Jump to content

rate my dephlegmator cooling capacity


Recommended Posts

Is there a calculator to work out cooling capacity? I am having this built - this is as big as i could make it without punching a hole in my ceiling.

I am in the UK and the mains water is cold enough.. today it is 46f - I know flowrate is also a consideration and I have a good flow rate also.

How can i calculate 100% reflux capacity?

9 tubes, 16mm diameter - 214mm long.

dephleg.jpg

Link to post
Share on other sites

Do yourself a favour;

1  Increase outer tube ring qty from 6 to say 8.  You have space for this.

2  Change the plate thickess from 0.8mm to say 1.5 or 2mm and also don't chamfer the tube prior to weld.  Unless you have a good welder, you will easily burn through the tube and plate. 

3  Change total length from 214.2 to at least 250 and better still 300mm

Link to post
Share on other sites
1 hour ago, richard1 said:

Do yourself a favour;

1  Increase outer tube ring qty from 6 to say 8.  You have space for this.

2  Change the plate thickess from 0.8mm to say 1.5 or 2mm and also don't chamfer the tube prior to weld.  Unless you have a good welder, you will easily burn through the tube and plate. 

3  Change total length from 214.2 to at least 250 and better still 300mm

Hi Richard,

It's already being produced and I have no control over height.. my ceiling dictates this.

I'm just after a calculator to understand capacity.

I can reduce power for it's intended use to accomodate and/or increase coolant flow - and introduce some scrubby to help out also.

If it's total cr4p I can always buy a better one and maybe punch through the ceiling.. not ideal but an option.

This only set me back 100 usd so not much lost.

Link to post
Share on other sites
19 hours ago, needmorstuff said:

Hi Richard,

It's already being produced and I have no control over height.. my ceiling dictates this.

I'm just after a calculator to understand capacity.

I can reduce power for it's intended use to accomodate and/or increase coolant flow - and introduce some scrubby to help out also.

If it's total cr4p I can always buy a better one and maybe punch through the ceiling.. not ideal but an option.

This only set me back 100 usd so not much lost.

ok i spoke to them and production hasn't started but i would like to keep height at 214 so i don't have to destroy my ceiling.

also the material used for construction is 1mm, 0.8mm is for the tubes.

so given my 214mm length - what tube configuration is best as they are saying if i add more tubes the diameter must decrease from 16mm.. i can easily argue that point but if i did decrease tube size to 10mm or 13mm I would be able to have a lot more of them.

so - 11 tubes of 16mm, 15 tubes of 13mm or 19 tubes of 10mm - i am just guessing the number of tubes here...

I know you can go too small with the tubes for a dephleg so that it doesnt allow both vapour and water in the tube at the same time and creates a partial vacuum, so i would like to maintain that theory as in the future i will forget the design phase and may put this to use as a dephleg.

i plan to use it to create 100% reflux for a soxhlet extractor and have 6kw of power i would ideally like to knock down.

Link to post
Share on other sites

Why not go wider?  6"

If you are planning to operate in 100% reflux, surface area is king.

You might also consider adding turbulators in the tubing to force contact with the tube walls.

Will you be leaving the top open to the atmosphere?  I think what you find that if they tubes are indeed too small, the dephlegmator starts acting like a perforated plate, holding liquid above it.  Highly unlikely you'll get to this point.

Another option is to use a larger product condenser, and position it horizontal, feed vapor into the shell side, not the tube side.

 

Link to post
Share on other sites

6" is a good point... will get a ton of tubes in a 6". it just has to be smaller than 8" so the condensed distillate is directed into the chamber

yes the top will be left open always! no bombs here.

I will ask how much 6" will cost me.

 

Link to post
Share on other sites

Have a look at this.

 

Length made shorter by 5mm either side for welding within ferrule.  I have presumed that the 4" ferrule has an ID of 97.6mm.  I have presumed that the tube OD is 16mm exact.  So the total face to face length of the 4" ferrule is 240mm as previously identified.

 

You will not be able to use the larger 6" dephleg because it will require reducers to fit 6" to 4" and there are height constraints.

 

 

483077224_UKASSY.thumb.jpg.9707242b9bf3f60120e2e24155d0111a.jpg397419065_UKASSY1.thumb.jpg.4d2a57bd9ffe1f2e172f6db72bca8149.jpg

Link to post
Share on other sites
8 hours ago, richard1 said:

Have a look at this.

 

Length made shorter by 5mm either side for welding within ferrule.  I have presumed that the 4" ferrule has an ID of 97.6mm.  I have presumed that the tube OD is 16mm exact.  So the total face to face length of the 4" ferrule is 240mm as previously identified.

 

You will not be able to use the larger 6" dephleg because it will require reducers to fit 6" to 4" and there are height constraints.

 

 

483077224_UKASSY.thumb.jpg.9707242b9bf3f60120e2e24155d0111a.jpg397419065_UKASSY1.thumb.jpg.4d2a57bd9ffe1f2e172f6db72bca8149.jpg

thanks so much for this Richard, they are also shrinking the 8" to 6" reducer to keep within my constraints. So the condensor is 6" x 240.6mm and the reducer now 64.5mm

I will keep it at 6" with 18 tubes as you can never have too much knock down power right. The price has gone from $100 USD to $140 USD so it is still a very good deal as a similar product is over $400 commercially.. a big caveat with pricing is that the commercially available product is no doubt better constructed. Whilst I think the baffles are amazing I do not want to over complicate the build and add more cost. Lets remember I only have 6kw.

Drawings attached.

IMG-50b002e8c8228c1a1fc8237265b7d0aa-V.jpg

IMG-df9a2c78a6864d921418170099230d82-V.jpg

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...