Method and device for cryocondensation

Abstract

A method and device for cooling and/or purifying a process gas, in which the process gas is precooled in a precooler by indirect heat exchange with a second coolant stream, and then cooled in a deep-freeze unit in indirect heat exchange with a first coolant stream. The first process stream is generated by vaporizing a condensed gas. At least one part of the first coolant stream leaving the deep-freeze unit is sent as at least part of the second coolant stream to the precooler, and at least another part of the first coolant stream leaving the deep-freeze unit is used with at least one part of the second coolant stream leaving the precooler to vaporize the condensed gas is vaporized and is vaporized. The part of the first coolant stream used to vaporize the condensed gas may be the part leaving the deep-freeze sent to the precooler.

1 . A method of cooling and/or purifying a process gas, comprising the steps of: 
 generating a first coolant stream by vaporizing a condensed gas;    precooling the process gas in a precooler by indirect heat exchange with a second coolant stream; and    cooling the process gas in a deep-freeze unit by indirect heat exchange with the first coolant stream;    wherein 
 at least a part of the first coolant stream leaving the deep-freeze unit is sent to the precooler as at least a part of the second coolant stream entering the precooler, and  
 the condensed gas is vaporized by indirect heat exchange with at least a part of the first coolant stream leaving the deep-freeze unit and at least one part of the second coolant stream coming from the precooler.  
   
   
   
       2 . The method according to  claim 1 , wherein quantities of the first and/or second coolant stream used for vaporization of the condensed gas are determined as a function of the temperature of the first process stream after indirect heat exchange to vaporize the condensed gas.  
   
   
       3 . The method according to  claim 1 , wherein the first coolant stream is obtained by vaporizing liquid nitrogen.  
   
   
       4 . The method according to  claim 1 , wherein impurities are condensed or frozen out of the process gas in the precooler and/or in the deep-freeze unit.  
   
   
       5 . The method according to  claim 4 , wherein impurities condensed out in the precooler and/or in the deep-freeze unit are removed from the precooler and/or from the deep-freeze unit.  
   
   
       6 . The method according to  claim 1 , wherein the part of the first coolant stream used for vaporizing the condensed gas is sent as the second coolant stream to the precooler.  
   
   
       7 . A device for cooling and/or purifying a process gas, comprising: 
 a precooler in the form of an indirect heat exchanger for exchanging heat between the process gas a second coolant stream, the precooler having a process gas inlet line, a process gas outlet line, a coolant inlet line, and a coolant exhaust;    a deep-freeze unit in the form of an indirect heat exchanger for exchanging heat between the process gas a first coolant stream, the deep-freeze unit having a process gas inlet line, a process gas outlet line, a coolant inlet line, and a coolant exhaust ( 12 ); and    an evaporator in the form of an indirect heat exchanger for generating the first process stream by vaporization of a condensed gas, the evaporator having a coolant inlet line, a coolant exhaust, at least one heating medium inlet line, and a heating medium exhaust,    wherein 
 the precooler process gas outlet line is connected to the deep-freeze unit process gas inlet line,  
 the evaporator coolant exhaust is connected to the deep-freeze unit coolant inlet line,  
 the deep-freeze unit coolant exhaust is connected to the precooler coolant inlet line, and  
 the deep-freeze unit coolant exhaust and the precooler coolant exhaust are connected to one of the at least one evaporator heating medium inlet lines.  
   
   
   
       8 . The device in accordance with  claim 7 , wherein the evaporator heating medium exhaust connected via the evaporator heating medium inlet line to the deep-freeze unit coolant exhaust is connected to the precooler coolant inlet line.  
   
   
       9 . The device in accordance with  claim 7 , wherein a storage tank for a condensed gas is connected to the evaporator coolant inlet line.  
   
   
       10 . The device in accordance with  claim 7 , wherein at least one of the precooler and the deep-freeze unit has a condensate outlet line.