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Starting from the general principles of material cutting, with applicability to coal and overburden excavation using bucket wheel excavators (BWEs), this paper proposes another method for calculating the drive power of the bucket wheel excavator by computer modeling. This approach required two steps. In the first step, the volume of the excavated material for one slewing movement of the boom and for a particular excavation geometry was determined, and the slewing time in the open pit coal mine was measured. In the second one, the values of the specific energy (SE) consumption for cutting were determined by laboratory tests on samples of material taken from the open pit mine. The proposed method allows for the estimation of the load of the bucket wheel drive motor by taking into account only the specific energy necessary for the cutting of the material, the excavated volume during one slewing, and the time required to excavate this volume, and not the wear coefficients of the teeth or bucket edge. This method is important for establishing the correlation between the height of the excavated slice and the slewing speed of the boom in order to optimize the drive power of the bucket wheel and thus improve energy efficiency, increase the performance of excavators, and reduce operating costs.
Ildiko Brînaș; Andrei Andraș; Sorin Radu; Florin Popescu; Iosif Andraș; Bogdan Marc; Alexandru Cioclu. Determination of the Bucket Wheel Drive Power by Computer Modeling Based on Specific Energy Consumption and Cutting Geometry. Energies 2021, 14, 3892 .
AMA StyleIldiko Brînaș, Andrei Andraș, Sorin Radu, Florin Popescu, Iosif Andraș, Bogdan Marc, Alexandru Cioclu. Determination of the Bucket Wheel Drive Power by Computer Modeling Based on Specific Energy Consumption and Cutting Geometry. Energies. 2021; 14 (13):3892.
Chicago/Turabian StyleIldiko Brînaș; Andrei Andraș; Sorin Radu; Florin Popescu; Iosif Andraș; Bogdan Marc; Alexandru Cioclu. 2021. "Determination of the Bucket Wheel Drive Power by Computer Modeling Based on Specific Energy Consumption and Cutting Geometry." Energies 14, no. 13: 3892.
The sustainable exploitation of raw materials, with improved safety and increased productivity, is closely linked to the development of mechanical mining installations. Mine hoists are designed for the transport of material, equipment and personnel between the mine surface and the underground. The mine hoist braking system is of paramount importance in its safe operation. Thus, for both drum and disc brake systems, the temperature of the friction surfaces is important for ensuring efficient braking, as exceeding the temperature threshold causes a decrease in the braking capacity. In this paper we present a numerical calculation model for the temperature of the braking disc of a mine hoist in the case of emergency braking. A real-scale model was built, based on the cable drive wheel and disc brake system of a hoisting machine used in Romania. Real material characteristics were imposed for the brake discs, the cable drive wheel and the brake pads. The simulation was performed for decelerations of 3, 3.5, 4 and 4.5 m/s2. The analysis shows that regardless of the acceleration and time simulated, the disc temperature reaches its maximum after 1.35 s of emergency braking. This value does not exceed the 327 °C limit where, according to previous studies, the braking power starts to fade. It means that the emergency braking is safe for the acceleration and masses under consideration, in the case of the studied mine hoist.
Florin Popescu; Sorin Radu; Andrei Andraș; Ildiko Brînaș. Numerical Modeling of Mine Hoist Disc Brake Temperature for Safer Operation. Sustainability 2021, 13, 2874 .
AMA StyleFlorin Popescu, Sorin Radu, Andrei Andraș, Ildiko Brînaș. Numerical Modeling of Mine Hoist Disc Brake Temperature for Safer Operation. Sustainability. 2021; 13 (5):2874.
Chicago/Turabian StyleFlorin Popescu; Sorin Radu; Andrei Andraș; Ildiko Brînaș. 2021. "Numerical Modeling of Mine Hoist Disc Brake Temperature for Safer Operation." Sustainability 13, no. 5: 2874.
