An optimizing control strategy for milling circuit operation

 

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dc.contributor.advisor Swartz, Chris en_ZA
dc.contributor.author Hart, Jarrod Rex en_ZA
dc.date.accessioned 2016-05-11T08:04:29Z
dc.date.available 2016-05-11T08:04:29Z
dc.date.issued 1998 en_ZA
dc.identifier.citation Hart, J. 1998. An optimizing control strategy for milling circuit operation. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/19569
dc.description Bibliography: pages 97-102. en_ZA
dc.description.abstract It has been recognized that significantly more benefit can be derived by operating processes at the economically optimal process conditions than by solely improving the regulatory control performance. This has been the motivation for an increased focus on optimizing control strategies where the set points are adjusted on-line in accordance with an economic criterion. Since plant conditions change, this adjustment needs to be made on a continual basis, but at a frequency lower than that at which inputs are manipulated at the regulatory control level. In the operation of tumbling mills, the fractional filling of the mill with slurry has a marked effect on the efficiency of the breakage process within the mill. The selection of the set point for this variable is critical in the optimization of throughput and energy efficiency in a grinding circuit. Unfortunately, the optimal value for this set point is a function of both circuit and ore characteristics, which means that it varies as the feed and plant characteristics change. This means that periodic re-evaluation of this optimal value needs to be performed in order to fully maximize circuit throughput. The mechanism for seeking this optimum on-line forms the basis for this thesis. Continuous evaluation of the function relating throughput to mill loading (if that were possible) would reveal the optimal set point for the load which could be regularly updated. A recent strategy tackled this issue by assuming power draw from the mill motors is related to circuit, throughput. With the aim to optimize throughput, power consumption can be used as a yardstick by which the load set point (set point for fractional filling in mill) can be selected. The load set point is simply adjusted periodically to optimize the power consumption and correspondingly, the circuit through put. The key proposal in this thesis is a strategy that employs a model of the plant to assist and improve the selection of the load set point. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Chemical Engineering en_ZA
dc.title An optimizing control strategy for milling circuit operation en_ZA
dc.type Master Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Engineering and the Built Environment
dc.publisher.department Department of Chemical Engineering en_ZA
dc.type.qualificationlevel Masters
dc.type.qualificationname MSc (Eng) en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Hart, J. R. (1998). <i>An optimizing control strategy for milling circuit operation</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering. Retrieved from http://hdl.handle.net/11427/19569 en_ZA
dc.identifier.chicagocitation Hart, Jarrod Rex. <i>"An optimizing control strategy for milling circuit operation."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering, 1998. http://hdl.handle.net/11427/19569 en_ZA
dc.identifier.vancouvercitation Hart JR. An optimizing control strategy for milling circuit operation. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering, 1998 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/19569 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Hart, Jarrod Rex AB - It has been recognized that significantly more benefit can be derived by operating processes at the economically optimal process conditions than by solely improving the regulatory control performance. This has been the motivation for an increased focus on optimizing control strategies where the set points are adjusted on-line in accordance with an economic criterion. Since plant conditions change, this adjustment needs to be made on a continual basis, but at a frequency lower than that at which inputs are manipulated at the regulatory control level. In the operation of tumbling mills, the fractional filling of the mill with slurry has a marked effect on the efficiency of the breakage process within the mill. The selection of the set point for this variable is critical in the optimization of throughput and energy efficiency in a grinding circuit. Unfortunately, the optimal value for this set point is a function of both circuit and ore characteristics, which means that it varies as the feed and plant characteristics change. This means that periodic re-evaluation of this optimal value needs to be performed in order to fully maximize circuit throughput. The mechanism for seeking this optimum on-line forms the basis for this thesis. Continuous evaluation of the function relating throughput to mill loading (if that were possible) would reveal the optimal set point for the load which could be regularly updated. A recent strategy tackled this issue by assuming power draw from the mill motors is related to circuit, throughput. With the aim to optimize throughput, power consumption can be used as a yardstick by which the load set point (set point for fractional filling in mill) can be selected. The load set point is simply adjusted periodically to optimize the power consumption and correspondingly, the circuit through put. The key proposal in this thesis is a strategy that employs a model of the plant to assist and improve the selection of the load set point. DA - 1998 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1998 T1 - An optimizing control strategy for milling circuit operation TI - An optimizing control strategy for milling circuit operation UR - http://hdl.handle.net/11427/19569 ER - en_ZA


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