Table 1 - uploaded by G. Lodewijks
Content may be subject to copyright.
Source publication
Belt conveyors play an important role in continuous dry bulk material transport. Large scale belt conveyor systems consume a considerable amount of electrical energy. The approach of controlling the belt speed in such a way that the belt's volumetric capacity is fully utilised under all operational conditions has been proven to significantly reduce...
Context in source publication
Context 1
... calculate the acceleration operation with initial acceleration time, simulations are carried out to analyse the belt and motor dynamic performance in transient operation. Table 1 illustrates the common risks and their suggested solutions. With respect to the fact that changing the design of an existing conveyor is not practical, the general method of improvement is extending the ac- celeration time and reducing the peak value of acceleration. ...
Citations
... These vibrations can be classified as longitudinal or transverse 6,7 , depending on their direction relative to the conveyor belt. The longitudinal vibrations of the belt are an extensive research issue [8][9][10] and are related to the propagation and damping of stress waves in the conveyor belt 11 . The transverse vibrations referred to in the article are cyclic displacements of the belt in the vertical direction that occur between the idler sets. ...
The transverse vibration of conveyor belts is a crucial aspect in their proper and safe design, as the correct determination of vibration frequencies is essential to avoid unsafe operating conditions and premature wear of components. This study presents the Moving Compressed Beam (MCB) transverse vibration model, that is based on the interpretation of a conveyor belt as a beam known from the literature. This approach allows you to include in the model the transverse flexural rigidity of a troughed belt-a parameter that is closely related to the belt geometry. While not commonly used in engineering practice, the MSB model was compared with other models during the laboratory tests based on changing of trough geometry. This study emphasizes the significance of considering the transverse flexural rigidity of conveyor belts during the design process, and the MCB model which offers a promising approach in aspect of vibration control.
... The acceleration or deceleration of a highly loaded conveyor creates considerable tension in the belt, leading to local stretching or even breaking of the belt [4]. In this study we will neglect this effect and treat the belt as a rigid body with the same velocity everywhere. ...
The simulation of transport processes, though inherently continuous, is often done in a discrete-event simulation environment. In the case of conveyors for dry bulk material, this can lead to modeling difficulties, especially regarding the coupling of two conveyors with different velocities. We will present a modeling approach solving such problems, describe an implementation in SimEvents and present results of systematic tests.
... In this study, Maximum belt tension occurs at the intake and loading points on horizontal or inclined conveyors when the belt is continuously conveying the designed load from the loading point to the discharge point. He et al. (2016) expected that speed control of the conveying system may reduce the total energy consumption of the belt conveyor. According to the design parameters of the transfer conveyor shown in Fig. 3, the power requirement was calculated Theoretical analysis of power requirement of a four-row tractor-mounted radish collector for an inclined conveyor with a tail pulley drive using equations 3 to 11 (Piotr, 2011). ...
Development of radish collectors may enhance radish production and promote upland crop mechanization in the Republic of Korea. Theoretical analysis of power is crucial to ensure the optimum design of agricultural machinery. The aim of the present study is to analyze theoretically the power requirement of a tractor-mounted radish collector under development and to propose design guidelines. The important components of the radish collector were belt-type conveyors, three hydraulic motors, and a direct current (DC) winch motor to operate the total radish collecting process. Theoretical equations were used to calculate the hydraulic motor's power, winch motor power, and draft power at loaded and unloaded conditions. A variety of tractors (44-74 kW) and different soil characteristics (hard, firm, tilted, and sandy) were considered to investigate the appropriate drawbar power. Variations of the power requirement of the tractor-mounted radish collector were observed due to modifications of the design parameters. The required hydraulic power of the stem cutting conveyor, stem cutting blade, and transfer conveyor of the radish collector were 0.23 and 0.24, 0.18 and 0.19, and 0.19 and 0.22 kW under unloaded and loaded conditions, respectively. The maximum draft power was calculated as 0.89, 1.07, 1.25, and 1.61 kW at a 30° tilted angle for hard, firm, tilted, and sandy soil, respectively. The calculation showed 2.07 kW DC power was required for unfolding or folding the stem-cutting conveyor. A maximum power of 4.78 kW was prescribed for conducting the whole process of the tractor-mounted radish collector. The analysis of power introduced in this study will be helpful to select the appropriate design parameters for the successful development of a tractor-mounted radish collector.
... The acceleration or deceleration of a highly loaded conveyor creates considerable tension in the belt, leading to local stretching or even breaking of the belt [4]. In this study we will neglect this effect and treat the belt as a rigid body with the same velocity everywhere. ...
The simulation of transport processes, though inherently continuous, is often done in a discrete-event simulation environment. In the case of conveyors for dry bulk material, this can lead to modeling difficulties, especially regarding the coupling of two conveyors with different velocities. We will present a modeling approach solving such problems, describe an implementation in SimEvents and present results of systematic tests.
... The proposed models should be divided into several large groups. The most common are the models of the conveyor, which use the finite difference method (FDM) [11,12,13]; finite element method (FEM) [14,15]; method using the Lagrange equations [16]; the aggregated method [9]; the method using neural network [15,18]; the system dynamic method [19]; multi-regression analysis [20,21]. A comparative analysis of several groups of models was performed in [22]. ...
