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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 m...
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To effectively solve the problem of regional verification of gas outbursts adjacent to close coal seam groups, a method of regional verification and index fusion of the working face was proposed to promote the general idea of advanced detection, index fusion, and the determination of the critical values, inspection, and verification. Based on the e...
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... The specific energy (SE) refers to the energy required by the cutter to cut a unit volume of rock. A lower specific energy indicates a higher crushing efficiency of the cutter [25][26][27]. The calculation formula is as follows: ...
To analyze the rock-breaking characteristics of an arcing-blade cutter in cutting red sandstone, a two-cutter cutting model was established based on the finite element method. Then, the cutting processes of the arcing-blade cutter at penetrations of 2 mm, 4 mm, and 6 mm with different cutter spacings were investigated, and the changing rules of the rock-breaking load, rock crushing state, and rock-breaking efficiency were obtained. Subsequently, the obtained simulation results were validated through linear cutting experiments. The research results showed that, as the penetration of the arcing-blade cutter increased, the rock-breaking load also increased; specifically, under 2 mm penetration, the rock-breaking load remained stable, irrespective of the cutter spacing. However, under 4 mm and 6 mm penetration, the vertical and rolling force increased and then stabilized with an increase in the cutter spacing, while the lateral force decreased and then stabilized, attributed to the synergistic effect between the cutters. At 2 mm penetration, the absence of interaction between the cutting of two cutters in sequence resulted in two separate crushed areas on the rock surface. However, at 4 mm and 6 mm penetration, the rock ridge could be crushed under a smaller cutter spacing. Meanwhile, with an increase in the cutter spacing, the synergistic effect between the cutters diminished, causing the rock ridge between two cuttings to remain uncrushed. The specific energy at the 4 mm and 6 mm penetrations decreased initially with an increase in the cutter spacing, then increased, and eventually stabilized. The optimal cutter spacings at these penetrations were determined as 50 mm and 60 mm, respectively. Conversely, at 2 mm penetration, the specific energy remained almost unchanged with an increase in the cutter spacing, maintaining at a high level and resulting in a low efficiency in cutting rock.
... The structural parameters and digging state of the bucket directly affect the digging resistance and energy consumption of the bucket [3,4]. At present, buckets have the problems of high digging resistances, high energy consumption and low bucket filling rates, which greatly limits the work efficiency of the excavator [5][6][7]. Therefore, it is very necessary to optimize the structural parameters of the bucket. By improving the structure of the bucket, the digging resistance of the bucket and the energy consumption of the whole machine can be reduced during the digging operation. ...
In this study, a dynamic–discrete element-finite element coupling method is proposed to investigate the influence of structural parameters on the excavation performance and stress deformation of the bucket. The main research work is as follows: through ADAMS-EDEM co-simulation of the digging process of the bucket, the digging resistance and the loose force of each part of the bucket are obtained. The influence law of the change of the structural parameters of the excavator bucket on the digging resistance, filling rate and energy consumption is revealed. Through the coupling simulation of EDEM-ANSYS, the loose force is introduced into the finite element model of the bucket to enable the coupling of ADAMS-EDEM-ANSYS. The influence of the change of the bucket structure parameters on the stress and deformation of the bucket components is explored. The results show that the cutting angle and angle of throat of the bucket has a major influence on the digging performance of the bucket. While the angle of the throat and the thickness of the ear plate have a minor influence on the digging performance of the bucket. In the process of excavation, the teeth of the bucket are subjected to the largest digging resistance, resulting in relatively large deformation. All of the components of the bucket are subjected to different degrees of excavation resistance, but the stress concentration at the ear plate is the most obvious. The deformation and stress of the whole bucket can be reduced, to some extent, by reducing the thickness of the ear plate along with increasing the thickness of the stiffening plate. The results can be used to improve the digging performance of the bucket and reduce the stress and deformation of the bucket.
... Construction machinery plays a vital role in human production activities, with its working devices significantly influencing the longevity and efficiency of the machines [1]. In line with the growing emphasis on low-carbon practices, contemporary research on construction machinery should focus on enhancing its performance while reducing energy consumption [2][3][4]. ...
