Oxidation is a common threat to a industrial heat transfer fluid’s service life, and it occurs when hot fluid — above 200°F (93°C) — is in contact with the atmosphere. This reaction forms acids in the fluid that eventually drop out to form sludge deposits that will restrict or block flow, foul systems and significantly shorten fluid life.
In a recent post on the company’s website, Duratherm Heat Transfer Fluids explains the benefits of a nitrogen blanket in extending the service life of heat transfer fluids.
Fluids that contain antioxidants slow this process, but they can only protect for so long. This is where the nitrogen blanket comes in, says engineers at Duratherm, especially if fluid sees air at temperatures above 200°F. This air contact is almost always in the expansion tank or reservoir, and a nitrogen blanket added there simply displaces the air (it is heavier than air) and protects the fluid.
Nitrogen is the ideal and most common inert gas used for this purpose; it is readily available, inert and not soluble in most thermal fluids.
There are other benefits to using a nitrogen blanket that are unrelated to extending service life. To learn more, visit www.heat-transfer-fluid.com.