Doc. 65/20Safe Operation of Reboilers/Condensers in Air Separation Units

This document addresses the operation of the reboilers of air separation plants. It contains a summary of the industrial practices used in their safe application.

It specifically applies to the main reboiler and oxygen product reboilers in which the oxygen concentration is above 75% in the liquid phase. Its guiding principles may be used for other reboilers within air separation plants, including auxiliary vaporizers, guard adsorber vaporizers, argon condensers, and the main reboilers in nitrogen generators.

The purpose of this document is to describe the design and operating practices that shall be followed in the reboiler sections of cryogenic air separation plants.

In particular, the potential hazard introduced by hydrocarbons or other contaminants that might be present in the ambient atmosphere is addressed.

It is thought that this has been the prime cause of the majority of reboiler incidents that have been reported.

This document is based upon the experimental data, operating experience, and design practices of major producers and operators of air separation plants. It is intended for those who design and operate cryogenic air separation plants.