Companies interested in EPS technology can determine an EPS Line’s potential throughput for their specific product mix by using the online EPS Operations Cost Calculator. They can also enter their cost for electricity and labor into the Calculator to obtain estimates for line operating costs and profitability.
The Cost Calculator also provides estimates of the downtime required for maintenance of the EPS Cell itself, but these estimates do not include the line’s terminal equipment (uncoiler, leveler, scalebreaker, recoiler) since the customer generally selects this equipment themselves. Fortunately, we’ve kept records of downtime and maintenance for our EPS coil line operating at TMW, including the terminal equipment, for its entire three years of operation. This EPS Update shares that experience and offers a comparison to push-pull acid pickling lines.
This analysis defines downtime as any period when the pickling line (either EPS or acid) is staffed, but is not running production. As such, this includes both unplanned outages and planned outages for maintenance.
For our EPS Coil Line, we can report that unplanned outages are rare. Yes, things do go wrong on the line from time-to-time, but we can usually compensate by adjusting its operation or changing product mix, without having to shut the line down.
As for EPS Coil Line maintenance, we follow the very same EPS maintenance schedule and procedures that we provide to all of our EPS Producer customers. Because we follow the schedule closely, we do not get behind on maintenance, which is very important for any pickle line, EPS or acid.
EPS Maintenance Procedures are available online and right from the operator’s panel.
Here’s what three years of our maintenance records reveals:
Our EPS Coil Line Total Downtime averages 7.5%. Here is how that 7.5% builds up:
- The EPS Cell, less the filtration system: 4.4%.
- The biggest single factor is replacing turbine blades , which accounts for much of the required maintenance time. Naturally, we are looking at ways to extend turbine blade life.
- New developments being evaluated should cut the filtration system maintenance time in half.
- This factor is larger than it should be. The manufacturer of our leveler focused on combining the scale breaker, anti-crossbow, and leveler into one unit, but leveler roll removal is less than desirable since we have to remove all of the drive shafts in order to remove our work rolls and backup bearings.
Good News: with the programs we have underway on turbine blade life and filtration system optimization (and assuming use of a more conventional leveler), we are confident that EPS maintenance downtime can be lowered to 4.5%
ACID PICKLING LINE DOWNTIME
For push-pull acid pickling lines operated by toll processors in North America, on average, maintenance downtime takes up 5.5% of staffed hours, while unplanned outages take up 9% of staffed hours for a total of 14.5% downtime. These figures come from a comprehensive, independent market study of 69 acid picklers in North America operating both continuous and push-pull pickling lines. Of the picklers included in the study, the group that best compares to an EPS Coil Line is comprised of 21 toll processors who operate push-pull pickling lines, processing predominantly low carbon steel.
EPS AND ACID PICKLING DOWNTINME COMPARED
The total downtime (maintenance plus unplanned outages) is nearly double that of the TMW EPS Coil Line. Also, the acid pickle line downtime figures do not include downtime needed to repair the acid pickling line’s facility due to deterioration. The acidic atmosphere accelerates corrosion of structural beams, ceiling/roof, etc. We are aware of entire roofs which have corroded away, wiring which has had to be completely replaced, and other interesting phenomena like area fans falling off the wall. Not the case with EPS.
On the other hand, there are EPS skeptics who think that the EPS equipment must also suffer from a shortened lifespan. They conclude this based on the logic that a ‘shot blaster beats itself to death’ so the EPS process must do the same. But that is not the case. TMW has a novel way of protecting its EPS cabinet and other components, plus the water in EPS’s slurry reduces wear significantly. We invite you to visit TMW to see that the interior of our EPS Cell looks virtually the same condition as it did three years ago when we commissioned our EPS Coil Line.
Whether you operate an EPS line or an acid pickling line, it is very important that the manufacturer’s maintenance schedule and procedures be strictly adhered to. Our EPS service technicians have visited EPS lines that are maintained quite well and others where unplanned outages and maintenance cost are a problem precisely because that particular EPS Producer does not follow the EPS Maintenance Schedule. One reason we commissioned our EPS line here at TMW was to show the industry that EPS can beat acid pickling’s maintenance performance.