... The second group of models allows us to give average estimates the value transport system parameters, but they are not used to calculate the distribution of material along the route. In papers [11,12,14], the modes of acceleration and deceleration of the belt are studied, the stresses that occur in the belt are evaluated, and recommendations for controlling the speed in transient conditions are given. An estimate of the propagation speed of the perturbation is presented in [13]. ...
The article considers the causes of dynamic stress when moving a conveyor belt with a material. The main factors of the occurrence of the dynamic resistance in the conveyor system are defined. It is demonstrated what the propagation speed of perturbations substantially depends on the loading level of the conveyor system with the material. When constructing a model of dynamic stresses, Hooke’s law was used, which is an accurate approximation for most solid bodies, as long as the forces and deformations are small enough. In the article, the main attention is given to the causes of dynamic stresses at the start of the conveyor system. When calculating the deformations, the inertia forces of the moving material and tape are considered. The analysis of the appearance of dynamic stresses at a constant value of the conveyor belt acceleration and the linear nature of the change in the value of the conveyor belt acceleration was carried out.
... Improper and frequent speed changes can cause serious damage to the belt conveyor elements if there are no appropriate restrictions. He, Pang and Lodewijks [14][15][16] note that in temporary acceleration or deceleration operations there are risks of belt slipping, material spilling away from the belt, belt breaking at the splicing area, motor over-heating and pushing the motor into regenerative operation. ...
... Ristic [8] suggests that the belt speed should be adjusted only if the needed speed is at least 10% higher than the current belt speed, while He, Pang and Lodewijks [15] suggest that it should be at least 15% higher, i.e. tyj -vt ft) ...
Belt conveyors play a very important role in the continuous transport o f bulk and piece material, especially in the mining industry. However, the use o f belt conveyors results in high electricity consumption. A reduction in the power consumption can be achieved by adjusting the speed o f the belt conveyor to match the material flow. However, inappropriate and frequent speed changes can cause serious damage to the conveyor elements. This paper presents a procedure for adjusting the belt conveyor speed to match the profile o f the material on the belt, as well as a detailed procedure for determining the time needed to accelerate/decelerate the belt conveyor. The research was performed on an actual 640 m long belt conveyor used for transport o f overburden at the surface mine Drmno (Serbia). The simulation results show that the speed regulation is completely justified because the conveyor operated at speeds lower than nominal throughout the testing.
... Among the common models of the control object used to design the control algorithms of the conveyor-based transport system, it is worth mentioning the models using the Finite Element Method (FEM) [3,25,26,27], the Finite Difference Method (FDM) [21], and the Discrete Element Method (DEM) [5,28]. The Discrete Element Method used by Cundall in 1971 to solve rock mechanics problems can be considered as a generalization of the Finite Element Method (FEM). ...
In this paper, the design method of optimal control for the conveyor-based transport system, when the quality criterion contains a variable delay in the controls, has been considered. The task of optimal control has been set and the Hamiltonian of the system has been written taking into account the delay in the controls. In the design of optimal control by the flow parameters of the transport system, a control object model containing partial differential equations was used. The mechanism that forms a variable value of the transport delay in the flow parameters of the transport system has been shown. Two characteristic modes of the conveyor system functioning are considered as follows: a transient state, when the value of the linear density at the transport system output is determined by the initial distribution of material along the transport route, and a steady-state state, when the value of the linear density at the transport system output is determined through the values of the movement speed of the conveyor belt and the intensity of the material at the conveyor section input. Equations that make it possible to calculate the controls of the flow parameters of the transport system for which the Hamiltonian of the system satisfies the Hamilton–Jacobi equation have been provided. Controls of the flow parameters are synthesized for the case when the phase coordinate does not reach the limits. It is shown that for the synthesis of controls, it is necessary to predict the magnitude of the output flow from the transport system.
... The overlook of belt dynamic behaviour may lead to problems like belt slipping or material spillage. Belt dynamics in transient operation was analysed in Ref. [13]. A finite element model of belt conveyor was built to analyse the dynamics. ...
Belt conveyor systems play an important role in dry bulk material handling. Speed control is a promising solution to improve energy efficiency of belt conveyors. Active speed control algorithm was proposed for application on individual belt conveyor. This work investigates its application on a multi-belt conveyor system. The Delft Systems Approach is used to model both operation and control systems. The dynamic behaviour of conveyor belts during transient state is taken into consideration. A Simulation study of a dual-belt conveyor system is carried out to verify the proposed active speed control algorithm. Simulation results show that during eight hours’ operation, active speed control can achieve hourly average energy saving of 16.21% compared with constant speed operation scenario. The simulation study verifies that active speed control on belt conveyor systems leads to more sustainable operation.
... Simulation model for the two degree differential equation was prepared in mathematical solver simulink [13]. Gravity take-up mass is divided equally to adjacent units [14]. Initial condition at conveyor started, ̇ spring and damping constants are formulated based on the belt properties for each unit. ...
