Purpose of this would be as a refrigerant working fluid. Ideally the aerogel will be able to be fluidised while still retaining a cellular structure. Within the cells of aerogel, hopefully closed pore, there is a gas that is close to it's transition temperature.
Hopefully the outcome is a fluid like slurry that can have its contents vaporised and condensed without destroying the cellular structure and the working fluid escaping.
The point of this state is that it requires a lot less energy to pump a liquid/slurry than to pump a gas.-- lostmind, May 26 2013 Nope, I genuinely can't see the point of this. I can't see the aerogel surviving the process. If we posit that you can come up with just individual cells of aerogel, what's the point? It'll just take up space that could be used for cooling gas.-- not_morrison_rm, May 26 2013 An aerogel's forte is as an insulator: what does that have to do with heat transfer, which is all about heat capacity ?-- FlyingToaster, May 26 2013 // it requires a lot less energy to pump a liquid/slurry than to pump a gas.// Are you sure?-- MaxwellBuchanan, May 26 2013 // it requires a lot less energy to pump a liquid/slurry than to pump a gas.// Are you sure?
Well, it was one of the engineering rules of thumb that we had to memorise in processing engineering...
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it stands to reason also, a liquid is incompressible so you get the movement travelling further, also easier to maintain laminar flows.-- lostmind, May 26 2013 The point is the efficency to pump a liquid over a gas. Perhaps a better form would be individually manufactured beads that are elastic.-- lostmind, May 26 2013 Sort of an interesting idea. Not sure about this principle of liquid being easier to pump than gas. If so, the human body uses a similar mechanism with red blood cells.-- rcarty, May 26 2013 The gas vs liquid transport is part of the process engineering heuristics, essentially rules of thumb-- lostmind, May 26 2013 I never trusted my thumb, always a bit shady about it. Even if is does have a digital action.-- not_morrison_rm, May 26 2013 I suppose it has something to do with gas compressing instead of flowing.-- rcarty, May 26 2013 // the efficency to pump a liquid over a gas. //
And yet, if I may rudely interject a few moments of rational thought into this idea, you seem to have invented something which has the viscosity of porridge yet retains the compressibility of a gas or, more accurately, the compressibility of a collection of balloons. The word "foam" springs, gazelle-like, to mind.
Did you get a refund on that processing engineering course?-- MaxwellBuchanan, May 26 2013 As [MB] is saying, the reason it is easier to pump a liquid is that it is incompressible. However an incompressible fluid is useless as a refrigerant. So either your aerogel mixture is incompressible, in which case it it is easy to pump but useless as a refrigerant, or it is compressible, in which case it is harder (owing to a higher viscosity and friction losses) to pump than the raw gas and still less useful than the raw gas because it is less compressible.
The former would be the case with a closed cell inelastic material, and the latter with an open cell or elastic material.-- MechE, May 26 2013 See now this is an interesting concept. If you did come up with a compound that was essentially a slurry of variously sized elastic baloons filled with gas, it might well be more efficient to pump this bulk material than the gas itself. This material might also have all sorts of interesting properties relating to it's compressibility and heat transfer behaviour. It would certainly be interesting to experiment with.-- Custardguts, May 27 2013 //See now this is an interesting concept. If you did come up with a compound that was essentially a slurry of variously sized elastic baloons filled with gas, it might well be more efficient to pump this bulk material than the gas itself. This material might also have all sorts of interesting properties relating to it's compressibility and heat transfer behaviour. It would certainly be interesting to experiment with.//
Yes that is where I was going with it. Or ended up..
The fundamental Idea was to allow gas to be efficiently compressed and transported via encapsulation. Having the capsules in a liquid phase allows isostatic pressing with little effort.
The testing comes in with the matrix material for the capsules, aerogel was the first thought because of its pore volume:total volume ratio is so large but other things may well be more suitable, particularly for heat and pressure transfer to the pore cavity.-- lostmind, May 27 2013 Ok. here's why I don't follow this idea. Let's assume you could make single cubes of aerogel at the level to contain one molecule of the gas. How are you going persuade the gas to enter the cube? The obvious way is to increase the gas pressure, but that involves pumping the gas.
Assuming there is a way to get the gas in without pumping, you'd have a nearly identical amount of aerogel cubes just floating around in the lower pressure side of the mechanism, which would tend to make it more bulky.
The closest I can get is if the gas is magnetic.-- not_morrison_rm, May 27 2013 not_morrison_rm,
"Aerogel is a synthetic porous ultralight material derived from a gel, in which the liquid component of the gel has been replaced with a gas."
"...variant on this process (supercritical drying) involves the direct injection of supercritical carbon dioxide into the pressure vessel containing the aerogel. The end result of either process removes all liquid from the gel and replaces it with gas, without allowing the gel structure to collapse or lose volume"
The desired working fluid, say ammonia, could be used instead of carbon dioxide.
Any way, it only works with aerogel if it has a closed pore structure. What maybe more suitable is perhaps micro poly styrene balls. or some sort of elastic capsule.-- lostmind, May 27 2013 //supercritical carbon dioxide into the pressure vessel
I think the "pressure vessel" there is something of a give-away.-- not_morrison_rm, May 27 2013 give away to what?-- lostmind, May 27 2013 pressure-- not_morrison_rm, May 28 2013 Aerogel also tends to be quite fragile if I recall.-- RayfordSteele, May 29 2013 random, halfbakery