536 research outputs found
Supervisory-plus-regulatory control design for efficient operation of industrial furnaces
A two-level system engineering design approach to integrated control and supervision of industrial multi-zone furnaces has been elaborated and tested. The application case study is the three-zone 25 MW RZS furnace plant at Skopje Steelworks. The integrated control and supervision design is based on combined use of general predictive control optimization of set-points and steady-state decoupling,at the upper level, and classical two-term laws with stady-state decouling, at the executive control level. This design technique exploits the intrinsic stability of thermal processes and makes use of constrained optimization, standard non-parametric time-domain process models, identified under operating conditions, using truncated k-time sequence matrices, controlled autoregressive moving average models. Digital implementations are sought within standard computer process control platform for practical engineering and maintenance reasons
Dynamic simulation of industrial grinding circuits : mineral liberation, advanced process control, and real-time optimisation
Ătant donnĂ© que les minĂ©raux apparaissent frĂ©quemment dans des associations complexes dans la nature, la libĂ©ration minĂ©rale est un aspect clĂ© du traitement de minerais et celle-ci est accomplie par comminution. Cette opĂ©ration est certainement lâune des plus importantes, mais aussi des plus coĂ»teuses dans lâindustrie. La rĂ©ussite globale dâune usine dĂ©pend souvent de la performance du circuit de broyage car il existe un compromis pour atteindre la taille des particules libĂ©rant les minĂ©raux ciblĂ©s afin dâobtenir des concentrĂ©s de haute puretĂ© tout en ayant de faibles coĂ»ts dâopĂ©ration, lesquels sont largement influencĂ©s par la consommation Ă©nergĂ©tique. Dans les annĂ©es rĂ©centes, les entreprises ont Ă©tĂ© confrontĂ©es Ă des objectifs de performance plus exigeants, une concurrence accrue sur les marchĂ©s, et des rĂ©glementations environnementales et de sĂ©curitĂ© plus strictes. Dâautres dĂ©fis supplĂ©mentaires sont inhĂ©rents aux circuits de broyage, par exemple les rĂ©ponses non linĂ©aires, le niveau Ă©levĂ© dâintercorrĂ©lation entre les variables et les recirculations de matiĂšre. Les problĂšmes ci-dessus soulignent la pertinence dâavoir des systĂšmes de contrĂŽle et dâoptimisation adĂ©quats pour lesquels les praticiens profitent de plus en plus des approches basĂ©es sur des modĂšles pour y faire face de façon systĂ©matique. La modĂ©lisation et la simulation sont des outils puissants ayant des avantages significatifs tels que les faibles coĂ»ts, les temps requis pour rĂ©aliser des expĂ©riences relativement courts et la possibilitĂ© de tester des conditions opĂ©rationnelles extrĂȘmes ainsi que diffĂ©rentes configurations des circuits sans interrompre la production. De toute Ă©vidence, la qualitĂ© des rĂ©sultats sera aussi bonne que la capacitĂ© du modĂšle Ă reprĂ©senter la rĂ©alitĂ©, ce qui souligne lâimportance dâavoir des modĂšles prĂ©cis et des procĂ©dures de calibrage appropriĂ©es, un sujet frĂ©quemment omis dans la littĂ©rature. Un autre aspect essentiel qui nâa pas Ă©tĂ© rapportĂ© est lâintĂ©gration efficace de la libĂ©ration minĂ©rale aux systĂšmes de contrĂŽle et dâoptimisation de procĂ©dĂ©s. Bien quâil sâagisse dâune information clĂ© directement liĂ©e aux performances de lâĂ©tape de concentration, la plupart des stratĂ©gies se concentrent exclusivement sur la taille de particule du produit. Ceci est comprĂ©hensible Ă©tant donnĂ© quâil est impossible de mesurer la distribution de libĂ©ration prĂ©sentement. BasĂ©e sur une librairie de simulation dâusines de traitement des minerais dĂ©jĂ existante, cette recherche aborde lesdits problĂšmes en (1) dĂ©veloppant un modĂšle de libĂ©ration minĂ©rale visant Ă coupler les Ă©tapes de broyage et de concentration ; (2) programmant et validant par calibrage un modĂšle phĂ©nomĂ©nologique de broyeur autogĂšne/semi-autogĂšne (BA/BSA), nĂ©cessaire pour complĂ©ter la librairie de simulation ; (3) couplant un simulateur de circuit de broyage Ă un procĂ©dĂ© de concentration avec le modĂšle de libĂ©ration, et (4) dĂ©veloppant un systĂšme de contrĂŽle et dâoptimisation qui considĂšre explicitement des donnĂ©es de libĂ©ration minĂ©rale pour Ă©valuer les avantages Ă©conomiques. Les principaux rĂ©sultats confirment que le modĂšle de libĂ©ration est capable de reproduire avec prĂ©cision des distributions de libĂ©ration minĂ©rale couramment observĂ©es dans lâindustrie. Cependant, si les donnĂ©es de calibrage correspondent Ă un point dâopĂ©ration unique, la validitĂ© pourrait ĂȘtre limitĂ©e aux rĂ©gions voisines proches. Le problĂšme de caractĂ©riser lâĂ©volution de la libĂ©ration minĂ©rale aux diverses conditions dâopĂ©ration ainsi quâaux rĂ©gimes transitoires reste Ă ĂȘtre abordĂ©. Le modĂšle de libĂ©ration sâest aussi rĂ©vĂ©lĂ© utile pour coupler des circuits de broyage avec des procĂ©dĂ©s de concentration, en particulier pour une unitĂ© de flottation. Quant au modĂšle de BA/BSA, celui-ci peut capturer le rĂ©gime statique ainsi que la dynamique dâun broyeur rĂ©el et conjointement avec le reste des Ă©quipements dans la librairie de simulation, des circuits de broyage industriels. Ceci a Ă©tĂ© confirmĂ© par le calibrage Ă partir des donnĂ©es dâopĂ©ration dâune usine et des tests en laboratoire, tout en suivant une procĂ©dure systĂ©matique, contribuant aussi au sujet de lâĂ©tablissement de mĂ©thodologies de calibrage standardisĂ©es. Pour terminer, les