7 replies to this topic

[azhar_uk]

can i use two vessel (Vertical Knock Out Drum) for reciprocating compressor ?

First stage is Vertical Knock Out Drum separate liquid droplets of larger than 150 micro meters by gravity (Pressure drop is NIL) .

Second stage is Vertical Wire Mesh Mist Eliminator and removal efficiency of wire mesh 99.9% removal over 10 microns. Pressure drop of wire mesh pad can be taken as 0.1 kg/cm2 including pressure drop of
inlet/outlet nozzles.

[DB Shah]

Yes you can have two in series, infact we have such combination in our plant. The Reformer exit Reformed gas+condensate is fed to vertical KOD near SMR area, About 16000 kg/hr of condensate is knocked off here. The saturated reformed gas is sent to 50 mtr away RC compressor train. At compressor suction we have another small KOD to remove any further condensed moisture from the gas. (In winter there is about 10~15 kg/hr condensate)

[azhar_uk]

can this configuration apply for HDS unit?

[Rajkumar Chate]

Yes it can be applied for HDS, but going with two KOD is not a economic soluiton. insted of going with two KOD replace your demister pad with high density mesh pad in exisiting KOD, this will help you to remove the fine liquid droplets.


Regards,

Rajkumar Chate

[azhar_uk]

I know this solution is not economic and can be reduce to one vessel with high efficiency wire mesh mist eliminator ( very economic ) but we have existing vessel ( gravity phenomena ) in old unit and we contract with new vendor ( Burckhardt Compression ) for new reciprocating compressors and vendor supply vessel with wire mesh mist eliminator therefore according to recommendation of vendor we will do this configuration .thank you for all

Edited by azhar_uk, 05 March 2012 - 04:09 AM.

[Himanshu Sharma]

its your choice but a gravity settling KOD designed for 150 Micron particle removal seems to have a good potential for installation of internals for meeting the desired efficiency.

For an HDS unit this can be either of a MUG or RGC compressor and the proposed particle removal efficiency of 10 Micron at 99.99% efficiency looks very high to me,typically such high removal is normally possible in a Basket or cartridge type filter albeit a higher pressure drop.

Still,consider an Inlet diffuser with mesh and vane combination that may save you additional cost of this vessel.

[J_Leo]

Based on my experience, it is not very common to have two KO drums before the compressor. You need not only the drum, but also instruments (such as level and control) and additional piping. It is very uneconomical

[GVillamizar]

Hi there,
normally you will have one ko-drum at each stage inlet, all of them equipped with demister or mist eliminator. These ko-drums are normally sized to separate 100 um. A pressure drop of .1 kg/cm2 is too high, normally a pressure drop of .1 psi is considered.

Additionally, a pipe bottle at compressor suction is sized to contain an extra liquid due to carry over in upstream ko-drum. In both bottle and kod a high-high level compressor shutdown is normally considered.

I hope this was helpfull.

Best regards,

GERARDO VILLAMIZAR PLATA
gvillamizar@tipiel.com.co