HEAT EXCHANGERS

Heat Exchangers Used in Gas Dehydration Process



These are two types of heat exchanger used to cool the glycol and the glycol dehydration unit. 
  • Glycol to glycol heat exchanger and 
  • Glycol to gas heat exchanger. 
Now, lean glycol leave the re-boiler must be cooled proper to entering the contactor the cooling allows to lean glycol to absorb the maximum quality of water from the gas in the contactor. The heat exchanger is very important in the overall operating efficiency of the dehydration unit they substantially reduce the amount of heat required by the re-boiler and allow maximum gas dehydration in the contactor. 


  • The first stage of glycol cooling occurrence the glycol to glycol heat exchanger. This heat exchanger cool the lean glycol coming from surge tank at 400oF(204oC) to temperature of 212oF (100oC). 
  • The final stage of lean glycol cooling occurrence the glycol to gas heat exchanger. Dry gas leaving the contactor passes through the glycol to gas heat exchanger where cools the incoming lean glycol to a temperature about 10oF-15oF (5oC-5oC) above than that of natural gas entering the contactor.

On small dehydration units this exchanger often a double pipe heat exchanger which is latterly a pipe within a pipe flows around outlet gas in the inner pipe. Larger units may utilize shell and tube type of heat exchanger (Nandpur Field).
Taking the temperature difference of glycol before and after passing through the heat exchanger tells you what conditions the heat exchanger surface are in, as the exchanger surface becomes more severally foiled the temperature differential across the heat exchanger decreases, means that the exchanger is not efficient as before. When this occurs, you will need more gas to fire the re-boiler.
Individual components that make-up the glycol dehydration unit how the components work together and how the components work together to dehydrate natural gas and to regenerate rich glycol.

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