expĂ©riences concernant la stratĂ©gie de contrĂŽle et dâoptimisation basĂ©e sur la libĂ©ration minĂ©rale suggĂšrent que lâutilisation de cette information peut amĂ©liorer la performance globale des circuits de broyage-sĂ©paration en rĂ©agissant aux variations des caractĂ©ristiques de libĂ©ration, qui Ă leur tour influencent lâefficacitĂ© de sĂ©paration. LâĂ©tude de cas rĂ©alisĂ© rĂ©vĂšle que cela peut entraĂźner une augmentation du dĂ©bit massique et de la teneur du concentrĂ©, de la rĂ©cupĂ©ration des mĂ©taux et des revenus de lâordre de +0.5%, +1%, +1% et +5%, respectivement, par rapport au cas oĂč ces informations sont omises.As minerals frequently appear in complex associations in nature, mineral liberation is one of the most relevant aspects in ore processing and is achieved through comminution. This operation is one of the most important, but also one of the most expensive ones in industry. The global efficiency of a plant often depends on the performance of the grinding circuit, since there is a compromise to achieve the particle size liberating the targetted minerals in order to obtain high purity concentrates while maintaining low operating costs, which are largely influenced by the energy consumption. In recent years, companies have been facing more demanding performance targets, stronger competition, and more stringent environmental and safety regulations. Additional challenges are inherent to the grinding circuits themselves, e.g. the nonlinear responses, high degree of intercorrelation of the different variables, and material recirculations. The abovementioned issues highlight the relevance of adequate process control and optimisation, and practitioners rely more often on model-based approaches in order to face them systematically. Modeling and simulation are powerful tools with significant advantages such as low costs, required times for conducting experiments are relatively short, and the possibility of testing extreme operational conditions as well as different circuit configurations without disrupting production. Evidently, the quality of the results will only be as good as the model capacity to represent the reality, which emphasises the relevance of having precise models and proper calibration procedures, the latter being a topic frequently omitted in the literature. Another crucial aspect that has not been reported yet is the effective integration of mineral liberation in control and optimisation schemes. Although it is a key piece of information directly related to the performance of the concentration stage, most strategies focus exclusively on the particle size. This is understandable given that it is currently impossible to measure the liberation distribution online. Based on an existing mineral processing plant simulation library, this research addresses these problems by (1) developing a mineral liberation model aiming at linking the grinding and concentration stages; (2) programming a phenomenological autogenous/semiautogenous (AG/SAG) mill model, required to complement the simulation toolbox, and validating it through calibration; (3) coupling a grinding circuit simulator to a concentration process by means of the liberation model, and (4) developing a plantwide control and optimisation scheme considering mineral liberation data explicitly to evaluate the economic benefits. The main results confirm that the liberation model is capable of reproducing accurately mineral distributions observed in industry. If calibration data correspond to a single operating point, its validity may however be limited to the close neighbourhood. Characterising the evolution of mineral liberation in different operating conditions and transient states remains to be addressed. The liberation model proved to be equally useful in coupling grinding circuits with concentration processes, specifically for flotation. As for the AG/SAG mill model, it can capture the steady state and dynamic behaviour of an actual device and, along with the rest of pieces of equipment in the simulation toolbox, of industrial grinding circuits. This was confirmed through calibration from plant data and laboratory testwork following a systematic procedure, contributing to the endeavour of establishing standard calibration methodologies. Lastly, the results of the designed control and optimisation scheme suggest that using liberation data for control and real-time optimisation can improve the overall performance of grinding-separation circuits by reacting to variations in the liberation characteristics, which in turn influence the concentration performance. The case study reveals that doing so can lead to increases in the concentrate mass flow rate and grade, metal recovery, and global profits in the order of +0.5%, +1%, +1%, and +5%, respectively, compared to the case omitting this information
A Control Evaluation on a Slurry-Filled Sump
Sump can be definedas a reservoir which is normally located at the downstream of
a process, from which water is pumped where solids accumulates. Sump is a
system which faces instability due to its dynamic behaviors. Application of control
strategies to the sump might add some advantages in handling the sump, where in
some process, sumpplays a significant role especiallywhen it involves in a process
that have highly hazardous stage. This project studies generally observe the
behavior of the sump by adapting control type such as the feedback, Smith
predictor, feedforward, and cascade control. In addition, the sump is adaptedwith a
