Downflow shell and tube reboiler-condenser heat exchanger for cryogenic rectification
AssigneePraxair Technology, Inc.
InventorsMichael James Lockett, Vijayaraghavan Srinivasan
Life of this patent
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Abstract
The invention comprises a downflow shell and tube condenser, especially useful for cryogenic rectification, which includes a shell having an upper tube sheet and a lower tube sheet, the shell extending above the upper tube sheet to create a first reservoir. A plurality of heat transfer tubes extend between the upper tube sheet and the lower tube sheet and also pass through the lower tube sheet. Cold liquid entering the heat transfer tubes flows down through the tubes and causes a condensation of vapor that is in contact therewith within the shell. The cold liquid is at least partially vaporized and exits from the lowermost ends of the heat transfer tubes.
Claims14
A downflow shell and tube condenser comprising:
- a shell having an upper tube sheet and a lower tube sheet, said shell extending above said upper tube sheet to create a first reservoir;
- means for introducing a cold liquid into said first reservoir;
- a plurality of heat transfer tubes extending between said upper tube sheet and said lower tube sheet, each heat transfer tube having one end which extends through said upper tube sheet and into said first reservoir and further having an aperture positioned above said upper tube sheet;
- means for introducing a vapor, which is less cold than said cold liquid into said shell and about said heat transfer tubes, whereby said cold liquid entering said heat transfer tubes via each said aperture and flowing down therethrough causes a condensation of said vapor within said shell to a liquid, said cold liquid, in turn, being at least partially converted to a vapor;
- and
- means for recovering said liquid.
A cryogenic air separation unit including a downflow shell and tube condenser and a low pressure distillation column, said condenser comprising:
- a shell located within said low pressure distillation column and having an upper tube sheet and a lower tube sheet, said shell extending above said upper tube sheet to create a first reservoir;
- means for introducing liquid oxygen into said first reservoir;
- a plurality of heat transfer tubes extending between said upper tube sheet and said lower tube sheet, each heat transfer tube having one end which extends through said upper tube sheet and into said first reservoir and further having an aperture positioned above said upper tube sheet;
- means for introducing into said shell and about said heat transfer tubes, a nitrogen vapor which is less cold than said liquid oxygen, said liquid oxygen entering said heat transfer tubes via each said aperture and flowing down said heat transfer tubes thereby allowing condensation of said nitrogen vapor within said shell to a nitrogen liquid, said liquid oxygen, in turn, being at least partially converted to an oxygen vapor;
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- means for recovering both liquid and gaseous products.
A cryogenic air separation unit including a downflow shell and tube condenser and a low pressure distillation column, said condenser comprising:
- a shell located external to said low pressure distillation column and having an upper tube sheet and a lower tube sheet, said shell extending above said upper tube sheet to create a first reservoir;
- means for introducing liquid oxygen from said low pressure column into said first reservoir;
- a plurality of heat transfer tubes extending between said upper tube sheet and said lower tube sheet, each heat transfer tube having one end which extends through said upper tube sheet and into said first reservoir and further having an aperture positioned above said upper tube sheet;
- means for introducing into said shell and about said heat transfer tubes, a nitrogen vapor which is less cold than said liquid oxygen, said liquid oxygen entering said heat transfer tubes via each said aperture and flowing down said heat transfer tubes thereby allowing condensation of said nitrogen vapor within said shell to a nitrogen liquid, said liquid oxygen, in turn, being at least partially converted to an oxygen vapor;
- and
- means for recovering said liquid nitrogen.
Dependencies are inferred from the claim text.