OT Vacuum Bottle

[OGY]

Looking for but not sure the technical name of the intermediated water
bubbler bottle that goes between the vacuum pump and the bell jar that
will clean the stuff that may appear in the bell jar as being evacuated
so as not to contaminate the vacuum pump.

Got links would be helpful

Thank you.

[Arie de Muynck]

Scrubber?

[Jeff Liebermann]

Are you sure that a water bubbler is what you want? If you draw down
to a reasonable vacuum, the water will boil (without heating). My
guess(tm) is that you're looking for a vacuum filter, trap, drier or
scrubber which removes water and other contaminants from the air
sucked out of the bell jar before they can wreck your vacuum pump.
This article gives an overview of available filters:
<http://www.mainpress.com/nederlands/dossier_pompen/pdf/vacuumcontamination.pdf>
<https://www.google.com/search?q=vacuum+pump+filter+drier>
Also, if you have large amounts of water involved, you may need a
refrigerated condenser to get rid of the water.




--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[OGY]

I still cannot find a bubbler.

I am sucking the air out of epoxy or molding compound and similar.

I have seen them at a factory.
Just a large bottle with water in the bottom. One long pipe into the
water and one short pipe.

Are these custom or commercially available ?

[Jeff Liebermann]

On Thu, 4 Jul 2019 18:08:38 -0700, OGY <X...@NOWHERE.COM> wrote:

>I still cannot find a bubbler.

If Google can't find it, it doesn't exist. (Liebermann's Law)

>I am sucking the air out of epoxy or molding compound and similar.

No problem. I've done that for epoxy potting compound. All we had
was a inlet filter. No water.

>I have seen them at a factory.

Which factory? What were they making? Can you contact them and ask?

>Just a large bottle with water in the bottom. One long pipe into the
>water and one short pipe.

I'll try one more time. If you draw down more the 30 mbar absolute
pressure (where atmospheric pressure equals the vapor pressure), the
water will boil at room temperature. Plug 30 mbara into the
calculator below and notice that the calculated temperature is room
temperature:
<https://www.engineeringtoolbox.com/water-evacuation-pressure-temperature-d_1686.html>
If you don't believe me, just evacuate a bottle with some water in it
and watch it boil. Or, watch a few YouTube videos demonstrating how
water boils in a vacuum at room temperature:
<https://www.youtube.com/results?search_query=boiling+water+at+room+temperature>
In other words, an inlet bubbler is not going to work.

>Are these custom or commercially available ?

I have no idea. Maybe if you disclose what manner of "epoxy or
molding compound" you're using, I could lookup the required vacuum? If
it's not much of a vacuum, you might be able to use water without
having it boil. Search for "vacuum inlet or intake filter" and you
might find something:
<https://www.google.com/search?q=vacuum+inlet+filter&tbm=isch>
Extra credit for disclosing the maker and model number of the pump
you're using so the flow rate (and size) of the filter can be
calculated or estimated.

I have an Edwards E2M1 two stage vacuum pump with plastic intake
filter:
<http://www.learnbydestroying.com/jeffl/crud/Vaccum%20Pump.jpg>
On Pg 29 of the service manual:
<https://shop.edwardsvacuum.com/Viewers/Document.ashx?id=1335&lcid=2057>
You'll find a drawing showing 8 different inlet filter types.

Also, you might want to look into resin degassing equipment such as:
<https://www.amazon.com/Gallon-Vacuum-Degassing-Chamber-Pump/dp/B01N11WMX2/>
<https://www.amazon.com/Gallon-Vacuum-Chamber-Degassing-Kit/dp/B07HM646VS/>

[Ralph Mowery]

In article <svqvhe5gg0fbceeb1...@4ax.com>,
je...@cruzio.com says...

>
> I'll try one more time. If you draw down more the 30 mbar absolute
> pressure (where atmospheric pressure equals the vapor pressure), the
> water will boil at room temperature. Plug 30 mbara into the
> calculator below and notice that the calculated temperature is room
> temperature:
> <https://www.engineeringtoolbox.com/water-evacuation-pressure-temperature-d_1686.html>
> If you don't believe me, just evacuate a bottle with some water in it
> and watch it boil. Or, watch a few YouTube videos demonstrating how
> water boils in a vacuum at room temperature:
> <https://www.youtube.com/results?search_query=boiling+water+at+room+temperature>
> In other words, an inlet bubbler is not going to work.
>
>
>

High vacuum does strange things to water. At work I have seen a 6 inch
diameter pipe that is in about 100 deg F area and steam traced with a
1/4 inch pipe and insulated form a ball of ice and clog the pipe. The
device making the vacuum was a hollow tube with steam blowing into it
through a hole about 1/8 of an inch in diameter. There are seveal of
thease in series to make the vacuum.

