Steel Cord Conveyor Research Articles

EMD-based noise reduction study of steel cored conveyor belt containing slag signal

This paper proposes a noise reduction technique that combines empirical mode decomposition (EMD) and wavelet thresholding to eliminate the noise interference caused by metal slag in the steel cord conveyor belt damage signal. Initially, the original signal undergoes decomposition by EMD into high- and low-frequency intrinsic mode function (IMF) components based on metal slag signal feature analysis. The wavelet threshold de-noising method is then applied to filter out the high-frequency noise while preserving the low-frequency IMF components. The IMF components containing slag noise are discarded, and the filtered signal and the low-frequency IMF components are used for signal reconstruction to obtain an optimal noise reduction effect. The study demonstrates that this method is more effective in suppressing metal slag noise, environmental noise, and other noise interferences than traditional EMD decomposition noise reduction and wavelet threshold noise reduction methods. This research provides a valuable reference for noise reduction in steel cord conveyor belt detection data.

Dynamics modeling and simulation of steel cord conveyor belt based on dynamic elastic modulus

Steel cord conveyor belts are widely used in long-distance transportation of various materials. The steel cord belt is composed of rubber and steel cord core, exhibiting excellent viscoelasticity and complex dynamic characteristics during operation. The existing static elastic modulus cannot accurately reflect the real dynamic properties of the conveyor belt. In this paper, based on the catenary theory, the formula for the dynamic elastic modulus of the conveyor belt is derived by introducing the sag and elastic deformation of the steel cord conveyor belt on the basis of the static elastic modulus. The dynamic modeling of the steel cord conveyor belt is carried out using rigid belt block element + flexible beam method. Then, the RecurDyn software is used to establish the dynamic simulation system of the belt conveyor and conduct simulations, which are validated through a test bench. The results show that dynamics simulation based on the dynamic elastic modulus is closer to the real dynamic characteristics of the belt conveyor. Finally, the dynamic characteristics of belt conveyors under different start-up times, different start-up speeds, and idler spacing are analyzed using this modeling and simulation method. The results demonstrate that the dynamic elastic modulus can accurately reflect the real dynamic properties of the conveyor belt, providing a more accurate dynamic modeling and simulation method for the design of belt conveyors.

Research on the tension of steel cord conveyor belts based on transverse vibration modelling

The accurate non-contact tension measurement of steel cord conveyor belt, an important load bearing medium, is critical for long distance belt conveyors. It is necessary to establish the relationship between the conveyor belt transverse vibration and the tension, in order to analyse the conveyor belt tension changes through indirect measurement of transverse vibration. The paper analyses the existing models of transverse vibration in conveyor belts, and finds that these models can hardly directly and accurately calculate the tension of the conveyor belt. Therefore, modifications are needed. Firstly, the paper establishes a dynamic model of the belt conveyor and conducts simulation analysis using RecurDyn software. This allows the authors to obtain the belt tension and transverse vibration displacement of the conveyor belt. Fast Fourier transform is employed to determine the vibration frequency, which is used to evaluate the vibration characteristics of conveyor belts under different operating conditions. Then, the paper conducts simulation analysis on the frequency and tension of the belt conveyor with different idler spacing, and performs nonlinear least squares calculation in MATLAB software to modify the coefficients of the transverse vibration model. This process involves nonlinear fitting, resulting in an improved transverse vibration model. Finally, the modified transverse vibration model is compared with the original model. The modified transverse vibration model can more accurately calculate the tension of the conveyor belt based on its vibration frequency. The validity of the modified model is verified by different types of conveyor belts.

Application of EMD combined with wavelet algorithm for filtering slag noise in steel cord conveyor belt

This study proposes a noise reduction technique that combines empirical mode decomposition (EMD) with wavelet thresholding to remove noise interference generated by metal slag in the damage signal of steel cord conveyor belts. The initial step involves decomposing the original signal into high-frequency and low-frequency intrinsic mode function (IMF) components using empirical mode decomposition (EMD), guided by the metal slag signal characteristics analysis. The high-frequency noise is filtered away while the low-frequency IMF components are kept intact through the wavelet threshold de-noising technique. The slag noise-containing IMF components are deleted, and the filtered signal and the low-frequency IMF components are utilized for signal reconstruction to provide the optimum noise reduction result. The study demonstrates that this method is more effective in suppressing metal slag noise, environmental noise, and other noise interferences than traditional EMD decomposition noise reduction and wavelet threshold noise reduction methods. This research provides a valuable reference for noise reduction in steel cord conveyor belt detection data.

