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Creative design has become the core of competitiveness for enterprises, and the design process is an activity based on multi-domain knowledge. Designers need to have a lot of interdisciplinary knowledge in this activity, and there may be a burden on understanding. To alleviate understanding burden and promote knowledge integration, a dual-layer concept network is established based on complex networks. Knowledge association in the network originates from the perspective of innovation and product design, facilitating in providing designers with creative and content-related knowledge. This paper takes function, invention principle and scientific principle as the label to build a creative attribute network, and uses the semantic similarity between knowledge texts to build a semantic association network. Combining creative attributes and content semantics of knowledge, a novel knowledge management and browsing method based on a dual-layer concept network is proposed. Meanwhile, due to the ambiguity and uncertainty of design activity and knowledge demand, designers repeatedly query knowledge based on a dual-layer concept network. During this process, designers’ think of diverges and associates, which inspire them to integrate knowledge and generate creative ideas. Finally, this paper takes the problem of vibrating screens as an example to verify the practicability and effectiveness of this method. The methodology is expected to be served as an essential supporting tool for sparking innovation. [ABSTRACT FROM AUTHOR]

To strengthen the layering effect of coal particles on the screen surface and improve the screening efficiency, a composite vibrating screen was proposed based on the void filling effect of mixed particles under vibration and the Lissajous vibration synthesis theory, and the theoretical basis and working principle of the composite vibrating screen were described. The Taguchi orthogonal experiment was designed with the composite, linear, elliptical, and circular vibrating screens as the object, and frequency, amplitude, and vibration direction angle as the variables, wherein the discrete element simulation of the traditional vibrating screen and the composite vibrating screen was conducted, and the comparison results showed that the composite vibrating screen was of great advantage in both screening efficiency and material processing. On the basis of the traditional vibrating screen, the composite vibrating screen further imposed on the particles an exciting force along the width of the screen surface, so that the particles were subject to the effect of exciting force in the xyz three directions; as a result, more diversified force to the particles, more loose mixed particle system, greater activity degree and better layering effect were realized, and then the composite vibrating screen can achieve a more ideal screening effect. [ABSTRACT FROM AUTHOR]

As a key technical equipment for improving coal quality, efficiency and promoting clean and efficient utilization, it is important for vibrating screens to detect their faults quickly and accurately. Traditional vibrating screen fault detection methods usually rely on the vibration signals collected by sensors, and identify the faults through spectral analysis, time domain feature extraction, etc. However, these methods face the problems of inaccurate detection, insufficient real-time performance and poor adaptability to environmental changes under complex working conditions. To address this limitation, this paper proposes a video frame prediction model, DST-UNet, to detect the operation of vibrating screens through video. The model combines convolutional units with different kernel sizes to simultaneously extract local detail information and global structural information in the operation of vibrating screens; uses ECA as a temporal attention mechanism to improve the model’s understanding and sensitivity to temporal sequences and employs convolutional units to generate spatio-temporal weights to dynamically fuse spatial and temporal features. In addition, an evaluation metric MTR is proposed to assess the model performance. The experimental results show that, compared with models such as SimVP, 3D convolution and PredRNN, the method improves the sensitivity, accuracy and processing speed of fault detection while reducing the model complexity and can realize efficient detection with limited data sets, which helps to identify equipment faults quickly and reduce the risk of damage. [ABSTRACT FROM AUTHOR]

The dynamics and modal characteristics are important basis for the stable operation of vibrating screen. A multi-body dynamic model of vibrating screen was established based on ADAMS, and the laws of change in the center of mass and the dynamic response of the vibration isolation system were obtained. The amplitude-frequency response results of acceleration under varying stiffness and damping coefficients were compared and analyzed, providing a crucial foundation for enhancing vibration isolation performance. The vibrating screen was analyzed for its modal characteristics using ANSYS, and the natural frequencies and vibration patterns were investigated. The distribution and main causes of the maximum resonance displacement were discussed. Drawing on the results of stress and modal shapes, the strength of the vibrating screen was significantly enhanced through multi-objective optimization methods without increasing its weight. The findings indicate that the optimized structure can achieve a 32.2 % reduction in peak stress. [ABSTRACT FROM AUTHOR]

A vibrating flip-flow screen (VFFS) is an effective solution for screening viscous and fine-grained materials. As one of the critical components, the load characteristics of the polyurethane screen panel primarily affect the fatigue life. However, more research is needed to understand the load characteristics of the screen panel. In this article, the discrete screen panel dynamic model is proposed to research the load characteristics of the screen panel based on the catenary model. The dynamic response parameters of the screen panel are obtained by the catenary model, and the finite element model of the screen panel is established to extract the dynamic characteristic parameters of the screen panel. The accuracy of the catenary model and the finite element model is verified by the experiment, and then the rationality of the dynamic theory is verified by the simulation. Moreover, the effects of hardness, amplitude, frequency, and angle on the tension and vibration strength of the screen panel are investigated. The results show that hardness, amplitude, frequency, and angle significantly affect the tension and vibration strength of the screen panel. The sensitivity of each factor on tension from high to low: amplitude > hardness > frequency > angle. Adjusting the value of each factor within a certain range is beneficial to increasing the vibration strength; meanwhile, it can reduce the tension of the screen panel. This research helps improve the service life and provides a theoretical basis for designing and optimizing the screen panel. [ABSTRACT FROM AUTHOR]

Screening is an important step in the preparation of machine made sand, and the screening performance of the screening machine is the key to improving the production efficiency and quality of machine made sand. This article first explores the influence of airflow generated by sieve plate vibration on particle motion on the sieve through numerical simulation, and verifies the reliability of the simulation model through experimental prototypes. Then, based on the CFD-DEM coupling model, the relationship between screening parameters and screening performance was studied. Finally, based on the screening results and the BP neural network optimized by the sparrow search algorithm, an evaluation model for screening parameters and screening performance was established, and a multi-objective genetic algorithm was used to optimize the high-performance screening parameter combination scheme. The comprehensive optimal performance parameters were obtained: vibration frequency of 15.5885 Hz, amplitude of 2.3789 mm, vibration direction angle of 50.5227, sieve obliquity of 16.6676, and feed rate of 20921 pieces/s. [ABSTRACT FROM AUTHOR]

As a material screening equipment, vibrating screen is widely used in metallurgy industries due to their simple structure and low production cost. Nevertheless, the traditional vibrating screen box is prone to structural resonance due to low natural frequency and close to the system excitation frequency, which has a serious impact on the service life of the vibrating screen. In order to enhance the natural frequency of the vibrating screen box to avoid resonance, an optimization study of frequency of the vibrating screen was conducted using the response surface analysis method based on a genetic aggregation algorithm. The finite element model of the vibrating screen was established, and a comprehensive analysis of is modal frequency and mode shapes was performed through modal simulation and experimental testing to validate the accuracy of the model and simulation results. Additionally, structural optimization design was implemented using a reinforcement method with ribs, and the response surface method was employed to systematically investigate the influence patterns of rib width and thickness on the modal frequency. Various reinforcement schemes with different rib configurations were designed, and the impact of reinforcement positions on the enhancement of modal frequency was studied. The results indicate that adding ribs at the beams significantly increases the modal frequency of the vibrating screen box. Specifically, the sensitivity of modal frequency to rib thickness is relatively low, while the sensitivity to rib width is higher. The most significant enhancement in modal frequency was observed when reinforcing the intermediate layer of the screen box. By adding reinforced panels to the middle and lower three layers above, the natural frequency of the first four stages of the screen box can be increased by more than 60%, and the optimization effect is good. Through the optimization of the modal frequency, the natural frequency of the vibrating screen can be far away from the exiting frequency, which can effectively solve the structural resonance problem. The aforementioned research findings provide valuable insights and references for the optimization design of the strength and stiffness of vibrating screen boxes. [ABSTRACT FROM AUTHOR]

