Any problems with 2” to 1/2”

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OklahomaShiner
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Any problems with 2” to 1/2”

Post by OklahomaShiner »

I’m building a 2” column. My liebig will have a 1/2” 90 on the intake side with a union fitting or it won’t have the 90 but just the union fitting. My plan to connect my liebig is from the 2” tee to a 1/2” NPT female tri clamp cover or from the tee to a 2” 90 with the 1/2” NPT female tri clamp cover. My question is would there be any problems with going from 2” straight to 1/2”?
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Re: Any problems with 2” to 1/2”

Post by Twisted Brick »

OklahomaShiner wrote: Wed Jul 14, 2021 10:43 am My plan to connect my liebig is from the 2” tee to a 1/2” NPT female tri clamp cover or from the tee to a 2” 90 with the 1/2” NPT female tri clamp cover. My question is would there be any problems with going from 2” straight to 1/2”?
You will be fine if you go from a tee with 2" TC cap with a 1/2" 90* into a 1/2" union. If you go off the riser into a 2" 90* and then through a TC cap with a 1/2" into your liebeig you will cause smearing. Better to triclamp off your 2" 90* a 2-1/2" reducer then into your condenser. Ideally, you would step your 2" down to 1/2" gradually.
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Re: Any problems with 2” to 1/2”

Post by still_stirrin »

Velocity.

The vapor will be slow rising in the 2” and then rapidly accelerate entering the 1/2”. In a sense, this will “choke” the flow. What happens as the flow accelerates, the static pressure drops because the density must go down in order to move the mass faster. And when the static pressure reduces, the boiling point of the fluid depresses as well. This can make heat transfer more difficult in a product condenser.

Slower vapor velocity will perform better in the pipes throughout.
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Re: Any problems with 2” to 1/2”

Post by OtisT »

OklahomaShiner, how much power/heat can your boiler provide?

Is this column a fractioning column or just a 2” riser on a pot still?

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OklahomaShiner
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Re: Any problems with 2” to 1/2”

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still_stirrin wrote: Wed Jul 14, 2021 11:55 am Velocity.

The vapor will be slow rising in the 2” and then rapidly accelerate entering the 1/2”. In a sense, this will “choke” the flow. What happens as the flow accelerates, the static pressure drops because the density must go down in order to move the mass faster. And when the static pressure reduces, the boiling point of the fluid depresses as well. This can make heat transfer more difficult in a product condenser.

Slower vapor velocity will perform better in the pipes throughout.
ss
What if I did a 2” to 1” reducer spool to 1” tee and from the tee to a tri clamp cap with a 1/2” NTP?
OklahomaShiner
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Re: Any problems with 2” to 1/2”

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OtisT wrote: Wed Jul 14, 2021 12:24 pm OklahomaShiner, how much power/heat can your boiler provide?

Is this column a fractioning column or just a 2” riser on a pot still?

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Re: Any problems with 2” to 1/2”

Post by River Rat »

Here's how I went from 2" to 1/2". StillCrazy posted a great thread on how to build it out of a piece of DWV pipe. Salty Staves built one too and I basically copied his. Depending on your setup you might not want something that long but you get the idea, you could make it as short or long as you want.
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Re: Any problems with 2” to 1/2”

Post by Saltbush Bill »

Nice work River Rat :thumbup: Great to see some building going on.
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Re: Any problems with 2” to 1/2”

Post by OklahomaShiner »

River Rat wrote: Wed Jul 14, 2021 5:02 pm Here's how I went from 2" to 1/2". StillCrazy posted a great thread on how to build it out of a piece of DWV pipe. Salty Staves built one too and I basically copied his. Depending on your setup you might not want something that long but you get the idea, you could make it as short or long as you want.DSCN0996.JPG
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I’ll check it out. That’s look nice by the way!
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Re: Any problems with 2” to 1/2”

Post by OklahomaShiner »

Or maybe I could do a 2” 90 off the column to a 2” to 1” reducer with the 1/2” female NPT tri clamp cap.
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Re: Any problems with 2” to 1/2”

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OklahomaShiner wrote: Wed Jul 14, 2021 6:17 pm Or maybe I could do a 2” 90 off the column to a 2” to 1” reducer with the 1/2” female NPT tri clamp cap.
Sounds good to me!
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Re: Any problems with 2” to 1/2”

Post by Deplorable »

Why not just go 2" all the way through the condenser and not have any change in vapor velocity? If you're building from the start, just build it all 2 inch, into a 2 inch shotgun with four 1/2 inch vapor tube in it.
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Re: Any problems with 2” to 1/2”

Post by subbrew »

Deplorable wrote: Thu Jul 15, 2021 6:17 pm Why not just go 2" all the way through the condenser and not have any change in vapor velocity? If you're building from the start, just build it all 2 inch, into a 2 inch shotgun with four 1/2 inch vapor tube in it.
You will get an increase in velocity as the vapor area of 4 half inch tubes is about 1/4 the vapor area of an open two inch tube. area of 4 half inch tubes is 3.14 inch square and of a 2 inch open tube is 12.57. So you will get about a 4X increase in vapor speed at the entrance but it will almost immediately drop off as the vapor cools and condenses. But it is still 4X less than going from a 2 inch column to a 1/2 condenser which would give a 16X increase in vapor speed.
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Re: Any problems with 2” to 1/2”

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subbrew wrote: Thu Jul 15, 2021 9:55 pm
Deplorable wrote: Thu Jul 15, 2021 6:17 pm Why not just go 2" all the way through the condenser and not have any change in vapor velocity? If you're building from the start, just build it all 2 inch, into a 2 inch shotgun with four 1/2 inch vapor tube in it.
You will get an increase in velocity as the vapor area of 4 half inch tubes is about 1/4 the vapor area of an open two inch tube. area of 4 half inch tubes is 3.14 inch square and of a 2 inch open tube is 12.57. So you will get about a 4X increase in vapor speed at the entrance but it will almost immediately drop off as the vapor cools and condenses. But it is still 4X less than going from a 2 inch column to a 1/2 condenser which would give a 16X increase in vapor speed.
So would going from 2” to 1” to 1/2” be ok?
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Re: Any problems with 2” to 1/2”

Post by subbrew »

you will still get the same increase in vapor speed. a smooth transition will allow for a more laminar flow as opposed to a turbulent flow. Given the small diameter of the condenser tubes in either case I don't think the type of flow really matters. there may be a small difference with the turbulent flow being condensed in a slightly shorter distance. In a larger tube condenser, laminar flow may allow channeling of the vapor possibly allowing vapor to exit the tubes. The key factor is faster vapor velocity requires a longer condenser tube to condense.
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Re: Any problems with 2” to 1/2”

Post by subbrew »

I should add that depending on configuration a smoother transition can lessen the chance of having places condensate can pool and lead to smearing.
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