4 replies to this topic

[sorour]

Hi

I work on Natural-gas condensate distillation tower design. The tower that I designed is Pilot and has 250 mm diameter and 15 stages with HETP of 600 mm.Now I need help about the space between the demister pad and above the tower . also I don't know the space between the bottom of the tower and the bottom of the first pack bed.

In addition I need some help about the references of mechanical design of packed tower .

[breizh]

Hi sorour ,

Consider to contact companies like Sulzer , they should be able to help .

Another resource is GPSA engineering data book .

 

Good luck,

Breizh

Edited by breizh, 02 January 2018 - 07:21 PM.

[Padmakar Katre]

Hi

I work on Natural-gas condensate distillation tower design. The tower that I designed is Pilot and has 250 mm diameter and 15 stages with HETP of 600 mm.Now I need help about the space between the demister pad and above the tower . also I don't know the space between the bottom of the tower and the bottom of the first pack bed.

In addition I need some help about the references of mechanical design of packed tower .

 

Hi,

I would suggest you to get in touch with column internals vendors like Koch-Glitsch, Sulzer etc. The diameter and bed height is already estimated by you, however pls keep in mind HETP varies with considered packing type (random, structured) and size of packing, this selection would also have impact on hydraulics. Just for your info, efficiency and pressure drop go hand-in-hand, in other words you may get lower HETP at the cost of increased pressure drop (up to an efficient capacity point, beyond which excessive entrainment would cause reduction in mass transfer / separation).

The theoretical stages required are 15 which can be achieved with different bed heights depending on type of packing used (generation of packing), there are limitations for maximum bed height as function of diameter, hence you may need to stagger these 15 stages among multiple beds (if not feasible to have in single bed).

The spacing required between beds, bottom vapor space, bottom sump height, vapor and liquid distributors styles being used etc. will have bearing on column height. Since you have asked about the spacing between column top to demister, the answer is to keep that spacing as minimum (column diameter - ovhd vapor nozzle dia) / 2. This is to ensure the entire demister cross-section is utilized thereby avoiding localized demister flooding which can lead to excessive droplet carryover.

 

Best way is to get in touch with these vendors, who will help you the great detailing. Hope this info helps.
 

[sorour]

 

Hi

I work on Natural-gas condensate distillation tower design. The tower that I designed is Pilot and has 250 mm diameter and 15 stages with HETP of 600 mm.Now I need help about the space between the demister pad and above the tower . also I don't know the space between the bottom of the tower and the bottom of the first pack bed.

In addition I need some help about the references of mechanical design of packed tower .

 

Hi,

I would suggest you to get in touch with column internals vendors like Koch-Glitsch, Sulzer etc. The diameter and bed height is already estimated by you, however pls keep in mind HETP varies with considered packing type (random, structured) and size of packing, this selection would also have impact on hydraulics. Just for your info, efficiency and pressure drop go hand-in-hand, in other words you may get lower HETP at the cost of increased pressure drop (up to an efficient capacity point, beyond which excessive entrainment would cause reduction in mass transfer / separation).

The theoretical stages required are 15 which can be achieved with different bed heights depending on type of packing used (generation of packing), there are limitations for maximum bed height as function of diameter, hence you may need to stagger these 15 stages among multiple beds (if not feasible to have in single bed).

The spacing required between beds, bottom vapor space, bottom sump height, vapor and liquid distributors styles being used etc. will have bearing on column height. Since you have asked about the spacing between column top to demister, the answer is to keep that spacing as minimum (column diameter - ovhd vapor nozzle dia) / 2. This is to ensure the entire demister cross-section is utilized thereby avoiding localized demister flooding which can lead to excessive droplet carryover.

 

Best way is to get in touch with these vendors, who will help you the great detailing. Hope this info helps.
 

 

Your advice can help me alot. Thanks

[sorour]

Hi sorour ,

Consider to contact companies like Sulzer , they should be able to help .

Another resource is GPSA engineering data book .

 

Good luck,

Breizh

Thank you for your helping