The transformation of the mining machinery industry is oriented towards the adoption of highly sophisticated technologies, with the aim of enhancing operational efficiency. Specifically, there is a focus on improving the nature and quality of operations carried out, such as vibrating screen. Vibrating screens, being one of the pivotal machines, have gained extensive utilization in mining processing plants. However, the demanding working conditions can lead to potential failures in certain components of vibrating screens. Bearings are one of the components that are susceptible to faults. Moreover, owing to the unique working environment and structure of vibrating screens, the signals extracted from defective bearings in vibrating screens exhibit greater complexity and distinctiveness, including (i) vibration interference related to the unbalanced shafts, (ii) cyclic impulses produced by the damaged bearing, (iii) non-cyclic random impulsive noise owing to pieces of coal falling into the deck, and (iv) inevitable noise from environmental conditions. To address this issue, an alternative procedure for bearing fault detection from vibrating screens served in the coal industry is proposed in the work. The strategy for bearing fault signature extraction covers three main steps: (a) a new fast resampled iterative filtering (FRIF) method is utilized to remove the vibration interference produced by the unbalanced shafts and simultaneously eliminate large amounts of background noise; (b) a signal processing method based stable distribution is designed to cancel the random impulses (impulsive noise); and (c) an improved energy operator demodulation technique is proposed to identify the bearing fault characteristics from the purified signal. The proposed strategy is validated using simulated and real tests. [ABSTRACT FROM AUTHOR]

In order to effectively reduce the failure rate of vibrating screens, a vibration monitoring system design was proposed based on the structure and working principle. The system should be able to monitor the operating state of the vibrating screen in real time, including vibration amplitude, frequency, axial displacement, etc., and be able to detect abnormal conditions in time and give warning prompts. The key hardware of the monitoring system was designed, including acceleration sensor, power module, signal filtering circuit, etc. The sensitivity of the acceleration sensor was measured using comparative method and accurately completed parameter calibration. The eccentric block was used to simulate different deviation of excitation force for system vibration signal test and calibration. The results show that under normal operating conditions, the amplitude of each frequency of the vibrating screen is less than 0.04 g. Under the condition of excitation force deviation, the amplitude of 16 Hz is obviously lower than that of other frequencies, which means that the vibrating screen is currently experiencing lateral oscillation. [ABSTRACT FROM AUTHOR]

In this study, a new flexible screen surface structure with an additional striking beam was proposed for improved efficiency and addressing the clogging issue while processing moist coal material. Vibration tests were used to analyze the time-frequency characteristics of the screen surface and the striking beam under no-load and load conditions. The effects of different process parameters on the elastic screening effect of viscous and wet materials were explored. Further, the industrial application of the equipment was preliminarily carried out. The results showed that the load did not affect the main vibration frequency of the elastic screen surface and the striking beam. When the axis distance was adjusted to 7.5 cm, the displacement from the feeding end to the discharge end gradually decreased, promoting the rapid loosening and stratification of the material group. Semi-industrial tests showed that the optimal screening effects had a screening efficiency of 92.16% and a total misplaced content of 5.95% when exciting force was 18 kN, the exciting frequency was 10.8 Hz, the feeding rate was 9.36 t/h, the distance was 7.5 cm, and the moisture content was 8.21%. The GQPSS1848 vibrating screen applied in the industry achieved a screening efficiency of 86.66% at a processing capacity of 85 t/h with a broad commercial prospect. The study aims to provide theoretical and technical support for the research and development of flexible screening equipment and the efficient classification of −3 mm sticky and wet materials. [ABSTRACT FROM AUTHOR]

In order to enhance the stability and reliability of the vibrating screen, modal and harmonic response characteristics were simulated and analyzed using the finite element method. The final assembly model was established in Creo, serving as an intermediate format for material definition and mesh accuracy verification. The analysis of natural frequency and mode revealed that the overall structural stiffness was basically satisfactory. However, harmonic response analysis indicated issues related to excessive stress and stress concentration within the structure. Subsequent optimization of the frame structure confirmed nearly unchanged low-order natural frequencies, while maximum stress was reduced by 22.15 %, holding significant implications for process cost control. [ABSTRACT FROM AUTHOR]

The article discusses the theory and practice of development in the field of separation and extraction of metals at mining and metallurgical enterprises through the creation and implementation of mine and bunker vibrating feeders, vibrating screen feeders and new designs of screening surfaces for them, as well as devices for eliminating buildup in bunkers. New scientific and practical results of research on the substantiation of improved vibrating machines for auxiliary mining operations are presented, including: vibrating mining feeders of the PVG type; vibrating hopper feeders such as PVB and ZhVB; vibrating feeders-screens of the PGV and GPV types; sifting surfaces for them; devices for eliminating equilibrium arches and material adhesion in bunkers; complex for screening and feeding coke breeze into the crusher; vibration delivery and ballasting installations; sleeper tamping vibration installation, as well as a rock mass transfer point in the quarry. A new mathematical model of the tamping process and a method for improving the tamping mechanism are proposed, which will increase the productivity of the sleeper tamping vibration installation. New vibration complexes make it possible to reduce the energy intensity of crushing by 15% and reduce the wear of the working surfaces of the crusher. It is shown that the construction of transfer points is carried out without additional preparation of the entire working bench. The operational capacity of the warehouse is selected within the range of 15–25 thousand m3 of rock mass. when used for loading iron ore cars with EKG-8I excavators with a daily productivity of up to 5000 m3, the warehouse stock is 3-5 days. The minimum specific energy intensity of release and loading of one ton of rock mass at the maximum value of productivity is ensured at frequencies of forced oscillations of the system ω = 15.5–17.5 Hz. The efficiency of the feeder-screen operation with spatial oscillations of the working body created by two multidirectional driving forces applied at two points at a distance from each other equal to 0.5 was determined. the width of the working body increases by 15%. Developers of technical documentation – SE "UkrNIPIIpromtekhnologii" (Zhovti Vody, Ukraine); Manufacturers: Krivoy Rog Ore Repair Plant (Krivoy Rog, Ukraine); Mechanical repair plant of the State Enterprise "Vostok GOK" (Zhovti Vody, Ukraine); Mechanical repair workshops of quarries, mines and processing plants, etc. It has been established that the research results represent a step in the theoretical generalization of the problem of developing the theory of interaction of grinding media in the grinding chambers of mills and increasing the efficiency of equipment for fine grinding of rocks, which is important for mining and metallurgical enterprises. [ABSTRACT FROM AUTHOR]

