LOUVERS FOR ACHE's

[dkm0038]

I was hoping that i could get some clearification on a topic that i wasn't quite sure on. And that is the purpose of manual louvers on an air cooled heat exchanger.

As far as i thought, they were to lower the air flow, and thus lower the heat transfer. And this is so that the fluid in the tubes wouldnt freeze or get too cold in the winter time.

Is my understanding corrector and is there any other purposes for them?

thank you

 

[gr2vessels]

Primarily, the louvres are used to control the cooling air flow, thus changing the amount of heat removed from the tubes / process fluid.
Secondarily, the louvres could be used (if located in the top) to prevent the rain / snow to affect adversely the tubes and the process fluid inside. Also, when louvres are closed,they may prevent the natural air flow (draft) during the inactive periods of the ACHE, if that is affecting adversely the process fluid.
Cheers,
gr2vessels