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Alma, Abitibi-Consolidated: Integrating automation from multiple vendors

The Abitibi-Consolidated paper mill in Alma, Quebec, was originally built in 1924. The first paper roll was produced in December 1925, so 2005 was the mill’s 80th continuous year of operation. The mill originally had four machines, all producing newsprint. In 1967, two of the machines were replaced by PM14 and, in 1986, the other two machines were converted to the production of directory paper. Prior to 2004, the mill produced 217,000 tons of directory paper per year and 134,000 tons of newsprint per year.

In the late 1990s, Abitibi-Consolidated determined that the paper market was changing. The newsprint market was stagnant and decreasing. Newsprint mills were closing all over North America. The company discovered a new market for lightly-coated paper that no one else was serving, and developed their Equal Offset brand.

Equal Offset is a coated grade that a printer can use instead of uncoated free-sheet paper, saving up to 15% in printing costs. The mill in Beaupr, Quebec, was converted from Alternative Offset paper to make this new standard of paper. The first Equal Offset paper was produced in 2000 and Beaupr currently churns out 110,000 tons per year. Of this total, about 90% goes to printers in the U.S.

Because of the success at Beaupr, in 2002 it was decided to convert PM14 at Alma to manufacture the same grade of paper. Making coated paper, especially a high-brightness grade like Equal Offset, is much different than making newsprint. It requires a nearly complete rebuild of a newsprint mill. Production runs are smaller, and the customer base is large. This is completely different from a newsprint mill, which is accustomed to making long production runs of the same paper grade. Changing a newsprint paper machine over to Equal Offset paper is a major project, requiring changes both in the machine itself and in the control system. Accordingly, it was decided to rebuild PM14, install a new paper machine from Voith Brazil, and install a new control system.

The PM14 process was rebuilt from the stock approach piping to the winder. Most of the existing machine was replaced or rebuilt. The original Foudrinier table and the primary headbox were retained. The main dryer section was also retained. The machine would receive a top sheet former, new press section, new coordinated drives, a coating kitchen and a recipe management system. The shutdown of PM14 started in April 2004 and the machine was down for 45 days for the rebuild.

While much of the existing paper machine had to be replaced or rebuilt, several systems were retained, including the stock prep system.

Selecting vendors

The mill control system had to interface to all the new and existing devices and systems. Complicating matters, the vendors came from five different countries, including Brazil, Japan, France, United States and Canada.

PM14 is a relatively new machine. Only one other machine like it exists in the world, but this would be the first time the machine would be used to make this type of paper. The team at the mill knew that a large amount of time would be spent — estimated at more than a year — in both debugging all the systems and optimizing the papermaking process. The control system had to have all the tools needed for equipment diagnostics, maintenance, loop tuning and process analysis.

Integration of all the systems was a major concern. One method for implementing a new paper machine is to allow the paper machine manufacturer or a system integrator to spec all the supporting systems and perform the system integration. The other method is to buy best-in-class systems from multiple vendors and integrate the systems.

In this case, it was decided to use best-in-class systems, which included taking a manageable risk on the systems integration. In other words, the potential benefits of a best-in-class system far outweighed the costs and time it would take to integrate all the different systems.

It was an interesting challenge: On the one hand, the team wanted to use proven technology, so wireless or Internet technologies were not wanted for control. On the other hand, they wanted a system with all the latest tools. The paper machine has several proven communication technologies, including Ethernet IP, DeviceNet, ControlNet, Infi 90 Bailey Ring, HART and serial links.

To ensure that the correct control system was chosen, an evaluation group was formed, consisting of a team of people from operations, engineering, maintenance and IT. The team had the responsibility of selecting a control system supplier.

The team’s first step in the selection process was to evaluate the available control system suppliers according to several criteria:

* Experience in the paper industry

* A proven system

* Local support

* Asset Management tools

* Maintenance tools

* Loop tuning tools

* Ability to integrate with all the mill systems

The team determined that six major process control vendors were capable of performing the necessary integration and had the required capabilities. All six were invited to visit Alma and make their presentations. From the original six, three finalists were selected and invited back for a configuration challenge.

