Optimization Design of Extrusion Roller of RP1814 Roller Press Based on ANSYS Workbench

Firstly, the force of an extrusion roller under actual working condition was analyzed while the contact stress between the roller shaft and the roller sleeve and the extrusion force between the roller sleeve and the material were calculated. Secondly, static analysis of the extrusion roller was carried out using ANSYS software, and conclusively, the stress concentration appears at the roller sleeve’s inner ring step. Furthermore, an optimization scheme of the setting transition arc at the step of the contact surface between roller shaft and roller sleeve was proposed, and a simulation test was carried out., Finally, the maximum equivalent stress of the extrusion roller was set at the minimum value of the objective function; the extrusion roller was further optimized by using the direct optimization module in ANSYS Workbench. The results from optimization show that the maximum equivalent stress is reduced by 29% and the maximum deformation is decreased by 28%. It can be seen that the optimization scheme meets the strength and deformation requirements of the extrusion roller design. The optimization scheme can effectively improve the bearing capacity of the extrusion roller and reduce its production cost. This can provide a reference for the design of the roller press.

Analysis of the Temperature Distribution on the Surface of Saddle-Shaped Briquettes Consolidated in the Roller Press

The unit pressure in the fine-grained material consolidation process in the roller press can reach over hundred MPa and is a parameter which results, among other things, from the properties of the consolidated material and the compaction unit geometry. Its value changes depending on the place on the molding surface. Generating different pressure on the surface of briquettes makes their compaction different. One’s own and other researchers’ experience shows that, in the case of exerting high pressure on the merged fine-grained material, the higher unit pressure exerted on the material, the higher temperature of the consolidated material is. The temperature distribution on the surface of the briquettes can testify the locally exerted pressure on the briquette. The stress distribution in the briquetting material is still a subject of research. The article includes thermography studies of the briquetting process of four material mixtures. Thermal images of briquettes were taken immediately after they left the compaction zone as well as forming rollers. The obtained thermograms and temperature variability at characteristic points of the surface of briquettes were analyzed. The correlation between the temperature distribution and the stress distribution in the briquettes was determined.

The Analysis of the Morphology of the Saddle-Shaped Bronze Chips Briquettes Produced in the Roller Press

This paper presents the results of the investigations of the properties of saddle-shaped copper alloy chips briquettes produced in a roller press. The physical and mechanical properties of the investigated briquettes were examined on their external surfaces as well as on their cross-sections. The density, chemical composition, microstructure analysis obtained with a 3D and scanning microscope, surface roughness and hardness of the obtained briquettes were investigated. The research proved the differentiation of the physical and mechanical properties of briquettes depending on the investigated area of their surface. The analysis of changes in the porosity of briquettes on their cross-section showed zones of various densification levels. This research expands the knowledge of the processes taking place during the compaction and consolidation of granular materials in roller presses as well as the knowledge concerning designing the geometry of forming tools.

Ore crushing in the high-pressure roller-press as a modelling object under stochastic properties of feed materials

The results of improving ore crushing in a high-pressure roller-press are presented. Application of a roller-press enables higher crushing efficiency due to both power saving and reduction of sizes of ore crush products to release mineral aggregates. Ore disintegration by compressive strain prevails among currently applied crushing methods. Disintegration occurs not only due to the compressive, but also to the shear strain. Considering smaller power consumption of the shear strain than that of the compressive strain, it is concluded that roller-press application is quite efficient. Simulation of crushing by using the Bond law frequently applied in practice is under consideration. It is essential to consider the stochasticity of the ore flow to be crushed. Presentation of this flow as a random figure by transforming it by the Bond crushing law results in a probabilistic characteristic of the crushing result. This characteristic enables finding properties of the crush product and probabilistic formulation of the problem of improving the crushing process by setting a relevant functional. To apply the results obtained to practical uses, the crushing process is simulated. The theoretical results are confirmed by setting the stochastic properties of the input ore flow by means of Rosen-Rammler’s law followed by statistical substantiation of the conducted calculations in Mathcad. After stimulation and considering stochastic properties of the feed ore flow, the solution of the optimal stabilization problem reveals that stabilization is achieved, while dispersion in relation to the stabilization goal reduces sharply almost five-fold

The Wear on Roller Press Rollers Made of 20Cr4/1.7027 Steel under Conditions of Copper Concentrate Briquetting

This paper defines the wear process of rollers made of 20Cr4. Rollers with a diameter of 1000 mm were installed in a roller press used for the production of drop-shaped briquettes and the copper concentrate was briquetted for 1100 h. Three-dimensional (3D) geometry analysis, metallographic analysis, macroscopy, scanning electron microscopy, as well as hardness measurements were performed. It was observed that the working surface was non-uniformly worn. The smallest wear affects the molding cavities situated on the outermost edges of the ring. The wear increases as the center of the ring is approximated, and it reaches its maximum at the middle of the ring. The molding cavities also wear asymmetrically. For the shape considered in this study, the lower part of a cavity is subject to a higher wear rate. We found that the material of the working ring was carburized, but its hardness was significantly lower than required. The roller ring microstructure changes depended on the distance from the cavity’s face. An investigation of the wear mechanisms showed different types of abrasive wear, corrosive processes, and plastic deformation. The exact type and course of wear were described, depending on the location on the working surface.

The Influence of the Use of Polymer Lining within the Roller Press Gravity Feeder on Briquette Quality

When considering the operation of roller presses for the consolidation of fine-grained materials, the main problems are disturbances in the proper flow of the material and its bridging in gravity feeders. This is especially true for small and medium capacity presses, where the hoppers for dosing the material are narrow. This article presents innovative laboratory tests of the impact of using a polymer plate lining in the gravity feeder of a roller press. Polymer materials Polyacetal C (POM C) and Ultra-High-Molecular-Weight Polyethylene (UHMW-PE) were used for the tests. The influence of the use of plates on the material flow and quality of briquettes was investigated in comparison with the case where such plates were not used. The research showed an improvement in the flow of fine-grained materials in the feeder and an increase of the briquette strength indexes, as compared to those cases when polymer linings were not used in the feeder.

Exploring Efficiencies: Examining the Possibility of Decreasing the Size of the Briquettes Used as the Batch in the Electric Arc Furnace Dust Processing Line

Sintering of well-prepared briquetted mixtures in a shaft furnace is one of the possible methods of electric arc furnace dust (EAFD) utilization. Simultaneously, some metal oxides from exhaust gases can be separated. In this way, various metals are recovered, particularly zinc. As a result, zinc-free briquettes are produced with a high iron content, which can be used in the steelmaking process. This method is still being developed. In Ostrowiec Świetokrzyski, Poland, a prototype line of a new method for the reduction of zinc oxide in a shaft furnace with simultaneous sintering of briquettes was installed. The batch for the shaft furnace was actually briquetted in the roller press, which produces briquettes with a volume of 13 cm3. It may prove beneficial to reduce the size of the resulting briquettes, as a smaller size could prove more efficient in reducing zinc in the furnace. Decreasing the volume of the briquettes causes an increase in the power consumption in the drive system and brings an increase in the briquetting force, which occurred in the compaction zone. It could be harmful to the roller press construction. The aim of this article was to prove that decreasing the volume of briquettes of the EAFD mixtures had no negative effects on the roller press which was installed in the prototype line.