Pumping Liquid Nitrogen

In article <vm4qm3te59l2uvotlesv5cibfqd2tnmag1.TakeThisOut@4ax.com>, Glen Walpert
says...
> On Fri, 21 Dec 2007 19:15:56 -0500, Robert Adsett
> <sub2.TakeThisOut@aeolusdevelopment.com> wrote:
>
> >I rather like the percolator idea as well but isn;t the surface tension
> >of liquid nitrogen rather low compared to water? You might just end up
> >with a stream of cool nitrogen vapour coming up the tube.
>
> The percolator pump can work well with LN2, for instance a percolator
> pump is used for a 6 foot lift in one air separation plant I know of.

There we go.

How large is the diameter of the pipes in the percolator?

Robert

--
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 >> Stay informed about: Pumping Liquid Nitrogen 

"Paul Hovnanian P.E." <paulh.DeleteThis@seanet.com> wrote in message
news:476EC718.E1089771@seanet.com...
> Absurd? That's how one gets a press fit bearing race on a shaft (by
> heating it).

Not simultaneously. The bearing (or other socket) is kept at room
temperature or heated, while the shaft (or peg, or...) is cooled or kept at
room temperature, respectively. Heat makes the inner diameter expand, not
cold.

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms
 >> Stay informed about: Pumping Liquid Nitrogen 

On Sun, 23 Dec 2007 18:08:25 -0600, the renowned "Tim Williams"
<tmoranwms.RemoveThis@gmail.com> wrote:

>"Paul Hovnanian P.E." <paulh.RemoveThis@seanet.com> wrote in message
>news:476EC718.E1089771@seanet.com...
>> Absurd? That's how one gets a press fit bearing race on a shaft (by
>> heating it).
>
>Not simultaneously. The bearing (or other socket) is kept at room
>temperature or heated, while the shaft (or peg, or...) is cooled or kept at
>room temperature, respectively. Heat makes the inner diameter expand, not
>cold.

And you have exactly one chance to get them into the correct position
before the temperature equalizes...



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff.RemoveThis@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 >> Stay informed about: Pumping Liquid Nitrogen 

On Sun, 23 Dec 2007 13:12:59 -0500, Robert Adsett
<sub2.TakeThisOut@aeolusdevelopment.com> wrote:

>In article <vm4qm3te59l2uvotlesv5cibfqd2tnmag1.TakeThisOut@4ax.com>, Glen Walpert
>says...
>> On Fri, 21 Dec 2007 19:15:56 -0500, Robert Adsett
>> <sub2.TakeThisOut@aeolusdevelopment.com> wrote:
>>
>> >I rather like the percolator idea as well but isn;t the surface tension
>> >of liquid nitrogen rather low compared to water? You might just end up
>> >with a stream of cool nitrogen vapour coming up the tube.
>>
>> The percolator pump can work well with LN2, for instance a percolator
>> pump is used for a 6 foot lift in one air separation plant I know of.
>
>There we go.
>
>How large is the diameter of the pipes in the percolator?

I don't recall the pipe size anymore but it was way too big for just a
few liters per day. You could calculate the optimal diameter using
the rather complicated methods described in "Two Phase Flows and Heat
Transfer" by Ginoux, or you could wing it and try 1/4" OD 3/16" ID
tubing or therabouts. Effective insulation will be the hard part.

Having once spent 3 days on a single cryo transfer choking
calculation, I suggest the "wing it" approach .
 >> Stay informed about: Pumping Liquid Nitrogen 

"Guy Macon" <http://www.guymacon.com/> skrev i en meddelelse
news:A_6dncuGjuhtK_Ta4p2dnAA@giganews.com...
>
>
>
> 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.

Lucky bastard! That what I want for chrismas.

> I think I need a small pump that can take the cold and
> not add too much heat to the liquid nitrogen. Any ideas?

How about a "bubble pump" or "vapour lift pump"?

Basically the principle used by aquariums. That way you "only" need to pump
very cold nitrogen gas - which could be the gas boiled off from the CPU
cooler
 >> Stay informed about: Pumping Liquid Nitrogen 

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

>
>
>
>Paul Hovnanian P.E. wrote:
>
>>What's the temperature spec on the CPU you will be using?
>>Odds are that it won't deal with LN2 temperatures well.
>
>Others have done it without any problems. Semiconductors as a
>rule do not mind LN2 temperatures as long as you avoid thermal
>shock and icing. Besides, overclockers pretty much expect to
>lose a few if they push the envelope.
>
>>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.
>
>It will buy me minus 196 degrees, and others who have tried it have
>reported a stable system with a 3GHz. CPU overclocked to 5GHz.
>
>>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)

That makes me wonder. You are in fact creating some sort of heat-pump
which doesn't sound very efficient (you will be heating the room!).
Isn't it easier to use a modified air-conditioner? All you need is to
evaporate gas in the CPU's heatsink and chipset's heatsink.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl
 >> Stay informed about: Pumping Liquid Nitrogen 

Richard Henry wrote:

> On Dec 21, 10:35 pm, "Paul Hovnanian P.E." <p....TakeThisOut@hovnanian.com> wrote:
>> Tim Williams wrote:
>>
>> > "Paul Hovnanian P.E." <pa....TakeThisOut@seanet.com> wrote in message
>> >news:476C19BC.94527DC6@seanet.com...
>> > > With an LN2 environment, the rotor and stator might shrink a bit, so
>> > > the
>> > ^^^
>> > > design should account for a slightly larger air gap than at room
>> > > temperature.
>>
>> > You mean smaller gap?
>>
>> I think if the rotor and stator shrink, the gap gets larger.
>
> Everything shrinks proportionally in all dimension. "Everything"
> includes the gap.