The technologies for trenchless execution of mini and microtunnels for an installation of municipal infrastructure in urbanized sites, used at present, are described in the article. The emphasis is laid on uncontrolled methods, in the case of the diameters of installations which do not exceed 200-250 mm and their length not bigger than 30-40 m. Some issues connected with making the installations of this type, using conventional methods, are also presented. A conception of equipment (ground rocket) for an trenchless execution of short-distance microtunnels of the diameter up to 200 mm and the length up to 30 m with an innovative electric drive, developed at the Department of Machinery Engineering and Transport of the AGH in Cracow as an alternative for the solutions applied nowadays, is described. An electric linear motor, whose conception is presented in the article, was installed in the head of the device. The goal of these works was possibility of using new solution of ground rocket without additional equipments for pneumatic supply with compressed air. New concept of proposed ground rocket can be used with feeding directly from the domestic electric network. The device is intended for execution of installation in incoherent and low-compact ground.
Krzysztof Kotwica; Hubert Suffner; Andrei Andras. Trenchless Execution of Microtunnels for Municipal Infrastructure in Urbanized Site – Conception of a New Solution. Management Systems in Production Engineering 2020, 28, 276 -282.
AMA StyleKrzysztof Kotwica, Hubert Suffner, Andrei Andras. Trenchless Execution of Microtunnels for Municipal Infrastructure in Urbanized Site – Conception of a New Solution. Management Systems in Production Engineering. 2020; 28 (4):276-282.
Chicago/Turabian StyleKrzysztof Kotwica; Hubert Suffner; Andrei Andras. 2020. "Trenchless Execution of Microtunnels for Municipal Infrastructure in Urbanized Site – Conception of a New Solution." Management Systems in Production Engineering 28, no. 4: 276-282.
Operation of vertical transport installations is based on adjustable electrical drive systems which must ensure the technical conditions regarding the variation in time of the speed, the current of the main motors and the accelerations at start and brake phases. Electric drives are part of the fast process of automation equipment. In the case of a vertical transport installation, speed is the characteristic which has to be controlled in command phase, while the dependent factor is the tachograph. The adjustment determines the dependence of the quantity in the process – based on a default law - with respect to the independent quantities and also to the process dependents, thus reducing the influence of the perturbations to the process. There are different ways to define the stability of an automatic system. The balance survey / analysis also approaches the determination of the functions of variation in time of the main actuation motor current and speed (main motor rpm), at the moments of starting the vertical transport installation, and the study of the variation in time of the speed in the case of a load shock. To perform calculations needed for stability assessment and draw all the diagrams a Turbo C 2.0 program was written by the authors.
Florin Dumitru Popescu; Andrei Andraş; Ildiko Kertesz (Brînaş). Balance survey / analysis of vertical transport installations using the Nyquist stability criterion. ITM Web of Conferences 2019, 29, 01013 .
AMA StyleFlorin Dumitru Popescu, Andrei Andraş, Ildiko Kertesz (Brînaş). Balance survey / analysis of vertical transport installations using the Nyquist stability criterion. ITM Web of Conferences. 2019; 29 ():01013.
Chicago/Turabian StyleFlorin Dumitru Popescu; Andrei Andraş; Ildiko Kertesz (Brînaş). 2019. "Balance survey / analysis of vertical transport installations using the Nyquist stability criterion." ITM Web of Conferences 29, no. : 01013.
The sustainability of lignite production requires, among other factors, cost reduction, high efficiency, as well as the increase of the production capacity. In order to rationalize and increase the efficiency of lignite mines, the optimization of the production process is necessary. In this respect, equipment revitalization and modernization is a key issue. This paper deals with the analysis of the time response of the boom structure of a bucket wheel excavator (BWE) during operation. For this, we propose a virtual model of the boom, on which a variable-in-time force generated by the bucket wheel acts. The kinematic drive chain of the bucket wheel and the conveyor belt, which are also vibration generators, were simulated only by the static load produced on the excavator’s boom. Thus, it is possible to highlight the time response of the load-bearing structure (the boom) of the bucket wheel to the action of forces resulting from the cutting of the face under pretensioning conditions. The forces generated by the excavation process have high values and a slow variation over time, depending on the bucket wheel’s rotation speed and the number of buckets installed on the wheel. The dynamic time response simulation was performed considering the global damping variation as dependent on frequency. The simulation was done for both the excavation of a homogeneous material and for the case of the sudden appearance of a hard material inclusion (boulder) during homogenous material cutting.
