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Hi Jop & Pipers
in CCPP all the steam line drains are routed to either ADV( Athmospheric Drain Vessel ) or BDT ( Blow Down Tank) ...
and the dischrge of these tanks are wasted to sea.....
if we are gonna to discharge these drains as waste .....
....why we use so much allloy steel piping and their supports ,just to waste .......why dont we dischrge them as ordinary drain ....
please comment
Regards
SG
Good question!
Did you ask your Process Engineer?
And what did he (or she) say?
hi Jop
process engineer and other colleagues were saying that it is not possible to drain such high temp. condensate and flash steam
in ordinary drain ; i mean that is not practical .
lots of mist and all ..........and the amount of drain is too low to reuse.
is that is the practical answer or some other theories behind that ?
Regards
SG
There were two questions stated or implied by your original post.
1. Why are "we" dumping condensate to drain?
2 Why are "we" using Alloy piping for a commodity that "we" are dumping?
According to your last post:
"process engineer and other colleagues were saying that it is not possible to drain such high temp. condensate and flash steam in ordinary drain; I mean that is not practical,lots of mist and all."This only tends to be the answer to the second question. However it does not address why the Condensate system piping is Alloy. Some Quench or dilution process may be required because the regular drain system may be Cast Iron or Clay Tile which will not survive high temperature service.
"The amount of fluids drained is too low to reuse."This tends to answer the first question.
Is that is the practical answer or some other theories behind that ?" Yes. There is a cost trade-off between what you will pay to run pipe from the "Drain" point back to the Condensate Collection Drum. It is possible that there is not sufficient pressure to drive the fluid all the way back. You would also need a local Condensate collection Drum ($), a foundation ($) a pump which also requires a foundation ($), Power ($), Level controls ($), Instrumentation ($). This adds up.
SG,
We can also look at it from following point of view:
Total Cost Incurred = Installation Cost + Operational Cost
When you were looking at it you were probably looking at the installation cost which is high but the operational cost would still be higher if you looked at recirculation instead of draining.
Secondly, ordinary drains will pose safety hazards as well.
5 and half years back when I was working in plant, the hiss of steam trap scared me once. It was a small pharmaceutical plant and not even Oil and Gas giant. I guess, there are many more perspectives so never one parameter can determine.
Regards,