Ammonia Sprinklers
Ammonia Sprinklers
(OP)
Should all ammonia tanks be fitted with sprinkler systems. What flow rates should I use, or where can I find on the web design guides for ammonia sprinklers?
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RE: Ammonia Sprinklers
By "ammonia sprinklers" I think you mean that you would be introducing the liquid NH3 into the tank through spray nozzles located in the internal vapor space. I believe the intent here is to produce some cooling effect through expansion of the liquid NH3 across the nozzles.
Although I have never used this method (nor seen it used), I have had a lot of liquid NH3 storage and transfer operations experience. I believe the spray system is used in the U.K. and some parts of Europe. All I've ever used is simple liquid injection through a pipe and refrigerated the tanks with a separate recompressor & condenser. I do know that you need not have an NH3 spray system to make the liquid transfer system work and work well. I am interested in knowing the justification for putting in such a system and the merits it can add to the operation. If it can refrigerate the tank contents (bring the vapor pressure down) without the need for a recompressor, it would be a great help. Maybe some Forum members can add their experience on this subject.
Art Montemayor
Spring, TX
RE: Ammonia Sprinklers
RE: Ammonia Sprinklers
RE: Ammonia Sprinklers
RE: Ammonia Sprinklers
RE: Ammonia Sprinklers
craigtiras@ifsolutions.com
RE: Ammonia Sprinklers
We also have two warm ammonia storage tanks with 100ton capacity. These tanks are installed with water spray system.
<Built horizontal with dished ends>
DIA: 144", Length: 50ft
Design: 275psig, @124'F(19.4kg/cm2, 51'C)
Rated Press': 200psig (14.08kg/cm2)
The warm ammonia tank are like surge drum.
The water flow for the sprinker is some 400GPM for one tank.
During the hot summer, we often water-spray the tank to control the internal pressure.
RE: Ammonia Sprinklers
You may also want to look at the Handbook of Compressed Gases prepared by the Compressed Gas Association, Inc. (otherwise known as CGA). If you don't have a copy, you may want to consider obtaining one. I've found this to be a good overall reference to add to your personal library.
Anyway, the handbook has a section discussing Ammonia (anhydrous) and the Safe Storage, Handling and Use. In that section they reference the ANSI K61.1 mentioned in a previous post and also CGA G-2.
Looking at the CGA website, it appears that CGA G-2.1 may have replaced or incorporated the ANSI K61.1. You can obtain a copy from them over the internet.
http://www.cganet.com/publication_detail.asp?id=G-2.1
I don't know what you can find in CGA G-2.1 but the referenced handbook also has a section Handling Leaks and Emergencies where they mention using water applied through spray or fog nozzles to reduce ammonia vapor in air but do not give a rate of application.
They do discuss what is considered sufficient water to put on liquid ammonia spills (100 parts water to 1 part ammonia) and also indicate liquid ammonia can be disposed of by discharging liquid ammonia into a vessel containing 10 parts water to 1 part ammonia.
The handbook does warn about applying water to a leaking ammonia vessel that may be colder than the water since the warmer water may tend to heat the ammonia and aggravate the leak.
For further information, the handbook references the Emergency Services Guide for Selected Hazardous Materials, published by the U.S. Department of Transportation or the Emergency Response Guide from Transport Canada.
RE: Ammonia Sprinklers