Pumping Liquid Nitrogen

Guy Macon wrote:
Dirk Bruere at NeoPax wrote:
Guy Macon http://www.guymacon.com/ wrote:

I want to pump the liquid nitrogen into a hole drilled
into the heatsinks of the CPU and GPU of a gaming PC
so I can overclock them farther than otherwise possible.
It would be easier to deal with the boiloff gas - it's still at 77K.
Do you actually need the LN2?

Yup. The latent heat of evaporation for Nitrogen is 198.3 Joules
per gram at one atmosphere, while the the specific heat capacity
for nitrogen is only 1.006 Joules per gram per degree Kelvin.
Also, liquids conduct heat far better than gasses.

I don't have an uploadable cooling curve for nitrogen
at hand, but take a look at the cooling curve for water:
[ http://www.physchem.co.za/Heat/Graphics/Heat42.gif ].
The portion of the curve labled D shows that the energy
needed to go from 99.99 degrees C to 100.01 degrees C
is much larger than from 0.01 degrees C to 99.99
degrees C. This is typical of boiling liquids.



The solder balls on the processor module will probably rip the pad
metallization right off the CPU, but if the PC is scrap anyway, it's
probably worth a try. Pumping LN2 is really hard--harder than pumping
boiling water, and for the same reason, namely cavitation on the
low-pressure side--so you'd be much better off just letting the dewar
pressurize itself a little.

You're going to run out of LN2 in a few hours anyway.

Cheers,

Phil Hobbs

On Dec 20, 7:34 am, Guy Macon http://www.guymacon.com/ wrote:

"Arguing with anonymous strangers on the Internet is a sucker's
game because they almost always turn out to be -- or to be
indistinguishable from -- self-righteous sixteen-year-olds
possessing infinite amounts of free time."
-Neil Stephenson, _Cryptonomicon_

*plonk*

Wouldn't your time be better spent correcting the it's/its errors on
your site, beard-boy?

"Before examining Structured Engineering, it is instructive to examine
it's predecessor,"

Argh.

Anyways, go spend some time with a woman this Christmas instead of an
inert box of crap that only excites teenagers and 45 year old
teenagers. With horror-beards. At least it's not a neck beard, I
suppose.

On Dec 19, 7:27 pm, Guy Macon http://www.guymacon.com/ wrote:
I have been offered a small (about the size of a water
cooler)liquidnitrogengenerator at an attractive
price. It generates four and a half liters per day,
using a gravity feed to keep a half liter dewar filled.

I want to pump theliquidnitrogeninto a hole drilled
into the heatsinks of the CPU and GPU of a gaming PC
so I can overclock them farther than otherwise possible.
(This is for a a "just for fun" personal project, not
for work).

My question is how best to pump theliquidnitrogen.
In the past I have worked with big dewars and let them
self-pressurize with a relief valve on top and a feed
tube going to the bottom -- sort of like an aerosol
can. This doesn't look feasible in this case; the back
pressure seems like it will back up the gravity feed.
I think I need a small pump that can take the cold and
not add too much heat to theliquidnitrogen. Any ideas?

BTW, I have seven old 500 MHz. Pentium 3 systems that
are ready to be scrapped that I will be doing my
initial experiments on before deciding whether to
risk a more modern PC.

--
Guy Macon
http://www.guymacon.com/

I just got involved with cooling a microscope chamber. The first
design, not by me, was a failure in every respect. Trying to cool a
copper chamber by a copper pipe about a foot long, from a thermos
filled around the end coil of the copper tubing. Gas was allowed to go
through the tube. Temp drop after several minutes was a couple degrees
below room temp. Next design gets the fluid right around the chamber.

I also recently was working with a pumped unit, rather expensive, out
of date, and didn't work right. Sometimes these things are not
repairable or is too costly. I would be interested in knowing what
type of pumps are suitable for moving the fluid around.

greg

'Guy Macon' wrote, in part:
| A: Because it messes up the order in which people normally read text.
|
| Q: Why is top-posting such a bad thing?
|
| A: Top-posting.
|
| Q: What is the most annoying thing on Usenet?
______

Being that you are more interested in heat than light, why the post on
liquid Nitrogen in the first place?

