Internal diameter of Economizer Header - HRSG

[hernanrmz]

Hello everyone,

Is there any design rule to define the internal diameter of HRSG Economizer headers?
In two reference Boilers books, I have found that the axial velocity inside the Economizer header should be less than 6 m/s?

I think there should be a minimum internal diameter to ensure correct distribution of water within the tubes.

Thanks for your help.

Best regards.

 

[Dhurjati Sen]

6 m/s is a standard threshold even mentioned in corrosion handbooks regarding cracking of air coolers.
Boiler manufacturers normally do not share such data as these are proprietary in nature.

 

[TomLee777]

You need to do a flow calc to determine the minimum I.D. in addition to tubing arrangement.