Coker on schedule despite set backBY LARRY TANGLEN Outlook Staff
Wednesday, September 27, 2006 3:25 PM MDT
CHS coker project manager Tom Davis said he expects the $325 million project to be completed by the end of next year and ready to start-up in January 2008.
Construction crews had to tear out and re-pour an estimated 1,650 cubic yards of concrete at the CHS Refinery for the $325 million coker project.
After the workers pulled concrete forms off the six legs that provide support for the coke cooker, inspectors found flaws in the concrete, project manager Tom Davis said. Inspectors discovered places where concrete hadn’t completely flowed into the forms and covered rebar inside the columns. CHS called in concrete experts to examine the columns before it made a decision to replace them.
“Those columns have to support an enormous amount of weight. We wanted to be sure they would hold up,” said Davis. Four of the 40 foot high columns were 6 feet by 6 feet and two center columns were 6 feet by 8 feet by 40 feet.
“We are a safety conscious company,” CHS refinery manager Pat Kimmet said. “We didn’t want to take any risk. We decided if we were going to err, it would be on the side of safety. So we replaced the columns.”
Davis said there was no “smoking gun” to point to as a cause for the concrete problem. He pointed to three possible contributing factors.
– The temperature was 103 degrees the day of the pour, July 29. JTL Group trucks started hauling concrete at 2 am. that morning and the crews didn’t complete pumping concrete into the six sets of column forms until nearly 2 pm. that afternoon.
– The crews used a sequencing technique to fill portions of each column during the course of the first pour, gradually filling each set of forms. When the columns were replaced, crews filled each column separately before moving on to the next column.
– Before making the second pour, the “mix” of the concrete was altered to enhance the flow characteristics and additional vibrators were used to settle the concrete into the forms.
Construction crews re-poured the first column again Sept. 14.
Davis and Kimmet agreed that having to redo the columns won’t put the project behind schedule for its December 2007 completion. “Sometimes these things happen on a project of this scale. Overall, we are pleased with the job the contractors are doing on this job,” they said. The general contractor on the project is Turner Industries Group of Baton Rouge, LA.
The coker unit will process the asphalt left from the crude oil refining and break down the asphalt further into more gasoline and diesel fuel, leaving coke as a residual product. The coke is a carbon product similar to coal used as a fuel in power generation plants.
