Search Results (3)

In the field of handling, storage and transportation, chutes are used to transfer bulk solids between conveyors and warehouses. In these systems, traditional analytical methods based on the principles of continuum mechanics approximate an accelerated flow that contains the physical body solid properties obtained from standardized tests. Because it is difficult to physically observe the flow inside the transfer structure, there have been few studies to validate the method at full scale. In contrast, discrete element modeling (DEM) allows flow visualization through a transfer chute and qualitative and quantitative analysis if accurate simulation parameters are selected. In order to adapt to the needs of modern intelligent warehousing, we reduced the grain crushing and damage in the process of grain storage. To design and investigate the motion performance of grain particles in a sliding dustpan, this paper utilizes rocky simulation technology, combined with the corresponding bench experiments, to study the impact of the angle arrangement of the dustpan, and to verify the results of the simulation analysis based on the stress–strain analysis of the particle impact. It was found that when the angle of the dustpan arrangement was 40 degrees, the flow of all particles had a better performance in terms of pass ability and energy loss. In the continuous cycle obtained from the simulation, the particle group state at each moment is almost the same as the particle characteristics in the experiment, indicating that the angle of the bucket has an effect on the particle permeability. In this paper, the results of the study on the state of the grain group on the silo device will provide a useful reference for the design of a grain silo device. Full article

The impact and damage caused by debris flow on concrete bridges have become a typical disaster scenario. However, the impact disaster mechanism of debris flow on bridge structures remains unclear. This study focused on investigating the impact mechanism of debris avalanches on concrete bridge piers. By employing the discrete element numerical simulation method to examine the effect of debris on concrete bridge piers, the analysis explored the influence of three significant factors: the pier’s section shape, the impact distance, and the slope angle of the sliding chute. The discussions included the accumulation pattern of rock debris, the impact force on the pier, and the shear force and bending moment at the pier’s bottom, as well as the displacement and velocity response laws at the pier’s top. The results demonstrate that rectangularly shaped piers have a high efficiency in obstructing debris, leading to higher impact forces and internal forces on piers. Arched-shaped piers exhibit a short-duration, high-peak instantaneous impact from debris. Increasing the impact distance of the piers can significantly reduce the impact force of debris. The accumulation height of debris, pier impact force, and the pier’s bottom internal forces decrease and then increase with the increase in slope angles, with a 45° slope angle being the critical point for the transition of debris impact on piers. The results can provide references for the disaster prevention design of concrete bridge structures in hazardous mountainous areas. Full article

The global steel industry is rapidly transitioning towards energy decarbonization to address the climate crisis. Sintering is one of the main sources of greenhouse gas emissions from steel mills. Traditional sintering processes use straight inclined chutes to feed raw materials into the sinter machine. However, this design suffers from insufficient horizontal momentum, resulting in poor segregation of the layered materials. This study proposes an improved charging chute design profile that uses a cycloid curve and rolls to enhance segregation, thus reducing coal consumption and increasing productivity. To achieve this, we first modeled a charging chute using the cycloid curve. Secondly, building upon the cycloid concept, we created a roll-type chute by strategically placing rollers along the cycloid trajectory. Finally, the cycloid roll-type charging chute, integrating the cycloid trajectory with the roll-shaped charging chute, was simulated. Pilot tests comparing the cycloid roll-type and straight chute models demonstrated a significant increase in dispersion for the cycloid roll-type design, with a 65% improvement in the Strand-ward segregation (Sw) index compared to the straight chute. Furthermore, actual filed implementation in a sintering process achieved a 2.9% increase in operational productivity and a 6% reduction in fuel consumption. This study is significant not only for proposing an optimal chute design, but also for successfully implementing it in a full-scale steel mill, contributing to a reduction in fuel consumption and carbon reduction in steel mills. Full article