MATHEMATICAL SIMULATION OF THE MOVEMENT OF GRAIN MATERIAL ON THE SURFACE OF THE SPREADER UNDER ITS INTRODUCTION INTO THE ASPIRATION CHANNEL OF THE SEPARATOR

Develop a mathematical model and calculated analytical dependences to determine the trajectories and parameters of grain movement on the surface of the vibrating feeder under the conditions of its introduction into the aspiration channel of the separator. They are based on the methods of mathematical modeling and theoretical mechanics with the application of the equations of motion of a material point under the variable action of vibrations. Theoretical research was conducted using mathematical analysis and modeling theory. The research results are processed using elements of probability theory and mathematical statistics using application packages. A mathematical description of the movement of grains of grain material components (GMC) on the surface of the vibrating feeder under the conditions of its introduction into the aspiration channel of the separator under the conditions of vibration on the GMC. The trajectories of grains on the surface of the vibrating feeder with different size are obtained. The obtained equation of motion of the particle under the action of vibrations allows to determine the dependence of the velocity of the material in the vibrated fluidized bed on a number of factors: geometrical parameters of the vibrating feeder, feed angle, initial kinematic mode of grain material, kinematic mode of the vibrating feeder and friction coefficient. The process of grain material movement on the flat surface of the vibrating feeder is described, which allows to determine the rational parameters of material introduction into the aspiration channel of the separator for its further fractionation. The dependence for the function of the grain flow rate on the flat surface of the vibrating feeder is obtained, which allows to determine the parameters of the grain material distribution by the cross-sectional area of the aspiration channel of the separator. The velocity of grain material on the flat surface of the vibrating feeder is estimated on the basis of a mathematical model constructed by hydrodynamic analogy, which in turn determines the analysis of grain recombination by the thickness of the vibrated liquid layer of grain material.

Spiral Vibration Cooler for Continual Cooling of Biomass Pellets

Cooling is an important process during the production of pellets (as post-treatment). The pellet cooling process significantly impacts the quality of the pellets produced and the systematic use of energy. However, the cooling systems currently in use sometimes encounter technical problems, such as clogging of the perforated grids (sieves), the discharge hopper, or pellet degradation may occur. Therefore, a prototype of a new pellet cooling system using a vibrating feeder was tested. The aim of the study is to present a new variation of pellet cooling system using spiral vibration cooler as a possible solution next to a counterflow cooler. The presented system was tested (critically evaluated and discussed) in two design variants. The first variant consists in cooling by chaotic movement of the pellets. The second is then in combination with the chaotic movement of the pellets together with the action of intense air flow using specially placed air hoses. All tests involved pelletization of rapeseed straw. It was found that both cooling system variants could, realistically, be used. However, the variant with an intense air flow was more energy-intensive, a factor which is, however, offset by the higher quality of the pellets. No negative impact of vibrations to pellets quality was occur. Studies provide insight into new usable technologies that do not reduce the efficiency of the process as a result of grate clogging.

Automated Screwing of Fittings in Pneumatic Manifolds

The task of screwing is based on a set of actions with no added value, requiring precision, attention, and repeatability. These set of actions could consist of alienating and demanding activity for a human operator. Collaborative robotics can facilitate the performance of such tasks. This investigation focuses on the development of a smart station for the automated screwing of fittings in pneumatic manifolds. The collaborative robot Sawyer produced by Rethink Robotics is equipped with an appropriate end-effector and was utilized to receive the fittings from a vibrating feeder towards the end-effector. This facilitated centering of the fittings on the threaded holes, and the performance of the screwing task on a set of manifolds placed on a rotating station. The design of the end-effector and its prototype is described. In addition, the proposed automated process was experimentally tested and its effectiveness was validated.

Structure Optimization of Vibrating Feeder Based on Inertia Release

Reliability is a key factor in the design and manufacture of vibrating feeders. In this paper, a method considering materials force was proposed to optimize the structure of the vibrating feeder. Discrete Element Method (DEM) was used to couple the materials force and the excitation force based on the phase characteristics of the vibrating feeder, and Finite Element Method (FEM) was used to analyze the vibrating feeder structure based on the inertia release method. In order to reduce the stress on the beam of the vibrating feeder, three structural improvement schemes were proposed, which were constructing a statically indeterminate structure, increasing the width of the rib-stiffened plates on the beam, and increasing the internal spacing of the beam. Then, these three schemes were compared using the FEM. Finally, the response surface method was used to optimize the width of the inner and outer rib-stiffened plates. The research results showed that when the vibrating feeder moved close to the highest point, the materials force reached the peak. The maximum first principal stress occurred at the middle and both ends of the vibrating feeder beam under the joint action of the excitation force and the materials force. The first principal stress value of the beam was most significantly decreased by increasing the width of the rib-stiffened plates on the beam of three optimization schemes. The optimal increment of rib-stiffened plate width was 30 mm with the maximum first principal stress value reduced by 40.12%.

