Претрага

Упит dcterms_subject_txt:auxiliary machines

78 items

  • Analysis of the exhaust emissions inventory from auxiliary mining machines

    Stevan Đenadić, Aleksandar Mirković, Jovana Mitrović, Filip Miletić, Predrag Jovančić, Dragan Ignjatović (2023)
    Open-pit coal mines are equipped with a large number of mining machines and vehicles with diesel engines. Due to common daily operation of these machines and vehicles large amounts of exhaust gases which contain numerous pollutants are emitted into the atmosphere. The demand to reduce air pollution induced the activities in developed countries to map and calculate all gases emitted by industries to formulate and select adequate preventive activities. In collaboration with machine manufacturers, emission standards for off-road machines ...
    emissions, mining, auxiliary machines

  • The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers

    Dragan Ignjatović, Predrag Jovančić, Stevan Đenadić, Ivan Janković, Ivica Ristović (2019)
    One of the most important prerequisites for the successful operation of the open-cast lignite mine is to carry out all the auxiliary works timely with the necessary quality. The most important and most commonly used auxiliary machines are bulldozers. Engaging time of bulldozers use is in direct relation with the coefficients of the time and capacity utilization of the continuous system for the excavation of coal and tailings, which indicates their importance. More than 100 bulldozers have been hired ...
    open-cast coal mine, auxiliary works, bulldozers, optimization, availability

  • Analiza primene višekriterijumskih metoda u optimizaciji izbora hidruličnih bagera na površinskim kopovima uglja

    Stevan Đenadić, Predrag Jovančić, Dragan Ignjatović, Filip Miletić, Ivan Janković (2019)
    Hidraulični bageri primenjuju se u različitim oblastima privrede a najzastupljeniji su u građevinarstvu i rudarstvu. Na površinskim kopovima sa kontinualnim sistemima, klasifikuju kao pomoćna mehanizacija a na površinskim kopovima sa diskontinualnim sistemima, kao osnovna mehanizacija. Kako je u oba slučaja njihova primena neizostavna, važno je izvršiti adekvatnu analizu postojećih podataka, u cilju optimizacije izbora tipa hidrauličnog bagera u odnosu na uslove rada datog površinskog kopa. U radu su opisane različite višekriterijumske metode koje su korišćene za analizu hidrauličnih bagera. ...
    višekriterijumske metode, površinski kop uglja, pomoćna mehanizacija, hidraulični bager

  • Application of the Fuzzy theory in the evaluation of operating parameters of auxiliary mechanization on open-cast coal mine, case study: pipelayers

    Stevan Djenadić, Miloš Tanasijević, Filip Miletić, Predrag Jovančić (2022)
    Achieved operating parameters are the main indicator of the work quality and selection of mining machines. The effectiveness of a coal mine is correlated with the availability of basic and auxiliary machines. The main task of auxiliary machines in lignite mines is to achieve optimal working conditions. From an economic point of view, auxiliary machines generate up to 20% of the lignite mines' total costs. These are the primary reasons for analyzing their current work and making decisions in ...
    upotrebni kvalitet, fazi teorija, rudarske mašine

  • Application of the Fuzzy Model in the Evaluation and Selection of Hydraulic Excavators on Open-Pit Lignite Mine

    Stevan Đenadić, Miloš Tanasijević, Vladimir Milisavljević, Dragan Ignjatović, Predrag Jovančić (2021)
    The production of lignite in large open-pit mines is mainly performed with continuously operating equipment, where bucket-wheel excavators, bucket-chain excavators, belt conveyors, and spreaders are the basic machines. Smaller machines, usually of discontinuous operating nature, are commonly categorized as auxiliary machines. This paper presents the research related to the analysis of auxiliary machine parameters with the case study for a hydraulic excavator. The purpose of the analysis was to develop a model of rating quality of service of the ...
    Fuzzy theory, hydraulic excavator, selection, quality of service, asset management
    ... excavators, belt conveyors, and spreaders are the basic machines. Smaller machines, usually of discontinuous operating nature, are commonly categorized as auxiliary machines. This paper presents the research related to the analysis of auxiliary machine parameters with the case study for a hydraulic ...
    ... lignite mines as auxiliary machines are characterized by smaller capacities. They represent very mobile machines that are used for various types of works. The working conditions are varying. Their presence in open-pit mines is necessary. The working efficiency of basic machines is directly related ...
    ... accomplishment of all auxiliary operations [1]. Delays or low performance of auxiliary works can endanger the safety of people and equipment. All the above mentioned are the reasons why open-pit mines must have available an adequate type, number, and quality of auxiliary machines. The selection ...

  • Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines

    Ugljesa Bugarić, Milos Tanasijević, Stevan Djenadić, Dragan Ignjatović, Ivan Janković (2022)
    This paper presents the model for the identification of reference points on the lifetime curve of engineering systems. This curve commonly represents the increase and decline of failure in relation to time. A direct correlation between failure rate and costs is assumed in this paper, therefore, statistical and empirical analysis of costs provided reference points. This approach is used for positioning stages of the engineering system’s lifetime with a minimal number of failures and costs, regardless of whether these ...
    Electrical and Electronic Engineering,Industrial and Manufacturing Engineering, Control and Optimization, Mechanical Engineering, Computer Science (miscellaneous), Control and Systems Engineering

  • Self-Engineering: Possibilities for Maintenance Operations in the Mining Machines Industry

    Steven Manders, Milorad Pantelić, Vladimir Milisavljević, Alberto Martinetti (2021)
    Self-engineering is a relatively new branch of knowledge that aims to understand how systems could “autonomously” re-configure or repair themselves without the intervention of the operators. A direct field of application is within the maintenance spectrum. Having systems or machines capable of self-detecting or even self-repairing could represent a game-changer, in capital asset fields such as the mining industry in particular. This paper aims to investigate the possible benefits and challenges of self-engineering / self-maintenance concerning mining machines, specifically bucket-wheel ...
    self-engineering, self-maintenance, maintenance operations, mining industry, bucket-wheel excavator, gearbox revitalization
    ... in the Mining Machines Industry Steven Manders, Milorad Pantelić, Vladimir Milisavljević, Alberto Martinetti Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Self-Engineering: Possibilities for Maintenance Operations in the Mining Machines Industry | Steven ...
    ... concerning mining machines, specifically bucket-wheel excavators (BWEs). Firstly, describing the state of the art and the main principles of self-engineering (and, particularly, the applications of self- maintenance) and the complexity of the mining industry in terms of machines and capital assets ...
    ... 10th International Conference on Through-life Engineering Services. Self-engineering: possibilities for maintenance operations in the mining machines industry Steven Mandersa, Milorad Pantelicb, Vladimir Milisavljevicc, Alberto Martinettid* aTata Steel Europe, The Netherlands bRB Kolubara ...

  • Development of the Availability Concept by Using Fuzzy Theory with AHP Correction, a Case Study: Bulldozers in the Open-Pit Lignite Mine

    Stevan Đenadić, Dragan Ignjatović, Miloš Tanasijević, Uglješa Bugarić, Ivan Janković, Tomislav Šubaranović (2019)
    Availability is one of the most used terms in maintainability engineering. This concept is used to denote: The quality of service of an engineering system, i.e., machines, weak points’ analysis, asset management, as well as making decisions in the process of life cycle management. Availability is an overall indicator and contains partial indicators that are oriented towards reliability, maintenance, and logistical support. Availability presents a variable value and changes in time and space. Usually, availability is shown as the ...
    raspoloživost, fazi teorija, AHP višekriterijumska analiza, eksperska ocena, buldozer

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    Each technical system within itself carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management of the mining companies. Availability is the overall concept of quality of service. Includes information regard to operating state, an idle state, a standby state and shut down. The ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri

  • Multi-Criteria Approach for Selecting Optimal Dozer Type in Open-Cast Coal Mining