To address the limitation of existing excavator optimization methods, which primarily focus on the force performance while neglecting energy consumption and fail to realize environmentally friendly and low-carbon designs, this paper proposes a new multi-objective collaborative optimization method for an excavator to reduce energy consumption during the working process while maintaining optimal performance. By formulating a mathematical model that quantifies the energy consumption during the working process, this paper optimizes the working conditions by analyzing the energy consumption characteristics under typical working conditions. To overcome the limitation of existing linear weighting methods in multi-objective optimization, such as imbalanced optimization quality among sub-objectives, this paper proposes a new modeling approach based on the loss degree of sub-objectives. A multi-objective collaborative optimization model for the excavator with reduced energy consumption is established, and a corresponding multi-objective collaborative optimization algorithm is developed and applied to achieve optimal solutions for sub-objectives. The optimization results demonstrate that applying the new multi-objective collaborative optimization method to the excavator achieves better optimization quality than traditional methods. It also provides a more balanced improvement in the optimization values of each sub-objective, resulting in a significant reduction in the energy consumption of the excavator during operation.
... The key difference between biological systems and contemporary technologies [89] lies within the energy efficiency of the biological systems that are used for industrial purposes. Converting traditional mining areas into pollution-free areas can be achieved using biotechnologies that allow for remediation [90,91] and economic profit [92] simultaneously from the extraction of useful and/or dangerous substances [93,94]. We must not forget that one of the reasons for the slow development of lithium-based batteries in modern cars is the limited resources of lithium, including the poor technologies employed to recover it from used products and its association with increased brain toxicity. ...
Cellular asymmetry is an important element of efficiency in the compartmentalization of intracellular chemical reactions that ensure efficient tissue function. Improving the current 3D printing methods by using cellular asymmetry is essential in producing complex tissues and organs such as the liver. The use of cell spots containing at least two cells and basement membrane-like bio support materials allows cells to be tethered at two points on the basement membrane and with another cell in order to maintain cell asymmetry. Our model is a new type of 3D bioprinter that uses oriented multicellular complexes with cellular asymmetry. This novel approach is necessary to replace the sequential and slow processes of organogenesis with rapid methods of growth and 3D organ printing. The use of the extracellular matrix in the process of bioprinting with cells allows one to preserve the cellular asymmetry in the 3D printing process and thus preserve the compartmentalization of biological processes and metabolic efficiency.
... Electricity consumption of the BW is strongly related to the bucket load. Between 60 and 90% of the electricity is consumed by BW excavators to cut and remove the material [40]. As a result, it is very important to reduce this component of power consumption, which is attributed to hard rock inclusions. ...
This work introduces a methodology for the automatic unmineable inclusions detection and Bucket Wheel Excavator (BWE) collision prevention, using electromagnetic (EM) inspection and a fuzzy inference system. EM data are collected continuously ahead from the bucket wheel of a BWE and subjected to processing. Two distinct methodologies for data processing were developed and integrated into the MATLAB programming environment. The first approach, named “Simple Mode”, utilizes statistical process control to generate real-time alerts in the event of a potential collision involving the excavator’s bucket and hard rock inclusions. The advanced processing flow (“Advanced Mode”) requires accurate instrument positioning and data from successive EM scans. It incorporates techniques of local resistivity maxima detection (Position Prominence Index) as well as Neural Network-based Pattern Recognition (NNPR). A decision support process based on a Fuzzy Inference System (FIS) has been developed to assist BWE operators in avoiding collision when digging hard rock inclusions. The proposed methodology was extensively tested using synthetic EM data. Limited real data, acquired with a CMD2 (GF Instruments) EM instrument equipped with GPS, were used to control its efficiency. Increased accuracy in the automatic detection of unmineable inclusions was observed using the Advanced Mode. On the other hand, the Simple Mode processing technique offers the advantage of being independent of instrument positioning as well as it provides real-time inspection of the excavated mine slope. This work introduces a methodology for hard rock inclusion detection and can contribute to the optimization of mine operations by improving resource efficiency, safety, cost savings, and environmental sustainability.
... Currently, both selective cutting roadheaders ( Figure 1a) [2,3] or continuous miners ( Figure 1b) [4,5] and longwall shearers (Figure 1c) [6,7] mine the face with cutting heads. They are used not only in mining machines, but also in construction and road machinery, such as road milling machines ( Figure 1d) [8,9] or excavators [10][11][12][13]. [1,9,14]. ...
