DuPont TiO₂ Technologies - New Johnsonville, TN
By Michael T. Saale, Graduate Student, Mechanical Engineering

Reprinted from the MRC NEWSLETTER, October, 2008

This is the third summer I have interned through the MRC at DuPont’s TiO2 Technologies facility in New Johnsonville, Tennessee. As usual, my supervisor was Eddie Bozman. He assigned three projects this summer: the analysis of pipe erosion in an Olympic swimming pool-sized heat exchanger, a plant-wide equipment piece mapping project, and the task of creating a database for all the state inspected pressure vessels on site.

The first project was to find a method to extend the lifespan of the pipes (called legs) in the heat exchanger (called the flue pond) and use statistical data to justify this method. The problem is that flow inside the legs erodes the walls. It costs between $11,500 and $61,500 to replace one of the legs. Three to four legs are replaced a month.

Every time a leg is removed, ultrasonic pipe wall thickness measurements are taken on twelve locations of each flue leg. The data appears as a spreadsheet that lists all twelve measurements in a single column. However, that month’s readings also appear in the same column as every other set of readings, dating back to 2006.

Due to the large amount of data, I worked with a programmer to write a macro in Excel that would auto-format the raw material. Gaining the ability to program in Visual Basic, the language that Excel is built upon, was worth a month’s pay.

A Meridium software package was then used to determine the general erosion rate per area and to identify events that caused rapid erosion. It was discovered that erosion took place at a significantly higher rate inside the bottom 45º of the pipe. This meant that the life span of each leg could be increased by rotating each leg at 45º increments. Using the statistical data, an equation was developed to determine when each leg was to be rotated based upon its current pipe wall thickness and its location in the flue pond. The first legs will be rotated on July 29. A conservative estimate of the savings to the plant over the next year is $45,500.

The second project was to create equipment piece layout drawings of all the major areas of the plant for use as maps. This required me to learn Microstation, the drawing software used by DuPont. I then collected all the existing structural steel drawings for each area and created new drawings for the area we did not have. The equipment piece layouts were then put on top of the steel drawings. The resulting files were then compressed into a printer friendly PDF and stored on the share drive.

The final project was to gather the state certificates of inspection and related data for all of the licensed pressure vessels in the plant. I then contacted vendors and fabricators to find any missing information. The database started at 15% complete. It is now 70% complete.