Designing a Steam Pipe Distrbutor for a Column

[Invinci]

Hello all,

Can anyone help me with the design of a Steam Pipe Distributor for an Absorption Column gas inlet.

Gas Specs: 10000 kg/ h of saturated steam (7 bar, 165 C, 3.66 kg/m3).

Any help is appreciated...Thank you.

 

[Invinci]

Column Spec: Vacuum Column

 

[katmar]

The design is really only critical at start up when the column contents are cold. If you do not break the steam flow up into small individual streams by using a sparger with holes of around 3 or 4 mm you will get hammer and vibration when the steam hits the cold liquid. Even with a sparger you will want to start up gently. If you consider a reboiler on a column - the vapor all comes in via one large nozzle and it all works well once everything is up to temperature.

The sparger could be a straight pipe, or a cross, or a ring - depending on the relative sizes of the sparger pipe and the column. Put the holes along the bottom of the pipe to aid draining.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[Invinci]

Katmar:

Thanks for the insight, yeah you are right, then I need to size the main (straight) pipe for steam input into the column.

Could you please tell me, how to calculate it?

 

[katmar]

There is a good section on sparger design in Perry. Google is sure to give you many hits as well - even a search here on Eng-Tips is likely to give lots of info.

Don't forget that in determining the pressure drop through the orifice holes you must allow some pressure drop for the control valve. Also include the liquid head of the submergence of the sparger and the actual pressure in the column. If the pressure across the orifice is more than 50% of the absolute pressure of the steam inside the sparger use only 50% as your design value because the flow will be choked.

Add a bit of a safety margin because in order to keep control the actual flow will at times be above the average flow.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[sshep]

Invinci,

Check out this thread
thread798-188767

In my opinion, if the steam is not going into a liquid level, then there is little need for a sparger with sized holes and all. Rather than a "sparger" you just need to break the momentum of the steam to avoid impingement problems.

If sparging steam into a liquid, then consider getting something already available (see example in thread). This "home-made" approach of sizing a sparge pipe is not always that much savings in the long run, and if it has problems then it can cost you far more than the initial savings.

best wishes,
sshep