Ideas with mercury

R

Robolf

Weaksauce
Joined
Mar 14, 2004
Messages
87
Has anyone tried using this in their cooling setup?

Apart from the environmental aspects, this seems like a good solution.

Its a metal and conducts heat well, its liquid and with the aid of hoses (braided steel or otherwise) can transport heat (even when not being pumped?) to wherever you want.

Any pointers or links to projects like this welcome.

Asking here first beause if anyones done it their well [H]ard!

Rob
 
Call me crazy, but I think the density and weight of mercury would make it very hard to pump, and it would not interact beautifully with radiator metals.

Also, a properly set up water system is doubtfully saturating the ability of water to carry the heat away... in other words, I think the law of dimishing returns is going to come into play big time with something like this.

BUT, it would look cool as hell.
 
Well the original idea that sprang into my mind was more like a waterblock(mercuryblock) with tubes going up into some kind of res that was just full of mercury, and let the heat move by conduction.

It was just a simple sketch in the head that i thought i would share and see if someone is already doing something crazy along these lines.

Hell my last idea was cooling using a pipe on a tap, one day i might hit gold :D

Rob
 
Did you actually look up the thermal conductivity of mercury? Or are you just assuming that it is really good?

Along with the thermal conductivity, you want to know the volumetric specific heat -- how many Joules of heat does it take to warm a cubic centimeter of it by one degree Celcius.

Report back, comparing these numbers with those of copper and water. Then we can discuss it.
 
Mercury

Silver colored liquid metal
Density: 13.5 g cm-3
Melting Point: -38.8 oC
Boiling Point: 356.6 oC
Specific Heat: 0.139 J g-1 K-1
Heat of Vaporization: 59.2 kJ mol-1
Heat of Fusion: 2.3 kJ mol-1
Electrical Conductivity: 0.0104 106 cm-1 Ohm-1
Thermal Conductivity: 0.0834 W cm-1 K-1

Copper

Reddish orange metal
Density: 8.96 g cm-3
Melting Point: 1,083 oC
Boiling Point: 2,567 oC
Specific Heat: 0.38 J g-1 K-1
Heat of Vaporization: 300 kJ mol-1
Heat of Fusion: 13.0 kJ mol-1
Electrical Conductivity: 0.596 106 cm-1 Ohm-1
Thermal Conductivity: 4.0 W cm-1 K-1

Water

erm will get back to you
 
The specific heat of water is 4.18 J / (g * C).

Hg would be a pretty bad choice for a cooling system. Ignoring the cooling aspect of it, for now, it would be a nightmare to handle. A small leak could easily become a disaster when dealing with Hg.

The specific heat of Hg is a lot less than that of water. That means it will get hotter a lot faster and will take less heat away from the CPU. To make it work you'd need to pump the Hg at a higher rate. Now, I've never looked at mercury pumps but I'm sure they're a lot more money considering the special nature of them and the density of the material that has to be worked with.
 
Signs and symptoms of mercury poisoning (EASY WAY TO LEAK TEST YOUR SETUP)

Acute poisoning commonly results from inhalation of elemental mercury vapor, or from deliberate or accidental ingestion of mercury or its salts. Owing to their corrosive nature, ingestion of mercury and its compounds can cause pain, inflammation and necrosis of the oropharyngeal mucosa, nausea, vomiting, abdominal pain, and renal damage with lesions of the proximal tubule and glomerulus. Severe cases may have acute papillary necrosis or chemical colitis with shock, edema, tremor, and ataxia. Chemical pneumonitis with cough, dyspnoea, retrosternal pain, basal late inspiratory crackles and patchy shadowing on CXR may follow copious inhalation. There may be pulmonary edema and blood stained sputum.

Chronic exposure to mercury salts can result in central nervous system toxicity, including personality changes, nervousness, irritability, fatigue, deterioration in memory, difficulty in concentration, insomnia, hearing loss, constriction of visual field, and a metallic taste. Tremors often have an intentional component which may impair fine and complex movements. Peripheral neuropathy (predominantly sensory) is more common in those with organic mercury poisoning. Gingivitis, stomatitis and excessive salivation may be early signs. The most common renal effect is tubular damage, with necrosis being more common in inorganic than organic poisoning. Glomerular damage may lead to albumunuria. Inorganic poisoning may occasionally result in nephrotic syndrome.

In children, mercury poisoning can result in the syndrome of acrodynia, which is characterized by severe leg cramps, irritability, paresthesia, excessive perspiration, pruritus, and painful redness and peeling of the palms of the hands and soles of the feet.
 
Specific heat is not of main importance in a fluid cooling loops, and is of no importance in a heatsink. What you want to do is maximize heat transfer coefficient between the block and the fluid. That depends on a variety of material properties and dimensional characteristics.
 
Specific heat in very important in a circulating coolant. As the specific heat goes down, the delta-t of the coolant across a heat exchanger rises, thus the average temperature of the coolant will rise.

Viscosity, thermal conductivity, and wetting angles play their roles in coolant suitability, too. But specific heat is easier for the tyros to find and understand.
 
Your biggest problem with mercury would be amalgam formation. Mercury is an excellent solvent for a lot of metals and metal oxides, and just loves copper and silver. It was actually used as a bore cleaner for just that purpose. So it would eat through your standard radiator fins rather quickly.
Specific heat is bad on a mass basis, but get's much better on a volume basis (density 13.6 kg/l). For pumping you probably want to go with some form of positve displacement pump instead of a centrifual type.
Oh, and try to keep your system low volume, half a liter of mercury will cost you about $760. And remember to reinforce your aluminum case, that half liter weighs in at 6.8 kg.
 
