Automation Extends Boiler Life
One major purpose of lifecycle management is to extend the useful life of an asset. Gary Crenshaw, a control systems engineer with Beam Global Spirits and Wine (www.beamglobal.com) in Clermont, Ky., did just that.
In the early 1990s, Beam Global had a coal-fired boiler that was scheduled to be replaced because it was running badly. "We decided to replace the original 1950s-60s controls until the replacement boiler could be budgeted. We put an L&N Micromax on the boiler and added O2 monitoring and other instruments. The boiler ran so much better with the new controls that the project to replace it was canceled."
That was 10 years ago. "The Micromax became obsolete," says Crenshaw. "We replaced the Micromax with an (Allen-Bradley) PLC5/40. Now, PLC 5s are nearing obsolescence and will soon be replaced, but the boiler is still in service."
Apparently, there was nothing wrong with the boiler itself. "The old controls were so bad it just appeared the boiler was no good," he notes. "The operators had to watch the drum level and control the feedwater valve manually. They would also have to watch the coal feed and air flow, and manually adjust these. That's because the old controls no longer worked. The automatic controls solved these problems."
Using automation to extend the boiler life also eased EPA permitting. Regulations said that existing coal-fired boilers could be permitted with upgrades, and a new coal-fired boiler would have been almost impossible to permit.
Reducing required maintenance, cutting time to repair and improving maintenance operations and assets are big advantages of improved lifecycle management.
"With thousands of pieces of equipment in a plant, knowing the health of assets and predicting problems can prevent upsets, reduce maintenance costs and improve availability," says Emerson's Feitel. "Predictive technologies alert staff when equipment such as motors, pumps and control valves are experiencing problems. By evaluating the performance of control valves, planned overhauls of critical valves can often be delayed for years, saving substantial costs and maximizing production uptime."
Studies by Rockwell Automation (www.rockwellautomation.com) have found that 15% to 40% of the indirect costs of a manufacturing facility are devoted to maintenance, with about 50% of that estimated to be unnecessary. "Almost half of all maintenance activity is corrective in nature, which is 10 times more costly than predictive maintenance," says Ben Mansfield, marketing manager, PlantPAx process automation systems, Rockwell Automation. "For lifecycle cost savings in maintenance, we recommend integrated condition monitoring on all rotating equipment."
Getting information to the maintenance system is also important, and the easier the interface the better. "One example of this is the integration between Endress+Hauser (www.us.endress.com) field devices and the Rockwell Automation PlantPAx process automation system," says Mansfield. "Using open, standard technology at every level, the system comes with tools that provide fast system engineering and reduced risks."
For example, in May 2009, the Colorado Springs Utilities (CSU) McCullough Complex water treatment plants converted to a fully integrated Rockwell and Endress+Hauser control system solution. "The new automation system reduced our concern about poor water quality because we could run more efficiently and now had time to fine-tune our operations," says Steve DellaCroce, customer operations superintendent at the McCullough Complex.
In addition to an increased confidence in water quality, CSU was able to reduce annual operating costs by $240,000 due to fewer system operator hours required to perform monitoring and trending tasks. CSU estimates an additional $40,000 annual savings on system support and maintenance.
In these and other instances, a well-designed automation system can cut lifecycle costs in myriad ways. The primary goals for most automation projects are to improve product quality and consistency while reducing labor costs. But once challenges are overcome, the reduction in lifecycle costs can turn out to be a key benefit of many an automation project.