBest 

Details

Category: Content №1 2021

Last Updated on 05 March 2021

Published on 30 November -0001

Hits: 2802

Authors:

V.P.Nadutyi, orcid.org/0000-0002-2453-0351, Institute of Geotechnical Mechanics named by N.Poljakov, Dnipro, Ukraine, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

V.S.Kurilov, orcid.org/0000-0003-3202-9003, Institute of Geotechnical Mechanics named by N.Poljakov, Dnipro, Ukraine, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

O.G.Cholyshkina, orcid.org/0000-0002-0681-0413, Interregional Academy of Personnel Management, Kyiv, Ukraine, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

V.F.Hankevych, orcid.org/0000-0002-8535-6318, Dnipro University of Technology, Dnipro, Ukraine

повний текст / full article

Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu. 2021, (1): 032 - 038

https://doi.org/10.33271/nvngu/2021-1/032

Abstract:

Purpose. To establish analytical dependences for calculating the characteristics of the ash suspension and the velocity of constrained settling of coal and quartz depending on the particle size and density of the medium, which is necessary for calculating the design and determining the operating modes of hydraulic devices for extracting coal from water mineral suspension of fly ash from thermal power plants.

Methodology. The research was carried out on the basis of a cellular suspension model and classical concepts of constrained particle motion in laminar and turbulent flow. For analytical evaluation of the characteristics of the suspension, the defining correlations and the Wend formula for viscosity were used. The Ergun equation and correlation analysis methods were used to calculate and analyze the speed of constrained movement of ash suspension particles.

Findings. Approximating nonlinear functions are obtained for determining the speed of constrained movement of coal and quartz particle size up to 4 mm in an ash suspension with a density of 1.31.8 g/cm³. It is shown that, for both settling and ascending of coal, there is a direct relationship between the velocity and particle size, in both cases it is nonlinear. For any coal size, the speed of ascent depending on the suspension density is of extreme nature; the rational density range is 1.551.8 g/cm³ with a maximum of 1.65 g/cm³. The established dependencies allow us to determine the size of coal and quartz particles, taking into account the counter-flow of the liquid phase, as well as the boundary size.

Originality. For the regime of weak-turbulence flows there were established dependences and approximation equations of the constrained movement speed of coal and quartz particles the main components of the water suspension of fly ash from the Novo-Kramatorska TPP, depending on the size and density of the ash suspensions with changes in the characteristics of the medium depending on density. The frames of the Stokes description of processes are established. It is shown that the movement of the liquid phase in a counter-flow with precipitating particles is effective for surfacing of thin coal classes.

Practical value. The described approach can be used for analytical evaluation of the characteristics and velocity of constrained movement in various water suspensions of discrete solid particles in weak-turbulence flows. The advantage is a wider coverage of hydraulic equipment operating modes. The results obtained are necessary for designing and determining the technological modes of operation of various hydraulic devices in the technology of complex processing of fly ash from TPPs.

Keywords: mineral suspension, fly ash, density, velocity, settling, ascend

References.

1. Nadutyi, V.P., Sevastianov, V.S., & Kostyria, S.V. (2016). Justification of expediency of complex processing of fly ash of Thermal Power Plants. Geotekhnchna mekhanka, 131, 59-66.

2. Shakirova, A.V. (2019). Trends in the production and processing of ash from power generating coal. nergetics of Thermal Technology, 2(6), 32-40. ISSN: 2541-9552.

3. Kwilinski, A., Ruzhytskyi, I., Patlachuk, V., Patlachuk, O., & Kaminska, B. (2019). Environmental taxes as a condition of business responsibility in the conditions of sustainable development. Journal of Legal, Ethical and Regulatory Issues, 22 (Special Issue 2), 6-15.

4. Ryabov, Yu.V., Delitsyn, L.M., Ezhova, N.N., & Sudareva,S.V. (2019). Methods of enrichment of ash and slag waste from coal TPPs and ways of their involvement in economic circulation (review). Thermal Engineering, 3, 3-24.

5. Polulyakh, A.D., Buchatsky, A.S., Vyrodov, S.A., & Polulyakh, D.A. (2016). Enrichment of coal in magnetite suspension: monograph. Dnepropetrovsk: NMU. ISBN 978-966-350-487-2.

6. Sklyar, L.V., & Prokopchuk, D.S. (2017). Technology of concentration of slags and sludge from Thermal Power Plants. Mining Journal, 102, 91-96.

7. elija, M., Rosi, A., Radovi, N., Vasi, M., ogo, M., & Joti, M. (2016). Laboratory testing of fly as]. Technical Gazette, 6(23), 1839-1848. https://doi.org/10.17559/TV-20150317171035.

8. Radkevich, E.V., Lukashev, E.A., & Vasilyeva, O.A. (2019). Hydrodynamic instabilities and nonequilibrium phase transitions. Reports of the Academy of Sciences, 486(5), 537-542.

9. Kelbaliev, G.I. (2015). Fundamentals of the theory of sedimentation and floating of solid particles, drops and bubbles in an isotropic turbulent flow. Azerbaijan Chemical Journal, 2, 6-27.

10. Semenenko, E.V., Demchenko, T.D., & Ryzhova, S.A. (2017). Determination of the effective viscosity of structured suspensions depending on the concentration and properties of the solid phase. Geo-Technical Mechanics, 136, 13-22.

11. Bulat, A.F., Nadutyi, V.P., Chelyshkina, V.V., & Kurilov,V.S. (2020). Determination of the characteristic properties of a mineral suspension for calculating the speed of movement of particles. Geo-Technical Mechanics, 152, 8-18.

• < Prev
• Next >