Water Sprays for Anhydrous Ammonia Storage Tank

[jives]

I'll be setting up a 1000 US Gallon, Anhydrous Ammonia Storage Tank.

I am looking for some tips on setting up a water spray nozzle system to abate an ammonia vapor cloud in the (unlikely) event of a major leak or tank rupture.

Any ideas or experience with this out there ?

Jonathan Ives
Project Engineer
Transalta, Alberta Thermal Plants
Duffield, Alberta

 

[deanc]

Do a Google search. To much to list,but it will lead you back to postings on this site. DuPont also has lots of info.

Check with your local Jurisdicton for boiler inspection,they have an excellent site.

 

[EGT01]

JIves,

The Compressed Gas Association has some recommendations in their handbook...Handbook of Compressed Gases
also see their publication... G-2 Anhydrous Ammonia
which also has the same recommendations. You can find these publications here...

http://www.cganet.com/

Another publication that is recommended is ANSI K61.1, American National Standard Safety Requirements for the Storage and Handling of Anhydrous Ammonia.

I have copies of the CGA publication but do not have a copy of the ANSI publication so I don't know what it has to offer.

The CGA publications indicate a water application rate of 100 parts water to one part of ammonia to address vapor leaks. For liquid spills, the application rate is 10 parts water to one part ammonia. In either case, you should review the referenced documents for complete understanding and other possible considerations.

The CGA documents also warn that "Under some circumstances, ammonia in a container is colder than the available water supply. At such times water must not be sprayed on the container walls since it would heat the ammonia and aggravate any gas leak."

Hope this helps.

 

[unclesyd]

The water spray system for our original NH3 storage system appeared to be just an elaborate sprinkler system, about double the number of sprinkler heads. The system was supplied from two different sources.

One of our main concerns was any water used for trapping NH3 vapors had to be contained on site and no allowed to get in the adjacent waterway. A teeny tiny bit of NH3 in a stream is hell on the little bitty yellow flipping fish.

 

[LSThill]

Reference Specification Table of Contents: NFPA 15, and Deluge System.