Run speed on a packed column

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myles
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Run speed on a packed column

Post by myles » Tue Dec 03, 2019 9:51 pm

Just a reminder, as some folks try to run too fast.

Typical product rates for packed (packed height = 24x to 30x column diameter) or plated columns, for azeotrope:

2" - 0.7 litres per hour on 1.5 kW (height 1.2 to 1.6 m)
3" - 2.5 to 3.8 litres per hour on 2.5 to 3 kW (height 2.5 to 3.2 m)
4" - 3 to 4 litres per hour on 4.5 to 5 kW (height 2.6 to 3.2 m)

If you halve the height, you also halve the product rate. A 2" column with 1 m of packing might only run at 0.4 litres per hour.

If you produce flavoured spirit, then your product rate can be faster.

Real picky (canadian snowflake vodka) drinkers might run a 4" column at just 1 litre per hour. Note: that this is on a 2nd or even 3rd spirit run of re-diluted hearts through the packed column.
You can easily run 94%+ product and still have flavour in it. 94%+ is NOT neutral, not unless it ONLY contains ethanol and water. Any other alcohols present leave flavours behind.

Personally I LIKE residual flavour in Vodka - I only use neutral as a base for infused products.

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Easydrinker
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Re: Run speed on a packed column

Post by Easydrinker » Wed Dec 04, 2019 1:38 am

Having just checked my book of runs, my Very Silly Still (1m packed column and a Torpedo) will produce almost 500ml at 90% + per hour.
If I turn the power down, I can get 93% at a lower rate, but it becomes twitchy.
I don't chase azeotrope anymore. :)

Robert.
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"Everyone's happy. Everyone's smiling. No-One here is sad anymore" :D

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Mash
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Re: Run speed on a packed column

Post by Mash » Wed Dec 04, 2019 6:24 am

Good post Myles. Good Reference for builders
To Gin-finity and beyond !

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Runningman
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Re: Run speed on a packed column

Post by Runningman » Wed Dec 04, 2019 3:00 pm

Hi Myles
First class info. Would the packing material alter these figures dramatically eg. SPP as opposed to say SS Scrubbers or Ceramic saddles etc. Your opinion on this would be very much appreciated.
Regards
RM

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myles
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Re: Run speed on a packed column

Post by myles » Wed Dec 04, 2019 9:23 pm

Only a bit with most packings, except for SPP.

SPP is a bit of a wild child. In my experience it is very good at one thing, and one thing only. Producing azeotrope.

I would say to ignore it if you are after a flavoured product. You get a wider operating window with less efficient packings, stainless scrubbers or pumice for example. Those give a range of product ABV whilst still maintaining column stability.

SPP is different. If you have it configured to produce azeotrope it is very difficult to get it to do anything else. I don't use it anymore myself.

If you want to push for max product rate at 94%+ ABV then use SPP. To optimise it though you need to run right on the edge of flooding the column. I just don't like doing that.

I have gone back to using simple stainless scrubbers in my packed column. It may not be super fast but it cruises along quite happily.

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Re: Run speed on a packed column

Post by Easydrinker » Thu Dec 05, 2019 12:03 am

I do not wish to knock or decry anothers efforts here.
I have watched many start distilling simply, and then chase the azeotrope fairy, because they can.
I no longer see or understand the need, well, maybe just the once, to prove that you can? :)
But I prefer a simpler life.
I am content.
While learning everyday.

Robert.
There is no ONE way.
"Everyone's happy. Everyone's smiling. No-One here is sad anymore" :D

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myles
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Re: Run speed on a packed column

Post by myles » Thu Dec 05, 2019 8:27 am

I agree with you Robert.
My packed column is simply a tool for re-cycling accumulated feints from the potstill, to make a reasonably clean base spirit for infused products.

As I prefer Genever to Gin anyway, I don't even bother trying to get a pristine "neutral", I just want to reduce the flavour to an acceptable level.

I have gone through the 3x through the column route in the past, and these days I don't bother. I never did see the point in actually drinking something with no flavour at all in it. Even with vodka I like it to have a slight residual flavour.

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Re: Run speed on a packed column

Post by Swedish Pride » Thu Dec 05, 2019 10:06 am

I don't care for flavourless products either.
My packed column have been run once to date and it was to clean up faints to make a voddy/ neutral, came off at 95+.
I run it on top of my plater where i get 93% normally, so don't have to slow down much to get the 95% out of it. and to me it had no flavour.
but then again my palete is totally shagged, I can detect next to no flavour in my UJ or Corn AG either.

I even use UJ hearts for lemoncello and apple pie :oops:

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Re: Run speed on a packed column

Post by Easydrinker » Fri Dec 06, 2019 1:25 am

Swedish Pride wrote:
Thu Dec 05, 2019 10:06 am
I don't care for flavourless products either.

I even use UJ hearts for lemoncello and apple pie :oops:
They may be bringing a little something to the party? :)

Robert.
There is no ONE way.
"Everyone's happy. Everyone's smiling. No-One here is sad anymore" :D

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