This article reflects the strategic part that software and control systems must play to ensure efficient running of the manufacturing process.
ABB is, of course, one of the major suppliers of power and automation technologies for the cement and other industries. The company’s famous Expert Optimizer (EO) has once again attracted much attention this year. In May, ABB won the contract from Votorantim Cimentos to provide the cpmPlus EO process optimisation system for eleven new cement plants being built in Brazil and elsewhere in Latin America. In addition, it will also upgrade the prior generation Linkman system with EO at eight other plants. Votorantim is now reported to be making the world’s largest investment for new and expanded cement production.
To optimise cement production, the EO uses neural networks, fuzzy logic and predictive control models. Divided into areas such as milling, kiln and cooler, it becomes a virtual operator, making decisions and defining the best control strategies automatically for each specific area of the process.
As mentioned in last month’s issue of WORLD CEMENT, the cpmPlus EO will also be installed in CRH’s Ozarow cement plant in Poland. Here it will be installed on the kiln, cooler and calciner. One of the motivations for installing the system is to increase the use of alternative fuels. CRH has installed the system at five of its other plants in Western Europe.
Nordkalk is the leading producer of high quality limestone-based products in Northern Europe. The products are used mainly in the paper, steel and building material industries, as well as in environmental care and agriculture. In January, ABB announced that it had successfully installed its EO at the Köping plant in Sweden. It was installed on the lime kiln and grate cooler last year. The plant has to change the limestone feed type on a daily basis, to meet market demands for various products. The Optimizer stabilises the kiln after each type change. The emissions control module controls the addition of dust, lime and waste oil to limit the emissions of HF, HCL, SO2 and NOx. The area of control, along with efficient AF consumption, proved to be very useful for the kiln operators. The grate cooler control improved bed depth stability, which led to increased heat recovery and lower product temperatures.
Siemens has been involved with the cement industry for many years and its CEMAT software technology has been installed in cement plants around the world. In January of this year, the company’s Industry Solutions Division introduced the Sicement IT MCO (Mill Control Optimization), an expert system that helps to forecast and then optimise the quality-relevant operating parameters in cement mills. The software has a knowledge-based approach, and uses current plant data to adapt control parameters automatically, thus relieving the operator of these tasks. This reduces energy consumption and has a positive effect on availability and profitability. The software is based on components of the Advanced Process Control (APC) library of Simatic PCS 7, a neural soft sensor, and a model-based predictive controller (MPC). The neural soft sensor first records different process input quantities, such as the quantity of fresh material and the selected recipe type. The system then uses this data to generate a prediction of the cement fineness, which can be compared with the laboratory analysis of samples from the current production. The final fineness value of the cement and the throughput of returns form the control parameters for the MPC. On the basis of a complete process model, the multiple variable controller calculates external set-point settings for the lower level individual controllers. To bring the control parameters as near as possible to the desired set-point values, the feed quantity and separator speed are modified to optimise the system behaviour.
The first Sicement IT MCO has been installed in the Suedbayerisches Portland-Zementwerk in Rohrdorf, Germany. It has replaced the previous optimisation system on one of the four 60 tph ball mills. The installation has increased the mill throughput at the desired fineness of grind, while reducing energy consumption per t of cement. As the new system has been totally integrated into the plant and the existing PCS control system, the plant operator does not incur any additional maintenance or servicing costs.
In May of this year, Fritz & Macziol issued VAC Version 5, which is said to ensure more efficiency and cost-effectiveness in the cement, lime, gypsum and bulk solids industries. VAS is a process-oriented software solution that depicts the whole process chain from delivery to vehicle scheduling and loading up to exit. It supports reporting and provides real time information in additional systems, such as for production, sales and controlling. The new Version 5 has an integrated web-based user interface that can be operated via every current web browser. It is also possible, using central templates, to define standard processes that only have to be adjusted to local peculiarities and statutory provisions in the individual plants. It is understood that the central control system makes it easier to integrate VAS in ERP or invoicing systems such as SAP, Oracle or Navison to support control at company head offices. Major players such as Holcim, HeidelbergCement, Lafarge and Dyckerhoff have been relying on standardised cross-border processes for some time. These will now be depicted easily and economically with the new version.
Planning a new quarry?
For the past 30 years, Maptek has been a leading innovator of geological modelling and mine planning software, as well as 3D laser scanning instruments and software, with deployments to major mining companies at sites all over the world. In April, the company launched the new Vulcan QuarryModeller, which is a bespoke platform for geological modelling and mine planning in the cement industry. The package provides tools for 3D CAD, 3D geological modelling, block modelling with grade estimation, compositing and open cut design applications in quarrying.
The I-Site 8800 laser scanner is a strong and robust instrument that is ideal for quarries. It has high accuracy and a range of up to 2 km, allowing scanning to be conducted from a safe distance, enabling surveyors to develop detailed 3D survey updates of excavations or stockpiles in a short time. The data is analysed and manipulated using the I-Site Studio software that is employed to calculate volumes, monitor rock movement and generate survey data, such as toes, crests and contours that can be taken into the local mine planning package. The I-Site Studio 3.5, which is being released this month, allows users to easily monitor changes in surfaces such as walls, batters and faces. Overlapping surfaces scanned at different times can be compared to reveal the extent and rate of change, for example to identify a slow moving failure in the quarry.
This is an abridged version of the full article from Paul Maxwell-Cook, which was published in the July 2011 issue of WORLD CEMENT. To read more and for end user experiences download the issue now (subscribers only).
Read the article online at: https://www.worldcement.com/europe-cis/12072011/cement_plant_control_systems/