    Ivan Janković, Stevan Đenadić , Dragan Ignjatović , Predrag Jovančić , Tomislav Šubaranović, Ivica Ristović (2019)
    Analitički hijererhijski proces (AHP), dozeri, eksploatacija uglja, površinski kopovi

  • Risk management of machines in open pit mines

    Kirin Snežana, Pantelić Milorad, Miljanović Igor (2013)

  • Analysis of noise sources in power transformers and rotating electrical machines

    Snežana Aleksandrović, Aleksandar Cvjetić (2015)

  • A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers

    Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić (2019)
    Effectiveness evaluation is one of the basic components of engineering asset management and maintenance engineering in general. Effectiveness is an overall concept representing a measurement of quality of service level for the analyzed engineering system. This concept contains a series of partial indicators relating to time in operation and time for maintenance activities, as well as functional properties of the system. This article describes the analysis and structuring of partial indicators, as well as the development of a model ...
    Efikasnost, Fazi zaključivanje, Prikupljanje podataka, Buldozer
    ... Krunić, D.J., Vujić, S., Tanasijević, M., B. Dimitrijević, T. Šubaranović, S. Ilić, S. Maksimovic, Model Approaches to Life Cycle Assessment of Auxiliary Machines Based on an Example of a Coal Mine in Serbia, Journal of Mining Science, 2018, 54, 3, pp 404–413 Liao, S.H. (2011) Expert system methodologies ...
    ... Comparison of obtained results (a) average grade of machines based on experts’ approach; (b) average grade of machines based on measurements; (c) comparative analysis of the experts (E) and measured (M) evaluations for machines; (d) comparative analyses of machines on the base of the center of mass point ...
    ... terrain – for all machines = 1) kg – coefficient relating to losses along the sides of scraper during pushing-transport (related to length of excavation and pushing of material) ηt –time utilization coefficient (same for all machines = 0.8) Tsm – shift time (same for all machines = 8 h) kr – bulking ...

  • Effectiveness Analysis of Different Bucket-wheel Excavators

    Stevan Đenadić, Predrag Jovančić, Dragan Ignjatović, Miloš Tanasijević, Filip Miletić (2021)
    Coal production in open-pit lignite mines in the Republic of Serbia is performed with continuous work systems. In addition to coal production, the same systems are used for the exploitation of large quantities of overburden. According to the reliability concept, continuous systems are in linear connection. If the failure occurs in one part of the system, that will produce a downtime of the entire system. The initial and most important factor of continuous systems is the bucket-wheel excavator. It ...
    bucket-wheel excavator, open-pit coal mine, mining, multi-criteria decision methods
    ... The results of the analysis indicate that new machines are about 53% more successful than old machines. Some of the old machines need to be revitalized, while certain machines need to be replaced with new ones. In that way, uniformity between machines is achieved, their reliability in work is increased ...
    ... been proven to be a useful tool for evaluating the performance of mining machines. Similar models can find their role in other areas of mining or for other machines. The analysis conducted in the paper shows that new machines have far better results. Downtime or insufficient quality of work can create ...
    ... way, it is possible to detect whether there is a significant difference that may propose the investment in the revitalization and modernization of machines. Keywords: bucket-wheel excavator, open-pit coal mine, mining, multi-criteria decision methods. 1. INTRODUCTION A stable and independent ...

  • Ostvarivanje dobiti pri uvođenju sistema agregatnih zamena na osnovnoj rudarskoj mehanizaciji površinskih kopova EPS

