Keeping manageable levels of metal ions, like copper (Cu+), in cooling tower water can be very important to the lifespan of the cooing tower system. It can also be environmentally harmful if too much of these metal ions is discharged from the cooling tower. This was the case for a commercial printer facility in central OH, when their copper levels being discharged were too high.
The municipal water treatment plant issued warnings to the plant about this problem, so Chardon assessed the cooling tower system. It was found that the copper levels were in fact too high, sitting around 4-6 ppm (normal levels are < 0.5 ppm). The discharge limits for the municipality is only 2.0 ppm, so the excess copper being discharged was a problem. These copper ranges can cause problems within the cooling tower system as well, contributing to galvanic corrosion and affecting the efficiency of the heat transfer.
In order to find the culprit for the excess copper in the water, Chardon inspected the piping system of the cooling tower system. Our technician found a stretch of about 100 yards of 1.5” copper piping that was the cooling tower make up water line. This created an issue, because if the copper was being stripped off this pipe and into the water, every time the tower ran another cycle of that water that copper number was being doubled in the system.
Cycling up a cooling tower is part of how a cooling tower efficiently uses water for cooling. To “cycle up” a cooling tower system, is to recirculate the water back through the system again before it is bled out. When this happens, the minerals left behind upon evaporation of the water stay in the system with the new make up water. So, in this case, copper was being added to the recirculated water from the makeup water line and cycling up the copper levels as well. Therefore, it is important to take accurate readings of the make up water (city or well water entering the system) to diagnosis problems.
It was determined after further inspection that the water flow rate within the copper pipe was too rapid, causing erosion of the pipe and copper ions in the water. When the flow of water through piping is causing erosion of the metal, here are some recommendations to install for solutions:
These pieces of equipment can help prevent the erosion process from building up and causing similar issues as this commercial printer. Chardon installed all 3 of these items to help fix the copper problem, and within a few weeks, the copper levels dropped from the 4-6 ppm range, to below 0.03 ppm. It’s an important step to monitor the make up water, to help diagnose when issues arise. And installing things like flow regulators, can help ensure that your water flow does not erode piping for your cooling tower.
To learn more about Chardon’s cooling tower treatment service, contact a representative today!
