Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering最新文献

{"title":"Application of Network Science to Extend the AHP and QFD Methods","authors":"E. Kulcsár, I. Gyurika, Tamás Csiszér","doi":"10.11159/icmie20.137","DOIUrl":"https://doi.org/10.11159/icmie20.137","url":null,"abstract":"Understanding customers’ needs and developing a product which meets expectations is a multi-criteria decision problem, and requires methods for solving complex tasks. The purpose of the present study is to apply network science for prioritization of customers’ needs and extend the applicability of the Analytic Hierarchy Process (AHP) and Quality Function Deployment (QFD) methods. These two methods can be used jointly in the customers’ needs prioritization. The customer’s needs are prioritized by using the AHP technique, and the technical requirements are ranked by using the QFD method. Although network analysis is a widely used method in several disciplines, it is not yet widespread in customer needs assessment. This study aims to fill this gap, replace and combine the AHP and QFD methods by one to facilitate the application. Preference and correlation networks are presented and evaluated in detail. By using a preference network, the importance of the customer needs is definable by calculating an in-degree or a PageRank value. In a correlation network, the effects of the technical requirements on each other can be evaluated by specifying their weights and directions.","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73409370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liberation analysis of South African Middle group seam chromite ore processed with Vertical Shaft Impactor Crusher","authors":"Mashudu Maruli, W. Nheta","doi":"10.11159/mmme20.135","DOIUrl":"https://doi.org/10.11159/mmme20.135","url":null,"abstract":"In this study, the impact of vertical shaft impactor (VSI) crusher on fine and ultrafine production during crushing of South African Middle group (MG) chromite seam was investigated. The chromite ore was subjected to size reduction with VSI crusher at varied rotor tip speed (30, 35 &40 Hz) and particle size distribution analysis was done on all the three products. The VSI crusher product particle size distribution indicated that as the VSI rotor speed was increased, the amount of ultrafine generated also increased. The product at rotor speed of 35Hz revealed a lower percentage of ultrafines at 6.16% in the -212+150μm and 0.85% in the 150+53μm particle size range. Ball mill product from the Plant was analysed and the results revealed that the ball mill is more efficient for chromite ore liberation as 84% of the -425+300μm was produced compared to the VSI which only produced 51.27% -425+300μm. However, the amount of ultrafines produced was high at 9.2% of -150+106μm size fraction, with most ultrafine particle size of 4.42% in the -53+26μm size fraction. The mineral liberation analysis conducted on the -425+300 and -300+212μm VSI crusher products indicated that the degree of chromite liberation was higher at 95% on the -300+212μm size fraction compared to 78% liberation on the -425+300 μm size fraction. From the liberation analysis conducted in this investigation, it can be concluded that VSI crusher has a greater potential in chromite size reduction as it has shown to produce a liberated product with reduced percentage of ultrafines. However more test needs to be done on the VSI residence time to improve the percentage mass of the required liberated product particle size.","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74126557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An investigation on flotation process of low-grade Niobium/Tantalum ore","authors":"W. Nheta, Brian Ruwizhi","doi":"10.11159/mmme20.137","DOIUrl":"https://doi.org/10.11159/mmme20.137","url":null,"abstract":"","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76898786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transmission of the topographic system and orientation from the surface to an underground mine using 2 vertical shafts. Comparison between the classical and gyroscope method","authors":"L. Sanmiquel, M. Bascompta, J. Rossell, H. Anticoi","doi":"10.11159/mmme20.125","DOIUrl":"https://doi.org/10.11159/mmme20.125","url":null,"abstract":"1 ICL Chair in Sustainable Mining. Polytechnic University of Catalonia (UPC), Avenue Bases de Manresa, 61-73, 08242-Manresa Spain lluis.sanmiquel@upc.edu; marc.bascompta@upc.edu 2 Department of Mathematics. Polytechnic University of Catalonia (UPC), Avenue Bases de Manresa, 61-73, 08242-Manresa Spain josep.maria.rossell@upc.edu 3 Department of Mining Engineering, Industrial and ICT Polytechnic University of Catalonia (UPC), Avenue Bases de Manresa, 61-73, 08242-Manresa Spain hernan@emrn.upc.edu","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82207280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beneficiation of South African chromite tailings using Magnetic