    Predrag Jovančić, Ignjatović Dragan, Đenadić Stevan (2021)
    Jedan od osnovnih zadataka na površinskim kopovima uglja je ostvarivanje zadovoljavajućeg vremenskog i kapacitetnog iskorišćenja kontinualnih sistema. Da bi se to postiglo, neophodno je izvršiti izmene u postojećoj strategiji održavanja. Preduslov je uvođenje agregatne zamene vitalnih delova na rudarskim mašinama. Benefiti su višestruki. Očekivani rezultati ovakvog pristupa su: smanjenje zastoja i povećanje vremena rada; direktne materijalne uštede; bolja organizacija rada; racionalizaciju radioničkih i magacinskih kapaciteta; povećanje vrednosti mašina. Da bi se uvela agregatna zamena neophodne su investicije za nabavku ...
    agregatne zamene, održavanje, mehanizacija, Benefit Cost analiza
    ... of vital parts on mining machines. The benefits are multiple. The expected results of this approach are reducing downtime and increasing operating time; economic savings; better work organization; rationalization of workshop and warehouse capacities; increasing machines value. To introduce aggregate ...
    ... fill the worn out in the dismantled aggregates. The results of the Benefit-Cost analysis indicate the justification of maintaining basic mining machines, based on the concept of aggregate replacement. Significant economic benefits are observed. Positive cash flows are realized for the third year ...
    ... eološki fakultet 3 Đenadić Stevan, Univerzitet u Beogradu - Rudarsko-geološki fakultet 26 Keywords: aggregate replacement, maintenance, machines, Benefit-Cost analysis 1. Uvod Eksploatacija lignita na površinskim kopovima uglja Elektroprivrede Srbije (EPS) obavlja se primenom me ...

  • Belt Weigher Accuracy Limiting Factors

    Aleksandrović Snežana, Jović Mihajlo (2010)

  • Underground loading-haulage equipment selection with application of topsis method with different weighting methods of criteria

    Vladimir Krivošić, Luka Crnogorac, Rade Tokalić (2024)
    The choice of adequate mining machines is one of the most complex problems in the underground exploitation of mineral raw materials. The weight of such a decision is reflected in the high prices of these machines and the occurrence of even greater costs during their use if their choice was wrongly conceived. There are numerous examples from practice in which such decisions were made solely on the basis of comparing the prices of machines, without considering any of the ...
    utovarno-transportna mehanizacija, izbor, TOPSIS, entropija, standardna devijacija, težina kriterijuma

  • Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic

    Miljan Gomilanović, Miloš Tanasijević, Saša Stepanović (2022)
    This work presents a model for determining the availability of continuous systems at open pits by applying fuzzy logic and fuzzy inference systems. The applied model was formed by the synthesis of independent partial indicators of availability. The model is based on an expert system for assessing the availability of continuous mining systems. The availability of the system, as a complex state parameter, is decomposed into the partial indicators, reliability, and convenience of maintenance, and the fuzzy compositions, used ...
    системи, континуални систем експоатације, површински коп, рударство, расположивост, фази логика, max–min композиција, min–max композиција

  • Fuzzy Model for Risk Assessment of Machinery Failures

    Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković (2020)
    The main goal of this research was the development of an algorithm for the implementation of negative risk parameters in a synthesis model for a risk level assessment for a specific machine used in the mining industry. Fuzzy sets and fuzzy logic theory, in combination with statistical methods, were applied to analyze the time picture state of the observed machine. Fuzzy logic is presented through fuzzy proposition and a fuzzy composition module. Using these tools, the symmetric position of the ...
    fazi teorija, rizik, otkaz rudarskih mašina

  • Integrating landslide magnitude in the susceptibility assessment of the City of Doboj, using machine learning and heuristic approach

    Cvjetko Sandić, Miloš Marjanović, Biljana Abolmasov, Radislav Tošić (2023)
    In this work, landslide assessment of the Doboj City area was modeled by combining machine learning and heuristic tools. The machine learning part was used to map the Morphometric factor. i.e. probability of landslides based on relation between the magnitude of events and morphometric parameters: elevation, distance to streams, slope, profile curvature, and aspect. The Random Forest and Support Vector Machines algorithms were implemented in the learning protocol, which included several strategies: balancing of the training/testing set size, algorithm ...
    podložnost na kliženje, magnituda klizišta, mašinsko učenje, heuristički pristup, Doboj