This is like the russian nuclear subs. They used a molton core of metal cycling around to cool the reaction. The plus side was, they were much more powerful than american subs. The negative side was, the metal got really radioactive really quickly and would poision the crew onboard, and if the metal melted improperly, it wouldnt cycle, itd just heat up, everything would get hotter and hotter, until you had a really big hot radioactive problem on your hands.
 
kronchev said:
This is like the russian nuclear subs. They used a molton core of metal cycling around to cool the reaction. The plus side was, they were much more powerful than american subs. The negative side was, the metal got really radioactive really quickly and would poision the crew onboard, and if the metal melted improperly, it wouldnt cycle, itd just heat up, everything would get hotter and hotter, until you had a really big hot radioactive problem on your hands.
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k19ish?
 
acascianelli said:
k19ish?
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no as i remember that was just a leak in the system, not the molton iron freezing up

but I could be wrong. I dont think they were too specific in the film.
 
Metal does not mean excellent heat transfer capabilities. I don't know how much mercury costs, but you can't exactly get it at the hardware store, and you would need a lot of it. Then you would probably need a $500 pump to handle it. Not to mention the whole thing would be a health risk. I'm willing to try crazy shit, but there is no way in hell I would ever try to use mercury in a cooling situation. That just scares me thinking about it.
 
Not to debunk all of this science in this thread because I agree with it, but I wonder how Koolance came up with this:
http://www.koolance.com/products/faq.html#14

"Water-based solutions are the most effective liquids at conducting heat (after mercury)-- better than alcohol, better than glycol, and far better than oil."
 
nweibley said:
Not to debunk all of this science in this thread because I agree with it, but I wonder how Koolance came up with this:
http://www.koolance.com/products/faq.html#14

"Water-based solutions are the most effective liquids at conducting heat (after mercury)-- better than alcohol, better than glycol, and far better than oil."
Click to expand...
I think someone should email them and ask them to show how they arrived at that.

edit: I just sent this with their stupid web contact form piece of shit. I don't like the looks of the "if applicable" part.
Your inquiry has been sent. If applicable, you may expect a response between 24-48 hours. (Koolance Homepage)
Requesting: Product or Pre
Name: John-Paul Allen
Company:
Email: xxx
Phone:
Remarks: On your faq page, you mention that mercury is a more effective at transferring heat than water. How did you determine this? Please share the numbers to back up the claim. Thanks.
Click to expand...
 
mercury?! that's crazy dude. if you can get your hands on a heck of a lot of mercury, more power to ya... ;)
 
No matter how wonderful Hg's properties might be for cooling your computer, I'm fairly certain that in the end costs, health risks and common sense will make one decide to just keep using water.

As mentioned earlier, Hg is very poisonous, requires expensive equipment to pump it around, acts as solvent for many metals and doesn't even cool as well as H2O.

If extreme (and expensive?) cooling is your thing, you might want to look at using freon and similar, in combination with liquid nitrogen. If something does go wrong with such a setup, at least it won't require an Hazmat team to clean up the mess (and your remains ;) ).
 
Okay, just got this from koolance:
Hello,

I believe this is based on two properties of liquid mecury, thermal conductivity and specific heat capacity. Mercury's TC is 8.3W/mK, as opposed to 0.67 for water (or only 0.026 for atmospheric air at sea level). Mercury's heat capacity is 0.14 kJ/kgK (most good-conducting metals used in cooling are below 1.0 kJ/kgK), as opposed to 4.184 for water.

Thank you for your inquiry,
Sales

Koolance, Inc.
www.koolance.com
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I'm not much of a chemistry man(I recognize the terms but that's about it), so can anyone interpret this? Are their claims valid?
 
I read that as meaning:

The heat from the CPU will transfer to the mercury much more quickly, however, the mercury will heat up much faster since it can't absorb as much heat as water. Meaning you would have to pump the mercury through at a much higher rate than water. Seems like a completely valid claim.
 
jpmkm said:
Okay, just got this from koolance:

I'm not much of a chemistry man(I recognize the terms but that's about it), so can anyone interpret this? Are their claims valid?
Click to expand...


um...why? why did you ask koolance, obviously all they did was parrot back some stuff they found on google. do people STILL think they know what theyre doing? hint: they dont.

in any case

the basic theory (as I remember it) is that water is better because it takes much more energy to raise 1 gram of it by 1C. the hotter a substance the harder it is for it to absorb energy, especially when there is a very small dT between the temperature of the substance and the heat being introduced.
 
v3rt1g0 said:
I read that as meaning:

The heat from the CPU will transfer to the mercury much more quickly, however, the mercury will heat up much faster since it can't absorb as much heat as water. Meaning you would have to pump the mercury through at a much higher rate than water. Seems like a completely valid claim.
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YES, EXACTLY, THANK YOU

also note that the mercury will heat up a lot quicker than the water.

can you tell I'm not going to be a teacher?
 
Well koolance had a section in their faq in which they stated that mercury is a more effecive cooling solution than water, so that is why I asked them. It does seem like they just spit out some numbers without actually knowing what the hell they are saying.
 
nweibley said:
You seemingly did ask sales and not some tech.
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you think they have DEPARTMENTS? theyre probabily the same person. koolance probabily invests more research into finding the cheapest parts possible than actual technical research. why should they have to? their goal and purpose is marginal acceptiable no-hassle watercooling.
 
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