Separation","authors":"T. Mokoena, W. Nheta","doi":"10.11159/mmme20.138","DOIUrl":"https://doi.org/10.11159/mmme20.138","url":null,"abstract":"","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91449006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Numerical Study of Capillary Driven Flow in Vane-type Tank under Normal Gravity and Microgravity Conditions","authors":"Ning Weng, Qinggong Wang, Yu-ying Wang, Jinyin Huang, L. Yao, Wei Yao, Jindong Li","doi":"10.11159/htff20.183","DOIUrl":"https://doi.org/10.11159/htff20.183","url":null,"abstract":"Extended Abstract Capillary flow of the low surface tension liquid in interior corners between two intersecting surfaces and/or in containers have received much attention in recent years. It relates to a wide range of applications in the fields of microfluidics, fluid management in space and microgravity, porous media, etc. To optimise the design and efficiency of reservoir applications which involve capillary flow in both normal gravity and microgravity, it is necessary to have a basic understanding of the involved flow physics. Particularly, when cryogenic liquids are used, such as the liquid hydrogen, liquid nitrogen, liquid neon and liquid helium, they show quite low surface tension and a low temperature out of the scope of current understanding on capillary flows. In the present study, a combined experimental and numerical approach is employed to study the capillary flow dynamics of a liquid subject to the different gravity levels. First, we perform experiments both on earth and in a 3.6 s drop tower. A normal working liquid of ethanol is used in the tests since it is somewhat hard to adopt the cryogenic liquid directly when it requires a strict control on the working temperature in the measurement. The experimental results show the transient development of the fluid in capillary structures, and it well meets the Concus–Finn condition. We use the results for model validation for the numerical studies. For numerical studies, computational fluid dynamics (CFD) models are developed using the Volume of Fluid (VOF) [1] and Continuous Surface Force (CSF) [2] method. A Kistler dynamic contact angle model [3] is used as the boundary condition at the three-phase moving contact line, which considers the effects of the contact angle hysteresis. An adaptive mesh refinement (AMR) is applied to refine the liquid–gas interface for higher accuracy. The dependence of numerical results on the mesh refinement is first examined, and the difference in the predictions of the hight of capillary rise of liquid is less than 5%. Then, the liquid flow in the corner is the investigated numerically in both normal gravity and microgravity. The experimental result and numerical result are basically consistent. It is certified that the numerical method with the dynamic contact angle model are able to predict accurately the dynamics of the capillary flow in both normal gravity and microgravity. After validation, we extend the numerical simulations for different cryogenic liquids, and examine the main operating parameters, including the capillary structure, number of vanes, and initial wettability of fluid. The results would provide some guideline for the design of the low surface tension vane-type vane tank for space applications.","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84843182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the shroud leading edge shape on the axial-fan noise","authors":"David Kohout, T. Hyhlík","doi":"10.11159/htff20.164","DOIUrl":"https://doi.org/10.11159/htff20.164","url":null,"abstract":"The paper is focused on the noise reduction of the low-pressure axial fan by the modification of the shroud leading edge shape. The CFD and CAA simulations of the fan are performed on commercial software PowerFLOW based on the Lattice Boltzmann method. The propagation of the acoustics waves to the far-field was carried out by the Ffowcs-Williams & Hawkings acoustics analogy. The far-field acoustic data from the simulation matches with the results from the ISO measurement in the semi-anechoic chamber. Direct acoustics results of the near-field capture dominant noise sources of the cooling axial fan in blade tip area. Vortexes produced by the flow separation from the shroud inlet edge are carried by the rotating fan blade. The interaction of these flow structures with the blade tip surface produces strong subharmonic component in the acoustic spectra with lower frequency compared to blade passing frequency. Four different shrouds geometry modifications are analyzed. The modification of the shape eliminates subharmonic component of the fan sound spectra and reduces overall fan noise.","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81244582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advantages in the design of open-pit and quarries by computer mean","authors":"L. Sanmiquel, M. Bascompta, Nor Sidki, H. Anticoi","doi":"10.11159/mmme20.126","DOIUrl":"https://doi.org/10.11159/mmme20.126","url":null,"abstract":"Extended Abstract In the last 15 years, there has been a great advance and diffusion of specific commercial software focused on mining design, planning and optimization, such as Vulcan, RecMin or Datamine. Thus, the case of this study will focus on the design of the expansion of an aggregate quarry carried out using Vulcan. An analysis of the most important advantages and disadvantages during the design of a quarry is through the use of this specific software, following the process below: 1Block model creation based on an initial drilling mesh with the aim to model the expansion of the extractive activity. This model had information about density, grade of the resource and bloc size. 2Economic analysis taking into account the main characteristics of the quarry. 