Condensate recovery system adequecy check 1

[amar122amar]

Low pressure (4.5 kg/cm2) steam is generated by flashing high pressure (42 kg/cm2) condensate in a flash tank. This LP steam is used in the plant which reduces LP steam import from CPP plant.
Due to under design of high pressure condensate flash tank we are not able to completely line up HP condensate (42 kg/cm2g) in the vessel. If we completely line up HP condensate to HP condensate tank, its PSV pops up.
Remaining condensate is flashed in LP condensate flash tank which recovers low pressure condensate and excess vent steam goes to atmosphere.
How to check adequecy of HP condensate flash tank? Its vent line?

 

[GHartmann]

It sounds as if you have a control system network problem. How do you dispose of excess 4.5 kg/cm2 steam?

You need to consider the case where you have 100% 42 kgcm2 condensate flow into your flash tank. Your control valve or letdown station (going????) must be sized for the flash at this condition as if there was no 4.5 kg/cm2 consumption.

The flash tank sizing can be checked utilizing standard separator sizing calculations. But IMHO, the size has nothing to do with your problem.

http://oilgasprocessing.com/Separator Sizing.htm

Draw out a sketch of your system and controls and post it so we can help you better

 

[LittleInch]

How many flash tanks are there? Wha tis there pressure rating / PSV setting?

What do mean by "completely line up"? to avoid the PSV popping what do you do? PSV located where? U/s of flash tank or the low pressure steam flash tank?

Need a system diagram or sketch to work this one out, but given you know the flash tank is "under designed", what is your question or issue?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[GHartmann]

LittleInch:

It always amazes me that once we start asking questions the OP "skulks" away never to return

 

[LittleInch]

Indeed.

We're clearly so experienced that we can diagnose issues remotely without any significant information...

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way