The Challenges
- Microbial induced corrosion was increasing the risk of internal pipe failure on the W3 starch line
- Bacteria were established inside existing nodules on the contaminated pipe
- Acids produced under the nodules were attacking the pipe wall from within
- Nodules could progress into pin-hole leaks
- Clean pipe needed ongoing protection so that new colonies did not take hold
The Solution
To test whether microbial induced corrosion could be controlled without dosing, one HydroFLOW® i120 was installed on the W3 starch line, a pipe of 4.5 inches outer diameter, approximately three metres upstream of the test spool sections. One spool came from contaminated pipe with established nodules and one from clean pipe. The HydroFLOW signal travels through the water in the line and disrupts the conditions bacteria need to attach and build biofilm on pipe surfaces. Both spools were inspected and photographed at the start and again after 15 weeks, with four individual nodules tracked on the contaminated spool.
For anyone managing pipework in a paper mill or another process plant, MIC is hard to see until it leaks. The value of this trial is that it was measured on the pipe itself: the same spools and the same four nodules, photographed before and after, on a line protected by one unit and no chemicals.
