Pumping Liquid Nitrogen

[Guy Macon]

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.

 

[amdx]

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.

Let me be the first to say, "that's going to be cool."
Mike

 

[Dirk Bruere at NeoPax]

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.

It would be easier to deal with the boiloff gas - it's still at 77K.
Do you actually need the LN2?

 

[D from BC]

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.

The only thing that comes to mind is pumps used for liquid fuel
rockets.

D from BC

 

[D from BC]

What's the temperature spec on the CPU you will be using? Odds are that
it won't deal with LN2 temperatures well.

Consider the heat capacity of LN2 (include the heat of vaporization)
compared to that of H2O. For the complexity of what you propose to do,
LN2 won't buy you much more than a good heat exchanger/radiator setup.

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.

CPU cooling with liquid nitrogen


D from BC

 

[Paul Hovnanian P.E.]

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).

What's the temperature spec on the CPU you will be using? Odds are that
it won't deal with LN2 temperatures well.

Consider the heat capacity of LN2 (include the heat of vaporization)
compared to that of H2O. For the complexity of what you propose to do,
LN2 won't buy you much more than a good heat exchanger/radiator setup.

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.

 

[Phil Weldon]

'Guy Macon' wrote, in part:
| 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.
_____

You could just Google a search string that includes [ overclocking CPU
liquid Nitrogen ] and get over 94,000 hits. Most (if not all) these Rube
Goldberg devices just build a tank around the CPU heatsink, fill the tank
with liquid Nitrogen and let it boil off as it may. For actually pumping
liquid nitrogen you could contact NASA for a few tips... especially safety
tips.

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

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.

Phil Weldon

"Guy Macon" <http://www.guymacon.com/> wrote in message
|
|
|
|
| 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.
|
| --
| Guy Macon
| <http://www.guymacon.com/>
|

 

[Paul]

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.

There is a whole forum devoted to LN2 and dry ice here.
Maybe someone here will have an answer.

http://www.xtremesystems.org/forums/forumdisplay.php?f=156

Paul

 

[[email protected]]

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.

That's wonderful; how are you going to deal with frost? Where's this
water gonna go when it melts?

 

[MooseFET]

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.

You can use a simple piston pump for the actual pumping. The motor
should be connected via a very long non conducting rod.

The construction of the pump can use Teflon parts where things need to
slide and silicone parts where a little springiness is needed.

The idea, however is quite insane. The thermal stress will break
things in the computer.

 

[default]

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.

You could be shooting yourself in the foot. I think the self
pressuring with a dip tube in the flask is the way to go. Back
pressure? Where is that coming from? Plan to regulate the boil off
at the outlet of the Pentium heat sink?

The gas is much less dense than liquid to it should get through the
heat sink without much back pressure .

The foot wound - check the low temp specs on the Pentium before you go
all out on this. Transistor gain goes way down at cryogenic
temperatures.
--

 

[Guy Macon]

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.

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.

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*

 

[Rich Grise]

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.

Notwithstanding the "it's _TOO_ cold!" warnings, if you own your own
house, you could use plain ol' gravity feed - just put the generator
on the floor above the comp, with a very tall dewar between.

Of course, that depends on whether modifying the house is cheaper
than a(an?) LN2 pump. ;-)

Good Luck!
Rich

 

[redbelly]

Notwithstanding the "it's _TOO_ cold!" warnings, if you own your own
house, you could use plain ol' gravity feed - just put the generator
on the floor above the comp, with a very tall dewar between.

Of course, that depends on whether modifying the house is cheaper
than a(an?) LN2 pump. ;-)

Good Luck!
Rich

Yup, gravity feed was exactly my thinking as I read through this
thread. Let me just add:

Keep the liquid nitrogen BELOW eyelevel. Think about not only spills,
but drops spattering about. (Imagine grease or water in a hot frying
pan. That's what liquid nitrogen does when it hits "hot" room
temperature objects).

Mark

p.s. that being said, I will mention that I violated the "eye level
rule" back in grad school. The main point is to be careful while
still having fun.

 

[Phil Hobbs]

Guy Macon <http://www.guymacon.com/> wrote:
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

 

[[email protected]]

"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.

 

[g]

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.

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

 

[Phil Weldon]

'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/>
|

 

[D from BC]

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

 

[Paul Hovnanian P.E.]

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.