The cross beam of a mining linear vibrating screen is prone to cracking under long-term cyclic load. In order to accurately predict the fatigue life of the cracked cross beam, a coupled analysis method of vibration and crack propagation is proposed. A 2D dynamic model of the vibrating screen is established based on the finite element method, which is verified by the vibration test platform. The cracked Euler beam element is used to model the cracked cross beam. The effects of crack depth, amplitude of excitation force, frequency of excitation force, and crack location on the crack-tip stress intensity factor of the cracked cross beam are investigated in detail. In addition, an iterative method is proposed on the basis of the Paris model. The residual service life of the beam under different frequencies of excitation force, amplitudes of excitation force, spring stiffness, crack positions, and degrees of stiffness imbalance are discussed. The results demonstrate that the fatigue life of the beam increases as the frequency of excitation force and spring stiffness increase. The increase of the amplitude of excitation force and spring permanent deformation reduces the fatigue life. The conclusion obtained provide some theoretical guidance for the design and routine maintenance of mining linear vibrating screens. [ABSTRACT FROM AUTHOR]

Regarding to the problem that excessive stem sliver in cigarettes could damage their physical properties and affect the smoking sensation, the separation technology and equipment for stem silver removing in the cigarette manufacturing process were reviewed in this study. It was summarized that the separation of stem sliver was concentrated in two key stages including cut tobacco making and cigarette packaging. The main technologies for stem sliver separation including air separation, vibrating screen, and composite processes. Among them, air separation was the main process. The separation efficiency could be improved through equipment improvement and parameter optimization. However, the balance between tobacco loss and purity still faced challenges. The vibrating screen was easily affected by the shortcomings of screen blocking and cleaning, but the composite process combining it with air separation were gradually receiving attention. The composite process of stem sliver separation combined optical identification selection and air separation had showed more accurate and intelligent separation solutions for the cigarette industry, but it was not been widely applied in actual production lines. In the future, the research and development of air separation technology can be strengthened, and it can be deeply and systematically integrated with vibration screen, light identification separation and other technologies. These will achieve the balanced development of cigarette product quality and material consumption. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Strong impacts and vibrations exist in various structures of rice combine harvesters in harvesting, so the bolt connection structure on the harvesters is prone to loosening and failure, which would further affect the service life and working efficiency of the working device and structure. In this paper, based on the vibration signal acquisition experiment on the bolt and connection structure of the vibrating screen on the harvester, failure feature identification is studied. According to the sensitivity analysis results and the primary extraction of the time-frequency feature, most features have limitations on the identification of failure features of vibrating screen bolts. Therefore, based on the establishment of a high-dimensional feature matrix and multivariate fusion feature matrix, the validity of the feature set was verified based on the whale optimization algorithm. And then, based on the SVM method and high-dimensional mapping of the kernel functions, the high-dimensional feature matrix is trained by the LIBSVM classification decision model. The identify success rates of time domain feature matrix A, frequency domain feature matrix B, WOA-VMD energy entropy matrix C, and normalized multivariate fusion feature matrix G are 64.44%, 74.44%, 81.11%, and more than 90%, respectively, which can reflect the applicability of the failure state identification of the normalized multivariate fusion feature matrix. This paper provided a theoretical basis for the identification of a harvester bolt failure feature. [ABSTRACT FROM AUTHOR]

Existing cleaning devices for edible sunflower have a low cleaning efficiency, high cleaning loss rate, and high impurity rate; therefore, a wind-sieve-type cleaning device for edible sunflower harvesting was designed. According to the characteristics of dislodged objects, a vibrating screen for the device was designed, and the dislodged edible sunflower objects in the device were used for a mechanical analysis of the force conditions to determine the displacement of the different edible sunflower objects dislodged by the action of airflow. Using FLUENT-DEM gas–solid coupling simulation technology, the velocity of the flow field, the velocity vector, and the trajectory of the dislodged objects inside the cleaning device were analyzed, and the law of motion applied to the airflow and the dislodged objects inside the device was clarified. According to the results of the coupled simulation analysis, the key factors affecting the operation of the cleaning device were wind speed, vibration frequency, and amplitude. Based on the key factors of wind speed, vibration frequency, and amplitude, an orthogonal rotary combination test was carried out with the loss rate and impurity rate of cleaned grains as the evaluation indexes, and the test parameters were optimized to obtain the optimal combination of operating parameters of the device, which were as follows: wind speed: 30 m·s−1; vibration frequency: 8.44 Hz; and amplitude: 41.35 mm. With this combination of parameters, the seed loss rate and impurity rate reached 3.47% and 6.17%, respectively. Based on the optimal combination of operating parameters, a validation test was performed, and the results of this test were compared with the results of the test bench using this combination of parameters. The results show that the relative errors of the loss rate and impurity rate between the bench test and the simulation test were 3.45% and 3.07%, respectively, which are less than 5%, proving the reliability of the simulation analysis and the reasonableness of the design of the test bench. [ABSTRACT FROM AUTHOR]

Vibrating flip-flow screens (VFFSs) provide an effective solution for deeply screening moist and fine-grained minerals, and an accurate dynamic model of VFFSs is critical for its dynamic analysis and optimization, thereby improving the vibration stability and symmetry of VFFSs. In this paper, uniaxial tension, uniaxial compression, plane tension, and shear stress relaxation experiments were conducted on screen panel samples to illustrate that the third-order Ogden model and the generalized Maxwell model can accurately describe the hyperelasticity and viscoelasticity of screen panels. Then, the coupling method of finite element and discrete element was adopted to establish the simulation model of the screen panel and material group coupling system, and the dynamics of the coupling system under different loading conditions were explored. Finally, the dynamic model of the coupling system of VFFSs mass, screen panel, and material group was proposed, and the non-dominated sorting genetic algorithm II was applied to optimize the system's dynamic response. The results reveal that the use of optimized shear springs can reduce the relative amplitude change rate of the main and floating screen frame by 44.30% while maintaining the periodic motion of the VFFSs under operation conditions, greatly enhancing the stability of the VFFSs system. [ABSTRACT FROM AUTHOR]

In the mining vibrating screen's working process, the support spring often fails due to alternating loads and a poor working environment. The six-degrees-of-freedom simplified rigid body dynamic model is established to obtain the vibration response of the mining vibrating screen with a faulty single-group spring and is verified using the ABAQUS (2020) simulation in this paper. Unlike previous studies focusing on multiple-group spring failures or using lower-degree-of-freedom models, this study addresses the common single-group spring failure with the comprehensive model capturing complex spatial motion. This study also reveals that the vibration angle can be used to diagnose the failure location, while the vibration displacement can be used to evaluate the health state of single-group springs. Based on these rules, the novel method for locating a faulty spring group and new evaluation formulas for their health states are validated by the simulations. The results indicate that the failure location is accurately diagnosed, and the errors of the health state evaluation are minimal. The evaluated values are 66.12% and 85.56% when the health states of the spring groups at the feed side and the out-feed side are 65% and 85%, respectively. Therefore, this diagnostic model provides significant theoretical assistance for diagnosing single-group spring failure in the mining vibrating screen, enhancing maintenance strategies and operational reliability. [ABSTRACT FROM AUTHOR]

The problem of soil and Chuanxiong tuber congestion on vibrating screens usually exists during the Chuanxiong mechanized harvesting process. To address this problem, the conveyance performance of a crankshaft rocker vibrating screen was studied. By establishing and solving the dynamics and kinematics equations for the crankshaft rocker vibrating mechanism and Chuanxiong soil residue, the acceleration of the vibrating screen and Chuanxiong-soil residue was studied. The sliding speed, motion process, and conveying distance of the Chuanxiong soil residue were also analyzed. The theoretical analysis results indicated that the acceleration of the vibrating screen depends on the rod lengths of the vibrating mechanism and the crank rotational speed and position. The displacement of the Chuanxiong-soil residue along the positive sliding direction in a cycle was more significant than that of the negative sliding direction. The appropriate advancement speed of the harvester was also obtained. The RecurDyn and EDEM coupling simulation was conducted. The simulation results verified the theoretical analysis. In the simulation, the Chuanxiong-soil residue was effectively conveyed. The field tests were conducted to verify the theoretical analysis. The harvester was tested in the field with crank rotational speeds of 0 r/min, 120 r/min, and 240 r/min, and advancement speeds of 0.5 m/s, 1 m/s, 1.5 m/s, and 2 m/s. The results showed that there was no congestion in the screen during the working process when the rotational speed of the crank was 240 r/min, and the advancement speed of the harvester was no faster than 1.5 m/s. When the crank rotational speed was 240 r/min, and the advancement speeds were 0.5 m/s, 1 m/s, and 1.5 m/s, the weights of Chuanxiong and soil on the screen after the test were 71.5 kg, 84.7 kg, and 105.7 kg, respectively. The field tests verified the conveyance performance of the vibrating screen. This study can provide a theoretical reference for designing the crankshaft rocker vibrating mechanism for the rhizome harvesting machine. [ABSTRACT FROM AUTHOR]

The bolts and connections of each working part of a rice combine harvester can suffer from severe instantaneous impacts and alternating loads, and these strong impacts and loads cause instantaneous fracture and fatigue failure of the bolt face and even the loosening, detachment, and fracture of the bolt. The main vibration directions and the most complex vibration parts of the bolts and connections in the main working parts of a combine harvester under time-variable multiload excitation were obtained through the analysis of response signals in terms of time-domain and frequency–domain characteristics via a vibration response experiment. This study revealed that the random peak value of the vibrating screen is 12.5622, which is the severe impact and collision standard. For the vibrating screen, the local peak in the 4-Y direction was the main load of the destroying bolt connection (the impact reached 60.57 m/s2, 96.91 m/s2) and the vibration energy intensity in the 4-Z direction was mainly concentrated at 12.42 m/s2, which is the maximum vibration energy value in the three directions (the peak vibration value reached 109~115.68 m/s2), so the bolted connections of the vibrating screen are the most vulnerable to destruction. Therefore, a kinetic model and a microscopic response model of a vibrating screen were established via the centralized mass method to explore the kinetic response characteristics of bolted structures subjected to multiple excitation loads, thus providing a mathematical model for identifying the features of bolted connections based on static characteristics. [ABSTRACT FROM AUTHOR]

The object of research is an element of equipment in a vibrating screen, which is an active working body in the form of a plate. The key element in the system of the flush purification unit is the vibrating screen. The basic design of the sieve does not allow the flush solution to be distributed evenly over the entire working surface. The concentration of drilling fluid in the central part of the equipment leads to premature abrasive wear and failure of the working element. Therefore, the structure of the vibrating screen needs to be improved in order to extend its service life. This task has been solved through the introduction of an active element to the structure for the redistribution of the solution through additional transverse vibrations. The use of such an active element is an important step for improving the quality and efficiency of the purification system, which could optimize production processes and reduce costs in industry. Taking into account transverse vibrations and calculating frequency parameters could help improve the design and use the vibrating screen more productively. An analysis of the frequencies of oscillations of the active element-plate for cleaning the flush liquid with a vibrating screen was performed and a comparison of the analytically obtained results with the simulation data using the finite element method in the COMSOL Multiphysics software was carried out. The results are the basis for designing vibrating screens, conducting experimental and industrial research, and testing the screens. Computer studies have confirmed the possibility of using the improved design of the vibrating screen. By comparing the results of the calculation and computer simulation, the error was determined to be within 5 %. The identified patterns could make it possible to select the plate oscillation frequencies depending on the known initial parameters, which would be useful for solving similar tasks. [ABSTRACT FROM AUTHOR]

The three-deck vibrating screen can separate the material into various particle sizes. There are a few types of researchers on the screening efficiency and processing capacity of multideck vibrating screens. In this work, the discrete element method was used to simulate the screening process of the three-deck vibrating screen under different vibration parameters (frequency, amplitude, and inclination angle) and a prototype experiment was carried out. The effects of vibration parameters on the screening performance were analyzed based on the orthogonal design of experiments. An approximate model, the Kriging model, was used to replace the simulation process for further optimization. Then, an optimization algorithm conducted multiobjective optimization, and three sets of optimization solutions were obtained via a traversal approach. In addition, the three optimized vibration parameters were verified by simulation. There is a guideline for the design of vibration parameters of the multideck vibrating screen. [ABSTRACT FROM AUTHOR]

To obtain large exciting force for elliptical vibrating screen, a new three-exciter vibration system with two elastic coupling coaxial exciters is proposed. For studying the vibration characteristics and synchronization capability of the system, the Lagrange equation is firstly introduced to establish the dynamic model of the system. Then, the steady-state responses of the system are determined. Subsequently, the synchronous condition of the system is discussed by means of the averaged small parameter method and existence conditions of solutions for the synchronization torque balance equations of the vibration system, the synchronous stability condition of the system is established by the stability of the solution of the torque balance equation, and some numerical calculations, computer simulations and vibration experiments are performed to verify the correctness of the theoretical derivation. It can be found that, the ideal synchronization of two elastic coupling coaxial exciters can be achieved by selecting a torsion spring with appropriate stiffness, the two coaxial exciters can realize in-phase synchronization even if power source of either of the two motors is cut off, and the average phase difference angles are very close to the situation when all three motors are powered on. By using the mechanical model and synchronous theory proposed in this paper, a double-layer elliptical shale shaker was developed and has been successfully applied to oil drilling engineering. [ABSTRACT FROM AUTHOR]

