The first installation of an EPS Generation 3 Cell has been running for 12 months in the TMW Technology Center. We have carefully collected operation and performance data, tested the line’s new features and controls, and painstakingly analyzed its total costs of operation. This update is a summary report of that work.
EPS OPERATING COSTS
For quite some time the EPS Cost Calculator has been available to provide projected EPS Cell operation costs for different configurations and materials. It was recently updated to reflect the latest results from our Generation 3 Cell. However, the Cost Calculator, while very useful, tells only part of the story because it doesn’t include terminal equipment operating costs which, of course, will vary by manufacturer.
Our one-cell EPS Coil Line has run thousands of coils of a wide variety of sizes and grades, from low carbon to AHSS, stainless to silicon steel. Our production mix even includes EPS’ing high strength coils for acid picklers.
We generally run a single shift with a two man crew who operate and maintain the line 5 days a week.
Each month, all variable costs of operation are captured and allocated over the tons processed that month. This approach captures the costs of the EPS Cell and the terminal equipment. Here’s what we found with the material we processed over the last several months:
- Average thickness: 0.130″ (3.30 mm)
- Average coil width: 53″ (1346 mm)
- Average $/ton revenue: $26.40/ton
- Average EPS Cell variable cost: $9.89/ton
- Average Terminal Equipment variable cost: $3.20/ton
- Total EPS Coil Line variable costs: $13.09/ton
These cost rollups, which reflect running a majority of low carbon steel coils, capture everything: grit, water, electricity (pretty expensive for us at $.12/kw-hr), labor – even maintenance, consumable parts and paper wrapping of finished coils. But beyond these numbers are some important developments that we want to share . . .
– EPS CELL COSTS –
While the Gen 3 EPS Cell does not (yet) process material any faster than its predecessor Gen 2 Cell, it does have enhancements that both reduce maintenance costs and extend the period between maintenance points (see “Armour-Plated EPS“).
In addition, we had upgraded the Slurry Turbine motors from 150 to 190 horsepower hoping it would allow us to use a smaller grit size and achieve a slightly better distribution across the strip width. However, there was no meaningful difference, and we are returning to the 150 horsepower motors in order to minimize electricity consumption.
|Our Generation 3 EPS Coil Line features the simplified Filtration System that eliminated the magnetic separator section and all of the maintenance it entailed. We upgraded the filter media we use and now our rinse water is so clean that a $220,000 ‘Post Brush/Rinse’ at the end of the line is no longer needed.|
In another respect, the new filtration media works too well – it actually traps some of the slurry additive and carries it out with the scale sludge. However, we found a way to extract that additive from the filter media and keep it in the system, so there’s no net cost increase for additive.
The new filter media is more expensive than its predecessor and that is reflected in the updated EPS Cost Calculator. The good news is we believe we’ll be able to cycle the new filter media through the system twice, thereby achieving a net savings. (Note that the $13.09/ton total line operating cost includes the 150 horsepower turbine motors and conserving the additive, but does not include running the new filter media through twice).
– COIL LINE AUTOMATION –
Part of our EPS Gen 3 line is a state-of-the art Siemens control and monitoring system that automates many tasks that were traditionally managed by line operators. This system has exceeded expectations: a level of automation has been achieved that it takes just two workers to run the line and they have time to perform the material handling chores and most of the regular maintenance inspections as well.
In fact, as one coil finishes and the next coil is staged on the coil car, the new control system performs entire coil change process in as little as 3 minutes with no operator involvement. The operators band and move coils in and out of inventory and check logs, while coils are loaded and processed nearly unattended. The coil more quickly ramps up to optimum speed and runs that optimum speed automatically. This all makes for higher net run time than was possible before which is reflected in the EPS Cost Calculator.
And to conserve energy, the new controls also power off virtually every pump and motor in the system any time there is not material moving through the cell.
The Generation 3 EPS Coil Line brought together ideas, equipment and automation to optimize performance of the entire EPS processing line. The last 12 months of operation have refined those factors and captured the actual operating costs of an entire Generation 3 EPS line. We’ve found that it continues to compare favorably with acid pickling costs, plus we see opportunities for further cost savings that we intend to share in future updates.
If you would like to schedule trial coils or a visit to watch our EPS Generation 3 Coil Line in operation, please contact Chris Liefer at 618 282-4200 ext. 103 or e-mail Chris.