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[sandwich]

Hi!

We were asked to design a water curtain for an ammonia tank. This is very new to us and I would like to know how to start. We were told that a dispersion model is not necessary but instead, a QRA study gave us a gas leak velocity of 0.65 kg/s for a scenario that could occur within 30 mins. The total tank volume is 25m3. What I want to know is how do I choose the nozzle type, nozzle orientation and how many nozzles to use for the water curtain. Are there any standards or models I can refer to for this purpose? Based on a previous study, 40:1 water to ammonia ratio would give 75% absorption efficiency. We are looking into using this flowrate for the water curtains. Hope you could enligthen me on this matter. Thanks!

Sandwich

[astro]

Where I've seen a static water spray system installed was on a 2000t refrigerated ammonia tank. To the casual observer, the system would appear similar to an active fire protection (AFP) system and in fact the water source was tied into the plant's fire water ring main.

Given the design criteria that you've got to work from, I'd be looking to marry it with design guidance from API and NFPA for AFP installations and see what you come up with.