Blowdown study/sizing help

[polishmoves]

I just recently been assigned the task of studying a client's pilot plant blowdown system. The objective of the study is to determine whether or not the blowdown tank they currently have is adequate for their system. If not they are going to want a redesign/new size. I am to study the system for normal process upset and for a fire case.

The only information given was:
the autoclave reactor (6000 psig, 1 gallon capacity)
3000 psi rupture disc
blowdown tank (DP-300 psig, DT-400F, capacity-16 gallons)
tank size
blowoff line size

reactor operating conditions:
it can be assumed the reactor is 70% full with liquid
liquid composition is 30% solids (TA/PTA)
balance = acetic acid
450 F
400 psig

I'm not really sure how to proceed with the calculations/analysis with the given information. No inlet or outlet flow rates were specified/given. I have a copy of API RP521 (read specifically thru section 5.4), Crane's 410, and some other papers online.

If someone could steer me toward some equations, book, or methodology that would be useful it would be much appreciated. Fluids is not my area of expertise, so any help would be appreciated.

thanks

 

[MortenA]

You will also need API520 for details on ruputure discs (allthough most of it is about PSV).

But this being a very small vessel - i think it will depressure very rapidly.

With regards to heat input: Check API 521 assume isothermal and make a spreadsheet.

Best regards

Morten

 

[polishmoves]

i guess my problem is relating the given pressures and finding a flow rate or velocity

 

[Shmulik]

polishmoves:
This topic had been discussed in detail many times in the past. Try searching for "Flash Tank" or "Flash Vessel". Some are herein:
thread124-125547
thread292-124152
thread794-105012
thread124-125878
thread124-163743
thread124-150805
thread794-125877