Fin Fan design for steam condensing

I would like to know some engineering tips for the specification / design of an air condenser to condensate low pressure steam (4 Kg/cm2 man).

Which are applicable standards for design or construction ?

And any other helpful information anyone can give me.

Tanks at all

 

[MJCronin]

So.....

At 4 Kg/cm2.... you have saturated(?)steam at about 57 psig (English units)

Air-type steam condensers are typically horizontally mounted fin tube assemblies with multi-speed fans used to induce air flow upward. They are typically mounted up high in the plant with an adequate "free area" beneath them to allow for the air flow upward.

At 57 psig, your steam temperature is about 306 F..... so carbon steel materials can be used.

I am only aware of the API code guidelines for heaters/coolers of this type (API-661). However, specifying a unit to the requirements of API-661 yields a very robust (and expensive) quote.

The piping system should have devices to allow for escape of non-condensibles and to allow for release of vacuum. A full-vacuum design is not a bad idea for the cooler anyway.

See

http://www.aerofin.com

or the people at GEA for more details on thier designs

Can anyone else add to this ?? Or perhaps tell us of other internet sites that may help ???

Good Luck !!

MJC

 

[KernOily]

I have tons of experience with low-pressure sat. steam condensing/cooling service. Is this a new application, or a retrofit of an existing condenser?

First thing to do is model the process using a simulator (or do the calcs by hand) because you will need a UA to talk intelligently with the cooler manufacturers. Or, just calculate the duty by hand, give them the duty and let them generate all the properties to size the cooler. Or, give the cooler manufacturer the inlet conditions and your desired outlet conditions and let him do all the work. Make sure you give him your inlet gas composition unless it is 100% steam.

In my experience most air-cooled exchangers do not need to be built to API 661 UNLESS the owner requires it. A non-API 661 cooler will be a lot cheaper, as MJ said. Don't forget your separator on the outlet to catch the condensate... Thanks!
Pete
P. J. (Pete) Chandler, PE
Principal Engineer
Mechanical, Piping, Thermal, Hydraulics
Processes Unlimited International, Inc.
Bakersfield, California USA
pjchandl@prou.com

 

[kstaylor]

Hudson Products Corp. in Houston, TX can do this work also. We have a Hudson 12 bay steam condenser on a steam turbine/generator set associated with our cogen facility.

 

[FRChem]

"Specifying Steam Surface Condensers" is an article that was made by Elliot Spencer of Graham Mfg. Co. It gives insight to factors affecting design & selection of such condensers. I find it helpful.

 

[unclesyd]

If you are going to reuse the condensate, say return to BFW, from the condenser you will need to assure its purity. We have gotten into more than a little trouble with dirty steam getting into condensers. The condensers that are still in service all have conductivity meters on the condensate. We also had several with contaminated steam episodes causing severe corrosion to one condenser. The problem was either CO2 or O2, we weren’t able to determine which one.
“MJCronin” statement concerning vacuum is very important. I understand the we had a problems due to vacuum and traps.
Another problem we had at our site was freeze protection, if needed in your area. Unexpected temperature drops, much lower than predicted, caught the utilities people by surprise and we lost some tubes/pipe around the condensers.