Effect of vibrating feeder pan geometry on radiometric separator performance

The article offers justifies the optimized shape for the vibrating feeder pan of a radiometric separator, which ensures the maximum travelling speed and uniform flow of ore material in the zone of radiation and recording. Three shapes of pans are discussed: rectangular, parabolic and triangular. It is found that motion of ore material along an inclined rectangular-shape pan is straight-linear. Distribution of ore particles along the width of the channel, which governs the scatter of the motion trajectories relative to the central axis of the channel, depends on the runoff point of particles from the outlet feeder. Proposed for the description of the motion trajectory of ore particles along an inclined channel of parabolic shape, the mathematical model demonstrates the curved and pendulum-wise motion of an ore particle with the attenuating amplitude. The motion of an ore particle in an inclined pan with the triangular-shape channel features the minimized scatter of motion trajectories relative to the central axis of the channel. The analysis of ore motion along vibrating feeder pans with different shape channels is carried out in Rocky DEM environment with regard to interaction of ore particles with the pan surface and with each other. The simulation modeling has proved the conclusions on the efficiency of the triangularshape profile of the vibrating feeder pan as it ensures uniform single-row flow of ore particles along the straight-line trajectory. The triangular shape of the pan contributes to the increased travelling speed of ore particles and, accordingly, to the enhanced capacity of the separator. The radiometric separator efficiency can be increased 1.5 times by changing from the parabolicshape channels to the triangular-shape profiles of vibrating feeder pans at the other operating conditions of radiometric separators being equal.

Improving the performance of vibration feeders with an electromagnetic vibration drive and a combined vibration system

Vibration loading devices are widely used in various branches of mechanical engineering to load piece blanks of automatic machines and automatic lines as well as robotic systems, automated systems and flexible automated production. Vibration devices for transportation and loading of miniature, small and medium-sized products are the most widely used. Modern designs of vibratory feeders, made according to the classical dynamic scheme and having a two-mass oscillating system, do not fully use the energy of the vibratory exciter to perform useful work. In addition, due to the presence of a heavy reactive mass, they have a fairly large weight. When the vibrating feeder is operating, the energy of the vibration exciter is spent on pumping both the hopper, which performs useful work, and the reactive plate, which performs idle vibrations. Thus, part of the energy of the vibration exciter is not used for performing useful work, but is spent idly. To increase the efficiency of the device, increase its performance and reduce its weight and metal consumption, it is necessary to change the design of the vibratory feeder and some of its elements, which affect the redistribution of the oscillation amplitudes of the working (hopper) and reactive mass of the vibratory feeder. Modern production involves the creation of new models of machines with high technical and economic indicators, therefore, improving the efficiency of existing equipment and the development of new schemes of machines is an important task for designers and manufacturers of technological equipment, as the minimum improvement of its technological and operational performance can lead to a tangible economic effect. To solve this problem we developed a new design vibrating hopper feeder, in which the increase of the horizontal component of the oscillation amplitude of the working element (hopper) is not at the expense of increased power of the vibratory exciter, but due to internal redistribution of energy between the elements of the oscillating system that makes better use of the energy of the vibratory exciter to perform useful work, i.e. to increase the coefficient of useful action. In addition, the weight and metal content of the vibrating feeder structure are simultaneously reduced.

Design of a centrifugal linear vibrating feeder driven by an eccentric motor

In this paper, a novel linear vibrating feeder is designed that uses the centrifugal motion of an eccentric motor as the driving source. First, the working principle of the linear vibrating feeder is theoretically analyzed and the dynamic model is established. Subsequently, a dynamic simulation of the system is carried out using ANSYS software. The relationship between the displacement amplitude, vibration speed, and frequency of the linear vibrating feeder prototype is tested using a three-dimensional vibrometer, with an OT-10A copper terminal used to test the prototype. The experimental results indicate that, at a vibration frequency of 125 Hz, maximum vibration speeds of 1.23 and 1.70 mm/s are reached in the X- and Z-directions, respectively. The corresponding maximum amplitudes are 0.7 and 0.99 mm, and the material feeding speed reaches a maximum value of 123 mm/s. Compared with similar piezoelectric and electromagnetic vibrating feeders, the total weight of the prototype is reduced by a third, the noise is reduced by more than 20 dB, and the driving voltage is only 3.6 V. Hence, the performance of the linear vibrating feeder has been successfully demonstrated.