5
$\begingroup$

How small/compact can a pump or other mechanism be, that would allow compressing gas (or liquid) to pressures of excess of 10GPa, continuously?

Throughput may be minuscule, of order of milligrams per hour; even lower is acceptable. Also, for "size of the device" let us count all the necessary infrastructure: if it requires energy of a nuclear power plant to operate, it's not compact. Let's say we have some 30 watt of energy "for free"; anything above that goes out of our "compactness budget".

Input gas is pressurized to "reasonable" levels - order of 30KPa; if more pressure is required, the container goes into "compactness budget" with at least 20kg of the gas inside.

There's abundant heat sinking capacity, but any extra heating goes out of our "budget". Operating (ambient) temperature - choose anything between 40K and 400K as you like. It should have operational lifetime of at least a year, preferably ~10 years.

(clarifying: "continuous" - we can assume a small "buffer" container on the output side, emitting the pressurized gas at rate that is the average of the intake speed, so short "discontinuity" like piston motion is fully acceptable - simply keep the "buffer" above 10GPa with losses of order of assumed average input (1mg/hour, or less if required, but fairly constant).)

$\endgroup$
  • 2
    $\begingroup$ 10 GIGApascals? That sounds unreasonable. This list shows that there are only a couple of materials capable of withstanding that sort of pressure, and that's in pure tension. $\endgroup$ – Trevor Archibald Apr 19 '15 at 18:11
  • $\begingroup$ @TrevorArchibald: somehow Ice-X has been made, and it requires 70GPa. There were quite a few experimental materials obtained in pressures exceeding 100GPa. Also, the list is for stretching, not compression. Walls disproportionately thick to material being pressurized will withstand stretching caused by the pressure; if a stage pump operates within a container pressurized to input pressure of that stage, it will not be badly affected. Imagine 0.1mm conduits in 10cm of non-porous metal. $\endgroup$ – SF. Apr 19 '15 at 19:02
  • $\begingroup$ momentarily creating huge pressures is easy, just add explosives. $\endgroup$ – ratchet freak Apr 19 '15 at 21:02
  • $\begingroup$ @ratchetfreak: Yes, obviously. The "sustained" part is tricky though! $\endgroup$ – SF. Apr 19 '15 at 21:04
  • $\begingroup$ I know diamond anvils are used to make the things at exotic pressure (like ice X). In theory, I don't see a problem with turning that system into a pump. But how do you plan on storing this gas? $\endgroup$ – Mark Jun 27 '15 at 13:54
2
$\begingroup$

Such high pressures can be achieved via diamond anvil cells (DAC). The heart of these cells are two diamonds mounted on tungsten seats symmetrically in front of each other which are separated by metallic plate. Metallic plate has an aperture with loaded sample (gas, crystal, powder, etc.). These diamonds are then brought closer to each other by tightening bolts or by extension of piezo actuators. Pressures in such DACs can reach up to 200GPa or higher depending on the size of the diamond, it's quality, temperature and type of material being compressed. Amount of sample which can be compressed usually ranges from micrograms to milligrams.

One would need a special chamber in order to load gas into DAC. In these chambers operator controls separation between diamonds in order to fill the aperture in metal gasket between diamonds with liquefied gas and enclose it safely for further compression

| improve this answer | |
$\endgroup$
0
$\begingroup$

You could use electrically-initiated pyrotechnics like in this video. They spontaneously ignite when electric current is applied, and immediately self-extinguish when current is removed. The pyrotechnics would be on one side of a piston and the gas to be compressed would be on the other side. When pressure falls below a certain threshold, you fire up the pyrotechnics for a bit until the desired pressure is reestablished, then turn them off.

While 10 GPa is rather high, realize that some military and research guns go as high as 1 GPa (granted, for only a few milliseconds at a time). 10 GPa is not unreachable, it would just require a vessel with very thick walls.

| improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.