If you are experiencing corrosion or your water is red within your closed loop industrial chiller system, you may consider using a chemical to minimize corrosion and to prevent bacteria development.
Let's take an example of a 2,500 gallon chilled loop system that operates at 65F and the water is a deep red and possibly filled with bacteria such as slime and algae.
Equipment Required The first thing you need to determine is if any other chemicals were previously used within the system such as a corrosion inhibitor or glycol. If not (which is not uncommon), the first thing is you need to consider installing a side stream filter system such as a Neptune VTF-2HP pot feeder. This feeder is used to filter the water through a side stream loop and it may be used to periodically add chemicals to the system. Now, if you have been using chemicals you need to obtain the SDS in order to determine what was injected into the system before continuing on to a solution.
Chemicals Required: If you are not using chemicals most likely you are experiencing corrosion and bacteria growth within the process water. Since the water is above 45F you typically want to stay away from a Nitrite based corrosion chemical and instead use a Molybdate based corrosion inhibitor. Both chemicals are great when controlling corrosion on iron, but Nitrite may be a food source for bacteria development above 45F.
ChemWorld 882 is an excellent choice as a "Nitrite" free corrosion inhibitor. A 5 gallon pail is enough to treat 5,000 gallons of fresh water. Add 3 gallons of ChemWorld 882 upon startup and is monitored with a molybdate test kit. You only add more chemicals if water is lost or water is accidentally dumped from the system.
The second chemical you require is a non-oxidizer chemical. Glutaraldehyde is your safest choice. This product should initially be feed at roughly 1/2 gallon to kill off any bacteria. After the initial feed, bacteria test paddles may be used to monitor bacteria development. If bacteria levels exceed 10^3 simply slug feed 1/2 gallon of Glutaraldehyde and wait a few days and check again. You only need to add more chemical if bacteria levels spike.
Both chemicals are compatible with ethylene glycol propylene glycol.