×
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

typical: BFP in recirculation?

typical: BFP in recirculation?

typical: BFP in recirculation?

(OP)
Kindly, any one help that we have recently erected Boiler feed pump and we want to commissinon the pump in recirculation mode as the other system is not ready. The path is BFP to Deaerator through ARC ( Modulation type). Whether is this advisable to commission the pump? Whether to close the deaerator vent or open? Pump can develop 200 bar pressure and temp rise across the pump is 11 deg.c. Just we want to run the pump in recirculation without steam inlet to deaerator. Can anybody suggest? How to go about it?

thanks

mah99

RE: typical: BFP in recirculation?

At what flow fraction is the head 200 bars and the temperature rise 11 degrees C and what is the flow fracton at recirculation flow? If your numbers are for pump rated best efficiency flow (ie, flow fraction=1.0=100%), and recirculation flow is around 40% or less, you're asking for a lot of trouble running such a high head-per-stage pump so far off its design rating presuming that it is a single-stage pump.The temperature rise will go way above 11C and if there are any flow instabilities at the recirc flowrate, such as rotating stall, you may risk serious damage to the impeller. If you've got a tight cutwater clearance then severe pressure pulsations could, in the worst case, blow pieces of shrouding out of your impeller. This has already happenened for some high head-per-stage pumps (approaching 1000 ft. head). US nuclear facilities pumps have, in recent years, gone away from running standby or emergency-use pumps in a recirc mode periodically, just to determine that they are runnable, because of the damage that has been found to result from far off-design operations.              vanstoja  

RE: typical: BFP in recirculation?

I am sorry i have not given full details of pump. It is a 14 stage Boiler feed pump. Its maximum flow 20 m3/hr, which has got one booster pump at the inlet. Effi. 40% at above capacity. We want to run the pump only in recirculation fully with 20m3/hr to deaerator. Pump suction also from Deaerator. How much time we can run the pump in this mode/path. Whether this is advisable? We want to stop when water temperature reaches to 90 deg.c. There is no pegging steam to deaerator right now during this mode.
kindly guide me anyone?

mah99

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