[Jeff Liebermann]

Yep. Put a bubbler in the vacuum intake and it will also produce ice.

"It's Scientifically Possible to Boil Water Until It Freezes Solid"
<https://www.sciencealert.com/you-can-actually-boil-water-so-hard-it-freezes>
If you watch the video, notice at the beginning, the effort put into
preventing water vapor from enter the vacuum pump.

The water boils when the vapor pressure equals atmospheric pressure.
If the vacuum is lowered to less than this point, the water starts to
evaporate, taking the higher energy water molecules with it, which is
also the residual heat in the water. Eventually, all the "hot" water
molecules end up in the water vapor, the water temperature drops to
freezing, and remaining low energy water molecules form ice crystals.

[Bob Engelhardt]

On 7/5/2019 9:38 PM, Jeff Liebermann wrote:
> ...
> I'll try one more time. ...

You've so much more patience than me. When they ignore my advice the
1st time, they don't deserve any more help.

[et...@whidbey.com]

Probably the reason you can't find what you want is because the water
boiling at low temp from the vacuum would dump water into the vacuum
pump. The vacuum drawn during the typical epoxy degassing operation is
plenty low enough to cause water to boil at room temp. Maybe what you
need is some type of system where oil, not water, is used. Actually
though I think what you really need is a standard filter available
from many sources, even Harbor Freight. If you can't find a filter
online to do what you want then I think you are probably not competent
enough be degassing epoxies.
Eric

On Thu, 4 Jul 2019 18:08:38 -0700, OGY <X...@NOWHERE.COM> wrote:

>

[Fox's Mercantile]

On 7/6/19 11:33 AM, et...@whidbey.com wrote:
> If you can't find a filter online to do what you want then I
> think you are probably not competent enough be degassing epoxies.

Being cheap, I use an old pressure cooker as a vacuum chamber.
That and a vacuum pump I acquired surplus from Hughes Aircraft.

The only problem I've had is the "safe time" before materials
start to cook off.
I've used it with silicon, Tru-Cast resins and Epoxies.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

[Jeff Liebermann]

Well, I have a rather different approach. I spend far too much time
answering questions on Usenet, mailing lists, and forums. I try to be
helpful, but in most cases, it's more for my personal benefit than for
any benefit to the person asking the question.

In order to produce a useful answer, I first needed to do some
research. I already knew that sucking water into a vacuum pump was a
really bad idea, but I didn't really understand why or what
alternatives were available. Some Goggling and fast reading provided
the necessary details, which I provided in my reply. While my answer
was probably beneficial to the person asking the question, it was
equally beneficial to me by adding yet another item of trivial
knowledge to my vast collection.

Reading between the lines, it would seem that the person asking the
question does not understand what happens in a vacuum. He seems to be
lacking in experience at asking questions on Usenet or in forums.
Tracing his IP address shows him on Road Runner Cable somewhere in
southern California. He's using:
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:49.0)
Gecko/20100101 Firefox/49.0 SeaMonkey/2.46
which seems rather old. I'm not sure what's happening there, but
offhand, it looks like an older machine and operating system. The
style of his question seems to be rather jumbled, terse, lacking in
technical terms, but where all the words are correctly spelled. That
suggests a smartphone user, using speed to text software. By the
sentence structure and apparent frustration, I would guess a fairly
young person, possibly a teenager.

So, after reading my analysis and guesswork, do you still think that
they don't deserve any more help?

[Bob Engelhardt]

On 7/6/2019 1:31 PM, Jeff Liebermann wrote:
...

> So, after reading my analysis and guesswork, do you still think that
> they don't deserve any more help?
>

First I'd like to say that I appreciate the effort that you put into
your replies, even when I'm not the OP. You have a great deal of
credibility and when there's a long thread that has sidetracks of the
"Yes it is" "No it isn't" variety I often skip most of it and read your
replies.

But, to the point here: your 1st reply brought up the
boiling-under-vacuum problem. Which he totally ignored in his reply to
you and repeated his original request for finding the device he thought
he needed. If they're not going to listen, I'm not going to waste my
time. If he won't listen, he probably can't be helped anyhow.