Screening is a critical technology to achieve clean and effective use of coal. Due to their ability to achieve equal-thickness screening and excellent working efficiency characteristics, banana screens are widely utilized for material classification. The current work employs a vibration test and analysis system to investigate the laboratory-scale and industrial banana screens' kinematic features. The screen surface's amplitude gradients at the inlet and outlet ends of the laboratory and industrial scale banana screens were 0.5 mm and 7.5 mm, respectively, verifying the "strong-in, weak-out" transfer law of the vibration energy. The results of the 6 mm screening experiment in the laboratory indicated that the coal samples were concentrated in the middle of the screen surface with the highest screening efficiency of 95.05% and the lowest total mismatch content of 2.68%. A Birtley's four-stage banana screen was utilized to classify the 6 mm raw coal during the on-site heavy media separation at the Tunbao coal processing plant. Besides, a better screening performance was obtained with an efficiency of 89.92% and total mismatch content of 5.31%. The differences in accuracy of the distribution rate curves were all less than 5%, indicating that the laboratory banana screen is a prominent guide for industrial applications. [ABSTRACT FROM AUTHOR]

To tackle problems such as the difficult separation from sand and the high power consumption of tiger nut harvesting in the sandy areas of Xinjiang, a conveying and separating device for tiger nut harvesters was designed. The axial and radial migrations of materials under screw action and the separation process of materials under vibratory action were analyzed dynamically. A simulation analysis was carried out on the conveying and separating process based on EDEM software. The migration trajectories of tiger nuts and sand particles were extracted, the displacement variations of sand particles on the X-axis, Y-axis, and Z-axis were analyzed in the action area of the screen-cleaning spike teeth and the screw action area, respectively, and the conveying and separation law of the tiger nut harvest mixture was clarified. With key parameters such as the screw velocity ratio, amplitude, vibration frequency, and machine operation velocity as test factors, and with the sand removal rate, crushing rate, and power consumption as test evaluation indicators, a four-factor, five-level orthogonal central composite test design was implemented. The test results were analyzed via the regression variance analysis method, and relation models between variable factors and evaluation indicators were constructed. The test results show that under the combined conditions of a screw velocity ratio of 0.88, an amplitude of 4.7 mm, a vibration frequency of 7.5 Hz, and a machine operation velocity of 0.92 km/h, the sand removal rate is 90.40%, the crushing rate is 1.66%, and the power consumption is 2.24 kW in theory. The optimized results were verified by tests. The sand removal rate was 88.92%, the crushing rate was 1.71%, the total power consumption was 2.29 kW, and the errors from the predicted values were 1.6%, 3.0%, and 2.2%, respectively, meeting the requirements for tiger nut harvesting conveyance and separation. This research can provide support for the development of technology and equipment for mechanized harvesting of tiger nuts in the sandy areas of Xinjiang. [ABSTRACT FROM AUTHOR]

The flip-flow vibrating screen (FFVS) is a novel multi-body screening equipment that utilizes vibrations to classify bulk materials in the field of screening machinery. The relative amplitude of FFVSs determines the tension and ejection intensity of elastic flip-flow screen panels, which is a critical operating parameter affecting the screening performance. However, FFVSs generally suffer from large variations of relative amplitude caused by the loading of materials and the changes in shear spring stiffness (the temperature changes of the shear springs lead to their stiffness changes), which significantly reduce the screening efficiency and lifespan of FFVSs. To address this problem, this paper proposes a nonlinear stiffness-based method for stabilizing the vibration amplitude of FFVSs using piecewise linear springs. By introducing these springs between the two frames, the sensitivity of the relative amplitude to shear spring stiffness is reduced, thereby achieving the stabilization of the relative amplitude of FFVSs. In this study, the variations of the vibration amplitude of the FFVS due to the loading of materials and the changes in shear spring stiffness were first demonstrated in a reasonable operating frequency range. Then the reasonable operating frequency range and dynamics of the resultant nonlinear flip-flow vibrating screen (NFFVS) with piecewise linear springs were investigated using the harmonic balance method (HBM) and the Runge–Kutta numerical method. The operating frequency region for the NFFVS lies between the critical frequency ω c s and the frequency ω l b corresponding to the saddle-node bifurcation point. Finally, a test rig was designed to validate the theoretical predictions. Theoretical and experimental results demonstrate that piecewise linear springs can effectively stabilize the relative amplitude of the FFVS. [ABSTRACT FROM AUTHOR]

Vibrating flip-flow screens are widely employed in the deep screening processes of coal washing, solid waste treatment, metallurgy, and other fields, playing a crucial role in enhancing product quality and production efficiency. The screen surface and material movement of vibrating flip-flow screens are highly complex, and there is currently insufficient understanding of their screening mechanism, limiting further optimization and application. In this paper, the Discrete Element Method (DEM), Finite Element Method (FEM), and Multi-Body Dynamics (MBD) were integrated to establish a numerical coupling model for vibrating flip-flow screens, considering material loads, screen surface deformation, and screen machine dynamics. The Response Surface Method was utilized to analyze the significant impact of relative amplitude, tension amount, amplitude of driving screen frame, vibration frequency, and screen surface inclination on screening efficiency and material velocity. The results indicate that the most significant factor influencing the screening of flip-flow screens is the screen surface inclination. Based on a BP neural network, a five-degree-of-freedom inclination surrogate model for flip-flow screens was established. The whale algorithm was employed for multi-objective optimization of the surrogate model, resulting in a screen surface inclination distribution that meets the requirements of different operating conditions. [ABSTRACT FROM AUTHOR]

Flip-flow vibrating screens (FFVSs) effectively tackle the challenges posed by the dry deep-screening of wet, fine, low-grade bituminous coal, thereby facilitating advancements in the thermal coal preparation process. The tensile lengths of the screen panels not only influence the service lives of the screen panels but also play a pivotal role in determining the screening performance of the FFVSs. To investigate the effect of the screen-panel tensile length on the screening performance of an FFVS, this study constructs a dual-mass flip-flow screening test rig. The experimental results reveal that when the fine-particle content and the external water content in the feed of low-grade bituminous coal are 55% and 16%, respectively, the most favorable tensile length of the screen panels is 2 mm. With a fine-particle content of 55% in the feed of low-grade bituminous coal and an increase in the external water content from 4% to 20%, the screening efficiency of the FFVS initially decreases and then increases. Notably, low-grade bituminous coal with 16% external water content poses the most challenging screening conditions. Furthermore, when the external water content of the low-grade bituminous coal is 16% and the fine-particle content in the feed increases from 25% to 55%, the screening efficiency of the FFVS gradually improves. [ABSTRACT FROM AUTHOR]

The research on particle size classification in lunar microgravity has gradually attracted the attention of scholars. Based on the discrete element method (DEM), this work proposes a double-layer auxiliary screening vibrating screen in the form of intermediate feeding, and takes the screening efficiency and screening time as the evaluation indicators. Firstly, the Helmholtz-Maxwell coil is used to simulate the force of particles under lunar microgravity, which verifies the reliability of the numerical simulation of particles under lunar microgravity based on the discrete element method. Then, the influence of the parameters of each screen on the comprehensive performance of screening was analyzed by a single-factor experiment. Finally, based on the BP (Back Propagation) neural network optimized by genetic algorithm, the evaluation model of screen parameters and screen performance is established, and the multi-objective genetic algorithm is used to optimize the screen parameters combination scheme with excellent performance. An efficient comprehensive model of screening is provided to improve the screening performance and the design of the screen machine under lunar microgravity. [ABSTRACT FROM AUTHOR]

