Vertical or Horizontal KODs (Knock Out Drums)

To get a good separation of liquid is preferable to instal the vessel in vertical position. Also the dimension of demister will be less instead horizontal position.

First of all i am sorry for replying so late...Yeah I agree with you, Vertical position will provide Much space for the separation, moreover the condesate will be clear from the forthcoming fluid. but is there any any particular limit upto whihc we cant use vertical KODs. Because i have seen so many horizontal as well as vertical KODs. Horizontal KODs occupy larger space too. Then why we go for Horizontal KODs or under what conditions.

Warning: I know nothing about this subject, so, I cannot comment on whether this is good information or not.

FROM:-

http://igs.nigc.ir/igs/bank-matn/IPS/e-pr-880.pdf - sorry, link no longer available

7.1 General

Conventional gas/liquid separators are usually characterized as vertical, horizontal, or spherical. Horizontal separators can be single or double barrel and can be equipped with sumps or boots.

7.1.1 Vertical separators

Vertical separators (see Fig. B.1-a of Appendix B) shall be selected when the gas-liquid ratio is high. In cases where there is a frequent fluctuation in inlet liquid flow or where re-vaporization or remixing of fluids in the vessel should be prevented, vertical separators should be preferred.

7.1.2 Horizontal separators

Horizontal separators (see Fig. B.1-b) shall be used where large volumes of total fluids and large amount of dissolved gas are present with the liquid. They are also preferred where the vapor-liquid ratio is small or where three phase separation is required.

In cases where limitations exist in vessel size, double barrel separator can be employed.

7.1.3 Spherical separators

These separators are used for high pressure service where compact size is desired and liquid volumes are small, (see Fig. B.1-c).

Mist extractor can be installed in this type of separators.

7.2 Design Criteria

Separators without mist extractors may be designed for gravity settling using Stokes, law equations.

Typically the sizing is based upon removal of 150 micrometers and larger diameter droplets.

For practical purposes, to be in safe side, use of the methods presented in the following sections is recommended.

Lots of other information by googling:-

http://www.google.co.uk/search?hl=en&q=vapor+liquid+separator+design&meta=&aq=1&oq=vapor+liquid+separator

If the KOD is a vertical cylinder, liquid/vapour separation will be improved if flow is introduced tangentially.

what's a knock out drum?

http://en.wikipedia.org/wiki/Vapor-liquid_separator