Florin Dumitru Popescu; Sorin Mihai Radu; Krzysztof Kotwica; Andrei Andraș; Ildiko Kertesz (Brînaș). Simulation of the Time Response of the ERc 1400-30/7 Bucket Wheel Excavator’s Boom during the Excavation Process. Sustainability 2019, 11, 4357 .
AMA StyleFlorin Dumitru Popescu, Sorin Mihai Radu, Krzysztof Kotwica, Andrei Andraș, Ildiko Kertesz (Brînaș). Simulation of the Time Response of the ERc 1400-30/7 Bucket Wheel Excavator’s Boom during the Excavation Process. Sustainability. 2019; 11 (16):4357.
Chicago/Turabian StyleFlorin Dumitru Popescu; Sorin Mihai Radu; Krzysztof Kotwica; Andrei Andraș; Ildiko Kertesz (Brînaș). 2019. "Simulation of the Time Response of the ERc 1400-30/7 Bucket Wheel Excavator’s Boom during the Excavation Process." Sustainability 11, no. 16: 4357.
Florin-Dumitru Popescu; József Kovács; Sorin Mihai Radu; Andrei Andraș; Ildikó Kertész. A method of continuous tilt control of the bucket wheel excavators using inclinometers. The publications of the MultiScience - XXXII. MicroCAD International Scientific Conference 2018, 1 .
AMA StyleFlorin-Dumitru Popescu, József Kovács, Sorin Mihai Radu, Andrei Andraș, Ildikó Kertész. A method of continuous tilt control of the bucket wheel excavators using inclinometers. The publications of the MultiScience - XXXII. MicroCAD International Scientific Conference. 2018; ():1.
Chicago/Turabian StyleFlorin-Dumitru Popescu; József Kovács; Sorin Mihai Radu; Andrei Andraș; Ildikó Kertész. 2018. "A method of continuous tilt control of the bucket wheel excavators using inclinometers." The publications of the MultiScience - XXXII. MicroCAD International Scientific Conference , no. : 1.
Ildikó Kertész; Sorin-Mihai Radu; Florin-Dumitru Popescu; Iosif Andras; Andrei Andras. A numerical method for the calculus of the operation power of the rotor of a bucket wheel excavator. The publications of the MultiScience - XXXII. MicroCAD International Scientific Conference 2018, 1 .
AMA StyleIldikó Kertész, Sorin-Mihai Radu, Florin-Dumitru Popescu, Iosif Andras, Andrei Andras. A numerical method for the calculus of the operation power of the rotor of a bucket wheel excavator. The publications of the MultiScience - XXXII. MicroCAD International Scientific Conference. 2018; ():1.
Chicago/Turabian StyleIldikó Kertész; Sorin-Mihai Radu; Florin-Dumitru Popescu; Iosif Andras; Andrei Andras. 2018. "A numerical method for the calculus of the operation power of the rotor of a bucket wheel excavator." The publications of the MultiScience - XXXII. MicroCAD International Scientific Conference , no. : 1.
MATEC Web of Conferences, open access proceedings in Materials science, Engineering and Chemistry
Ovidiu-Bogdan Tomuș; Andrei Andraș; Mihai Magyari. Study on the reliability of the underground conveyor belt system installed at Vulcan Mine, the Jiu Valley Basin in Romania. MATEC Web of Conferences 2017, 121, 01016 .
AMA StyleOvidiu-Bogdan Tomuș, Andrei Andraș, Mihai Magyari. Study on the reliability of the underground conveyor belt system installed at Vulcan Mine, the Jiu Valley Basin in Romania. MATEC Web of Conferences. 2017; 121 ():01016.