neurocontrol from Neural Network Control strategies. The neurocontrol used is the
NARMA-L2 controller. The variation of simulation have resulted in a way that
majority of the controller are at highest performance when the percentage of solids
in is 80%. The application of neurocontrol to the system somehow does not meet
the target due to high error that the controller sustained. However, the neurocontrol
can be enhanced more by data training and this is recommended for further
researchby using other neurocontrol that is available in the Neural Networkcontrol
strategies
Technology 2002: the Third National Technology Transfer Conference and Exposition, Volume 1
The proceedings from the conference are presented. The topics covered include the following: computer technology, advanced manufacturing, materials science, biotechnology, and electronics
Development of a tube ball mill mathematical model for mill condition and safety monitoring
The PhD research project is to examine if it is possible to minimize the mill faults and fires in the Tube Ball mill operation by using a model based approach. The research outcome proves that the risks of mill fault can be monitored and alerted by implementing the model based on-line condition monitoring software that developed through the PhD project.
Coal fired power stations nowadays regularly use coal with higher volatile contents and Biomass materials to satisfy the government regulations on sustainable and renewable energy. This greatly increases the risks of explosions or fires in milling plants. However, there are no acceptable measurement methods available at the present and it is difficult to identify if there will be a fire in the mill. Therefore, the project is carried out from the study mill mathematical model to mill condition monitoring.
Monitoring the mill operation conditions only based on currently available on-site measurement without requiring any extra hardware is a cost effective solution and will pose a great challenge. A mathematical model of coal mills is developed using computational intelligent algorithms for prediction of potential mill faults
Technology 2003: The Fourth National Technology Transfer Conference and Exposition, volume 2
Proceedings from symposia of the Technology 2003 Conference and Exposition, Dec. 7-9, 1993, Anaheim, CA, are presented. Volume 2 features papers on artificial intelligence, CAD&E, computer hardware, computer software, information management, photonics, robotics, test and measurement, video and imaging, and virtual reality/simulation
Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes
The book documents 25 papers collected from the Special Issue âAdvances in Condition Monitoring, Optimization and Control for Complex Industrial Processesâ, highlighting recent research trends in complex industrial processes. The book aims to stimulate the research field and be of benefit to readers from both academic institutes and industrial sectors
XVIII International Coal Preparation Congress
Changes in economic and market conditions of mineral raw materials in recent
years have greatly increased demands on the ef ïŹ ciency of mining production. This
is certainly true of the coal industry. World coal consumption is growing faster than
other types of fuel and in the past year it exceeded 7.6 billion tons. Coal extraction
and processing technology are continuously evolving, becoming more economical
and environmentally friendly. â Clean coal â technology is becoming increasingly
popular. Coal chemistry, production of new materials and pharmacology are now
added to the traditional use areas â power industry and metallurgy. The leading role
in the development of new areas of coal use belongs to preparation technology and
advanced coal processing. Hi-tech modern technology and the increasing interna-
tional demand for its effectiveness and ef ïŹ ciency put completely new goals for the
University. Our main task is to develop a new generation of workforce capacity and
research in line with global trends in the development of science and technology to
address critical industry issues.
Today Russia, like the rest of the world faces rapid and profound changes
affecting all spheres of life. The de ïŹ ning feature of modern era has been a rapid
development of high technology, intellectual capital being its main asset and
resource. The dynamics of scienti ïŹ c and technological development requires acti-
vation of University research activities. The University must be a generator of ideas
to meet the needs of the economy and national development. Due to the high
intellectual potential, University expert mission becomes more and more called for
and is capable of providing professional assessment and building science-based
predictions in various ïŹ elds.
Coal industry, as well as the whole fuel and energy sector of the global economy
is growing fast. Global multinational energy companies are less likely to be under
state in ïŹ uence and will soon become the main mechanism for the rapid spread of
technologies based on new knowledge. Mineral resources will have an even greater
impact on the stability of the economies of many countries. Current progress in the
technology of coal-based gas synthesis is not just a change in the traditional energy markets, but the emergence of new products of direct consumption, obtained from
coal, such as synthetic fuels, chemicals and agrochemical products. All this requires
a revision of the value of coal in the modern world economy
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