Analysis of the Influence of the Type of Belt on the Energy Consumption of Transport Processes in a Belt Conveyor

Results of tests into the energy-efficiency of belt conveyor transportation systems indicate that the energy consumption of their drive mechanisms can be limited by lowering the main resistances in the conveyor. The main component of these resistances is represented by belt indentation rolling resistance. Limiting its value will allow a reduction in the amount of energy consumed by the drive mechanisms. This article presents a test rig which enables uncomplicated evaluations of such rolling resistances. It also presents the results of comparative tests performed for five steel-cord conveyor belts. The tests involved a standard belt, a refurbished belt and three energy-saving belts. As temperature significantly influences the values of belt indentation rolling resistance, the tests were performed in both positive and negative temperatures. The results indicate that when compared with the standard belt, the refurbished and the energy-efficient belts generate higher and lower indentation rolling resistances, respectively. In order to demonstrate practical advantages resulting from the use of energy-saving belts, this article also includes calculations of the power demand of a conveyor drive mechanism during one calendar year, as measured on a belt conveyor operated in a mine. The replacement of a standard belt with a refurbished belt generates a power demand higher by 4.8%, and with an energy-efficient belt—lower by 15.3%.

EPDM/SBR Blends for Skim Compound of Steel Cord Conveyor Belt: Mechanical Properties, Thermal Stability and Adhesion Level

In this paper, the influence of some ingredient concentrations such as SBR ratio, DCP/S, CBS/DPG accelerator, EPDM-g-AM and cord surface on mechanical, thermal aging properties and adhesion between rubber compounds and cord have been investigated. The results showed that with suitable ingredients loading such as EPDM/SBR is 85/15 phr, DCP/S is 2.0/1.5 phr and EPDM-g-AM content is 2.0 phr with respect to rubber, the vulcanizates had good mechanical properties, thermal stability and adhesion level to the zinc/copper galvanized cord. The highest tensile strength, elongation at break and pull out strength reached 18.1 MPa, 432% and 60.3 N/mm respectively, and the highest retention after thermal aging at 150°C for 168 hours was about 0.76.

Path Optimization of Gluing Robot Based on Improved Genetic Algorithm

The steel cord conveyor belt surface is prone to damage in mining. The worn belt surface has acceleration characteristics, so timely and rapid repair is very necessary. To quickly and automatically repair the worn belt surface is a core design objective of the gluing robot (GR). Based on this objective, a new variant Traveling Salesman Problem (TSP) is put forward: after the worn segments are divided according to the worn information and GR’s workspace, path optimization of the gluing robot (POGR) problem is presented at a certain worn segment; then the POGR is simplified into a “double vertices” TSP problem by Hamilton graph, and the mathematical model is built. An improved genetic algorithm (IGA) is proposed to handle the POGR problem, which is called IGA-POGR. The main benefit of the proposed IGA-POGR is the ability to solve POGR of different scales in different ways. The performance of the IGA-POGR is illustrated on four well-known TSP problems. Numerical results show that IGA-POGR does not give any deviation (0%) from the optimal solution. Compared with discrete particle swarm optimization (DPSO), IGA-POGR has better performance in terms of the solving quality and time consumption when solving four idealized POGR problems.

Quantitative analysis of bond and splice strength of steel cord conveyor belt

Steel cord conveyor belt has the advantages of high tensile strength, high friction resistance and strong impact resistance. It is widely used in coal, mining, port, electric power and other fields. The splice area is the weakest link in the whole steel cord conveyor belt, and the splice deformation often occurs. In order to prevent a serious belt breakage accident, we need know the quantitative relationship between splice deformation and splice strength clearly. In this paper, the finite element simulation analysis is carried out on the relationship between deformation and strength of steel cord conveyor belt splices. The change of the bond strength between steel cord and rubber under the action of external force is mainly studied. The emphasis is on the influence of length, number and diameter of steel cords. In these three different factors, the value of A is different. At the same time, we have also analyzed each situation accordingly. Finally, the quantitative relationship between the splice deformation and the overall strength of the splice was summarized. The research results can provide theoretical basis for safety inspection, splice performance analysis, maintenance and renewal of steel cord conveyor belt.