The configuration challenge consisted of having a technician program a basic control loop, build a graphic, and perform a bench test. One of Alma’s technicians sat down with a representative from each system vendor and worked through all the procedures and configuration steps necessary to create the control strategy and the display. This would show how user-friendly the control system was, and how easy each was to learn.

The winner of the configuration challenge was Emerson Process Management, as the team decided that the DeltaV digital automation system was much easier to use than the other two systems. Although the configuration challenge was not the key to selecting the system, it was very important.

The control system now consisted of a DeltaV digital automation system for controlling the three process areas: PM14, the bleaching plant and the coating kitchen, with an interface to the existing hybrid PLCs. A legacy DCS is the original stock prep system which the DeltaV system integrates, enabling the operator to control the Stock Prep area directly from a DeltaV operator station. The paper machine drives, as well as the wet end and dry end of PM14 and the GL&V winder are also integrated by the DeltaV system.

At the wet end, six redundant DeltaV controllers and I/O control the bleach plant and the coating kitchen. At the dry end, four redundant DeltaV controllers and I/O control the paper machine and auxiliary services.

Operator stations are located throughout the plant, including six DeltaV workstations in the main control room, three workstations in the wet end control room, four engineering workstations in the maintenance department, and a workstation in the stock prep area. A redundant Ethernet control network links all the DeltaV controllers, workstations and I/O. To aid in maintenance and diagnostics, smart valves and field instrumentation have HART connections.

The overall system is composed of 2,900 process I/O points, 158 control valves with Fisher Fieldvue DVC Hart positioners, 70 magnetic flowmetres, 156 transmitters (pressure, level and temperature), 25 Micro Motion Coriolis flowmetres, and 127 drives. Other networks and instrumentation connect via Ethernet IP, serial links, DeviceNet and an existing DCS Ring Network.

Asset management and troubleshooting are accomplished with the use of Emerson’s AMS Suite, process historian, DeltaV event logger, DeltaV Inspect performance monitoring, and diagnostics software.

System integration

System integration and configuration was a combined effort between Abitibi-Consolidated and Emerson, as represented by Laurentide Controls, the co
mpany’s local business partner in Montreal. Working together, the team developed a complete configuration scheme for the paper machine control system in six months. At the same time, training on the DeltaV system began for Abitibi-Consolidated operators and engineers.

When the configuration plan was approved, integration began. The integration of each major system required specialized teams, consisting of personnel from Abitibi-Consolidated and Emerson. The automation company and its local partner provided the integration expertise for ensuring the integration of all systems.

Major systems that used PC-based controls were interfaced via OPC. The OPC integration enabled the operator to run the paper machine processes from a common DeltaV interface and have the diagnostic status of the different systems within the same console.

For example, integration to the Honeywell-Measurex DaVinci QCS system was made via OPC. OPC connectivity allowed an efficient split between the DaVinci supervisory control loops and DeltaV field control loops.

OPC also allowed an easy connection to the paper machine drives, enabling the DeltaV system to read the status of each drive for display on operator consoles. Even more important, OPC enabled the digital system to read diagnostic data and messages from the drives. This proved to be very valuable when starting up and debugging the paper machine.

The stock prep system was interfaced via DeltaV Bailey Connect, an Emerson interface to the existing control system.

Systems that were primarily PLC based — such as the ControlLogix motor controls, Voith paper machine controls, coater, and Solaronics Infrared Dryer — were interfaced via RS232 serial links to the DeltaV system.

This overall integration scheme combined information from all systems on the same operator interface, facilitating start-up and operation of the machine.

Emerson invited every key vendor to send a team to Laurentide’s offices in Montreal for a customer acceptance test (CAT). Over a two-week period, the interface to every major system was vigorously tested with simulations and the interfaces were all approved by Abitibi-Consolidated.

Startup

There were no major problems during startup. Although a lot of finger-pointing was expected because of the large number of system vendors, everyone worked as a team. The customer acceptance tests solved most of the integration issues, and every supplier contributed to solving any remaining problems.

