11 replies to this topic

[curious_cat]

Does anyone know of a list / resource that shows the typical  nominal densities for structured packings used for distillation?

 

Specifically I am looking for something like Sulzer's BX / CY wire gauze packing typically used for high performance vacuum distillation. 

 

I have emailed my Sulzer Rep but am just getting impatient to finish my preliminary weight estimate for which even an approximate value will do. 

 

Any ideas? 

[PingPong]

You can instead search for the void fraction of gauze packing, and use that to calculate the bulk density of the packing.

 

Void fraction gauze packing seems to in the order of 86 - 90 % according to:

 

https://dspace01.hit....pdf?sequence=1

 

https://books.google...raction&f=false

 

https://books.google...raction&f=false

 

Void fraction of metal dumped packing is in the order of 93 - 98 %.

 

Void fraction of metal structured packing is in the order of 98 - 99 %.

 

You can google further to find more data.

Edited by PingPong, 28 June 2016 - 11:04 AM.

[breizh]

http://www.structure...ed-packing.html

 

Take a look !

 

Breizh

[Napo]

Curious_cat,

 

I attached information, from this supplier for BX --> 140 kg/m3, and CY --> 180 kg/m3, this values are diferents of the Breizh information, please you need take caution.

 

Napo.

Attached Files

•  CHEMPACK_Metal_structured_packing.pdf   345.75KB   28 downloads

[curious_cat]

Thanks @Napo!!

 

Indeed this needs caution. I have three different estimates now:

 

(a) Per @Ping Pong's reference the void fraction of BX is 0.9. Using SS316 density as 7900 kg/m3 that gives me a nominal density for BX as 790 kg/m3

 

(b ) Per @breizh's link BX is 250 kg/m3

 

(c ) Per @Napo's link BX is 140 kg/m3

 

So the values are more than 100% different from each other. I wonder why! 

 

PS. Is my conversion of void fraction to packing density done correctly?

Edited by curious_cat, 29 June 2016 - 01:29 AM.

[curious_cat]

@breizh 

 

In the table provided in the link you posted some parameters seem suspect. 

 

e.g. For CY packings they quote an HETP of 333-400 mm but 8-10 theoretical plates per meter. That seems inconsistent, correct?

[breizh]

Hi Curious ,

Yes you are right !

I remember some people within my organization who purchased  BX from ,,,,, and have to replace them with BX from Sulzer due to lack of performance .

 

My answer was related to density only , I should have pay more attention about other characteristics.

 

Breizh

[curious_cat]

Hi Curious ,

Yes you are right !

I remember some people within my organization who purchased  BX from ,,,,, and have to replace them with BX from Sulzer due to lack of performance .

 

My answer was related to density only , I should have pay more attention about other characteristics.

 

 

No No, Breizh! Not your fault at all. You only tried to help and we as Chemical Engineers face this problem of corrupt data all the time so we must just be on the lookout. 

 

I only posted the descripancy to check my evaluation and also to guard against anyone else depending on the erroneous value. 

 

What is ironic is, I have now a value from our local rep. and he gave a 250 kg/m3 value for BX too! Exactly matches with that in your link. Could be just a happy coincidence! 

[PingPong]

I did not realise that my suggestion to calculate it from void fraction would give such a high number for gauze packing, having no experience with that type of packing myself. Apparently void fraction of gauze packing means something else than we thought.

 

But luckily you now have a reliable number from the vendor.

 

In the table provided in the link you posted some parameters seem suspect. 

 

e.g. For CY packings they quote an HETP of 333-400 mm but 8-10 theoretical plates per meter. That seems inconsistent, correct?

It seems to me that that is just a typing error in the table: in that column they accidentally switched the data of the first and last row.

[curious_cat]

 

It seems to me that that is just a typing error in the table: in that column they accidentally switched the data of the first and last row.

 

 

Wow. Good catch! That was a good piece of detective work.

Edited by curious_cat, 29 June 2016 - 12:01 PM.

[Napo]

Sirs,

 

I have written to CHEMPACK for confirm the values. I´m waiting the answer.

 

I saw other providers in the web, they give the Breizh values, but the problea is we don´t have a confiable source of information.

 

Napo.

[Napo]

Curious cat,

Maybe, Have you obtained the Sulzer information?.

Napo.