Paper360 - November/December 2009 - (Page 20)

ENERGY UPDATE SMARTMILL Saving machine energy at the paper Scorecard system continues to save money DICK REESE I n an article in the August 2008 issue of Paper360°, we introduced a scorecard system that allows mills to compare the energy performance of their paper machines to that of other machines producing similar grades, in order to identify opportunities to reduce energy consumption and cost. Today the scorecards are being used all over the world; more than 100 copies have been requested and they have been translated into French and Spanish. The scorecards include separate worksheets for grade related parameters, energy monitoring, drying, pressing, and auxiliary equipment (refining, vacuum application, water systems, stock preparation and pumps, steam showers, cross machine profile control, size press, and machine room ventilation). Energy savings recommendations implemented by paper mills have reduced annual energy cost by over US$ 20 million. It is also possible to implement 20 to 40 percent of the scorecard recommendations without any capital cost. The chart on the next page shows the relationship between energy monitoring scores and total energy scorecard scores. The best-fit line shows a strong correlation between the two. Note that average scores for energy monitoring and total energy are near 50 percent. WATER USE REDUCTION Water use reduction presents a major opportunity for reducing energy consumption. Only 10 percent of the machines surveyed have met TAPPI good-performance guidelines for water use per gross ton of production. Machine grades meeting the targets include recycled paperboard, linerboard, corrugating medium, LWC, and pulp. Water use has been observed as low as 129 gallons per ton in a recycled paperboard mill and as high as 25,520 gallons per ton on a specialty fine paper machine! Reducing mill water infiltration into stock and whitewater streams saves energy by reducing the amount of steam needed to heat the water to process temperature. Opportunities for reducing steam include: • Maximizing entering-stock temperatures • Determining the optimum silo temperature for each machine • Using warm water from the pulp mill to supply the paper machine warm water system • Utilizing a modern saveall in good operating condition, rebuilding segments if necessary • Providing good straining and filtering (mechanical or floatation-type) to allow increased use of clarified whitewater • Using filtered/polished whitewater for low- and SAVINGS PROGRESS As of press time the scorecard system has been used to evaluate energy performance on more than 100 paper machines in the U.S. and to identify costreduction opportunities of over US$ 90 million. Key steps for an effective energy management program • Appoint an “energy champion” to monitor and reduce machine energy consumption • Use index tags and systems to track key factors affecting energy consumption • Utilize rounds to monitor energy-related items not in the DCS or data historian system • Factor energy consumption and cost into the paper machine centerlining process—both process setpoints and factors reflective of system health • Discuss energy consumption and cost in daily production meetings • Include energy consumption and cost reduction performance in personnel review systems Paper360º November/December 2009

Table of Contents for the Digital Edition of Paper360 - November/December 2009

Paper360 - November/December 2009
Over the Wire ... News Summary
Effluent Clean Enough to Drink
A Klass Act
Verso Awakens Maine
Twenty-Three Years of Bringing Students to the Industry
Marcal Rises From the Ashes
Buckeye Turns Lemon to Lemonade
Forty Years and "Still Doing It"
There's No Business Like Paper Business
Saving Energy at the Paper Machine
Low Alkali System Meets the Challenges of ONP/OMG Recycling
Around the Industry
Conquering Innovation Fatigue
Give Yourselves a Hand
Index of Advertisers

Paper360 - November/December 2009