System commissioning was done using the AMS software. This simplified calibration, control configuration and verification of various field devices. With AMS, commissioning took less time than was expected, and made it possible to document every step. AMS maintained a database of instruments and control valve settings and calibrations. Problems were found and diagnosed during testing and startup. Many tests were performed on the various systems before the actual startup and AMS was extremely valuable when troubleshooting.

The project startup schedule was:

May 2003 – Configuration and integration began.

Nov 2003 and March 2004 — Customer Acceptance Tests (CAT) at Laurentide Controls.

February 2004 – Started up the bleach plant.

June 2004 – Restarted the paper machine to make newsprint again, to make sure everything was working properly.

October 2004 – Reconfigured the machine to make Equal Offset paper, and started it.

The machine has been running successfully for a year.

Stumbling blocks

There were two stumbling blocks: First, the team had no experience making Equal Offset paper at the Alma mill, so many assumptions were made, some of which proved to be incorrect. Some of these problems are still being dealt with as the system is being optimized and the control system configuration is being refined.

The second problem involved motor logic. The problem was that both the DeltaV system and the ControlLogix controllers tried to control the drives. This caused several conflicts in the motor logic that had to be resolved. Essentially, putting logic in both control platforms meant that the drives were receiving commands from two masters. It was resolved by having the DeltaV send commands to the ControlLogix controller.

In subsequent projects, one layer can be removed and the DeltaV system can send commands directly to the drives. The ControlLogix PLCs connect to motors and actuators via DeviceNet. The DeltaV system also supports DeviceNet, so it is possible to connect those motor drives and actuators directly to the DeltaV system and eliminate the need for the ControlLogix PLCs. Abitibi-Consolidated decided to use the ControlLogix controllers in this installation because Voith uses Rockwell Automation PLCs as standard.

Operations

The first year of operation was all startup, where paper was made, the processes optimized, and tuning loops refined with the help of AMS tools. Most helpful were the DeltaV Historian, Trending, Event logger, Tune and DeltaV Inspect functions.

The continuous process improvement team at Alma includes engineers and operators who are dedicated to solving problems that come up during operation, and devising ways to further optimize and refine the process. This team has a dedicated set of DeltaV workstations in a separate room, where it can analyze data from the DeltaV Historian, Event logger and AMS, and the PI historian. The team spends 100% of its time solving problems and optimizing processes.

The team is solving process problems faster than ever thought possible, thanks to the volumes of data available.

The team is just beginning to take advantage of AMS tools to optimize the maintenance process. The maintenance group has been trained on how to use, for instance, equipment diagnostics. The team now has a full year of equipment performance data, such as valve signatures, and is learning how to perform predictive maintenance. For example, the current signature of a valve can be compared to the signature when it was installed, and determine if the valve is working properly.

In the paper industry, valves tend to clog and stick because of the nature of the pulp passing through them, and they need to be cleaned and adjusted on a regular basis. Even brand-new valves can require maintenance after only a few weeks of operation. Using AMS diagnostics, valves that need service can be identified long before they cause problems. Maintenance warnings are received early enough so valve service can be scheduled during downtime. In the past, it was not known when a valve was having problems; if the valve failed, the machine had to be shut down. Now the team anticipates that machine shutdowns because of failed valves or instrumentation will be minimized.

Results

Abitibi-Consolidated Alma is very happy with the performance of its new process and system. Targets have been exceeded for product quality, production speed, and overall productivity. Year to date, the market for this new paper grade has grown by 60% more than expected because of the good quality of the product. The overall project implementation is considered to be very successful.

The team was also pleased with the speed of optimization and problem solving, as well as the fast learning curve for the employees. The operators and maintenance staff have learned a new paper product, a new paper machine and a new control system very quickly.

Michel Gaumond is the coordinator of electrical maintenance at the Alma Division, Abitibi-Consolidated, Alma, Quebec.

Claude Mercier is the account manager at Laurentide Controls, Emerson Local Business Partner, Montreal.