The Flip-Flow Screen is extensively utilized in the vibrating screening process for the treatment of particle matter. In this study, a four-degree-of-freedom (4-DOF) Flip-Flow Screen was proposed. The granules in the 4-DOF Flip-Flow Screen were modeled using the discrete element method. The screening process of the 4-DOF Flip-Flow Screen was simulated by multi-flexible body dynamics-discrete element method (MFBD-DEM) coupling. The impact of vibration frequency and amplitude on the sieving effect of the Flip-Flow Screen was studied. The vibration parameters of the 4-DOF Flip-Flow Screen were optimized using the response surface method to improve sieving performance. Analysis of variance (ANOVA) was employed to assess the simulation findings. The results show that the variables with the greatest influence on the screening efficiency are z-direction frequency and x-direction frequency, respectively. The best outcome corresponding to the maximum screening efficiency is found to occur as the z-direction frequency, x-direction frequency, x-direction amplitude, and y-direction amplitude are all at 7.5 Hz, 15 mm, and 3 mm, respectively. [ABSTRACT FROM AUTHOR]

The behavior of oil sunflower seeds penetrating screen holes is an important factor that affects the screening performance of oil sunflower seeds. In this study, a double-deck reverse-motion vibrating screening device for oil sunflower seed screening was designed. The force condition and motion law of the oil sunflower seeds on the screen surface were analyzed. This study compared the effect of particle filling amount of discrete element model of oil sunflower seeds on the simulation effects. The screening process was numerically simulated using the coupled Discrete Element Method and Multibody Dynamics (DEM-MBD) technique with the screening percentage of oil sunflower seeds as the index. The influence of the operating parameters of the vibrating screen on the screening effect was analyzed using a multiparameter collaborative optimization scheme. The results of this study can provide a reference for the numerical simulation of crop screening behavior and the development of screening devices. [ABSTRACT FROM AUTHOR]

For the same frequency, a vibrating screen usually can only achieve a circular or linear motion trajectory, which will lead to the phenomenon of screen clogging. The compound frequency vibrating screen can achieve various motion trajectories according to different frequency ratios, thus perfectly solving this problem. Thus, the multi-frequency control synchronization problem of the dual induction motor-driven vibration system based on the fixed speed ratio was studied. Firstly, by establishing an electromechanical coupled dynamics model of the vibration system driven by dual induction motors, the response equation of the fixed speed ratio vibration system was derived. Then, the master–slave control strategy was used to control the two induction motors through PID control optimized by a genetic algorithm. The slave motor tracked the main motor through the speed ratio method and achieved fixed speed ratio control synchronization. The simulation analysis showed that the two induction motors vibration system could not achieve self-synchronous motion with a fixed speed ratio, but by using the back propagation proportion-integral-derivative control (BP PID, PID based on BP neural network), we were able to achieve control synchronization with a fixed speed ratio. Herein, the arbitrariness of the fixed speed ratio parameter is also discussed, and controlled synchronous motion of the vibration system with a non-integer fixed speed ratio was realized. Finally, the simulation results were verified through experiments with the fixed speed ratio parameter n = 1.5, which verified the validity of the synchronization theory of fixed speed ratio control in vibrating systems and made it possible to apply it in compound frequency vibrating screens. [ABSTRACT FROM AUTHOR]

With a requirement of miniaturization in modern vibrating screens, the vibration synchronization method can no longer meet the process demand, so the controlled synchronization method is introduced in the vibrating screen to achieve zero phase error state and realize the purpose of increasing the amplitude. In this article, the controlled synchronization of a vibrating screen driven by two motors based on improved sliding mode controlling method is investigated. Firstly, according to the theory of mechanical dynamics, the motion state of the vibrating screen is simplified as the electromechanical coupling dynamical model of a vibrating system driven by two inductor motors. And then the synchronization conditions and stability criterion of the vibrating system are derived and numerically analyzed. Based on a master-slave controlling strategy, the controllers of two motors are respectively designed with Super-Twisting sliding mode control (ST-SMC) and backstepping second-order complementary sliding mode control (BSOCSMC), while the uncertainty is estimated by an adaptive radial basis function neural network (ARBFNN). In addition, Lyapunov stability analysis is performed on the two controllers to prove their stability theoretically. Finally, simulation analysis is conducted based on the dynamics model in this paper. [ABSTRACT FROM AUTHOR]

Backgrounds: In this paper, a kind of mining MR damper with shear and valve working mode is designed. Compared with the traditional damper, this MR damper has better energy dissipation characteristics and can provide greater damping force in a short time. Its damping can be adjusted with the excitation current. Purposes: The aim of the present paper is to analyze and study the performance of this novel mining MR damper and test the working performance and feasibility of this MR damper. Methods: Optimizing and establishing a Simulink dynamic simulation model based on Bingham model and testing the performance parameters of the MR damper. The vibration mitigation experiment of mining vibrating screen based on spring damper is designed. Results: This paper compares the experimental and simulation results and found that the error of the maximum damping force shall not exceed 3%.Compared with traditional metal spring and ROSTA spring, the MR damper can reduce the downtime of the vibrating screen by more than 80%. Conclusions: From the results, the present paper provides theoretical basis for the performance test of the damper. The excitation current is the main factor affecting the maximum damping force of the MR damper. The correlation between the excitation current and the maximum damping force is more than 90%. MR damper can not only effectively avoid the resonance of the vibrating screen, but also will not affect the stable amplitude of the vibrating screen when it works, and can also greatly reduce the downtime of the vibrating screen. [ABSTRACT FROM AUTHOR]

To strengthen the screening efficiency of traditional vibrating screens, a new type of vibrating screen, namely the composite vibrating screen, has been proposed based on the Lissajous vibration synthesis theory. The working principles of composite vibrating screens have been explained. Numerical simulations of the sieving processes for such composite vibrating screens were carried out using the discrete element method. Compared with traditional linear vibrating screens, the force, stratification mechanisms, and throwing principles of the material on the screen's surface were studied, and the vibrating screens' material transportation and screening efficiency were analyzed. The results showed that with the existence of xyz three directions sub-vibrations of the composite vibrating screens, the material particle group is more diversified by the forces, the particle system is loose, the stratification effects are adequate, and the material is evenly distributed on the screen surfaces. Under the same vibration parameters, the composite vibrating screens' screening efficiencies and material transportation capacities were better than those of linear vibrating screens. This work provides a necessary reference for the development and application of new composite vibrating screens. [ABSTRACT FROM AUTHOR]

