| 1. |
- Asbjörnsson, Gauti, 1985, et al.
(author)
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Modelling of Discrete Downtime in Continuous Crushing Operation
- 2015
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In: Computational Modelling 2015, MEI conference.
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Conference paper (peer-reviewed)abstract
- Crushing is a harsh process and production units are subjected to wear and failure over time which will reduce the overall performance of the plant. To achieve optimum process performance, both time dependant process dynamics and operating conditions should be taken into account.In this paper the aim is to create a framework for simulating the process from a more operational perspective to evaluate process performance and process optimum for different operational scenarios. The objective is to model and simulate the discrete phenomena that can cause the process to alter performance and implement it with dynamic process simulations. A method for combining discrete probability simulations with time-continuous simulations for process evaluation and optimization is presented. The proposed framework demonstrates a systematic approach to evaluate the process performance and locating optimum process configuration, for a given condition. The developed models can be used to optimize different aspects of the operation depending on the defined objective function and the system boundaries. Optimization of process throughput by manipulating configuration of both the grizzly and the crushers, as well as the time between calibrations has been illustrated in this paper. Adjusting the process continuously and calibrating it at the appropriate time can have major benefits when it comes to the process availability and utilization, increasing performance by 4.1-9.3 % in these cases. Evaluation of process robustness with regards to different maintenance strategies and process variation gave an indication of the process and unit performance under a long operating period. By combining discrete and dynamic simulation, a higher simulation fidelity can be achieved to provide a more operational perspective to the optimization and process analysis.
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| 2. |
- Bengtsson, Magnus, 1973, et al.
(author)
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ADVANCED MATERIAL MODELLING IN CRUSHING PLANTS USING REAL TIME ALGORITHMS
- 2015
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In: Computational Modelling 2015, MEI conference.
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Conference paper (other academic/artistic)abstract
- In process control of crushing plants the traditional control is focused on stability control ofsingle machines and not on controlling material utilization. The reason for this is that the use ofmaterial property models is not that well known. The material models describe properties as e.g.capacity over time for a given product and this may depend on many parameters and dynamic effectsin the process. Due to this it is complicated to model and thus a methodology is needed to solve thisproblem. In this paper a novel method for modeling the current effect that the production units haveon the material presented. The paper presents a methodology how to use process data from SCADAsystem to analyze and suggest dynamic material model properties in real time.
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| 3. |
- Bengtsson, Magnus, 1973, et al.
(author)
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Cost And Performance Optimization Of A Tertiary Crushing Stage
- 2015
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In: ESCC 2015 Conference. - Göteborg : Chalmers University of Technology. - 9789188041012
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Conference paper (peer-reviewed)abstract
- There is increasing demand to optimise performance and profit of crushing plants. Research in this area has resulted in the development of numerous optimisation tools, and resent research has shown that the quality aspects of production have great influence on the optimisation results. The quality, cost, profit and capacity of a product is influenced by several parameters, and in order to control all of these parameters it is necessary to use some sort of optimisation software. In this paper, a novel approach use the parameters cost, profit, capacity and quality in order to perform a multi objective optimization of a crushing plant is presented. As an example a tertiary crushing stage consistent of a cone crusher and a vertical shaft impact crusher (VSI) is used as base for the designed objective function. The process has a given set of constraints that represents the conditions normal in these type of crushing applications. The first step in this paper is to identify if the range of the constraints can cause undesirable production costs when reaching for a given product property. The next step in the optimization shows how a strategy for relaxing constraint can increase overall productivity and still reach certain product properties. The conclusions made in this work are that multi objective optimization is essential when optimizing crushing plant production against multiple objectives. Relaxation of constraints can increase the overall performance of the crushing plant.
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| 4. |
- Bengtsson, Magnus, 1973, et al.
(author)
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Framework for material modelling in a processing plant
- 2015
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In: Computational Modelling ‘15.
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Conference paper (peer-reviewed)abstract
- Material modelling within a crushing plant is closely dependent on both manual and automatic operations as well as a close follow up on the utilization of the plant performance from a management perspective. The desire to fully be able to utilize the crushing plant with respect e.g. to material handling is limited due to the lack of possibility to fully observe actions within the process. There are large quantities of data that can be monitored in the crushing plant SCADA system. However the data collected are governed by the quantity of actual sensors in the process. The aim with this paper is to propose a method for how-to pre-process the automatically gathered SCADA data in order to fill up dynamic models for process simulations. There is a fundamental need to increase the resolution of how the crushing plant behaves. This will be structured as a framework for analysing and suggesting model improvements that will increase the utilization and decrease both manual operations and give better performance when controlling the process.
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| 5. |
- Bengtsson, Magnus, 1973, et al.
(author)
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Improving Yield and Shape in a Crushing Plant
- 2009
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In: Proceedings of 12th European Symposium on Comminution and Classification (ESCC2009).
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Conference paper (peer-reviewed)abstract
- There is increasing demand to optimise yield and increase capacity of crushing plants. Research in this area has resulted in the development of numerous optimisation tools, and resent research has shown that the quality aspects of production have great influence on the optimisation results. The quality and capacity of a product is influenced by several parameters, and in order to control all these parameters it is necessary to use some sort of optimisation software. In this paper, a novel approach to analyse parameters influence on product capacity and quality is presented. As an example a cone crusher and a vertical shaft impact crusher (VSI) is simulated in a tertiary stage. The simulation shows how capacity and product quality for a range of products will be affected when a parameter is changed. The paper also shows how wear will affect product capacity and quality.
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| 6. |
- Bhadani, Kanishk, 1991, et al.
(author)
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Application of Multi-Disciplinary Optimization Architectures in Mineral Processing Simulations
- 2018
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In: 11th International Comminution Symposium. - 9781510883789
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Conference paper (peer-reviewed)abstract
- Optimization is a pivotal point in distinguishing the competitiveness between industries that are developing, designing and operating products and processes. Mineral processing is an industry which operates various sub-processes and produces one or several products. The sub-processes involved are dynamic in nature and differs in discipline of operation. These dynamic sub-processes are sequentially integrated forming a mineral processing system. Currently, the developed simulations for the mineral processing systems have the potential to be used to design, operate and control mineral processing plants to an increased extent, but need broader optimization strategies to integrate multiple sub-processes involved. The scope of this research is to demonstrate application of multi-disciplinary optimization (MDO) architectures into a mineral processing simulation. A case study consisting of two sub-processes of comminution and classification circuits to produce aggregate products is used to demonstrate the application of MDO architectures. The MDO architectures are compared based on problem formulation, computational resources required and validity of the results. The optimization results using MDO architectures can be used to illustrate trade-offs between different sub-processes within the considered scope. The application of MDO architectures can facilitate the linking mathematical models of various disciplines such as comminution, and liberation in mineral processing simulation.
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| 7. |
- Bhadani, Kanishk, 1991, et al.
(author)
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Application of Structural Optimization for an Early Stage Product Development
- 2017
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In: NAFEMS World Congress 2017, A World of Engineering Simulation, Stockholm, Sweden. - 9781910643372 ; , s. 13-
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Conference paper (peer-reviewed)abstract
- In today’s automotive industry there is a growing demand for more fuel efficient vehicles and reduced development times. These trends are driven by stricter environmental regulations, a growing environmental awareness, and increasing technological development and competitiveness. Finding an optimized and balanced component that fulfils the requirements in an early phase of the product development is a prerequisite for enabling more competitive lead times, costs, weights and minimizing the risk for late design changes. The aim with this paper is to show a process capturing CAE driven development for an early stage development of components in a complex system. The process utilizes structural optimization techniques to generate knowledge, optimize and balance packaging volumes of adjacent components in complex systems. The paper also highlight the organizational challenges and technical challenges involving the use of structural optimization for realizing the process completely. The paper will illustrate the simultaneous use of topology and shape optimization to generate knowledge for the optimized design volume for multiple adjacent components linked together. The linking of the multiple component is carried out using morphing technique and the design space between the multiple components is dynamic in nature during simulation. The mesh in one component is allowed to change according to the mesh of the other component during the simulation. The result from the simultaneous topology and shape optimization simulation generates the knowledge if it is feasible to change design volume to meet the weight and performance targets. The process also indicates how much performance increase is possible if the design volume is allowed to change and thus generating a trade-off between the components performance.The new process has a potential to be extended to other conflicting scenarios in adjacent components which exists in early stages of development process especially, cases involving conflicting structural requirements in various industries.
