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- Evertsson, Magnus, 1967, et al.
(författare)
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Control systems for improvement of cone crusher yield and operation
- 2014
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Ingår i: Proceedings of Comminution '14.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Gyratory and cone crushers are regaining interest and are becoming more frequently used in order to create more energy efficient comminution circuits. A typical example is found in coarse comminution circuits were HPGRs are used as a first milling stage. In this case the preparation of a suitable feed with a well-defined width of the particle size distribution and a controlled top size are of high importance. In turn, this emphasizes the importance of a stable and controlled operation of the preceding crushing stages. Control systems for cone and gyratory crushers were first introduced during the early 60ths. The common opinion is that if these systems are able to compensate for the wear of the crushing liners the production yield can be increased with 20-25%. Over the years these types of systems have been widely used but the theory behind the principles have not been thoroughly scientifically scrutinized and presented. Of special interest is the capability to protect the crushers from long term overloading commonly defined as fatigue.With developments in electronics and plant control the crusher control systems have become more refined over the years. Though, there are sometimes conflicting interests in the control strategies between process requirements and crusher protection. In the paper an overview of the challenges, opportunities and existing control systems for cone and gyratory crushers is presented. A requirement specification for a system that is possible to fully integrate into modern plant control systems is outlined.
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- Bhadani, Kanishk, 1991, et al.
(författare)
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Application of Multi-Disciplinary Optimization Architectures in Mineral Processing Simulations
- 2018
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Ingår i: 11th International Comminution Symposium. - 9781510883789
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Konferensbidrag (refereegranskat)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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- Bhadani, Kanishk, 1991, et al.
(författare)
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Application of Structural Optimization for an Early Stage Product Development
- 2017
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Ingår i: NAFEMS World Congress 2017, A World of Engineering Simulation, Stockholm, Sweden. - 9781910643372 ; , s. 13-
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Konferensbidrag (refereegranskat)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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4. |
- Evertsson, Magnus, 1967, et al.
(författare)
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Monitoring and validation of life time prediction of cone crusher with respect to loading and feeding conditions
- 2016
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Ingår i: Comminution 16. - 9781510826670 ; 904 (1 Vol)
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Konferensbidrag (refereegranskat)abstract
- The interest and need for compressive crushing in gyratory, cone and HPGR crushers are increasing since ores become more competent and more difficult to break. Compressive crushing is energy efficient as a consequence of the crushing principle and the imposed stress-state. The stress variations can be described by stress amplitudes and it is a known fact that many different materials, components and machines suffer from cyclic loading which shortens the service lifetime. This phenomena is explained by density variations of the particle beds in the equipment which in turn originates from particle segregation and feeding alignment. The phenomena is often called fatigue and the consequence is premature breakdowns and a relatively shorter lifetime than expected. In this paper, a previously developed theory for lifetime assessment of cone crushers will be used as a foundation for evaluation of full-scale operating cone crushers in minerals processing plants. Lifetime is calculated as a consequence of the load spectrum. The data shows that improper feeding conditions will substantially decrease the lifetime of the crusher equipment leading to excessive operating costs. An adequate control system should be able to recognise the hazardous lifetime decreasing overloads and to warn the operator. There are sometimes conflicting interests in the control strategies between production yield (process requirements) and crusher protection.
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- Schneegass, Stefan, et al.
(författare)
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SimpleSkin : towards multipurpose smart garments
- 2015
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Ingår i: Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2015 ACM International Symposium on Wearable Computers. - New York, New York, USA : Association for Computing Machinery (ACM). - 9781450335744 - 9781450335782 ; , s. 241-244
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Konferensbidrag (refereegranskat)abstract
- Smart textiles have been researched in the lab over thelast 20 years. However, the gap between research andavailable mass-market products is huge. We identifychallenges that are the core reasons for this gap. Totackle these challenges, we present our work towards amultipurpose smart textile with dierent sensingmodalities. It separates the concern of developing textiles,electronics, infrastructure, and applications. Furthermore,it uses a similar application model as current smart-phonesallowing developers to create applications for the smarttextiles. We believe that this approach is capable ofmoving smart textiles from niche to mainstream.
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- Cahyari, Khamdan, et al.
(författare)
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Harvesting biohydrogen (BioH2) and biomethane (BioCH4) from fruit waste through sequential thermophilic fermentation
- 2011
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Konferensbidrag (refereegranskat)abstract
- A sequential two stages thermophilic fermentation of fruit waste i.e. orange, banana, apple, grape, melon to produce biofuels i.e. biohydrogen (BioH2) and biomethane (BioCH4) was investigated. In the first stage, fermentative BioH2 from each waste was successfully carried out without any methane being detected. Among the wastes, apple generated more gas with cumulative BioH2 yield (CHY) as 19.91 mmol/g VS (90% of theoretical value), while the lowest one resulted from melon (8.14 mmol/g VS or 36.8%). In the second stage, fermentative BioCH4 of residual liquid from the first stage was achieved successfully for banana, VEMF, apple, grape, melon, and orange with the cumulative BioCH4 yield (CHY) as 10.62, 14.23, 15.88, 16.26, 16.74, and 18.50 mmol CH4/g VSadded respectively. It was also showed from chemical oxygen demand (COD) measurement that COD removal efficiency achieved significantly high from 48% up to 60% for all the waste except orange which was only 16.7%. It was presumed that orange contained difficult-to-degrade materials such as limonene. In fact, fermentative BioH2 of orange in higher limonene concentration at 18 mg/l was totally inhibited. A simulation of potential generated energy (PGE) from the fruits waste being treated through this method was carried out based on the quantity of worldwide harvested fruits in 2009 (FAO UN), in consideration that 10% of the fruits were wasted. It is surprisingly understood that each of the fruits waste can deliver more than 64 MWh of electricity.
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- Jeihanipour, Azam, et al.
(författare)
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Acid Hydrolysis of Cellulose-based Waste Textiles
- 2011
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Konferensbidrag (refereegranskat)abstract
- The present study focused on conversion of cellulosic part of waste textiles into biogas and its challenges. The annual global fiber consumption exceeded 70 Mt with a cellulosic fraction of around 40%. This huge amount of fiber is further processed into apparel, home textiles and industrial products and after a certain time delay end up in waste streams. This amount of cellulose has the potential of production of approximately 20 billion liters of ethanol. Assuming a good collection and waste management system, however, there are still challenges facing the process of conversion. For instance, high crystallinity of cotton cellulose makes it hard to achieve enzymatic or bacterial hydrolysis. In addition, waste textiles are composed of different materials including natural and synthetic fibers, and the cellulosic fibers should be separated from the other materials. Furthermore, presence of dyes and reagents in the fibers can also be challenging in the bioprocessing of textile waste. In the present work, we examined the process of dilute acid hydrolysis of viscose and cotton (i.e. jeans) textiles. Hydrolyses were performed at different lengths of time (8 and 15 min), temperatures (180 and 200 °C), and acid concentrations (0.5, 1.5, and 3% w/w). Hydrolysis of viscose and jeans under identical conditions resulted in significantly different yields of glucose. This may be due to differences in the structure, i.e. high crystalline cellulose in jeans and low crystalline cellulose in viscose.
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