Cooling unit, and apparatus for separating air by means of cryogenic distillation including such cooling unit

Abstract

The invention relates to a cooling unit consisting of an exchange line capable of heating nitrogen originating from the system of columns by exchanging heat with the air to be cooled for the system of columns, and a cooling tower for the heat- and mass-exchange between the water to be cooled sent to the top of the tower and the nitrogen originating from a system of air distillation columns, the lower portion of the tower including an inlet connected to a nitrogen pipe, and the nitrogen pipe being connected to at least one exchanger body of the exchange line, which is capable of heating the nitrogen originating from the system of columns by exchanging heat with the air to be cooled for the system of columns, wherein the tower is arranged above at least one portion of the exchange line.

1 - 15 . (canceled) 
     
     
         16 . A cooling unit comprising of an exchange line capable of heating up the nitrogen coming from a system of columns by exchange of heat with air that is to be cooled that is bound for the system of columns and a cooling tower allowing exchange of heat and mass between the water that is to be cooled, sent in at the top of the tower and nitrogen coming from a system of air distillation columns, the lower part of the tower comprising an inlet connected to a nitrogen pipe and the nitrogen pipe being connected to at least one exchanger body of the exchange line, wherein the tower is positioned above at least part of the exchange line. 
     
     
         17 . The cooling unit as claimed in  claim 16 , in which the cooling tower is supported on at least part of the exchange line. 
     
     
         18 . The cooling unit as claimed in  claim 16 , in which the cooling tower is supported by a structure mounted on at least part of the exchange line. 
     
     
         19 . The cooling unit as claimed in  claim 16 , in which the lowermost point of the cooling tower is above the exchanger body or bodies. 
     
     
         20 . The cooling unit as claimed in  claim 16 , in which the nitrogen pipe is connected to a point above the tank of the cooling tower. 
     
     
         21 . The cooling unit as claimed in  claim 16 , comprising two exchange lines each one comprising several exchange bodies, the two exchange lines preferably having substantially the same height. 
     
     
         22 . The cooling unit as claimed in  claim 21 , wherein the cooling tower is supported by a structure mounted on the two exchange lines. 
     
     
         23 . The cooling unit as claimed in  claim 21 , wherein the cooling tower is positioned above a space between the two exchange lines. 
     
     
         24 . The cooling unit as claimed in  claim 23 , in which at least one air inlet pipe connected to the two exchange lines passes through the space underneath the tower. 
     
     
         25 . The cooling unit as claimed in  claim 16 , in which the nitrogen pipe is connected to the upper part of the exchanger body. 
     
     
         26 . The cooling unit as claimed in  claim 25 , in which the nitrogen pipe is arranged in such a way that the nitrogen reaches the tower without being conveyed downward. 
     
     
         27 . The cooling unit as claimed in  claim 25 , in which the nitrogen pipe comprises at most one single pipe elbow between the exchanger body and the nitrogen pipe. 
     
     
         28 . A device for separating air by cryogenic distillation, comprising the cooling unit as claimed in  claim 16 , a system of columns, a pipe conveying air to the exchange line, a pipe conveying air from the exchange line and a pipe conveying air from the exchange line to the system of columns, the nitrogen pipe being connected to the system of columns. 
     
     
         29 . A method for separating air by cryogenic distillation using the cooling unit as claimed in  claim 16 , in which air is cooled in the tower and in the exchange line, separated in a system of columns, the nitrogen is sent from the system of columns to the exchange line and from the exchange line to the tower. 
     
     
         30 . The method as claimed in  claim 29 , in which the pressure drop in the nitrogen pipe between the outlet of the exchanger body and the inlet of the tower is less than 7 mbar, preferably less than 6 mbar.