Reviving an Aluminum Closed-Loop System (Factory Cooling Loop)
A facility’s semi-open, closed-loop cooling system (with aluminum piping) was fouled by iron deposits: water analysis showed elevated dissolved iron. We recommended a dynamic flush with a non-acid cleaning solution to remove the sludge. As industry literature notes, iron is “the most common corrosion by-product in closed loops,” which precipitates out when inhibitor levels drop. After days of continuous flush until clear, we refilled with high-quality water and restarted a tailored corrosion inhibitor program (nitrite/molybdate blend with pH 8–9 target for aluminum systems).
- Actions: Performed a thorough cleaning sequence: (1) flushed out debris, (2) chemically cleaned with a biodegradable chiller flush, and (3) recharged the loop with fresh inhibitors and biocide. Monitored conductivity to match makeup water.
- Results: Post-cleaning conductivity/ion levels dropped to normal, and no new iron particles appeared. The system now runs stably: pumps operate smoothly and heat exchangers have recovered capacity. Ongoing maintenance (periodic bleed & refill) keeps ion levels low. In short, dynamic flushing plus the right chemistry restored the aluminum loop’s performance and eliminated recurring clogging.