Phil Weldon

"Guy Macon" http://www.guymacon.com/ wrote in message
...
|
|
|
| A: Because it messes up the order in which people normally read text.
|
| Q: Why is top-posting such a bad thing?
|
| A: Top-posting.
|
| Q: What is the most annoying thing on Usenet?
|
| Phil Weldon wrote:
|
| For actually pumping liquid nitrogen you could contact NASA
| for a few tips... especially safety tips.
|
| You are talking to the person who taught the cryogenic
| safety classes for Parker Hannifin on the space shuttle
| 17 inch disconnect project -- under contract with NASA.
|
| Taking a flyer with a Pentium III is hardly worth the effort.
|
| You prefer I ruin a few Core Duos while I experiment?
|
| One possibility for a more or less continuously operating
| cooler would be to use the boil-off of liquid nitrogen to
| chill an anti-freeze mixture (propylene glycol & water
| ~ 50:50 should be good to below - 40) that you could then
| pump through a more or less stock CPU water block.
|
| I don't want minus 40. I want minus 196.
|
| --
| Guy Macon
| http://www.guymacon.com/
|

On Thu, 20 Dec 2007 00:27:26 +0000, Guy Macon
http://www.guymacon.com/ wrote:




I have been offered a small (about the size of a water
cooler) liquid nitrogen generator at an attractive
price. It generates four and a half liters per day,
using a gravity feed to keep a half liter dewar filled.

I want to pump the liquid nitrogen into a hole drilled
into the heatsinks of the CPU and GPU of a gaming PC
so I can overclock them farther than otherwise possible.
(This is for a a "just for fun" personal project, not
for work).

My question is how best to pump the liquid nitrogen.
In the past I have worked with big dewars and let them
self-pressurize with a relief valve on top and a feed
tube going to the bottom -- sort of like an aerosol
can. This doesn't look feasible in this case; the back
pressure seems like it will back up the gravity feed.
I think I need a small pump that can take the cold and
not add too much heat to the liquid nitrogen. Any ideas?

BTW, I have seven old 500 MHz. Pentium 3 systems that
are ready to be scrapped that I will be doing my
initial experiments on before deciding whether to
risk a more modern PC.

How about a magnetically coupled centrifugal pump.
A magnet in a rotor can be spun by a magnet on a motor or by coils
that emulate a rotating mag field. This is not too different than my
interest in magnetic stirrers. (See DIY Magnetic Stirrer post and my
posts on etchant pumps.)
Some liquid nitrogen can probably be fed to the field inductors to
enhance the drive performance.
Likewise I think the rotor magnet gets a boost too from the cold
temperature. (I can't recall what magnets do when super cooled.)

I"ve been tempted to design a pump like this, but it would be to pump
etchant. If you make one, let me know..


D from BC

Guy Macon wrote:

Paul Hovnanian P.E. wrote:

[snip]

Also, keep in mind that in an enclosed space (your mom's basement? ;-))
the nitrogen gas will displace air and asphyxiate the user if not
properly ventilated.

Nope. that's for systems with a *source* of nitrogen. A nitrogen
generator takes as much out of the room air as the boiling nitrogen
puts back in. (I would ventalate it anyway, but for the opposite
reason; to avoid any Oxygen concentration around the generator)

True. Some time ago, I had to stop someone from setting up a
refrigeration system with the LN2 generator located in a different area.
It made too much noise.

--
Paul Hovnanian
------------------------------------------------------------------
Do not mold, findle or sputilate.

In article , says...



~misfit~ wrote:

Phil Weldon wrote:

For actually pumping liquid nitrogen you could contact NASA
for a few tips... especially safety tips.

You are talking to the person who taught the cryogenic
safety classes for Parker Hannifin on the space shuttle
17 inch disconnect project -- under contract with NASA.

And you're asking your questions here because all those
contacts you made are ob holiday?

Experience designing the 17 inch wide valve that connects the
external tank to the space shuttle doesn't apply much to the
problem of finding a small, cheap pump for less than a liter
per hour of liquid nitrogen.

Taking a flyer with a Pentium III is hardly worth the effort.

You prefer I ruin a few Core Duos while I experiment?

Sure, with the money you made from a morning's teaching cryogenic
safety classes

The word "taught" is past tense. I no longer work for Parker.
The Jamboree Blvd. plant closed down quite some time ago.

you could ruin a few Core Quads. After all, you can afford
a liquid nitrogen generator, what's a few hundred bucks
worth of CPUs? Trying it with a PIII is like learning to
drag-race in a pedal-car.

If I was thinking of trying something that could burn out my
expensive drag racer, I might very well try it on a few pedal
cars first. Even if I could afford to destroy multiple race
cars.

One possibility for a more or less continuously operating
cooler would be to use the boil-off of liquid nitrogen to
chill an anti-freeze mixture (propylene glycol & water
~ 50:50 should be good to below - 40) that you could then
pump through a more or less stock CPU water block.

I don't want minus 40. I want minus 196.