The article presents the results of research on the trajectory and amplitude values during the startup of a vibrating screen, depending on the set startup time. The research was conducted using a suspended vibrating screen with a segmental vibration trajectory, where vibration excitation was achieved through two vibratory motors directly attached to the screen frame. The vibratory motors were powered with three-phase voltage and connected to the grid through frequency converters, allowing for current control in steady-state and startup conditions. The analysis focused on the vibration trajectory and the resulting amplitude values for nine selected startup times (ranging from 0 s to 8 s). Two measurement methods were employed: using piezoelectric acceleration sensors and optical recording. Additionally, the momentary power consumption by the screen drive was recorded, and the maximum current flowing in the power supply circuit was determined. These studies enabled the determination of the most favourable startup parameters that reduce the power demand of the drive without significantly affecting the kinematic parameters of the screen during its startup. The results of experimental research presented in the article regarding the startup time of the screening machine and its influence on vibration parameters have shown that the startup time significantly impacts the amplitude values that occur during startup. In the analysed case, the most favourable startup time was 3 s. Power consumption studies during startup revealed that startup time has a notable influence on momentary power consumption. The conducted research demonstrated that for startup times below 0.2 s, the maximum momentary power was the highest (reaching 5 kW, with a current consumption of 4.5 times the rated current). Regarding energy efficiency, the most favourable startup times exceed 2.0 s. Extending these startup times can significantly reduce the power demand of the drive, even up to threefold, thereby enabling the selection of motors with much lower power ratings. [ABSTRACT FROM AUTHOR]

Screening of pulp can be expressed as a process where solid contaminants are removed from a pulp slurry without an excessive loss of fibres of acceptable quality. The impurities originate from the feedstock, or they are generated during the transport, handling, storage, or pulping process. The most typical impurities include bark, fibre bundles or shives, knots, plastic, rubber, and sand. Moreover, there are also other objectives for screening, such as the improvement of the pulp quality, savings in bleaching chemical consumption, and protection of process equipment. In industrial applications, pulp screening is typically carried out with more than one screen for a more beneficial screening result. The pulp screening equipment can be divided into different types by the separation technique employed, such as atmospheric or pressurized screens, centrifugal screens, vibrating screens, etc. In addition, there are other types of related equipment that are common in the pulp screening process, such as knotters, refiners, and hydrocyclones. The main objective of this review is to discuss the advantages and disadvantages of modern screening equipment as well as introduce contemporary screening strategies for chemical pulp mills. [ABSTRACT FROM AUTHOR]

The condition-based maintenance of vibrating screens requires new methods of their elements' diagnostics due to severe disturbances in measured signals from vibrators and falling pieces of material. The bolted joints of the sieving deck, when failed, require a lot of time and workforce for repair. In this research, the authors proposed the model-based diagnostic method based on modal analysis of the 2-DOF system, which accounts for the interaction of the screen body and the upper deck under conditions of bolted joint degradation. It is shown that the second natural mode with an out-of-phase motion of the upper deck against the main screen housing may coincide with the excitation frequency or its higher harmonics, which appear when vibrators' bearings are in bad condition. This interaction speeds up bolt loosening and joint opening by the dynamical loading of higher amplitude. The proposed approach can be used to detune the system from resonance and anti-resonance to reduce maintenance costs and energy consumption. To prevent abrupt failures, such parameters as second natural mode frequency, damping factor, and phase space plot (PSP) distortion measures are proposed as bolt health indicators, and these are verified on the laboratory vibrating screen. Also, the robustness is tested by the impulsive non-Gaussian noise addition to the measurement data. A special diagram was proposed for the bolted joints' strength capacity assessment and maintenance actions planning (tightening, replacement), depending on clearance in the joints. [ABSTRACT FROM AUTHOR]

To solve the problem of grain loss caused by nibbling during the working process of the maize ear and stem harvesting machine, a vibrating screen-type grain-recovery device with an upper centrifugal fan was designed. The device mainly consists of a centrifugal fan and vibrating screen. The work process of the grain-recovery device is theoretically analyzed, and it is clarified that the turning of the bracts is the key to separating the bracts from the grains, and the design criteria of the vibrating screen are obtained. The CFD–EDEM coupled single-factor simulation experiment was carried out on the size of the vibrating screen sieve hole and the number of draft bars, and the motion posture of the bracts was simulated. Based on the previous CFD–EDEM coupled simulation study, the orthogonal experiment was carried out on the fan speed, vibration screen drive-shaft speed, and operation speed of the grain-recovery device. The orthogonal experimental results show that, when the fan speed is 1000 r/min, the vibration screen drive-shaft speed is 300 r/min, and the operation speed is 3.62 km/h, the performance of the grain-recovery device reaches the optimum level, and the grain recovery rate is approximately 85%. [ABSTRACT FROM AUTHOR]

It was possible to conduct a study on the shape and parameterization of the vibrating screen so as to explore the relationship between detailed vibrating screen motion parameters and particle group distribution under different screen surface states. The motion characteristics of particle groups in various scenes were investigated, screening performance of vibrating screen with complex parameters was studied, interaction between motion parameters of screen surface and motion of material groups in multi-component mixed particle groups was analyzed, segregation distribution law of multi-component mixed material groups was revealed, and this study presents simulation findings based on the discrete element program EDEM. The ensemble learning approach was used to examine the optimized model screen. It was revealed that the screen's amplitude, vibration frequency, vibration direction angle, swing frequency, swing angle, and change rate of screen surface inclination all had a major impact on its performance. As a result, the vibrating screen's running state was described by various parameter combinations, and the trend changes of several factors that affected the performance of the screen were examined. The investigation revealed that the particle swarm optimization backpropagation (PSO-BP) neural network model outperformed the backpropagation (BP) neural network model alone in terms of prediction. It had lower root mean square error (RMSE), mean square relative error (MSRE), mean absolute error (MAE), and mean absolute relative error (MARE) than the BP neural network model, but a larger R2. This model's greatest absolute error was 0.0772, and its maximum relative error was 0.0241. The regression coefficient R value of 0.9859, which displayed the model's strong performance and high prediction accuracy, showed that the PSO-BP model was feasible and helpful for parameter optimization design of vibrating screens. [ABSTRACT FROM AUTHOR]

In the vibrating screening operation, each area of the screen surface has a different screening environment, and the material layer thickness, target particle proportion and other parameters of each area are different, which limits the screening efficiency of a vibrating screen with a traditional screen surface. In this paper, a double-deck variable screen surface screening method is proposed to optimize the design of the double-deck screen surface. The relationship between the elements of the screening process, screening parameters and screening efficiency of a double-deck variable screen surface vibrating screen is investigated through DEM numerical simulation. Using the particle swarm algorithm to support the vector regression model for global optimization, the parameters of the double-deck variable screen surface vibrating screen further optimized to obtain screening parameters: screen area A screen hole edge length of 4.7 mm, screen area D screen hole edge length of 2.7 mm, screen area D screen surface inclination angle of 6.3°, amplitude 2.6 mm, vibration frequency of 22.2 Hz, vibration direction angle of 35°, and through the experimental prototype for physical experimental verification. [ABSTRACT FROM AUTHOR]

