Re: [PSUBS-MAILIST] Compressed Air Quality

[Robert Carlson <rob.carlson@gte.net>]

Joe,

You are probably correct that there is little danger of creating ice cubes
unless one was to use some form of orifice to restrict flow (why, I'm not
sure).  However if you calculate the tempature change in your example (2000 psi
to 500 psi) your gas tempature will drop to 1/4 of the original tempature.
Consequently, your nozzle tempature will be below freezing tempature for water
(assuming that you started around room temp).  If there is sufficient moisture
in the air then you will form ice - how much is the question.  If your piping
is large enough then I would guess it would be hard to turn it into an ice cube
machine.

As for the Thresher (I'm no expert here): I had heard that there were two
things that compounded the sinking. First, there was a steam line rupture in
the piping (weld problem, perhaps).  As it turns out the procedure at that time
was to SCRAM the reactor (steam ruptures cool down the reactor too quick and
there was a fear of loss of control of the nuetron reaction) and shut the main
steam stops.  Unfortunately, they were not able to perform a fast startup and
so once the leak was isolated they had to start up the reactor the old fashion
way (which takes longer than 30 min).

So in the meantime they start losing nuetral bouyancy with no propulsion.
Emergency Blow was ordered when they began sinking faster than they had time to
pump.  When they blew the MBTs the lines froze and so no air got into the MBTs.

So here they are: heavy, no propulsion (except a 150 HP retractable outboard)
and now no Emergency blow!!

The US Navy made a few changes in submarine operations as a result:  a means to
recover the reactor quickly, and stringent HP air standards i.e. dry air.

Just some food for thought,
Regards,
Rob Carlson
Seattle. WA

Marsee Skidmore wrote:

> Rob,
>
> I was hoping that someone who knew would answer your question. Since no one
> has, I'll say, "I dunno, but I think so." I concur with all of your
> suppositions. I don't intend to blow ballast at depth, since I'm kinda
> partial to droppable ballast. In the event that I do, I intend to have 2,000
> psi (min) in the high pressure air bank competing with 500 psi (max)
> ambient. With big lines, that would take a mighty long ice cube to block.
>
> I'm curious about your Thresher reference. I thought that Thresher's
> plumbing problem was due to a defective weld. - Joe
>