Browsing by Author "Akdogan, Guven"

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    CFD modelling of global mixing parameters in a Peirce-Smith converter with comparison to physical modelling
    (Berkeley Electronic Press, 2011) Chibwe, Deside K.; Akdogan, Guven; Aldrich, Chris; Eric, Rauf H.
    The flow pattern and mixing in an industrial Peirce-Smith converter (PSC) has been experimentally and numerically studied using cold model simulations. The effects of air volumetric flow rate and presence of overlaying slag phase on matte on the flow structure and mixing were investigated. The 2-D and 3-D simulations of the three phase system were carried out using volume of fluid (VOF) and realizable k - ɛ turbulence model to account for the multiphase and turbulence nature of the flow respectively. These models were implemented using commercial Computational Fluid Dynamics (CFD) numerical code FLUENT. The cold model for physical simulations was a 1:5 horizontal cylindrical container made of Perspex with seven tuyeres on one side of the cylinder typifying a Peirce-Smith converter. Compressed air was blown into the cylinder through the tuyeres, simulating air or oxygen enriched air injection into the PSC. The matte and slag phases were simulated with water and kerosene respectively in this study. The influence of varying blowing conditions and simulated slag quantities on the bulk mixing was studied with five different air volumetric flow rates and five levels of simulated slag thickness. Mixing time results were evaluated in terms of total specific mixing power and two mixing time correlations were proposed for estimating mixing times in the model of PSC for low slag and high slag volumes. Both numerical and experimental simulations were in good agreement to predict the variation characteristics of the system in relation to global flow field variables set up in the converter through mathematical calculation of relevant integrated quantities of turbulence, Volume Fraction (VF) and velocity magnitudes. The findings revealed that both air volumetric flow rate and presence of the overlaying slag layer have profound effects on the mixing efficiency of the converter
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    Lean applications : a survey of publications with respect to South African industry
    (Southern African Institute for Industrial Engineering, 2017) Dondofema, Richmore Aron; Matope, Stephen; Akdogan, Guven
    ENGLISH ABSTRACT: South African industry faces immense global competition from developed countries such as Germany probably because of the adoption of lean manufacturing techniques by the latter. This study is a survey on publications concerning implementation and adoption of lean manufacturing in South Africa. To assess South Africa with regards to research publications on lean manufacturing, a benchmark exercise was conducted with Germany for the period 2014 to 2015. The study concludes by highlighting the gaps identified during this survey and recommendations.
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    Mining-Related Selenium Contamination in Alaska, and the State of Current Knowledge
    (MDPI, 2017) Khamkhash, Aibyek; Srivastava, Vaibhav; Ghosh, Tathagata; Akdogan, Guven; Ganguli, Rajive; Aggarwal, Srijan
    ENGLISH ABSTRACT: Selenium pollution has been a topic of extensive research dating back further than the last decade and has attracted significant attention from several environmental and regulatory agencies in order to monitor and control its discharge from myriad industrial sources. The mining industry is a prime contributor of hazardous selenium release in the aquatic systems and is responsible for both acute and chronic impacts on living organisms. Herein we provide an overview of selenium contamination issues, with a specific focus on selenium release from mining industries, including a discussion of various technologies commonly employed to treat selenium-impacted waters from mining discharge. Different cases pertaining to selenium release from Alaskan mines (during years 2000–2015) are also presented, along with measures taken to mitigate high concentration releases. For continued resource exploration and economic development activities, as well as environmental preservation, it is important to fundamentally understand such emerging and pressing issues as selenium contamination and investigate efficient technological approaches to counter these challenges.
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    South African iron and steel industrial evolution : an industrial engineering perspective
    (Southern African Institute for Industrial Engineering, 2017) Dondofema, Richmore Aron; Matope, Stephen; Akdogan, Guven
    ENGLISH ABSTRACT: The paper focuses on the evolution of the South African iron and steel industry from the industrial engineering perspective. The earliest ironmaking in South Africa dates to the fifth century CE; but the major evolution of the industry began in 1882 and, by the year 1934, steel production from native ore was in full swing. The study highlights the major developments in South Africa’s iron and steel industry, and ends by exploring the extent of the application of industrial engineering techniques to published research into the steel industry.