5 replies to this topic

[bhaskaran]

I want to calculate the vapour line sizing of distillation column.What formula we have to use? Can i use PM = Density x RT to findout the line sizing.Whether anyone having spreadsheet for this purpose. Please do needful.

Thanx
Bhaskaran.r

[Sarmad]

Dear bhaskaran,

I think instead of using formula for the design of vapour line size you should click the link below. I think it would help you alot.

http://www.vatran.co...ch/NWVAPLN.html

Regards,

Sarmad Nazir Ahmad

[mabu]

Bhaskaran

Check this site could be helpfull for engineers.
http://www.mycalcula...chem/index.html

regards

[abhi_agrawa]

Bhaskaran

Line sizing has (in my opinion) two very important criteria:
1) Pressure drop : As it has already been said, maximum pressure drop should not exceed 10% of line pressure, however, this has also to be checked against the allowed pressure drop also. Allowed pressure drop is the maximum available pressure drop. Let us say, you are sizing the vapour outlet from a distillation column. It is desired to operate the top of the column at some pressure and the reflux drum at some other pressure. The difference in these pressures is the allowed pressure drop for this circuit. It is important that the line pressure drop be checked against this.
2) Velocity: Due to erosion corrosion, in some applications, then allowed velocity is restricted. some people insist on a maximum allowed vapour momentum (represent by the Fs factor). You should check this requirement also. In vacuum service, usually the velocity of vapor is quite high, and then it is important to check against sonic velocity also.

Hope this helps,
abhishek

[fallah]

maximum pressure drop should not exceed 10% of line pressure

As i know, in compressible flow lines there is no above mentioned limitation for pressure drop, but if we want to use Darcy Equation we must follow that limitation.

Regards