Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Mar 3;23(5):2805.
doi: 10.3390/s23052805.

Advanced Process Control for Clinker Rotary Kiln and Grate Cooler

Silvia Maria Zanoli  1 , Crescenzo Pepe  1 , Giacomo Astolfi  2
Affiliations

Advanced Process Control for Clinker Rotary Kiln and Grate Cooler

Silvia Maria Zanoli et al. Sensors (Basel). .

Abstract

The cement industry includes energy-intensive processes, e.g., clinker rotary kilns and clinker grate coolers. Clinker is obtained through chemical and physical reactions in a rotary kiln from raw meal; these reactions also involve combustion processes. The grate cooler is located downstream of the clinker rotary kiln with the purpose of suitably cooling the clinker. The clinker is cooled through the action of multiple cold air fan units as it is transported within the grate cooler. The present work describes a project where Advanced Process Control techniques are applied to a clinker rotary kiln and a clinker grate cooler. Model Predictive Control was selected as the main control strategy. Linear models with delays are obtained through ad hoc plant experiments and suitably included in the controllers' formulation. A cooperation and coordination policy is introduced between the kiln and the cooler controllers. The main objectives of the controllers are to control the rotary kiln and grate cooler critical process variables while minimizing the fuel/coal specific consumption of the kiln and the electric energy consumption of the cold air fan units within the cooler. The overall control system was installed on the real plant, obtaining significant results in terms of service factor and control and energy-saving performances.

Keywords: advanced process control; cement industry; clinker production; electric energy consumption; energy-saving; fuel/coal specific consumption; grate cooler; model predictive control; rotary kiln.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Clinker rotary kiln and grate cooler.
Figure 2
Figure 2
Project phases.
Figure 3
Figure 3
Data acquisition and storage architecture.
Figure 4
Figure 4
APCs cooperation architecture.
Figure 5
Figure 5
Details on the modules of the APC systems.
Figure 6
Figure 6
Rotary kiln APC system: example of an APC system GUI synoptic (MVs, main CVs and DVs).
Figure 7
Figure 7
Grate cooler APC system: example of process variables GUI synoptic.
Figure 8
Figure 8
Grate cooler APC system: GUI synoptic for MVs nominal targets computation and parametric law modification.
Figure 9
Figure 9
Grate cooler APC system: parametric law between second sub-chamber pressure/height of the clinker bed and grate speed.
Figure 10
Figure 10
Rotary kiln APC system: data analysis results (clinkering temperature).
Figure 11
Figure 11
Rotary kiln APC system: data analysis results (oxygen).
Figure 12
Figure 12
Rotary kiln APC system: data analysis results (nitrogen oxides).
Figure 13
Figure 13
Rotary kiln APC system: modelization results (fan oxygen).
Figure 14
Figure 14
Rotary kiln APC system: modelization results (fan nitrogen oxides).
Figure 15
Figure 15
Rotary kiln APC system: modelization results (second-stage exit temperature).
Figure 16
Figure 16
Rotary kiln APC system: virtual environment simulations results (kiln filling degree CV).
Figure 17
Figure 17
Rotary kiln APC system: virtual environment simulations results (meal flow rate MV).
Figure 18
Figure 18
Rotary kiln APC system: virtual environment simulations results (rotation kiln speed MV).
Figure 19
Figure 19
Rotary kiln APC system: field results (cyclone oxygen CV).
Figure 20
Figure 20
Rotary kiln APC system: field results (second-stage exit temperature CV).
Figure 21
Figure 21
Rotary kiln APC system: field results (first-stage left temperature CV).
Figure 22
Figure 22
Rotary kiln APC system: field results (kiln motor torque CV).
Figure 23
Figure 23
Rotary kiln APC system: field results (kiln filling degree CV).
Figure 24
Figure 24
Rotary kiln APC system: field results (meal flow rate MV).
Figure 25
Figure 25
Rotary kiln APC system: field results (kiln coal MV).
Figure 26
Figure 26
Rotary kiln APC system: field results (rotation kiln speed MV).
Figure 27
Figure 27
Grate cooler APC system: field results (second sub-chamber pressure CV).
Figure 28
Figure 28
Grate cooler APC system: field results (height of the clinker bed CV).
Figure 29
Figure 29
Grate cooler APC system: field results (grate speed MV).
Figure 30
Figure 30
Grate cooler APC system: field results (clinker exit temperature CV).
Figure 31
Figure 31
Grate cooler APC system: field results (meal flow rate DV).
Figure 32
Figure 32
Grate cooler APC system: field results (cold air fan 1 flow rate MV).
Figure 33
Figure 33
Grate cooler APC system: field results (cold air fan 6 flow rate MV).
Figure 34
Figure 34
Grate cooler APC system: field results (cold air fan 7 flow rate MV).
Figure 35
Figure 35
Grate cooler APC system: field results (cold air fan 8 flow rate MV).
Figure 36
Figure 36
Rotary kiln APC system: KPI evaluation (monthly energy-saving and cumulative energy-saving after APC system activation).
See this image and copyright information in PMC

References

    1. Alsop P.A. The Cement Plant Operations Handbook. 7th ed. Tradeship Publications Ltd.; Dorking, UK: 2019.
    1. Chatterjee A.K. Intelligent and Sustainable Cement Production: Transforming to Industry 4.0 Standards. CRC Press; Abingdon, UK: 2022.
    1. International Energy Agency . CO2 Emissions from Fuel Combustion 2019. IEA; Paris, France: 2019. - DOI
    1. International Energy Agency . Cement. IEA; Paris, France: 2022. [(accessed on 30 November 2022)]. Available online: https://www.iea.org/reports/cement.
    1. Stadnicka D., Bonci A., Pirani M., Longhi S. Information Management and Decision Making Supported by an Intelligence System in Kitchen Fronts Control Process. In: Burduk A., Mazurkiewicz D., editors. Intelligent Systems in Production Engineering and Maintenance—ISPEM 2017. Volume 637. Springer; Cham, Switzerland: 2018. Advances in Intelligent Systems and Computing. - DOI

LinkOut - more resources