Well Mr. Cryo-teacher, be sure to let us know how it works
out for you. Or not.

"Arguing with anonymous strangers on the Internet is a sucker's
game because they almost always turn out to be -- or to be
indistinguishable from -- self-righteous sixteen-year-olds
possessing infinite amounts of free time."
-Neil Stephenson, _Cryptonomicon_

Resistor maybe. Evaporate a little nitrogen, use the pressure to move
the rest. Use the exhausted nitrogen from the other end to keep the
rest of the box cool and dry.

Robert

--
Posted via a free Usenet account from http://www.teranews.com

How about a percolator arrangement; can't get much simpler and no moving
parts? I think that if you submerge one end of a piece of tubing in the
LN2 you will get spurts of LN2 forced up the tube. I don't know what
geometry would be best but I think a few small entrance holes with area
a good bit less than the inside cross sectional area of the tubing.
Maybe look online at pulse jets for ideas, or your oldfashioned coffee
pot :-).

--
Regards,
Carl Ijames carl dott ijames aat verizon dott net
(remove nospm or make the obvious changes before replying)

Somewhere on teh intarweb "Guy Macon" typed:
~misfit~ wrote:

Phil Weldon wrote:

For actually pumping liquid nitrogen you could contact NASA
for a few tips... especially safety tips.

You are talking to the person who taught the cryogenic
safety classes for Parker Hannifin on the space shuttle
17 inch disconnect project -- under contract with NASA.

And you're asking your questions here because all those
contacts you made are ob holiday?

Experience designing the 17 inch wide valve that connects the
external tank to the space shuttle doesn't apply much to the
problem of finding a small, cheap pump for less than a liter
per hour of liquid nitrogen.

Taking a flyer with a Pentium III is hardly worth the effort.

You prefer I ruin a few Core Duos while I experiment?

Sure, with the money you made from a morning's teaching cryogenic
safety classes

The word "taught" is past tense. I no longer work for Parker.
The Jamboree Blvd. plant closed down quite some time ago.

you could ruin a few Core Quads. After all, you can afford
a liquid nitrogen generator, what's a few hundred bucks
worth of CPUs? Trying it with a PIII is like learning to
drag-race in a pedal-car.

If I was thinking of trying something that could burn out my
expensive drag racer, I might very well try it on a few pedal
cars first. Even if I could afford to destroy multiple race
cars.

One possibility for a more or less continuously operating
cooler would be to use the boil-off of liquid nitrogen to
chill an anti-freeze mixture (propylene glycol & water
~ 50:50 should be good to below - 40) that you could then
pump through a more or less stock CPU water block.

I don't want minus 40. I want minus 196.

Well Mr. Cryo-teacher, be sure to let us know how it works
out for you. Or not.

"Arguing with anonymous strangers on the Internet is a sucker's
game because they almost always turn out to be -- or to be
indistinguishable from -- self-righteous sixteen-year-olds
possessing infinite amounts of free time."
-Neil Stephenson, _Cryptonomicon_

*plonk*

Indeed, what one would expect from someone with little grasp of the English
language.

I'm a great believer in the passage that you quoted above. That's why I
don't engage in *arguments* "on the internet". (Hint: Look up the word,
re-read my post...)

Oh, and from your website:

"HARDWARE DESIGN; I am an *expert* in *all areas* of electronics, including
analog, digital, microcontroller, high-power, low-power, high volume,
aerospace and consumer electronics."

(My ** emphasis)

Seems that you should be helping us instead of only coming here for help.
Mr. Expert.

Buh-bye.
--
TTFN,

Shaun.

"another academic failure.... trying to prove that your smart"
'blanking', nz.comp, 20 Dec 2007.

Robert Adsett wrote:

Evaporate a little nitrogen, use the pressure to move the rest.
Use the exhausted nitrogen from the other end to keep the
rest of the box cool and dry.

That was my original thought as well, and is the method I have
used in larger cryogenic systems. There is even an outfit that
will sell you a microcontroller-operated sensor/valve that you
put on the gas vent to regulate flow through the liquid output
-- sort of like an aerosol can that never loses pressure.

The problem is that those systems all depebded on deliveries
of liquid nitrogen, so getting a full dewar to self-pressurize
was no problem. The system I am looking at here generates
liquid nitrogen from the air (it was originally used in a
medical office) and gravity-fills a half liter dewar. I am
pretty sure that if I let it self-pressurize the gas will
escape through the intake tube rather than by forcing liquid
out through the output tube. thus the question about a pump.

--
Guy Macon
http://www.guymacon.com/