Cutting Downtime in Half for a Kiln and Dryer Replacement at DuPont

DuPont-1-web-300x300

With critical production timetables for chemical processing, a DuPont plant cannot afford to take its dryer offline for multiple days for a much-needed replacement. Using the API Radian laser tracker, DuPont engineers are able to ensure the new dryer is properly aligned in less time than traditional optics. And when they run into confusion, an API engineer takes a late-night house call to talk them through the measurement job.

Products made by DuPont show up everywhere: in homes, at work, and even in our food. This creates huge production demands for the company to meet and an ongoing need for precision and efficiency in its manufacturing process. Recently, a team of workers and engineers from DuPont replaced an aged dryer that was part of the manufacturing process of a chemical found in hundreds of household consumer products. They used the Radian laser tracker from API to ensure the dryer was installed and aligned perfectly.

While the dryer might appear huge and cumbersome, it must fit and be positioned in a very specific way, said Micheal Callan, a DuPont Equipment Alignment Specialist in the Rotating Machinery Group. The plant where this project took place replaced another dryer, a few weeks earlier. Those measurements were taken using traditional optics, taking more than 14 hours. Callan believed that a laser tracker could provide a much more reliable and accurate measurement, which was critical in the job.

“A house is only as good as its foundation. It’s the same with the dryer vessel. We have to have accurate equipment, like the Radian, to ensure it’s in place,” Callan said.

The replacement job required Callan and his partner on this job, rotating machinery consultant Mike Burgess, to know both the position and slope of the dryer. The trunnions upon which the rollers were placed had to be set up at different heights to ensure the exact angle. There was virtually no room for error, Callan said.

Three-thousandths of an inch off would be unacceptable.

The Lightweight and Portable Measurement System

Callan has been doing alignment jobs for more than 16 years. He saw that laser trackers would make set-up and operations faster and easier, so, in 2012, he acquired a Radian from API. He said he chose the Radian for its portability – compared to other trackers, the Radian is the lightest tracker capable of continuous measurement. He also liked the support and attention the API provided him.

Since then, Callan has taken the Radian on many measurement jobs, mostly for roller alignment work similar to this recent job. He also used it to measure sole plates and equipment installations at other facilities.

Inside and Outside the Dryer

In order to meet demand, DuPont focuses on improving production times and increasing yield, and the dryers were critical. Reducing downtime is a major factor in meeting production goals, so this alignment job had to go fast.

The project began with a measurement of the old dryer. This dryer was then removed by crane from its place, but the Radian had tracked and held a virtual “line” in place that acted as the reference point for the measurements. In addition, Callan put up measurement targets in four spots around the tracker to use as references that he could see and measure after the new dryer was installed.

Callan then measured the proper positioning for the new trunnions, getting three dimensional and positional coordinates for all four rollers.

Two pairs of trunnions sat apart from each other at slightly different heights, which helped angle the dryer down. Callan took distance and angular measurements of the rollers, which were later found to be accurate by plant officials using tape measurements.

Challenges

With support structures and piping in the way, Callan had to deal with a limited line of sight, and relied upon his four reference points to ensure that the new dryer, when it is put in place, would comport to his virtual line. The job had other complexities that proved challenging, including:

  • Vibrations from a nearby dryer carried through the steel girders and potentially jarring the measurements.
  • Temperature fluctuations from water pipes possibly causing the steel girders to warp slightly.
  • The position of the reference points could be too close together or otherwise not in the right place.

API Engineers on Call

Whenever Callan had a question, however, API engineers were available to give him answers and guide him through the job. After a long day of taking positions of the trunnions, Callan needed to ensure his data was accurate. He emailed the measurement data, recorded in Spatial Analyzer, to API Services Engineer Will Austin. Upon looking at the file, Austin was able to reconstruct Callan’s entire measurement project.

Over the course of an hour-long call, which Austin took at home, he advised Callan to place more measurement targets around to get a more accurate reading, including behind the Radian.

“The more you spread your measurement network out, the better. It makes any error less problematic,” Austin said.

Being able to share his measurement results and talk through the entire project with an API engineer gave Callan the confidence to know his measurements would be accurate.

“That was just amazing how he could find those problems just by looking at the file. He was a tremendous help,” Callan said.

Being able to share his measurement results and talk through the entire project with an API engineer gave Callan the confidence to know his measurements would be accurate.

Despite the high tolerances and the complexities of the measurement job, Calland and Burgess ahd the measuremet data and calculations to esnure that teh dryer was placed by crane at the exact position it needed to be. With it perfectly aligned, DuPont is likely to experience fewer maintenance problems, and the usable life of the dryer should be longer.

Taking the Radian to the Next Job – Wherever it Is

Since the dryer alignment, Callan has taken the API Radian to Europe for a variety of measurement jobs. He plans to use it to help DuPont engineers move a tank at an upcoming job.

Coming into new facilities with the laser tracker occasionally takes some of the staff by surprise. Older engineers and workers especially are more comfortable measuring theodolites or other optical methods. But Callan knows the Radian will win their confidence.

“The equipment proved itself in the end among the doubters,” he said.