Steel maker uses automation to extend asset lifecycle
Arlington Heights, Ill. - A representative from Canada's second-largest steel maker says he has helped apply automation and controls to keep assets working longer and more efficiently throughout products' lifecycles. Vlad Djuric, Dofasco Inc. (Hamilton, Ontario, Canada) explained how automation helped maximize asset reliability, doing its part to turn the company around from an economic abyss in the mid-1980s.
Arlington Heights, Ill. - A representative from Canada's second-largest steel maker says he has helped apply automation and controls to keep assets working longer and more efficiently throughout products' lifecycles.
Vlad Djuric, Dofasco Inc. (Hamilton, Ontario, Canada) explained how automation helped maximize asset reliability, doing its part to turn the company around from an economic abyss in the mid-1980s.
With new processes in place, many examples are emerging. One is effective blast-furnace tap-hole maintenance-using sensors, data collection, and analysis-which will save an expected $19 million.
Dofasco has $5 billion in assets at an 800-acre bay-front facility, and makes an annual $3 billion in revenue from producing about 4.5 million tons of steel, primarily for automotive, manufacturing, construction, and packaging industries.
Iron ore pellets and scrap are cast in two electric arc furnaces and hot rolled into slabs and coils. The 60,000-lb coils are stacked 10 high prior to shipping. The 1980s hit the facility hard. Inflation raised costs as prices dropped and offshore imports came in at better quality and lower prices, requiring a shift to market-based pricing before the company's cost structure could support it; shareholders were taking their money elsewhere, Mr. Djuric says.
A global examination of maintenance benchmarking examined varied information systems, revealing that no single country, industry, or plant had comprehensive best practices. There were pockets of excellence; many were short-lived. Computerized maintenance management system (CMMS) and product data management (PDM) software fell short of user expectations.
A three-year, $15 million in-house effort examined the asset reliability business process and maintenance and developed enabling technologies, with sustained corporate support, says Mr. Djuric.
In the 1980s, maintenance practices were 70% reactive and 30% proactive; now the ratio is 20% reactive and 80% proactive, with a goal of 15/85. Other measures of improvement showed a shift from 78% average equipment availability to 91% now; prime yield shifted from 76% to 91% (saleable goods versus scrap); and a mostly voluntary maintenance workforce reduction from 3,460 to 1,700, Mr. Djuric says.
The company is now a benchmark leader, winning multiple benchmark awards, including the most-profitable North American steel producer.
All of that required a shift from a "fix things more quickly" mentality to an asset-management culture. That required considering product quality, delivery price, how equipment is operating, and what environmental regulations are, according to Mr. Djuric. With increasingly complex equipment and systems, new computer and diagnostic technologies allow tracking functional failure (inability to meet specifications) as opposed to breakdown.
Condition monitoring acknowledges that failure starts at installation. Analysis showed that less than 20% of failure is predictable by time, requiring more attention to operating conditions that cause failure before it happens, rather than checking or replacing things only at preset intervals, he says.
This requires measuring for key changes in pressure, flow, temperatures, velocities, and forces compared to original design parameters, then realizing the business consequences of unsafe equipment or off-specification products.
Appropriate business practices help gather scattered knowledge and unify inconsistent actions by capturing information in a common repository, he explains.
Dofasco developed software to apply rules-based diagnostics and condition-based management to trigger maintenance jobs based on indicator analysis and tracking. Information from the CMMS and human-machine interface was also used, ensuring that the right work was done at the right time, says Mr. Djuric.
The Dofasco software package, called the Intelligent Condition Monitoring System (ICMS), is being commercialized and marketed by Ivara Corp. (Burlington, Ontario, Canada) as Ivara.EXP (Expert Maintenance Program). Dofasco now has 30% interest in Ivara.
Life extension for the refractory liner of two blast furnaces result from Dofasco's maintenance analysis. Installation of a linear variable differential transformer (LVDT), a rugged noncontact electromechanical measurement device, provided needed information about how molten steel flowed out of the furnace, which aided effective timing of trough maintenance. Data output goes to a PLC, which collects information about the stroke of the swing cylinder every 30 sec. Built-in values around the outputs ensure unneeded information isn't collected. An alarm sound when degradation exceeds the setpoint. The software then can generate a work request, Mr. Djuric says.
Effective blast-furnace tap-hole maintenance, using sensors, data collection, and analysis saves $1 million a year for every year furnace lining life can be extended beyond a previously expected eight-year life. Anticipated life is now 15 years for one furnace 20 years for the other, for total savings of $19 million.
Mr. Djuric told the story as the keynote speaker at the PlantSuccess seminar held here April 11.
Control Engineering Daily News Desk
Mark T. Hoske, editor-in-chief