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| 8. |
- Bhadani, Kanishk, 1991, et al.
(author)
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State of the Art in Application of Optimization Theory in Minerals Processing
- 2017
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In: European Symposium on Comminution and Classification, Izmir, Turkey.
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Conference paper (other academic/artistic)abstract
- There has been continuous development going over the past 40 years related to the creation of models and simulation techniques to predict the behaviour of equipment and processes in minerals processing. At the same time, application of optimization theory into such modelling and simulation schemes has been applied to generate knowledge to improved performances of the equipment and processes.Different optimization techniques have been applied to design and configure different equipment and processes, yet there are no well-established formulations to reproduce the results. The research is scattered and focused on the need and application of the specific equipment or process not utilizing the optimization’s full potential.The aim of this paper is to highlight the trends in development of optimization schemes in minerals processing. By understanding the state of the art in application of optimization theory into mineral processing will further pave the possibility to develop utility in this field. The paper presents two classification schemes: State of Development Stage and State of Application Area as a basis to classify research within optimization related to mineral processing. In order to make smart and strategic decisions in minerals processing operations, it is required to further develop optimization techniques into modelling and simulation schemes to extract the relevant information. The classification schemes can be useful in defining the future focus area for research and development.
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| 9. |
- Bhadani, Kanishk, 1991, et al.
(author)
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Student Perspectives on Video-Based Learning in CDIO-Based Project Courses
- 2017
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In: The 13th International CDIO Conference Proceedings, Calgary, Canada. - 1796-9964. - 9780889533998 ; , s. 689-704
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Conference paper (peer-reviewed)abstract
- This paper aims at demonstrating the applicability of video learning in CDIO based project courses and at evaluating to what extent it benefits students. The courses are Machine Elements (PPU210), Product Planning - Needs and Opportunities (PPU085) and Engineering Design and Optimization (PPU190) in the Mechanical Engineering programme at Chalmers University of Technology. The research was carried out by first creating a set of videos for selected topics in three courses. In total, 22 videos were created including topics such as “Benchmarking”, “SWOT”, and “Prototype lab equipment instructions”. The learning outcomes of the video lectures were mapped to the CDIO syllabus. A blended learning environment was developed, i.e. the videos were utilised as additional support alongside existing learning activities. The videos were then used in the courses and the students’ feedbacks collected through a dedicated questionnaire, the regular course evaluation survey, and in student-teacher group meetings during and after the courses. The collected data was analysed to produce inferences about the applicability and utility of the video lectures. The resulting analysis shows the students’ preferences regarding the evaluated video lectures and instructions. The students find videos more appealing compared to traditional lectures. One of the main benefits highlighted is the possibility of watching the videos in parallel to the design-build-test project execution rather having the classroom lecture only. This helps in reinforcing concepts, and results in less dependency on supervisors during the project execution. Videos proved to be suitable for creating a blended learning environment and improved the perceived learning experience for the students. In order to maximize student satisfaction and interaction with the videos, the videos should be short and closely aligned to the other learning activities. The paper also suggests future improvements to be carried out for video-based learning in the courses, and proposes an easy adaptable way for teachers to develop video material.
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| 10. |
- Davoodi, Ali, 1984, et al.
(author)
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Analysis of Screening Performance using Discrete Element Modeling
- 2017
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In: Proceedings of the Conference in Minerals Engineering. ; 2017
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Conference paper (peer-reviewed)abstract
- Screening is an important process in size classification of granular materials. It is a complex process due to the collision between particles and also a number of different operational parameters that effect the screening process. The aim of this paper is to evaluate screening performance in one of the LKAB crushing platforms. In this work an industrial vibration screen has been simulated by using Discrete Element Method (DEM). The simulations were validated with data from experiments and the screening performance has been analyzed by changing the parameters such as feeding rate. The result shows that DEM simulation is an effective tool for understanding the process of screening and because of the contact model between individual particles and particles and geometries the result is comparable with real process. It is shown that by increasing the feeding rate to 100 ton/h the screening efficiency can be improved by 20 percent.
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