The material feeding changing of combine harvester is easy to cause accumulation and blockage of the vibrating screen, which seriously affects the harvest operation. In order to alleviate such accumulation and blockages on the vibrating screen surface, the guide chute rotation angle of the improved variable amplitude screening mechanism was selected as the target variable, and EDEM-RecurDyn was employed to simulate the anti-blocking process of the variable amplitude under a changing feeding quantity (0.5 kg/s abnormal, 0.2 kg/s normal) of materials (rice grain and stem mixture). A BP (an error back propagation algorithm) neural network was designed and the prediction model of the material distribution was subsequently constructed on the variable screening surface under different chute angles during abnormal feeding. The results revealed a continuous decrease in the quality and time of the material blockage at the front end of the screen surface with the increasing guide chute angle. At the guide chute angle of 20°-45° and adjustment time of 3-6 s, the blocked and accumulated materials at the front-end screen surface was be moved back to Grid 6 for screening. However, overtime, the screen surface materials continued to move back under the chute angle of 40°-45°, which had a great impact on the screening performance. At the guide chute angle of 30°-35° and adjustment time of 4 s, the materials on the screen surface were evenly distributed in Grid 1-6. This was able to alleviate the accumulation and blockage of the screen surface materials. The R of the material distribution prediction model (BP neural network) on the screen surface was determined as 0.97, indicating the high reliability and accuracy of the material distribution model on the screen surface based on the BP neural network. This work provides an important reference for the variable amplitude intelligent control of screen surface material anti-blocking. [ABSTRACT FROM AUTHOR]

The vibrating screen with statically indeterminate mesh beam structure (VSSIMBS) is a novel type of large vibrating screen, which is widely used in coal preparation plants due to its high strength and processing capacity. In this study, the VSSIMBS motion differential equations were obtained via on Lagrange equation, and the dynamic vibration system model was established. The eccentric block force conditions during the operation were analyzed, and the stable vibrating screen operational conditions were obtained. The electromechanical coupling simulation model of VSSIMBS was built in Simulink, allowing frequency control and vibration synchronization experiments. Experimental frequency control results have shown that when the output characteristics of both motors are either the same or similar, synchronous movement can be achieved. Regarding vibration synchronization, experiment results have shown that when two motors are in synchronous motion, and the power supply of one motor is cut off, they still can operate synchronously. Thus, the experimental results obtained in this study provide a theoretical reference for improving the motion stability of large vibrating screens. [ABSTRACT FROM AUTHOR]

Moisture content has an important influence on the stratification and screening of materials on the surface of screens, and materials with different external moisture concentrations present different screening characteristics. A vibrating flip-flow screen (VFFS) is a two-body vibration system with a high-vibrating-strength screen surface developed based on a circular vibrating screen (CVS), which offers significant advantages in terms of handling sticky fine particles. To better understand the difference in screening performance between a VFFS and CVS under different external moisture concentrations, it is necessary to conduct a comparative study on the distribution characteristics of materials on the screen's surface. In this paper, a CVS dynamic model considering the stiffness force and position of the damping spring is proposed, and the influence of different arrangements of damping springs on the amplitude and angular displacement of the screen is analyzed. Under different external moisture concentrations, the screening percentages of the 3–1 mm sized fractions in sections I–IV of a VFFS and a CVS are greater than those of 1–0 mm sized fractions. The screening efficiencies of CVSs and VFFSs are 92.54% and 92.19%, respectively, at an external moisture content of 4.30%, so the screening effect of a low-vibration-intensity screen surface is better in the case of better material stratification. When the external moisture content of the material was increased from 4.30% to 8.19%, the screening efficiency of the VFFS and the CVS decreased by 33.85% and 41.32%, respectively. The screening efficiency of the CVS is more sensitive to the external moisture content of a material. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to study the screen surface parameters of the double deck vibrating screen, in sections, to determine the influence of each part of the screen surface on the screening efficiency of the vibrating screen. Finally, the best screening parameters were calculated to obtain the best screening performance. Design/methodology/approach: In this paper, the discrete element method is used to simulate the process of two-layer subsection screening. Response surface test was used to analyze the influence of various factors and their interactions on screening results. Finally, based on the binomial regression model of screening efficiency, the optimal combination of vibration parameters is calculated. Findings: In the screening process of vibrating screen, due to the different screening environments in each area of the screen surface, the single-layer linear vibrating screen with equal screen surface parameters cannot obtain the best screening performance. Among the single factors, the effect of vibration frequency is the most significant. Originality/value: To address the issue of single layer linear vibrating screens with equal screen surface parameters being unable to maintain optimal screening performance when handling large amounts of materials. This article proposes a double layer vibrating screen with different screen surface grids and screen surface angles to address the problem of low screening performance of traditional single layer linear vibrating screens. [ABSTRACT FROM AUTHOR]

According to the requirements of the current drilling fluid vibrating screen for high efficiency, high reliability and low energy consumption, an elliptical vibrating screen based on disk motor is proposed. The dynamic analysis model of the vibrating screen of the three-excited motor is established, and the dynamic characteristics of the whole system and key structures are studied by multi-body dynamics and finite element method. The dynamic stress response characteristics of the rigid flexible coupling system of screen box are mainly analysed. Based on the deformation and stress of the flexible body damage node analysis results, through the fatigue cumulative damage theory and rain-flow counting method against casing load surface fatigue life prediction, verifying the reliability of fatigue life of screen box. The result shows that: Three Eccentric Rotors elliptical vibrating screen can achieve balanced elliptical vibration track, meeting the requirements of high stable amplitude vibration, and its natural frequency, structural strength and fatigue life all meet the engineering requirements, verifying the feasibility and effectiveness of the design scheme. [ABSTRACT FROM AUTHOR]

• Theorem of spring control synchronization and self-synchronization are revealed. • The realization of torsion spring control synchronization is inevitable. • Zero-phase synchronization is achieved by increasing torsion spring stiffness. • Influence of structure parameters on synchronization behavior is discussed. • The theoretical analysis results are accurately verified by simulation. In oil drilling processes, vibrating screen is a crucial solid control equipment for separating harmful solid-phase particles. However, the conventional utilization of either dual-motor or triple-motor is inadequate demanding the excitation force of large vibrating equipment. Moreover, self-synchronization in zero phase is difficult to achieve in multiple motors system. To avoid cancellation of the excitation force caused by the phase inconsistency of multiple motors, the adoption of a four-motor excitation with torsion spring coupling system is proposed this work. Initially, the mathematical model of the vibrating system is formulated through the Lagrange's equation. Subsequently, the steady-state solution is determined using Laplace transform. Then the conditions and characteristics in stable equilibrium state are elucidated employing the small parameter averaging method. Ultimately, the reliability and applicability of the theoretical results are substantiated through numerical simulations. The findings reveal that with the increase of the torsion spring stiffness, the phase difference between the motors connected by torsion springs (MCTSs) is exponentially decreased, and desired zero-phase synchronization in engineering is eventually achieved. Furthermore, the present study uncovers two distinct synchronization mechanisms in the torsion spring coupling system: mechanical controlled synchronization between MCTSs is inevitably achieved, while the self-synchronization between motors unconnected by torsion springs (MUTSs) is limited by the synchronization conditions. The study provides valuable insights for designing mechanical controlled synchronization and self-synchronization vibrating machines. [Display omitted] [ABSTRACT FROM AUTHOR]