Measurement Of Oxygen Concentration In Blanketing And Inerting Operations

By Mettler-Toledo International Inc.

Tank blanketing is the process of filling the headspace in storage vessels and reactors with an inert gas, usually to protect its contents from exploding, degradation or polymerization due to the presence of oxidation but also to protect equipment from corrosion. A blanketing system is normally designed such that it operates under higher than atmospheric pressures, therefore preventing outside air from entering the vessel. As oxygen and moisture in the air can be undesired in numerous processes and applications, blanketing is done in a wide range of industries, varying from (petro)chemical-to food and beverage-, pharmaceutical- to pure water- and so on.

Inertization and nitrogen blanketing of vessels and process equipment is gaining ground globally thanks to safety- and product quality awareness. Price increases on the world nitrogen market however, cause users to look for more economical technologies with lower nitrogen consumption. One of the most efficient ways of minimizing the use of nitrogen and increase safety at the same time is controlling the inerting or blanketing based on oxygen concentration. Drawbacks however are the high maintenance demands and the high installation costs. Advances in sensor technology and intelligent automation of the measurement point, enable reliable oxygen measurement in an extremely simplified way, eliminating the need for extensive sample conditioning. Nitrogen savings and the lowest possible maintenance needs allow for a fast pay-back of the oxygen analyzer.