3The study of different scenarios based on several parameters such as: economic, geotechnical and specific constraints of the mine. Each scenario was optimized by the Lerchs-Grossmann method in order to find the most economical design according to the parameters considered in each case. Ensuring the highest economic profitability while complying the mining design requirements established in each case. (Baek et al., 2016) The results obtained showed that the use of this type of tools provide considerable advantages in the design of a quarry and its economic optimization. Besides, it can also help to increase safety levels and solve environmental issues related to the mining activity.","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74826711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assess the use of Solar Dryer with Photonic Solar Reflectors and PCMs in Farming Products in the Andean Region","authors":"Estefanía Orquera, Á. Aguinaga, Carlos Ávila, V. Hidalgo","doi":"10.11159/icmie20.102","DOIUrl":"https://doi.org/10.11159/icmie20.102","url":null,"abstract":"Dehydration food products is seen as an alternative to preserve them in quality and extend their period of live and consumption, this procedure usually happens using non-renewables resources, or in the open air, which, in some cases, could contaminate the final product. An alternative is the use of solar energy for solar dyers to dehydrate agricultural products. Since Ecuador has an excellent radiant resource and an economical dependence of Agriculture activities, it is suggested to assess the performance of a solar dryer, that consider, as an improvement the use of Integrated Photonic Solar Reflectors and thermal energy storage with Phase Change Materials (PCMs) in the Province of Pichincha, in the Andean Region, applied to farming products harvesting by a local community in Cayambe. For this evaluation, in the begging will be analysed food products such as Maize and Cedron leaves, and it will be evaluated the reduction of their moisture content. The use of thermal energy storage (PCMs) will allow to show that this incorporation increase the efficiency of the solar energy system, and the addition of Integrated Photonic Solar Reflectors to the panels, also, it will be possible to suggest improvements in the design of the chosen solar dryer taken as reference for the purposes of this research.","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89664116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterisation of South African Chromite Middle Group Seams","authors":"Mashudu Maruli, W. Nheta","doi":"10.11159/MMME20.136","DOIUrl":"https://doi.org/10.11159/MMME20.136","url":null,"abstract":"In this paper, detailed physical and chemical characterisation of the South African chromite Middle group seams (MG 1, 2, 3 and 4) was conducted to determine the effect it has in choosing the type of milling equipment and establish how the mineralogical characteristics vary in order to decide whether they should be processed separately or blended together. The chemical composition was analysed using XRF, mineralogical phases determined using XRD and elemental analysis as well as grain particle sizes were obtained from SEM and EDS. XRF results showed that the Cr2O3 content in all seams was between 30 and 35% by weight and mostly associated with Fe, Si, Mg, and Al elements. Most dominant phases are that of chromite and magnetite in all the samples. The amount of chromium element by % weight in all seams ranged between 20% to 28 % as obtained from the EDS. The particle size of the grains in the ore ranged between 20 to 420μm, with majority being between 150 and 200μm. SEM showed that minerals were well distributed within the ore, with very few that were clustered together. From above mentioned mineralogical analysis that has been conducted thus far it was observed that all Middle group seams showed very similar characteristics, and blending them for processing would be most recommended, however they can also be processed separately depending on the availability of the ore.","PeriodicalId":20694,"journal":{"name":"Proceedings of the 6th World Congress on Mechanical, Chemical, and Material Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83700436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}