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Is there anyway to get a hard vacuum using chemicals?

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LAN_403

Bored Chemist

Sun Sept 18 2011, 05:31PM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

If you can get liquid nitrogen then you just need to ask the supplier if you can borrow their electrical supply.

Seriously, a diesel driven vac pump would do the job easily, quickly and reliably.

Ash Small

Sun Sept 18 2011, 08:37PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Belt drive vacuum pumps are definitely the thing to use if you can drive them.

testtest

Tue Sept 20 2011, 02:28AM

Registered Member #3271 Joined: Mon Oct 04 2010, 02:29AM
Location: Canada
Posts: 159

If you do not want to use liquid nitrogen... Cant get away from mech pump or water aspiration initially. Then sorption pump then titanium sublimation. maintain with ion pump afterwards for vhvacuum. Otherwise get a cheap turbo off e-pay and be done with it for normal applications.

Bored Chemist

Tue Sept 20 2011, 06:15PM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

The OP says "I am doing reasearch in a device I plan to use in places where power is not located."
Do you plan to run the titanium pumps with a blow torch? Perhaps you could couple the turbo pump to a bike dynamo.

BTW, unless you chill it with liquid nitrogen (or something similar, zeolite barely absorbs air so it's not a lot of use for this purpose.

testtest

Thu Sept 22 2011, 02:07AM

Registered Member #3271 Joined: Mon Oct 04 2010, 02:29AM
Location: Canada
Posts: 159

Bored Chemist wrote ...

The OP says "I am doing reasearch in a device I plan to use in places where power is not located."
Do you plan to run the titanium pumps with a blow torch? Perhaps you could couple the turbo pump to a bike dynamo.

BTW, unless you chill it with liquid nitrogen (or something similar, zeolite barely absorbs air so it's not a lot of use for this purpose.

I think that if you have to cycle from atm to high vacuum at regular intervals with no mechanical pump or electricity it will be difficult. Sorption pumps, zeolite and the rest are fairly limited to get there. On the other hand, once you have reached close to the desired vacuum (perhaps by hand pumping or water aspiration) then it can be maintained a long time with zero to minimal energy input to conteract outgassing with the above mentionned techniques.For high vacuum and if you can initially get to a vacuum level where titanium adsorption or even sublimation at long intervals from a long term battery or even solar to ensure getter pumping in the long term. Need more details on application but could be doable. All depends on the vacuum range you need.

CZA

Wed Nov 02 2011, 06:32PM

Troll, banned on 11/1/2011.
Registered Member #4171 Joined: Sat Oct 29 2011, 03:20PM
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Barium used to be used to create better vacuums, they're called barium getters, but I don't know where you could get them. I don't know much about it.

hboy007

Thu Nov 03 2011, 01:45PM

Registered Member #1667 Joined: Sat Aug 30 2008, 09:57PM
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Interesting question. Does flushing the recipient with a reactive gas (CO2, O2) and burning magnesium turnings inside a chamber connected to the system count? Fine turnings can be ignited with a battery or with a capacitor charged by a hand-cranked generator. If there's a power supply around, a small arc furnace with a magnesium puddle and a tungsten electrode can be constructed. Lithium, sodium, potassium and calcium may be used as well in an oxygen-rich atmosphere.
Perhaps an arc welder can introduce enough heat to form nitrides (works for magnesium).

Could you give us a hint what this is supposed to be used for? Sounds exciting!

Ocean Waves

Thu Nov 03 2011, 09:31PM

Registered Member #4181 Joined: Thu Nov 03 2011, 02:39PM
Location:
Posts: 42

what about a mercury gas entrapment column?
its basically a venturi that uses falling mercury to entrap and compress the entrapped gas, and thus venting it to the atmosphere, at the bottom of the mercury pool.

I have never seen one but i have herd of them, they consist of a column about 32 inches high which has a reservoir at the top with an inlet valve, and a collection pool at the bottom, at the top is a venturi pipe that shoots down into column, as the mercury flows around the pipe it sucks and entraps gases from the center pipe.

When the reservoir at the top becomes close to empty the valve is shut, more mercury transfered from the bottom pool to the top reservoir and the process is repeated until the desired vacuum is reached, I believe you could make a model of this using about 3 pounds of mercury, or even gallium as a substitute, but the gallium would need to be heated to body temperature of left in the hot sun en-order to stay liquid. 35 microns might be possible after many cycles if a small chamber is to be evacuated.

If anyone can find a picture or diagram of one I sure would like to see exactly how they are constructed, as my information is vague and possibly inaccurate, as this trick was told to me by a man that used to design nuclear reactors for living I tend to believe its true, but the details are elusive, he had said that it was widely used before common mechanical pumps where invented, and mentioned something about Edison using one for a time to evacuate light bulbs. if that helps any, I never looked into it I just bought a rotary vane pump, in fact you might be better off hooking a rotary vane pump to a exercise bike, you know the kind that has the car alternator it, drive system included just add pump and tighten the belt

good luck, and I recommend mercury its far safer than gallium IMO, though more expensive

BTW why would you need a vacuum in a a place that has no power? Sounds fishy at best, what gives?

Ocean Waves

Thu Nov 03 2011, 09:45PM

Registered Member #4181 Joined: Thu Nov 03 2011, 02:39PM
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Posts: 42

damit, no sooner did i say i havent seen one did google turn one up, so here is my foot in my mouth lol, notice this little blurb at teh top says 1/100 of an atmosphere thats about 10 microns......... this could be built cheaply using scraps ad scroungings and bits of glass and plastic tubing, the only expencive part would the the liquid metal

a nice picture

a nice referance including what they are called notice that edison had on in 1879

google litature on the "sprengel pump"

so fat some of the stuff I have scaned through claims that some of these pumps, are capable of an ultimate vacuum 1/90,000,000 atmosphere, which i find very impressive............

check out page 57 of this book

here is edisons pump love this diagram page 19

have fun would love to see someone build one of these.........

hboy007

Tue Nov 08 2011, 11:57AM

Registered Member #1667 Joined: Sat Aug 30 2008, 09:57PM
Location:
Posts: 373

Any news? You can't just get us all excited and then walk away, can you?

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