HEX tube layout: 30 vs 60 degree

[david6245]

Hello,

I have gone out for bids on 2 different exchangers, one is condensing on the shell side and the other vaporizing on the shell side. One exchanger manufacturer has recommended to use a 60 degree tube layout. They say that this reduces the possibility of vibration in the exchanger. This is the first time that I have heard this in my young career. Do any of the veterans out there see this as a recommended practice? Especially for 2-phase conditions in the shell?

I can see that a 60 degree layout may reduce the amount of fluid impinging on tubes, is there a better explanation out there for this?

Thank you,

 

[MrBTU]

60 degree layout gives you reduced pressure drop compared to the same unit with 30 degree layout, but also a lower coefficient of heat transfer. There will also be less vibration due to vortex shedding.
However, all of these factors are also dependent upon baffle spacing, type of baffle, shell size, window area, etc.