jprocess

Posted 06 November 2006 - 03:24 PM

Sandeep01

Posted 06 November 2006 - 03:43 PM

vkiocl

Posted 06 November 2006 - 08:34 PM

Art Montemayor

Posted 07 November 2006 - 01:29 AM

Flare Ko Drum (View original topic)

Cheresources.com Community -> Industrial Professionals -> Flare Ko Drum

Dear All,I have read about Flare KO Drum that it should be horizontal and we should not use demister pad for it!Could you please explain about the reason(s)?!Thanks in advance.Best Regards.

Vertical flare drums are common in the industry.

This being the last vessel in the flare system, a demister should not be used for fear of its choking/clogging (e.g.under a possible fire scenario), thus not permitting flow and resulting in overpressure of the Flare KOD. Ifunavoidalble, a demister could be used provided suitable pressure protection is provided for. This is NOTcommon in the industry, and not a preferred option.

RegardsSandeep

If there is any entrainment in the gas from KOD to flare water seal,it should get overflowed via the overflowline in the water seal inside the flare structure.Hence demister is not required,i think.vijay

Let's stop and think first about what the operation is and what it requires/doesn't require to bring aboutthe desired results:

1. A horizontal drum inherently can handle a large liquid capacity; therefore, it is usually the orientationof choice when considering a flare K.O. Drum design. It not only offers a large liquid retentioncapability, it also offers the lowest superficial vapor velocity as opposed to a vertical orientation.Therefore, the vapor disengagement is superior in a horizontal orientation. The large liquid reservoircapability allows it to be used for emergency discharged liquid fluids that must be separated prior toflaring the associated gas(es).

2. The objective of the K.O. Drum is to prepare the separated vapors/gases for subsequent burning inthe downstream flare. Flares burn vapors; they don't burn liquids. Why would any self-respectingChemical Engineer design and employ internals such as a de-mister pad in order to increase the qualityof the size/quantity of liquid particles going to flare? The flare doesn't care what it incinerates andwithin a certain range of particle sizes, it will burn all vapors and liquid droplets. The droplet sizeproduced by a simple vane separation device is more that sufficient for effective flaring. In fact, I'veseldom even used vanes (never de-mister pads) because if I design a conservative superficial velocity inthe horizontal K.O. Pot, that will be more than sufficient for flaring. Of course, a lot depends on whattype/kind of liquids you are dealing with; but in the normal, usual situations a horizontal K.O. potwithout any fancy internal is all that is needed.

3. A practical reason for not using internals is that sooner or later you will have to inspect and/orreplace and service them. You don't want to send someone into any vessel if you can avoid it - muchless a vessel that doesn't have a turn-around period available. Sending someone into a confined vesselspace is just asking for trouble. You should avoid it whenever you can. Unless you have strong safety,operational, or economic reasons I would definitely never use any internals in a flare K.O. Drum.

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