×
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

Air heating for small incinerator waste to energy

Air heating for small incinerator waste to energy

Air heating for small incinerator waste to energy

(OP)
Hi, i am designing a small scale incinerator plant for waste to energy.
Concern is over the need to preheat combustion air prior to it entering the air heat exchanges utilising exhaust flue gas. Due to the corrosive nature of the flue gas and its relatively high acidic dew points i am concerned that using air at ambient temperature at the inlet of the air heaters, with the flue gas approaching its dew point (after passing through a heat recovery boiler) will cause excessive corrosion.
I have become aware of the use of steam-air preheaters, where steam from the incinerator-boiler can be blead prior to superheating, or alternatively some of the steam exiting the turbine can be condensed for pre-heating air.
Has anyone any experience in incinerator air heating and steam air heaters.
Thanks

RE: Air heating for small incinerator waste to energy

You are right to expect corrosion on the flue gas side of the preheat exchanger if the acid gas dewpoint is high enough in the flue gas.  Have you calculated the dewpoint yet?  Using waste steam to preheat the cold air is a good approach in this case, if maximum heat recovery is needed.  Steam preheat has been used before in certain types of incinerators, but is not common.  An alternate is to use an acid-proof alloy to construct the affected part of the exchanger - you may find that the extra cost for alloy is comparable to the cost for steam preheater, etc.    

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