1 reply to this topic

[rajih99]

In the beginning I would like to introduce my self for you;
Fresh Process engineer works in polymer (PP,LLDPE&HDPE) plants under construction, at this time we are preparing documents, so I have some point’s needs to be clarified.
1. Dry seal by N2 on the knout drum (pressure control).(Totally no water seal)
2. Can we consider N2 as vacuum breaker?
3. The flow rate is 10.4T/hr during normal operation pressure control (0.05-1 Kg/cm2)
4. Maximum pressures of knout drum 3.5 Kg/cm2.
What do you think N2 will be fed during normal operation? Because we did not recive the decoments from the vedor.


For more information to answer let me know


thanks in advace.

rajih99

[djack77494]

1. Dry seal by N2 on the knout drum (pressure control).(Totally no water seal)
2. Can we consider N2 as vacuum breaker?
3. The flow rate is 10.4T/hr during normal operation pressure control (0.05-1 Kg/cm2)
4. Maximum pressures of knout drum 3.5 Kg/cm2.
What do you think N2 will be fed during normal operation? Because we did not recive the decoments from the vedor.
rajih99

rajih99,
I would love to be able to provide you with the answers you seek, but you have not supplied questions that make much sense (to me). If we start with your terminology, you are talking about a "knout drum". What is that? It seems like you may mean a Knock Out Drum (or K.O. Drum); please confirm. Moving on, I don't know what you mean by a dry seal. If this is indeed a Flare Knock Out Drum, you will probably have some type of seal in the Flare itself. The issue is further confused with your mention of pressure control, which is not a common feature of a K.O. Drum. Vacuum breaking adds to the confusion. Some flare systems are at risk of developing negative pressure brought about by the cooling of hot relief gases. Frequently, one would have a system to introduce an inert gas, such as nitrogen, if this is a concern. If needed, nitrogen addition would best be done at the farthest point away from the flare, in my opinion. It would then serve to "sweep" the flare system and to prevent the formation of a vacuum. Per your third point, I would expect the NORMAL flowrate to be ZERO. There is no flow of nitrogen into a system for vacuum relief unless/until a vacuum is near ready to form. Furthermore, your value of 10.4 tons(?) per hour sounds incredible. Please check into your understanding of this system better. What I've seen doesn't look feasible.

One final point - If by "vendor" you mean the supplier of this vessel, then do not expect to receive from him any meaningful information regarding nitrogen flowrates. The engineer/system designer is the one to supply this information.

Good luck and try to spend considerable time with your seniors reviewing this system,
Doug