×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

sizing boiler headers
2

sizing boiler headers

sizing boiler headers

(OP)
Is it rigth sizing a header boiler with velocity of steam 3000 fpm?
what is the correct velocity in a header boiler according code?  
thanks

RE: sizing boiler headers

there are 2 interpretations of "header".

 For the case of a "header type boiler config" , the "header' is the common steam transfer pipe from the multiple boilers to the steam user. In that case, the header size is based on limiting the frictional pressure drop and /or noise , vibration and wet steam erosion/corrosion. For frictional pressure loss, you would first define the allowable pressure drop ( 3% of inlet pressure, for example), and then calculate the frictional pressure drop for various  pipe sizes, and select the smallest pipe size that also meets the noise and vibration limits. The noise and vibration limits might require the the max velocity not be greaer than ( 15% ) soundspeed.

The other interpretation of the term "header" is the large distribution /collection pipe that feeds steam to the individual heat exchangers in the boiler, such as for example the primary superheater. That header is sized to limit the tube to tube flow unbalance to the ensemble  of tubes in the heat exchanger, so that the tube to tube temperature unbalance at the outlet of the heat exchanger is below allowable metallurgical limits. That sizing calculation is a bit more complicated to describe, and not as easily summarized as the first header term.

RE: sizing boiler headers

Saturated steam Boiler leads are normally sized for 6000 - 12,000 fpm
Saturated steam Main and auxiliary Headers...Auxiliary Steam and exhaust headers are normally sized for 6000 - 15,000 fpm
Superheated steam Large turbine and boiler leads 10,000 - 20,000 fpm

You might check the Piping Handbook (Crocker & King) or Navco Datalog
 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources