Plant and process for low-temperature fractionation of air

Abstract

The invention relates to a plant for low-temperature fractionation of air, having a rectification column system comprising a high-pressure column, a divided low-pressure column and an argon column, and a coldbox system comprising a first coldbox, a second coldbox and a third coldbox. The high-pressure column is disposed beneath the lower section of the low-pressure column. The high-pressure column together with the lower portion of the low-pressure column is disposed in the first coldbox, and the top portion of the low-pressure column in the second coldbox. It is proposed that the argon column or one or more sections of the argon column be disposed in the third coldbox. The pure oxygen column is disposed in the second coldbox. The present invention likewise provides a corresponding process.

1 . A plant for low-temperature separation of air, having
 a rectification column system having a high-pressure column, a low-pressure column, an argon column and a pure oxygen column, and a cold box system, wherein   the pure oxygen column and the argon column or a base section of the argon column are arranged side by side such that an orthogonal projection of at least one upper part of the pure oxygen column onto the horizontal plane (H) does not overlap with the orthogonal projection of the argon column or the base section of the argon column onto the horizontal plane (H),   the pure oxygen column has a feed point for a first transfer liquid and the argon column or the base section of the argon column has an extraction point for the first transfer liquid, wherein the pure oxygen column and the base section of the argon column are arranged such that the extraction point for the first transfer liquid is geodetically above the feed point for the first transfer liquid,   wherein   the low-pressure column is divided into at least a base section and a top section,   the base section and the top section of the low-pressure column are arranged next to one another in such a manner that an orthogonal projection of the base section of the low-pressure column onto the horizontal plane (H) does not intersect with an orthogonal projection of the top section of the low-pressure column onto the horizontal plane (H),   the high-pressure column is arranged below the base section of the low-pressure column in such a manner that an orthogonal projection of the high-pressure column onto the horizontal plane (H) intersects with the orthogonal projection of the base section of the low-pressure column onto the horizontal plane (H),   the pure oxygen column and the argon column or the base section of the argon column are arranged side by side such that an orthogonal projection of at least one upper part of the pure oxygen column onto the horizontal plane (H) does not overlap with the orthogonal projection of the argon column or the base section of the argon column onto the horizontal plane (H),   the cold box system has a first cold box, a second cold box and a third cold box,   the high-pressure column-together with the base section of the low-pressure column is arranged in the first cold box,   the top section of the low-pressure column is arranged in the second cold box,   the argon column or one or more sections of the argon column is or are arranged in the third cold box, and   the pure oxygen column is arranged in the second cold box.   
     
     
         2 . The plant according to  claim 1 , wherein the argon column is divided at least into a base section and a top section, wherein the base section and the top section of the argon column are arranged next to one another in such a manner that an orthogonal projection of the base section of the argon column onto the horizontal plane (H) does not intersect with an orthogonal projection of the top section of the argon column. 
     
     
         3 . The plant according to  claim 1 , wherein the argon column is designed as a crude argon column and further a pure argon column is provided, wherein the pure argon column is arranged in the first cold box or the second cold box, in particular in the cold box in which the top section of the argon column designed as a crude argon column is arranged. 
     
     
         4 . The plant according to  claim 1 , wherein the extraction point for the first transfer liquid is 1 to 30 theoretical plates above a sump of the base section of the argon column. 
     
     
         5 . The plant according to  claim 1 , wherein the base section of the argon column has a feed point for a second transfer liquid, and the top section of the low-pressure column has an extraction point for the second transfer liquid, wherein the top section of the low-pressure column and the base section of the argon column are arranged such that the extraction point for the second transfer liquid is above the feed point for the second transfer liquid. 
     
     
         6 . The plant according to  claim 1 , wherein an empty section of the argon column or in the base section of the argon column is arranged. 
     
     
         7 . The plant according to  claim 1 , having a subcooling heat exchanger which is arranged in the first or second cold box, in particular in the second cold box below the top section of the low-pressure column. 
     
     
         8 . The plant according to  claim 1 , wherein the top section of the low-pressure column has a feed point for a second transfer liquid, and the base section of the argon column has an extraction point for the second transfer liquid, wherein the base section of the argon column and the top section of the low-pressure column are arranged in such a way that the extraction point for the second transfer liquid is above the feed point for the second transfer liquid. 
     
     
         9 . The plant according to  claim 8 , having a subcooling heat exchanger which is arranged below the base section of the argon column. 
     
     
         10 . The plant according to  claim 1 , in which all cold apparatus parts are arranged in the first or the second cold box and no third cold box is used. 
     
     
         11 . The plant according to  claim 1 , wherein the first section of the crude argon column is formed by the base section thereof. 
     
     
         12 . A method for the low-temperature separation of air, wherein a plant according to  claim 1  is used.