Madison Paper remains competitive with program of technology renewal

Pulp & Paper, May 1994 by Yeager, Bob

As a one-machine mill that produces a specialty paper grade, Madison Paper Industries has had to focus on quality, efficiency, and productivity to remain competitive in a global market. The Madison, Maine, mill's "Simmetry" supercalendered (SC-A) paper competes not only with grades from domestic manufacturers but also with paper from Finnish and Norwegian suppliers.

"Nordic competitors benefited from a sizable (about 30%) currency devaluation in 1993," says Jack Chinn, Madison president and CEO. "So the Madison mill must be a world-class competitor in every sense of the word."

Part of Madison's efforts has been to focus on ongoing technological development, remaining in the vanguard of papermaking processes and automation systems. When Madison Paper started up in 1980, it was the first U.S. facility dedicated exclusively to the manufacture of SC paper grades. Since then, Chinn has maintained a strategy to keep the mill ahead of worldwide competition.

"Though our mill is 13 years old chronologically, we aggressively update our technology to keep us as competitive as we were during our first year of operation," Chinn says. "We're a one-year-old, thirteen-year-old mill." This strategy is exemplified by the mill's most recent technological effort, called "Project 4200."

TECHNOLOGICAL RENEWAL. The goal of Project 4200 was to increase design speed of the mill's paper machine to 4,200 fpm from a previous 3,500 fpm, while improving product quality. Of course, this had an effect on the mill's automation systems, which at the time consisted principally of Valmet Automation scanning gauges and a Damatic Classic distributed control system (DCS).

"Although the goal seemed fairly straightforward, the steps required to get there were very challenging," says Martin Troy, E&I superintendent. After eight months of planning, the project was implemented during a shutdown in June 1992. Key project items included the following:

Sectional press roll. The press section was extensively modified, and a Valmet Sym-ZS zone-controlled roll was installed in the new third section of the press for wet-end CD moisture control. Individual setpoints control profile pressures in each of eight sections across the toll plus the dive and tending side loading. Pressure targets are entered manually by a control room operator and controlled by the Damatic-XD DCS. All logics are handled by the DCS.

Added remoisturizing. Controlled remoisturizing is at the heart of SC paper production, in which moisture literally "explodes" from 2% to 8% just prior to the reel. The machine speedup called for more remoisturizing capacity and a wider range of control. Another VIB remoisturizing boom was added, raising the number of CD moisture control nozzles from 292 to 438.

Larger dryer and drive capacity. Larger motor drives were installed throughout (including refiners) to gain the needed machine speed. All new paper machine drives are digital and microprocessor-based and are interfaced to the DCS. Dryer reconfiguration added three cans of drying capacity. An increase to 15 individual and group dryer can controls from an original of five provided improved MD moisture control.

DCS replacement. Madison was one of the first U.S. users of the Valmet Damatic Classic DCS, a system widely used by European paper mills but not in the U.S. According to E&I engineer Todd Pineo, "The Damatic Classic was a 'bulletproof system; it never failed. But the controls we needed for Project 4200 simply went beyond its capacity." The mill reviewed several DCSs and selected the "Damatic-XD." The new DCS would control all papermaking functions, plus the groundwood mill, located a mile away from the paper mill.

Valmet engineers converted all Damatic Classic controls to Damatic-XD language and configured the new control loops for the system. Engineering, final assembly, documentation, and factory test for the DCS were done by a Valmet project manager and his team in Norcross, Ga. With the combined effort from Madison and Valmet, project startup took only 15 days. In addition, operators and engineers each received two days' training on the Damatic-XD.

CONTROL SYSTEM SPECIFICS. As a single-machine mill, Madison is especially sensitive to paper machine downtime and has built substantial redundancy into its automation system. The DCS and PLC systems include redundant controllers and power supplies, plus redundant system communication buses. A redundant fiber optic link exists between the paper mill and groundwood mill. Redundant PLCs control paper machine functions. And redundant DCS process stations control operation of the groundwood mill. "I can pull half of the power supplies in the DCS and never bother system performance," says Pineo.

With the power provided by modern DCSs, creative operators and engineers can find new ways to benefit operations. Madison's personnel employed the power of their new DCS in various beneficial ways, including the following:

Process graphics. Operators must make quick and intuitive decisions, and good process graphics allow them to do so. "The new graphics show us how all process elements relate to each other," says John Kennard, chief operator in the wet-end control room. "So our operators can make quicker decisions and see the effects of those decisions immediately. This becomes very important as we speed up the machine." The mill is also developing a windows-like function, producing a drop-down window for each graphic component--giving key descriptive material as well as the component's physical location in the mill. This speeds up the process of investigation, repair, or replacement.