Condensate Relief To Atmosphere

Hi,

I am currently working on relief system for an existing Condensate Recovery system.

MP Condensate is flashed, LP steam is recovered and the condensate is sent to the condensate recovery system

During blocked liquid outlet for the condensate flash drum, there will be liquid overfill and since the operating pressure of the MP steam is higher than the design pressure of the flash drum, it will lead to over pressurization.

The RV is adequately sized, but there will be relief to the atmosphere. The relief will be two phase, but at the moment the relief is to atmosphere like we have for vapour relief. There would be hot water sprayed from the outlet piping of the RV in the current set-up.

The issue is that, based on my past experience, I have never seen RV on a condensate flash drum where-in hot liquid condensate relief is routed to safe location most of them are similar to vapour relief. I assume that in all the condensate system there would be liquid overfill scenario.

Am I missing something, or my view is correct. 

Revert in case of any query.

Regards,

Edited by Chemitofreak, 28 April 2023 - 11:44 AM.

A sketch might help. If I understand the scenario, the condensate recovery system drum normally operates near atmospheric pressure and the maximum inlet pressure will be LP steam pressure from the upstream flash drum. The question is 'what is the safe location for the relief discharge?' Consider relieving to a vertical pipe open at top and bottom. Discharged steam will travel skywards while discharged hot water will travel downwards to grade.

Edited by Pilesar, 28 April 2023 - 12:28 PM.

what is the design pressure of flash drum? 

if the outlet of drum is blocked. and the drum is connected to upstream high pressure process, the drum would be pressurized by MP steam. So the a PSV is needed. 

Hi,

Yes, the PSV is needed for the reason explained above. To me the problem is where to route the release to prevent people to receive a shower of hot water during release. A Catch pot might be considered.

My view 

Breizh

Thanks a lot for your response guys. Highly appreciated.

Like shvet1 explained, we are also looking at something similar, but it is turning out to be damn expensive.