System Integration & Control Systems Design


Foxboro revamp at Aracruz Celulose pulp mill

May 2012 System Integration & Control Systems Design

Aracruz Celulose is unusual in that the mill uses eucalyptus trees for making pulp, which is shipped around the world to paper producers who make tissue, fine printing, writing and specialty paper products. The advantage of eucalyptus trees is that they grow so quickly, reaching mature heights of about 35 metres within just seven years of growth. This means that they can be harvested much more frequently than the slow growing pine forests of North America.

In 1995, Aracruz management overhauled the production lines to modernise and eliminate bottlenecks, while expanding overall production capacity to 1,2 million tons per annum. At this time, the original pneumatic control systems were replaced with a Foxboro I/A Series DCS. This was configured in a five node local area network, combining multiple application processors and user workstations interfaced to PLCs. As many as 125 field enclosures provided the I/O interfacing to more than 1500 field instruments, using FoxCom communications. In addition, InTouch Human Machine Interface software from Wonderware was installed to create new process visualisation screens for operator control of wood yard operations.

This approach to production control worked so well that in 2000 Aracruz management undertook their largest project of all – the construction of Fiberline C and the upgrading of Line A and B controls. The goal was to allow each line to operate independently, but to provide a unified view into all operations for better management of overall plant productivity.

Following a year of planning, consultation and project definition, Aracruz management decided to continue their strong relationship with Invensys Operations Management and used the Foxboro I/A Series DCS to operate Fiberline C. The Fiberline A controls architecture was so effective that it was used as the basis for the Fiberline C plant expansion with significant savings generated from reusable engineering. Retrofitting controls on Fiberline B was simplified using Foxboro’s plug-in migration strategy. I/A Series I/O modules, manufactured to be one-for-one, form fit replacements for the original Provox I/O modules, plug-in to the legacy I/O racks. The physical switchover was accomplished without moving any field wiring with total process downtime to migrate this 1000 point system less than 3 hours and 15 minutes.

The complete Foxboro I/A Series DCS on Fiberline C consist of five network nodes with Windows NT workstation processors. A Trident triple modular redundant safety shutdown system from Triconex is used for protection of the oxygen reactor. All Foxboro field instruments – ranging from pressure and temperature devices to magnetic, mass, pH and conductivity devices – are interfaced with the system by means of the FoxCom protocol, using remote I/O racks that are physically close to the process. Motor controls are connected via intelligent MCCs to as many as 25 Micro I/A nodes via Profibus networks, without having to use PLCs. Foxboro I/A Advanced Controls packages were also installed in each production area to gather baseline measurements for evaluating performance improvements obtained from the advanced process controls. All engineering work for regulatory control is being managed by Invensys as well, through subcontracts with the nine primary equipment suppliers. Simulation packages for this effort, to emulate actual use of all control processors and Micro I/A units, were supplied by SimSci-Esscor.

Foxboro command centres with thin profile LCD displays have now been installed in all three control rooms. The processors and I/O cards have been swapped out for Foxboro I/A replacements that have the same form factor, but which incorporate today’s latest electronics circuitry technology. This helped bring the new line on-stream faster and provides a strong avenue for future growth in production capacity. In fact, with this facility upgrade, Aracruz was the first pulp mill to start up with all advanced controls in place and running. That is a good situation to be in because the so called ‘paperless revolution’ that has been talked about for years never really occurred. That means this world will always need fine papers for use in computer printout, copiers and old fashioned hand written letters.

For more information contact Jaco Markwat, Invensys Operations Management, +27 (0)11 607 8100, tech@invensys.co.za, www.iom.invensys.co.za





Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Four ways the global parts shortage has led to innovation and openness
System Integration & Control Systems Design
For those who use automation parts, the unpredictable nature of the supply chain is one of the biggest problems faced today. The shortfall has impacted every industry, but automation components have been especially affected.

Read more...
Iritron’s year of consolidation
Iritron Editor's Choice System Integration & Control Systems Design
Despite the multiple challenges faced by businesses in South Africa, the buoyancy of the technology sector worldwide has produced some green shoots for automation specialist, Iritron.

Read more...
Five edge opportunities for SIs to maximise revenue in 2024
Editor's Choice System Integration & Control Systems Design
System integrators continue to face the challenge of doing more with less – supporting complex operations, while meeting production schedules with limited resources, and innovating to increase efficiency, maximise safety and reduce risk.

Read more...
Condition monitoring in a forging press retrofit
Beckhoff Automation System Integration & Control Systems Design
Significantly increased vibration on machines can result in many forms of negative impacts such as reduced system performance or damage to the machine and foundation. Using the example of retrofitting a forging press with a maximum press force of 2000 tons, Wölfel Engineering explains how efficiently the process was tailored and implemented with PC-based control and measurement technology from Beckhoff.

Read more...
System integration in the digital age
System Integration & Control Systems Design
To meet the challenges of an increasingly competitive marketplace, many manufacturers (end users) must focus on their core competencies and outsource the rest to experts.

Read more...
Choosing a system integrator
Editor's Choice System Integration & Control Systems Design
Automation is an essential part of manufacturing today. Whatever the size, an upgrade or migration project can be complex, and the risks can be high. This is where system integrators (SIs) can help. They can bring together complex subsystems or components of a larger system and make them operate as a whole.

Read more...
Iritron awarded international contract for furnace control
Iritron System Integration & Control Systems Design
Iritron has been awarded two international, multimillion-Rand furnace drying projects. The company has extensive expertise in furnace drying control systems, and provides solutions in the fields of electrical, instrumentation, control systems, and decision support systems.

Read more...
Capitalise on risks by turning them into opportunities for growth
Iritron System Integration & Control Systems Design
In spite of the challenges facing the global and local economy, systems integration expert, Iritron remains optimistic for the year ahead, and believes that there are significant opportunities to be found during a challenging economic climate.

Read more...
Control loop case history 185: Temperature cascade control on boiler desuperheaters.
Michael Brown Control Engineering Editor's Choice System Integration & Control Systems Design
This is a wonderful example of how the use of a cascade flow control still allowed excellent control of the primary temperature control loop to be achieved, in spite of a valve with severe problems.

Read more...
Loop Signatures 15: Digital controllers – Part 7: The D term, concluded
System Integration & Control Systems Design
This third and final article on the subject of the derivative term in digital controllers deals with choosing the right response if you wish the derivative action to work on both setpoint changes and load changes.

Read more...