quench in sulfur recovery unit

[rgrokkam]

In a sulfur recovery unit(from -amine acid gas and sour water stripper acid gas), the exit gas from BSR at 344degC goes to a quench column where it is cooled to 40degC. There's caustic circulation in this column as well. The quenched gas is again reheated to 190degC before sending to 190degC.
Can anyone explain the purpose of this quench?

Thanks

 

[Milutin]

Main purpose is caustic wash, to remove traces of SO2. If SO2 pass to amine section it going to degrade amine.

Regards,

Milutin