Pretty much, but it still depends on the materials TCE.

--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.  
--Schiller
 >> Stay informed about: Pumping Liquid Nitrogen 

Tim Williams wrote:
>
> "Paul Hovnanian P.E." <paulh.TakeThisOut@seanet.com> wrote in message
> news:476EC718.E1089771@seanet.com...
> > Absurd? That's how one gets a press fit bearing race on a shaft (by
> > heating it).
>
> Not simultaneously. The bearing (or other socket) is kept at room
> temperature or heated, while the shaft (or peg, or...) is cooled or kept at
> room temperature, respectively. Heat makes the inner diameter expand, not
> cold.

That's how you get a press fit bearing race _off_ a shaft as well. Not
much chance of maintaining a temp difference between them in this case.

--
Paul Hovnanian paul.TakeThisOut@hovnanian.com
-----------------------------------------------------------------------
Procrastinators: The leaders for tomorrow.
 >> Stay informed about: Pumping Liquid Nitrogen 

"Paul Hovnanian P.E." <paulh.RemoveThis@seanet.com> wrote in message
news:4772C1BC.CA4C76A6@seanet.com...
> That's how you get a press fit bearing race _off_ a shaft as well. Not
> much chance of maintaining a temp difference between them in this case.

Except for certain circumstances: I've heard of CNC heads which have
ferrite transformers in the cutting head to inductively heat the spindle,
expanding it away from the cutter's shank quickly. Sweet!

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms
 >> Stay informed about: Pumping Liquid Nitrogen 

On Dec 19, 4:27 pm, 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.
>
> --
> Guy Macon
> <http://www.guymacon.com/>


How about pushing the liquid nitrogen instead of pumping it?

Imagine an insulated chamber, half-filled with liquid nitrogen, having
a lid with two holes. One hole is for the nitrogen output tube, which
goes all the way from the lid down to within say 1/8 inch from the
bottom of the chamber. The other hole is for the input tube, which is
just a short tube. This is where you blow.

Now you just need a way to blow measured amounts of gas into the short
tube, pushing the liquid nitrogen up the output tube.

Compressed air tank with a needle valve... aquarium pump... CO2 gun
cylinders... ?

Have fun

Michael
 >> Stay informed about: Pumping Liquid Nitrogen 

On Wed, 26 Dec 2007 22:58:12 -0800 (PST), mrdarrett DeleteThis @gmail.com wrote:

>On Dec 19, 4:27 pm, 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.
>>
>> --
>> Guy Macon
>> <http://www.guymacon.com/>
>
>
>How about pushing the liquid nitrogen instead of pumping it?
>
>Imagine an insulated chamber, half-filled with liquid nitrogen, having
>a lid with two holes. One hole is for the nitrogen output tube, which
>goes all the way from the lid down to within say 1/8 inch from the
>bottom of the chamber. The other hole is for the input tube, which is
>just a short tube. This is where you blow.
>
>Now you just need a way to blow measured amounts of gas into the short
>tube, pushing the liquid nitrogen up the output tube.
>
>Compressed air tank with a needle valve... aquarium pump... CO2 gun
>cylinders... ?
>
>Have fun
>
>Michael

With that idea, I think the LN2 could pump itself..
How about using gas pressure regulator.
Feed the 'exhaust' N2 gas back to pressurize the tank.
Excess pressure is vented.

D from BC
 >> Stay informed about: Pumping Liquid Nitrogen 

"D from BC" <myrealaddress DeleteThis @comic.com> wrote in message
news:qsj6n35786v90ecb06lcj6bpihaert42jq@4ax.com...
> With that idea, I think the LN2 could pump itself..
> How about using gas pressure regulator.
> Feed the 'exhaust' N2 gas back to pressurize the tank.
> Excess pressure is vented.

So where does the pressure come from?

If I could pull my emitter follower up entirely by its boostraps, I
wouldn't need a battery anymore.

Maybe with a seperate expansion chamber and keen connections, but offhand,
it doesn't work: internal pressure is internal pressure.

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms
 >> Stay informed about: Pumping Liquid Nitrogen 

On Thu, 27 Dec 2007 01:41:09 -0600, "Tim Williams"
<tmoranwms.RemoveThis@gmail.com> wrote:

>"D from BC" <myrealaddress.RemoveThis@comic.com> wrote in message
>news:qsj6n35786v90ecb06lcj6bpihaert42jq@4ax.com...
>> With that idea, I think the LN2 could pump itself..
>> How about using gas pressure regulator.
>> Feed the 'exhaust' N2 gas back to pressurize the tank.
>> Excess pressure is vented.
>
>So where does the pressure come from?
>
>If I could pull my emitter follower up entirely by its boostraps, I
>wouldn't need a battery anymore.
>
>Maybe with a seperate expansion chamber and keen connections, but offhand,
>it doesn't work: internal pressure is internal pressure.
>
>Tim

A nice demo of pressure from nitrogen.
Bottle blowing up from liquid nitrogen
http://www.youtube.com/watch?v=zCNn2hXJPcg

I was thinking this..

Release +-----------------------+
Valve ||<----+A |+---------------------+|
+---------||-----||----||-+ ||
| N2 pressure | ||
|~~~~~~~~~~~~~~~~~~~~~~~~ | B ||
| LN2 +->-----------------||
+--------------------------->------------------+
~CPU~

'A' is a pressure sensor which operates an electrically controlled
valve.
'B' is a one way valve.

After awhile, the LN2 eventually disappears and the system blows up.



D from BC
 >> Stay informed about: Pumping Liquid Nitrogen