Method And Installation For Enriching A Gas Stream With One Of The Components Thereof

Abstract

The invention relates to a method of enriching a pressurised gas stream ( 1 ) with one of the components (A) thereof. The inventive method comprises the following steps: the stream is separated into at least first and second fractions ( 2, 3 ); at least one part of the first fraction ( 2 ) is sent to a separation unit (ASU); the separation unit supplies at least two discharges, including a first discharge ( 10 ) having a greater A content than that of the fraction ( 2 ) supplied to the separation unit; at least one part of the first discharge ( 10 ) is mixed with at least one part of the second fraction ( 3 ) such as to form a pressurised gas mixture ( 15 ); the second fraction ( 3 ) is expanded and, subsequently, at least one part of the first discharge ( 10 ) is mixed therein.

1 - 18 . (canceled) 
     
     
         19 . A method of enriching a pressurized gas stream with one of its constituents A, which comprises the steps of:
 a) dividing the stream ( 1 ) into at least first and second fractions ( 2 ,  3 ); in which said gas stream ( 1 ) is air and constituent A is oxygen.   b) sending at least one portion of the first fraction ( 2 ) into a separation unit (ASU);   c) supplying, from the separation unit, at least first and second streams, the first stream ( 10 ) of which has a content of constituent A greater than that of the first fraction; and   d) mixing at least one portion of the first stream with at least one portion of the second fraction in order to form a pressurized gas mixture ( 15 ),   
       characterized in that the second fraction is expanded before at least one portion of the first stream is mixed therewith. 
     
     
         20 . The method of  claim 19 , in which the pressurized gas stream is air intended for a blast furnace (BF). 
     
     
         21 . The method of  claim 19 , in which the separation unit is a cryogenic distillation separation unit (ASU). 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . The method of  claim 19 , in which:
 a) in a first operation, at least one portion of the first fraction is compressed and the second fraction is not expanded before at least one portion of the first stream is mixed therewith; and   b) in a second operation, at least one portion of the first fraction is not compressed (the first fraction is not compressed) and the second fraction is expanded before at least one portion of the first stream is mixed therewith.   
     
     
         25 - 28 . (canceled)