The cutting heads currently used in longwall shearers, roadheaders, road milling machines and excavators are equipped with cutting tools called picks. The most commonly applied are conical picks, less frequently—radial picks or tangent picks. The picks are detachably mounted in holders installed on the body of the cutting head, to which they are usually welded (shearers) or, less frequently, form-connected (road milling machines). The arrangement of picks and holders (positioning) on the body of the cutting head, according to a previously designed diagram (pick arrangement), enables extraction of the mineral with a specific width (web) and diameter (height). Ideally, the pick arrangement should generate the lowest cutting resistance, which loads the cutting machine. The pick arrangement is characterized by design parameters (number of holders, pitch in the line and between the cutting lines) and kinematic parameters (rotational speed and advance speed). The values of these parameters result mainly from the properties of the mineral and the type of mining machine. Therefore, the correct positioning of the holders on the cutting head and their setting (cutting angles) are vitally important. This applies to both the design and implementation stages. For this purpose, the authors first developed models of pick arrangements and, next, the algorithm and software enabling the determination of cutting resistance, both in terms of the average value and its variation. Then, based on the performed calculations and the obtained results, it can be assessed whether the cutting head and the pick arrangement are properly designed. As a result of the performed calculations and analysis of the test results, the average values of the cutting resistance moment and the cutting machine advance forces were determined. It was found that the proposed pick arrangements are characterized by similar values of moments and forces. The greatest differences were found in the variability of these parameters, which translates into the dynamics of the cutting machine operation.
... Based on the model of the excavator, we have developed a new method for calculating the energy and power needs of Bucket Wheel Excavator. [3] Using CAD, the method presented determines the amount of rock extracted during swinging ( figure 15). Knowing the specific energy demand, we calculated the energy and performance parameters. ...
The paper deals with theoretical bases of the implementation in mining equipment design of up-to-date methods using modelling and simulation, supported by examples of personal research. This has become necessary due to the structural complexity of this equipment, and the variety and aggressiveness of their operating environment. The presented examples refer to different kinds of the equipment used in the mechanical extraction of mineral raw materials, from overall system to working part or tool.
... The shape of the amplitude vs. time is illustrated in Figure 23 for two cuts. This figure also shows the slewing time for the excavation of the first slice t cut = 438 s, followed by repositioning of the BWE and then the time needed for a second slice, with the total time based on the geometric characteristics of excavation (slewing angles, radius etc.) for this BWE model as determined in [61]. This average displacements resulting from the time response analysis are in accordance with experimental strain gauge measurements [36,57,62]; these are used as values for the input data, as strains acting on the boom, with the boom treated as a solid in a SOLIDWORKS static simulation. ...
Breakdown of stackers and excavators in opencast mines is possible because of operating, manufacturing and structural causes, and it produces high financial losses. These can be prevented by using various measures, including analyses and strength tests, with computerized modeling and simulation using FEA or other techniques being implemented in the recent years. In this paper a fatigue study is conducted on the boom of a BWE. Based on a computer model of the boom previously developed in SOLIDWORKS by our author team, first the modal analysis is conducted for three positions of the boom by studying the frequency response during the excavation process. This is followed by the time response determination corresponding to the maximum displacement frequency, in order to assess the stress during the excavation process, which causes the material fatigue in the boom structure. It was found that the maximum displacements appear when the BWE boom operates in a horizontal position. The aim was to estimate the period of time to failure in order to prevent unwanted accidents, and to develop a method that is applicable to any surface mining or industrial machine with similar structure.
... They concern the efficiency of the working process, the use of the excavators' potential (Nan et al. 2008;Rašić et al. 2016;Zhao-xue, Yan-long 2014;Galetakis, Roumpos 2015), maintaining the required safety as well as the reliability conditions of the machine (Daničić et al. 2016;Ilić 2021). Most of the research related to the technology of wheel excavators' work focuses on determining the efficiency in a single slice, with constant geometric parameters of the block, i.e., a constant height and width of the haul itself and individual terrace (Kressner 2006;Kołkiewicz, Szatan 1993;Brînaş 2021). Their common feature is the strictly deterministic character, as they are based on functional dependencies between the parameters of the working front's geometrical structures, the ranges and kinematics of the excavator's working units, as well as geotechnical and operational constraints. ...
The article presents the results of the numerical experiments designed to determine the effect of obstacles in the form of the drainage wells/piezometer on the basic efficiency parameters of the excava-tor's work. Simulation research on built model included defining the basic parameters of the excavator working in the front block on stabile front (as a comparison) and on the non-stable front for two variants of drainage infrastructure exposing.
... They concern the efficiency of the working process, the use of the excavators' potential (Nan et al. 2008;Rašić et al. 2016;Zhao-xue, Yan-long 2014;Galetakis, Roumpos 2015), maintaining the required safety as well as the reliability conditions of the machine (Daničić et al. 2016;Ilić 2021). Most of the research related to the technology of wheel excavators' work focuses on determining the efficiency in a single slice, with constant geometric parameters of the block, i.e., a constant height and width of the haul itself and individual terrace (Kressner 2006;Kołkiewicz, Szatan 1993;Brînaş 2021). Their common feature is the strictly deterministic character, as they are based on functional dependencies between the parameters of the working front's geometrical structures, the ranges and kinematics of the excavator's working units, as well as geotechnical and operational constraints. ...