Analysis of Strength Factors of Steel Cord Conveyor Belt Splices Based on the FEM

Conveyor belt is an important element of the conveyor. The strength of the steel cord conveyor belt largely determines the carrying capacity, and it also has a great impact on operational safety. In this paper, the effect of different factors on the strength of the steel cord conveyor belt splices was studied. The FEM was used for simulation analysis, and the corresponding tensile experiments were carried out to verify. Steel cords of different lengths were simulated, and the simulation results agree well with the experimental results. On this basis, the steel cord length, steel cord diameter, rubber thickness, and different number of steel cords were investigated to study the effect on the pullout force of the steel cord conveyor belt splice. The numerical simulation results show that different steel cord diameters have more significant effect on the strength of the conveyor belt splice compared to rubber. The steel cord length and steel cord diameter impact on the steel cord conveyor belt is approximately linear. For the different number of the steel cords, the increase in the number of steel cords does not mean that the tension will increase by the same multiple, and the increase in pullout force is less than the increase in the number of steel cords. It provides guidance for the production of steel cord conveyor belts.

Magnetic methods in monitoring changes of the technical condition of splices in steel cord conveyor belts

The article focuses on problems related to diagnosing splices in steel-cord conveyor belts. Data used for the analysis was acquired from belt core testing using the HRDS system. The measurement data served to extract and describe several parameters, whose values depend on the geometry and technical condition of the splice. Initial results have shown that evaluation of the technical condition of the splice can be performed using statistical analysis.

Forecast of the remaining lifetime of steel cord conveyor belts based on regression methods in damage analysis identified by subsequent DiagBelt scans

Changes of damage to the belt core that are not controlled during the exploitation can lead to dangerous accumulation of the defects (strains) in the cross-section. It can lead to serious weakness and even rupture of the belt. Early detection of the microdamage of the covers and evaluation of the increase speed of the damage allows the user to plan maintenance more precisely. Furthermore, it allows more effective cost management when conveyor belt maintenance is scheduled.This paper is based on the data gathered with the use of the DiagBelt mobile system for non-invasive diagnostics of conveyor belts with steel-cord core. The object of the tests comprised a slow-burning ST 3150 conveyor belt, having width B-1200. The tests were performed on a belt conveyor operated in a Polish underground mine. Four tests were performed at different time intervals in order to monitor the development of conveyor belt core damage. The regression model was based on data gathered from several sections of the inspected belt and on three indicators of defects (the sum, the number and the surface of defects). The analysis was performed not only for the linear regression model, but also for the quadratic regression model, which seems to provide promising results.

Influence of Natural Aging Processes in Steel Cord Conveyor Belt on Adhesion Between Core and Covers

The paper presents the results of tests on the changes in adhesion strength of the rubber covers to the core of a conveyor belt type St 3150. The investigations focused on four conveyor belts from the same manufacturer, produced in 1987, 1998, 2007 and 2016. The tests demonstrated that the values of adhesive strength decreased with time. The decrease of this parameter was caused by the natural aging of belts operated in a mine and therefore exposed to various atmospheric factors such as variable ambient temperature, snow, rain and solar radiation. The results of adhesion strength tests of the cover to the steel cord served to evaluate the usefulness of such belt in further operation on belt conveyors. The evaluation was made with regard to the admissible values for belts operated in a mine.

