Advanced Control Schemes for Cement Fabrication Processes

Arad, Victor; Bobora, Bogdan

doi:10.5772/6195

Cited by 6 publications

(6 citation statements)

References 9 publications

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“…The latter results into irregular clinker production as indicated in Figure 7. This phenomenon is also supported by the findings of [39,53]. In Reference [39], it was observed that too large an amount of secondary air fed to the burning zone interrupted clinker formation, where the flame becomes unstable, the burning zone is cooled, and a lot of dust is in circulation in the kiln and precalciner system.…”

Section: Variation Of Primary Air and Its Impact On Clinkersupporting

confidence: 74%

“…These changes are usually caused by the increase of oxygen. Arad et al [53] pointed out that a nonuniform clinker product output suggests that large temperature gradients exist near and within the rotary kiln bed. Generally, the demand of combustion air in the burning zone appears to have a large influence on the results.…”

Section: Variation Of Primary Air and Its Impact On Clinkermentioning

confidence: 99%

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Parametric Studies of Cement Production Processes

John

2020

Journal of Energy

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The cement industry is one of the most intensive energy consumers in the industrial sectors. The energy consumption represents 40% to 60% of production cost. Additionally, the cement industry contributes around 5% to 8% of all man-made CO2 emissions. Physiochemical and thermochemical reactions involved in cement kilns are still not well understood because of their complexity. The reactions have a decisive influence on energy consumption, environmental degradation, and the cost of cement production. There are technical difficulties in achieving direct measurements of critical process variables in kiln systems. Furthermore, process simulation is used for design, development, analysis, and optimization of processes, when experimental tests are difficult to conduct. Moreover, there are several models for the purpose of studying the use of alternative fuels, cement clinker burning process, phase chemistry, and physical parameters. Nonetheless, most of them do not address real inefficiency taking place in the processes, equipment, and the overall system. This paper presents parametric study results of the four-stage preheater dry Rotary Kiln System (RKS) with a planetary cooler. The RKS at the Mbeya Cement Company (MCC) in Tanzania is used as a case study. The study investigated the effects of varying the RKS parameters against system behaviour, process operation, environment, and energy consumptions. Necessary data for the modelling of the RKS at the MCC plant were obtained either by daily operational measurements or laboratory analyses. The steady-state simulation model of the RKS was carried out through the Aspen Plus software. The simulation results were successfully validated using real operating data. Predictions from parametric studies suggest that monitoring and regulating exhaust gases could improve combustion efficiency, which, in turn, leads to conserving fuels and lowering production costs. Composition of exhaust gases also depends both on the type of fuel used and the amount of combustion air. The volume of exit flue gases depends on the amount of combustion air and infiltrating air in the RKS. The results obtained from the study suggest a potential of coal saving at a minimum of about ṁcoal=1263 kg·h−1, which approximates to 76,126 tons per year at the current kiln feed of 58,000 kg·h-1. Thus, this translates to a specific energy saving of about 1849.12 kJ·kgcl-1, with relatively higher clinker throughput. In this vein, process modelling provides effective, safe, and economical ways for assessing the performance of the RKS.

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Section: Variation Of Primary Air and Its Impact On Clinkersupporting

confidence: 74%

Section: Variation Of Primary Air and Its Impact On Clinkermentioning

confidence: 99%

Parametric Studies of Cement Production Processes

John

2020

Journal of Energy

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“…The kiln fuel is introduced through a burner placed at the end of the kiln. Raw meal, after its entry in the furnace, is subjected to calcination, solid phase reactions and clinkering [1], [2], [6].…”

Section: A a Briefly Description Of The Processmentioning

confidence: 99%

“…Finally, mechanical constraints involve kiln torque. Furthermore, "quality constraints" are related to free lime analysis, performed on clinker samples, collected at the end of the cement rotary kiln [1], [2].…”

Section: B Control Specificationsmentioning

confidence: 99%

“…In this context may be placed the process control optimization, which, by using advanced control strategies, has the task of finding a compromise between the economic goals and the productive ones. This idea has an enormous benefit: payback time is in the order of the weeks, or months, in opposition to the years required by a relevant replace of an old hardware unit [2]. This challenge has motivated the present work, which consists in the study, development and implementation of an advanced control system for the optimization of a rotary kiln process located in an Italian cement plant.…”

Section: Introductionmentioning

confidence: 99%

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Improving Performances of a Cement Rotary Kiln: A Model Predictive Control Solution

Zanoli¹,

Pepe²,

Rocchi³

2016

JOACE

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In this work an advanced control system design aimed to the improvement of economic benefits and control performances of a cement rotary kiln located in an Italian cement plant is discussed. A Model Predictive Controller, together with other functional blocks designed to manage normal and critical situations, constitutes the core of the proposed strategy. Accurate identification procedures, aimed at obtaining accurate dynamical process models, have been performed. A suited cooperation of system modules and an ad hoc design of each of them allowed the meeting of control specifications, the increase of system reliability and the reduction of the standard deviation of critic process variables. In this way, the system can more safely operate closer to its operative bounds. The implementation of the proposed control system on a real plant has proven its soundness, leading to improvements in terms of energy efficiency, product quality and environmental impact, compared to the previous control system.  Index Terms-cement rotary kiln, advanced process control, model predictive control, economic optimization, environmental emissions, process control in 2012 and 2015, respectively. His master thesis concerned the development of an industrial controller for a rotary cement kiln based on model predictive control strategy. He currently works in i.Process s.r.l. for the development of new predictive control solutions. His area of interest include process control, model predictive control and process modeling and identification.

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