Cleaning the long, narrow tubes in a heat exchanger can be an arduous and hazardous process. At Newmont Mining Corp. in Carlin, Nev., employees -- confined to a small space for extended periods of time -- hand drilled the tubes to clean them for future use. This process posed several problems for the company.
First, extended periods of time in cramped spaces created health and safety issues for its employees. Second, the heat exchangers were inoperable during the one-month exchanger cleaning process, resulting in productivity losses. Third, hand drilling would often damage the cooling fins in each tube. And fourth, the drilling approach cost Newmont $450,000 in lost revenue for each day that an exchanger was off-line. As a result of these drawbacks, Newmont Mining Corp. began investigating other processes. One of its corporate partners recommended Nitrocision’s NitroJet LN2 cleaning process.
Using this technology, the company was able to reduce the time required to clean the heat exchangers from 14 days to only two days. The precise jet technology enabled employees to rapidly and thoroughly clean the exchanger tubes, and, because the liquid nitrogen evaporates into the atmosphere, the LN2 jet eliminated the secondary waste stream traditional cleaning methods had produced.
Since Newmont first used the technology in 2004, the company has contracted with Nitrocision every year to complete the exchanger cleaning project during a planned two-week maintenance outage period. By using LN2 cleaning, Newmont has saved nearly $6 million annually due to reduced downtime.
Bottom Line Benefits of LN2 Cleaning
April 1, 2008