An Improved Skewness Decision Tree SVM Algorithm for the Classification of Steel Cord Conveyor Belt Defects

Skewness Decision Tree Support Vector Machine (SDTSVM) algorithm is widely known as a supervised learning model for multi-class classification problems. However, the classification accuracy of the SDTSVM algorithm depends on the perfect selection of its parameters and the classification order. Therefore, an improved SDTSVM (ISDTSVM) algorithm is proposed in order to improve the classification accuracy of steel cord conveyor belt defects. In the proposed model, the classification order is determined by the sum of the Euclidean distances between multi-class sample centers and the parameters are optimized by the inertia weight Particle Swarm Optimization (PSO) algorithm. In order to verify the effectiveness of the ISDTSVM algorithm with different feature space, experiments were conducted on multiple UCI (University of California Irvine) data sets and steel cord conveyor belt defects using the proposed ISDTSVM algorithm and the conventional SDTSVM algorithm respectively. The average classification accuracies of five-fold cross-validation were obtained, based on two kinds of kernel functions respectively. For the Vowel, Zoo, and Wine data sets of the UCI data sets, as well as the steel cord conveyor belt defects, the ISDTSVM algorithm improved the classification accuracy by 3%, 3%, 1% and 4% respectively, compared to the SDTSVM algorithm. The classification accuracy of the radial basis function kernel were higher than the polynomial kernel. The results indicated that the proposed ISDTSVM algorithm improved the classification accuracy significantly, compared to the conventional SDTSVM algorithm.

Influence of different cord pitch on the pullout force of steel cord conveyor belt splice

The splice is the weakest part of the entire steel cord conveyor belt. And it occurs steel cord twitch fault frequently. If this fault cannot be dealt with timely and accurately, broken belt accidents would be occurred that affecting the safety of production seriously. In this paper, we investigated the different cord pitch pullout of the steel cord conveyor belt splice by using ABAQUS. The finite element model of the ST630 type steel cord conveyor belt was established, same as to the standard of the experimental sample. The pullout force of length 50.0, 70.0, 80.0 and 100.0 mm single steel cord impacted at steel cord conveyor belt splice was numerically computed respectively. The finite element model consists of rubber, steel cord and failure unit. Failure unit is used to simulate the bonding relationship between steel cord and rubber. Mooney-Rivlin hyper-elastic model for rubber was employed in the numerical simulations. Typical results obtained have been validated by experimental result and the relative error between simulation results and experimental results is within 10%. Simulations were also done for cord pitch of 4.0, 4.5, 6.0, 7.0 and 8.0 mm to study its effect on the pullout force of steel cord conveyor belt splice. The variation of cord pitch at normal impact was found to have influence as long as the cord pitch was different. It provides us the numeric value of the pullout force with the different cord pitch, and conducts us selecting the correct steel cord configuration spacing for the steel cord conveyor belt splice, as well for the steel cord conveyor belt. This is an efficient way for avoiding the steel cord twitch fault and the broken belt accident, while ensuring their high reliability and service life.

Finite element simulation and experimental verification of steel cord extraction of steel cord conveyor belt splice

The splice is the weakest part of the entire steel cord conveyor belt. And it occurs steel cord twitch fault frequently. If this fault cannot be dealt with timely and accurately, broken belt accidents would be occurred that affecting the safety of production seriously. In this paper, we investigate the steel cord pullout of the steel cord conveyor belt splice by using ABAQUS software. We selected the strength of steel cord conveyor belt ST630, the same as experiment sample in type specification. The finite element model consists of rubber, steel cord and failure unit. And the failure unit is used to simulate the bonding relationship between the steel cord and the rubber. Mooney-Rivlin hyper-elastic model for rubber was employed in the numerical simulations. The pullout force of length 50.0 mm single steel cord, on both sides of a single steel cord and on both sides of the double steel cords each impacted at steel cord conveyor belt splice were numerically computer and typical results obtained have been validated by experimental result. It shows that the relative error between simulation results and experimental results is within 10% and can be considered that the simulation model is reliable. A new method is provided for studying the steel cord twitch fault of the steel cord conveyor belt splice.

The use of magnetic sensors in monitoring the condition of the core in steel cord conveyor belts – Tests of the measuring probe and the design of the DiagBelt system

