Jump to content



Featured Articles

Check out the latest featured articles.

File Library

Check out the latest downloads available in the File Library.

New Article

Product Viscosity vs. Shear

Featured File

Vertical Tank Selection

New Blog Entry

Low Flow in Pipes- posted in Ankur's blog

Boiler Blowdown Cooling


This topic has been archived. This means that you cannot reply to this topic.
3 replies to this topic
Share this topic:
| More

#1 Sridhar P

Sridhar P

    Veteran Member

  • Members
  • 44 posts

Posted 25 November 2010 - 05:34 AM

Dear Sir,

In power plants, boiler blowdown is cooled by quenching with water before sending to ETP/Central Monitoring basin. This quenching water requirement increases the consumption of water.

Is there any other alternative to cool the blowdown water other than quenching or cooling across heat exchangers.

Is there any natural or other means of cooling the boiler blowdown, pratcised in power plants.

Please advice.

Thanks.

#2 ankur2061

ankur2061

    Gold Member

  • Forum Moderator
  • 2,484 posts

Posted 25 November 2010 - 11:26 AM

Sridhar,

Boilers require combustion air and if it is pre-heated before entering the fire box bettter combustion efficiencies can be obtained. You can have a heat exchanger which heats the combustion air by utilizing the hot blowdown water. However, the heat exchanger may be very big due to the poor heat transfer characteristics of air.

Alternatively use a air cooled heat exchanger for cooling the blowdown water. However, the economics of quenching with water and using a air cooled heat exchanger which requires electric power needs to be worked out to determine the optimum quenching medium.

Regards,
Ankur.

#3 breizh

breizh

    Gold Member

  • ChE Plus Subscriber
  • 4,310 posts

Posted 26 November 2010 - 01:56 AM

Hi,
Preheating the feed water is a good solution ,

Breizh

#4 kkala

kkala

    Gold Member

  • Banned
  • PipPipPipPipPip
  • 1,939 posts

Posted 28 March 2011 - 03:38 PM

Blow down is normally less than 1% of feed water. As I have seen in two boilers, an energy efficient practice combines following steps.
1. Reduce pressure of continuous blow down drum (1st drum) to slightly higher pressure than of deaerator, leading flash steam there.
2. Install a coil of cooling water in discontinuous blow down drum (2nd drum) to cool blow down down to 45oC.
If the blow down goes to water treatment, temperature not killing "bugs" is 45 oC in the mentioned cases.
Mentioned BFW preheating by Breizh is realized in this way.
I have not seen air cooling, but it must be feasible in some cases. Air cooled condensers, applied in condensing turbines of Power Plants, make a similar case of air cooling.




Similar Topics