Chicago/Turabian StyleOvidiu-Bogdan Tomuș; Andrei Andraș; Mihai Magyari. 2017. "Study on the reliability of the underground conveyor belt system installed at Vulcan Mine, the Jiu Valley Basin in Romania." MATEC Web of Conferences 121, no. : 01016.
MATEC Web of Conferences, open access proceedings in Materials science, Engineering and Chemistry
Sabin Ioan Irimie; Sorin Mihai Radu; Dan Codruț Petrilean; Andrei Andras. Reducing the environmental impact of a gas operated cogeneration installation. MATEC Web of Conferences 2017, 121, 10005 .
AMA StyleSabin Ioan Irimie, Sorin Mihai Radu, Dan Codruț Petrilean, Andrei Andras. Reducing the environmental impact of a gas operated cogeneration installation. MATEC Web of Conferences. 2017; 121 ():10005.
Chicago/Turabian StyleSabin Ioan Irimie; Sorin Mihai Radu; Dan Codruț Petrilean; Andrei Andras. 2017. "Reducing the environmental impact of a gas operated cogeneration installation." MATEC Web of Conferences 121, no. : 10005.
Andrei Andras. OVERVIEW OF THE UNWANTED EFFECTS OF UNMINEABLE ROCK FORMATIONS ON THE MINING SYSTEM OF BUCKET WHEEL EXCAVATOR DURING THE EXCAVATION PROCESS. 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies 2017, 1 .
AMA StyleAndrei Andras. OVERVIEW OF THE UNWANTED EFFECTS OF UNMINEABLE ROCK FORMATIONS ON THE MINING SYSTEM OF BUCKET WHEEL EXCAVATOR DURING THE EXCAVATION PROCESS. 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies. 2017; ():1.
Chicago/Turabian StyleAndrei Andras. 2017. "OVERVIEW OF THE UNWANTED EFFECTS OF UNMINEABLE ROCK FORMATIONS ON THE MINING SYSTEM OF BUCKET WHEEL EXCAVATOR DURING THE EXCAVATION PROCESS." 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies , no. : 1.
Iosif Andras. OPTIMIZATION OF GEOMETRIC AND STRENGTH PARAMETERS OF TEETH FOR BUCKET WHEEL EXCAVATOR IN VIEW TO INCREASING THE CUTTING EFFICIENCY. 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies 2017, 1 .
AMA StyleIosif Andras. OPTIMIZATION OF GEOMETRIC AND STRENGTH PARAMETERS OF TEETH FOR BUCKET WHEEL EXCAVATOR IN VIEW TO INCREASING THE CUTTING EFFICIENCY. 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies. 2017; ():1.
Chicago/Turabian StyleIosif Andras. 2017. "OPTIMIZATION OF GEOMETRIC AND STRENGTH PARAMETERS OF TEETH FOR BUCKET WHEEL EXCAVATOR IN VIEW TO INCREASING THE CUTTING EFFICIENCY." 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies , no. : 1.
Andrei Andras. MATHEMATICAL MODELS OF POWERED ROOF SUPPORT INTERACTION WITH SURROUNDING ROCKS. 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies 2017, 1 .
AMA StyleAndrei Andras. MATHEMATICAL MODELS OF POWERED ROOF SUPPORT INTERACTION WITH SURROUNDING ROCKS. 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies. 2017; ():1.
Chicago/Turabian StyleAndrei Andras. 2017. "MATHEMATICAL MODELS OF POWERED ROOF SUPPORT INTERACTION WITH SURROUNDING ROCKS." 17th International Multidisciplinary Scientific GeoConference SGEM2017, Energy and Clean Technologies , no. : 1.
Ildikó Brînaș; Andrei Andras. The Study of the Kinematics of a Barrel Cam Mechanism. The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference 2017, 1 .
AMA StyleIldikó Brînaș, Andrei Andras. The Study of the Kinematics of a Barrel Cam Mechanism. The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference. 2017; ():1.
Chicago/Turabian StyleIldikó Brînaș; Andrei Andras. 2017. "The Study of the Kinematics of a Barrel Cam Mechanism." The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference , no. : 1.
Andras Iosif; Jozsef Kovacs; Mircea Risteiu; Andrei Andras; Tomus Ovidiu –Bogdan. Study on the Theoretical Background of in Situ and Test Rig Measurements of Load in Boom of BWE Working in Hard to Excavate Rocks. The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference 2017, 1 .
AMA StyleAndras Iosif, Jozsef Kovacs, Mircea Risteiu, Andrei Andras, Tomus Ovidiu –Bogdan. Study on the Theoretical Background of in Situ and Test Rig Measurements of Load in Boom of BWE Working in Hard to Excavate Rocks. The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference. 2017; ():1.
Chicago/Turabian StyleAndras Iosif; Jozsef Kovacs; Mircea Risteiu; Andrei Andras; Tomus Ovidiu –Bogdan. 2017. "Study on the Theoretical Background of in Situ and Test Rig Measurements of Load in Boom of BWE Working in Hard to Excavate Rocks." The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference , no. : 1.
Jozsef Kovacs; Andras Iosif; Sorin Mihai Radu; Maria Lazar; Andrei Andras. Requirements to Be Fulfilled by Existing BWES Working in Hard to Excavate Rock formations. The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference 2017, 1 .
AMA StyleJozsef Kovacs, Andras Iosif, Sorin Mihai Radu, Maria Lazar, Andrei Andras. Requirements to Be Fulfilled by Existing BWES Working in Hard to Excavate Rock formations. The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference. 2017; ():1.
Chicago/Turabian StyleJozsef Kovacs; Andras Iosif; Sorin Mihai Radu; Maria Lazar; Andrei Andras. 2017. "Requirements to Be Fulfilled by Existing BWES Working in Hard to Excavate Rock formations." The publications of the MultiScience - XXXI. MicroCAD International Scientific Conference , no. : 1.
Andras Iosif; Andrei Andras; Stela Dinescu. On the Correlation of Cutting Resistance and Physical-mechanical Properties of Lignite and Overburden Rocks from Oltenia Coalfield. The publications of the MultiScience - XXX. MicroCAD International Scientific Conference 2016, 1 .
AMA StyleAndras Iosif, Andrei Andras, Stela Dinescu. On the Correlation of Cutting Resistance and Physical-mechanical Properties of Lignite and Overburden Rocks from Oltenia Coalfield. The publications of the MultiScience - XXX. MicroCAD International Scientific Conference. 2016; ():1.
Chicago/Turabian StyleAndras Iosif; Andrei Andras; Stela Dinescu. 2016. "On the Correlation of Cutting Resistance and Physical-mechanical Properties of Lignite and Overburden Rocks from Oltenia Coalfield." The publications of the MultiScience - XXX. MicroCAD International Scientific Conference , no. : 1.
József Kovács; Andrei Andras. Reliability Analysis of the Belt Conveyors at Vulcan Mine Plant, Jiul Valley, Romania. The publications of the MultiScience - XXIX. MicroCAD International Scientific Conference 2015, 1 .
AMA StyleJózsef Kovács, Andrei Andras. Reliability Analysis of the Belt Conveyors at Vulcan Mine Plant, Jiul Valley, Romania. The publications of the MultiScience - XXIX. MicroCAD International Scientific Conference. 2015; ():1.
Chicago/Turabian StyleJózsef Kovács; Andrei Andras. 2015. "Reliability Analysis of the Belt Conveyors at Vulcan Mine Plant, Jiul Valley, Romania." The publications of the MultiScience - XXIX. MicroCAD International Scientific Conference , no. : 1.
Andrei Andras. Analysis of winning performance of shearer loader cutter head using modeling. 2009, 1 .
AMA StyleAndrei Andras. Analysis of winning performance of shearer loader cutter head using modeling. . 2009; ():1.
Chicago/Turabian StyleAndrei Andras. 2009. "Analysis of winning performance of shearer loader cutter head using modeling." , no. : 1.