The DiagBelt system for monitoring the technical condition of conveyor belts comprises five modules: a vision module, a magnetic module, a prediction module, a rip detection (prevention) module, and a safety factor module. This article focuses on the magnetic module, which consists of the BeltGuardTM measuring probe and the DiagBelt application, the latter being used to process the digital signal produced by changing magnetic field generated around defects in the magnetized steel cord. Owing to the high resolution of the multi-coil measuring probe, it is possible to detect not only cuts of individual cords but also broken wires in the cords, and even the corrosion of cords in the core. The application automatically and precisely detects the location of defects along the belt axis and on the belt section (due to the position of the coil which traces the changes in the magnetic field). It also detects the location of all splices in the belt loop. This function allows the changes to be visualized as a 2D image of belt core defects on all belt sections and splices. The system automatically divides the belt into sections and counts the defects and their surface area, thus offering useful damage measurement units such as damage density or damage surface area per 1 running meter of belt. These in turn serve as the basis for a color-coded image showing the condition of belt loop sections in the DiagBelt system. Such comprehensive diagnostics of conveyor belts and their splices reduces the number of unexpected failures and facilitates the planning of maintenance works and of belt replacement procedures, thus contributing to improved conveyor belt management.

The influence of natural ageing processes on the strength parameters of steel cord conveyor belts

The article presents an analysis of the influence of the natural ageing time on the strength parameters of steel cord conveyor belts. The investigated phenomena include the influence of temperatures both above and below 0 °C, as well as exposure to sun, rain and snow. The tests were performed on conveyor belts which have been operated in the Bełchatów lignite mine for 30 years, transporting ROM material. The tests included adhesion of the steel cords to the belt’s core rubber and the tensile strength of both the carry and the pulley covers. The obtained results allowed determining the number of years after which belts operated in mines lose their properties. The results also indicate how long a conveyor belt, after launching it into service, retains such strength parameters that enable its further usage after revulcanisation. This information is of significant importance for the splicing and regeneration processes.

Regression method-based analysis of damage development in the core of steel cord conveyor belts

This paper is based on the data gathered with the use of the DiagBelt mobile system for non-invasive diagnostics of conveyor belts with steel-cord core. The object of the tests comprised a slow-burning ST 3150 conveyor belt, having width B-1200. The tests were performed on a belt conveyor operated in a Polish underground mine. Four tests were performed at different time intervals in order to monitor the development of conveyor belt core damage. The regression model was based on data gathered from several sections of the inspected belt and on three indicators of defects (the sum, the number and the surface of defects). The analysis was performed not only for the linear regression model, but also for the quadratic regression model, which seems to provide promising results.

Automatable Splicing Method for Steel Cord Conveyor Belts – Evaluation of Water Jetting as a Preparation Process

The increased demand of mineral resources leads to worldwide application of incessantly longer conveying systems. The length between axes can amount to 15 km and more. Owing to manageable dimensions and weight, appropriate conveyor belts are produced in segments of up to 300 m. Final assembly takes place at the conveyor system, where the multitude of segments is connected to a long conveyor belt. An important point in assembly preparation is the stripping of the steel cords, which is mainly carried out manually using rudimentary techniques. The optimization potential is high, since the adoption of automatable and application-oriented preparation methods can minimize the conveyor downtime and improve the joint quality. In this study, the application of the pure water jet is investigated, since this selective stripping method offers a lot of potential for automation and the creation of rough surfaces. The objective was to determine if an efficient, homogenous and selective removal of the rubber is possible without damaging the zinc coating of the steel cords. Following a parameter study, the generated kerf geometries and surfaces were investigated. The stripped steel cords and zinc coatings were analyzed through the preparation of micrographs. Concluding, an evaluation about the qualification of water jetting as an automatable method for joint and repair preparation is made.

Noise Reduction of Steel Cord Conveyor Belt Defect Electromagnetic Signal by Combined Use of Improved Wavelet and EMD

In order to reduce the noise of a defect electromagnetic signal of the steel cord conveyor belt used in coal mines, a new signal noise reduction method by combined use of the improved threshold wavelet and Empirical Mode Decomposition (EMD) is proposed. Firstly, the denoising method based on the improved threshold wavelet is applied to reduce the noise of a defect electromagnetic signal obtained by an electromagnetic testing system. Then, the EMD is used to decompose the denoised signal and then the effective Intrinsic Mode Function (IMF) is extracted by the dominant eigenvalue strategy. Finally, the signal reconstruction is carried out by utilizing the obtained IMF. In order to verify the proposed noise reduction method, the experiments are carried out in two cases including the defective joint and steel wire rope break. The experimental results show that the proposed method in this paper obtains the higher Signal to Noise Ratio (SNR) for the defect electromagnetic signal noise reduction of steel cord conveyor belts.