USE OF AN OXYGEN TURBINE IN A CRYOGENIC AIR SEPARATION UNIT (18-Aug-2009)
It is sometimes required on an existing plant that part of the oxygen be produced at a lower pressure than that originally used. With the projected increase in energy costs, this type of problem will probably be encountered more frequently.
We suggest that part of the oxygen produced at the original high pressure be expanded in an oxygen turbine at the warm end of the heat exchanger. The oxygen emerging from the turbine is at a cold temperature and can be used to precool air to be sent to the main heat exchanger, before that air is liquefied.
In this way, the liquid production of the apparatus can be increased without increasing the power consumption. By coupling a generator with the oxygen turbine, the power consumed may even reduce.
The air precooled may be taken upstream or downstream a booster coupled to an air turbine, feeding for example the high pressure column. Even if the air cooled is taken downstream of the booster, the booster aftercooler is still required.
It is also possible to produce all the oxygen at high pressure using a single pump, to vaporise the oxygen and then withdraw the fraction to be produced at low pressure by withdrawing it from an intermediate point of the exchanger and then to expand the oxygen in a cold turbine. The expanded oxygen is then warmed in a dedicated heat exchanger and used to cool high pressure air.
It is possible to...
Find More Documents Like This
Download this Disclosure
- a representative PDF of the primary disclosure file (contains all the relevant information for most users)
- the full disclosure ZIP file containing the primary disclosure, packaged metadata, and attachments (as appropriate)
