## Column pressure

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• I am now building a new still and i am wondering about one thing. My first column is designed in the offset style reflux condencing, L shape or cactus
Message 1 of 4 , Nov 2, 2005
I am now building a new still and i am wondering about one thing. My
first column is designed in the offset style reflux condencing, "L
shape or cactus design". The cooling part, the vertical one, is
effective enough so the vapor become condenced around the middle of
it heights. At the top of the vertical part is a hole so actually
the reflux head is vented resulting in that above the packing in the
column is only the atmospheric pressure, and the temp in the column
top is constant 78.2 - 78.4 C

Now i am building a larger system and the reflux head will be
different so the vapor will be condensed to a small pool at the
bottom and then lead back to the column top through a special pipe.

Then we are coming to the point. I am not sure that it will be
possible to have the head vented, resulting in possible pressure in
the top of the column. The question is: On which way does that
affect the vapor temperature for the pure ethanol? Does i have to
calculate the vapor temp in relation to the pressure reading from a
gauge, if any, to know which purity i am working with at the top?

Thanks,

HG
• The way I understand your description is that there is vapor access into the condenser section, and liquid return via a separate (lower?) pipe. So far so good.
Message 2 of 4 , Nov 2, 2005
The way I understand your description is that there is
vapor access into the condenser section, and liquid
return via a separate (lower?) pipe. So far so good.
What I can't understand is why you cannot vent to the
atmosphere (unless you are feeding vapor in from above
the cooling coils).
With no venting, you will indeed have a pressure build
up.... right until you start traking off product: then
you will have a jet of superheated ethanol vapor
shooting out.
Cheers,
Rob.

--- project880 <project880@...> wrote:

>
> I am now building a new still and i am wondering
> first column is designed in the offset style reflux
> condencing, "L
> shape or cactus design". The cooling part, the
> vertical one, is
> effective enough so the vapor become condenced
> around the middle of
> it heights. At the top of the vertical part is a
> hole so actually
> the reflux head is vented resulting in that above
> the packing in the
> column is only the atmospheric pressure, and the
> temp in the column
> top is constant 78.2 - 78.4 C
>
> Now i am building a larger system and the reflux
> different so the vapor will be condensed to a small
> pool at the
> bottom and then lead back to the column top through
> a special pipe.
>
> Then we are coming to the point. I am not sure that
> it will be
> possible to have the head vented, resulting in
> possible pressure in
> the top of the column. The question is: On which way
> does that
> affect the vapor temperature for the pure ethanol?
> Does i have to
> calculate the vapor temp in relation to the pressure
> gauge, if any, to know which purity i am working
> with at the top?
>
> Thanks,
>
> HG
>
>
>
>

Cheers,
Rob.

__________________________________
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• Without a drawing or sketch it is almost Hit or Miss situation with the answer. If you want an intelligent answer please post a drawing. Re-reading your post
Message 3 of 4 , Nov 2, 2005
Without a drawing or sketch it is almost "Hit or Miss" situation with the answer. If you want an intelligent answer please post a drawing.
Re-reading your post I might think you are building a closed system subject of internal pressure applied against this "liquid pool"...

project880 <project880@...> wrote:
Now i am building a larger system and the reflux head will be different so the vapor will be condensed to a small pool at the bottom and then lead back to the column top through a special pipe. Then we are coming to the point. I am not sure that it will be possible to have the head vented, resulting in possible pressure in the top of the column. The question is: On which way does that affect the vapor temperature for the pure ethanol? Does i have to calculate the vapor temp in relation to the pressure reading from a
gauge, if any, to know which purity i am working with at the top?

---------------------------------
Yahoo! FareChase - Search multiple travel sites in one click.

[Non-text portions of this message have been removed]
• ... I am not sure that it will be possible to have the head vented, resulting in possible pressure in the top of the column. jeez. hope you don t live next
Message 4 of 4 , Nov 4, 2005
--- In Distillers@yahoogroups.com, "project880" <project880@y...>
wrote:
>
>
I am not sure that it will be possible to have the head vented,
resulting in possible pressure in the top of the column.

jeez. hope you don't live next door to me. ka-boom.
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