[3dem] Help about ice condensation on LN2 tank mounted to Titan Krios

[Daniel Dai]

Thanks a lot for your input.

We have this problem with the LN2 tanks from outside gas vendor and our newly purchased tanks (brand-new).

Since there are used and new tanks, I would like to guess it may be not because of LN2 tanks.

For the filling lines/pipes/tubes leakage, I'm not sure now and need to talk to FEI engineers about this possibility.

About the suggestion to remove the tank before emptiness, I'm thinking about that too, some remaining issues:

1) Dense ice on top of the tank, the gause could be hidden under ice. A industrial scale could be the solution.

2) The timing of a full tank on our Krios varies much, from 3 days to 6 days, so a scheduler might be not very useful here.

Anyway, thanks a lot for the info that you don't have this issue, then I can talk to FEI about it.

Have a good weekend!


Best regards,

Aguang at UT Austin


________________________________
From: Jaime Martín-Benito Romero <jmartinb at cnb.csic.es>
Sent: Friday, March 2, 2018 7:24:27 PM
To: Daniel Dai
Subject: Re: [3dem] Help about ice condensation on LN2 tank mounted to Titan Krios

Dear Daniel,

I'm sure there's a problem with your tank. We have two 180 litre tanks
and we have never observed condensation/ice in the valves of the tanks
(we also always keep the valves open for refilling)

Best regards,

Jaime


At Fri, 2 Mar 2018 15:20:30 +0000 Daniel Dai <dawaylong at hotmail.com> wrote:

> Hello 3DEMers
>
>
> We put a 230L lN2 tank in Krios room to cool Autoloader and scope.
>
> The valves of gas/liquid are always open to make sure auto-refilling work.
>
> Unfortunately, because the temperate of the valves area is much
> colder than the room temperature, the water molecule in the room
> condenses onto the valve area, a dense ice growing on top.
>
> This ice melts into water and flows to the ground when the tank is
> close to emptiness, which bugs me a lot since there are nearby
> pipes/pumps.
>
> It's almost impossible to remove the tank immediately every time
> when the tank is almost empty, since the gauge is not that accurate
> to know the liquid level.
>
> I'm wondering how your facility deal with this issue.
>
> Any suggestion would be greatly appreciated.
>
> Thanks.
>
>
> Best regards,
>
> Aguang at UT Austin



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20180303/7a2fbdc7/attachment.html>