We start with a tallish vortex container. The device pumps air through a loop. In the main chamber (openable) we insert our frozen french fries, ready to be cooked. When the device is turned on, a blast of air lifts the potato pieces up off the floor of the chamber, where they basically continuously fall through the moving air.
Now we inject a very hot cooking-oil mist or fog, using a "superspray" type of device (see link). The particles of oil are so fine that they are barely able to "wet" any surface they touch, much less "soak" it. It is our fog-filled vortex of air that the overall device blows through its loop.
There is a place in the loop where we can apply a static- electric charge to the oil drops, after which they can be attracted out of the moving air, re-heated, and re- sprayed back into the moving air, which itself will get hotter, also.
Net effect, the hot air provides the heat that cooks the oil- free interior of the fries, finishing about the same time that droplets of hot oil, interacting with the surface, have given us that crispy coating we all like so much.-- Vernon, Jan 03 2014 Superspray http://books.google...0superspray&f=falseAs mentioned in the main text. [Vernon, Jan 03 2014] A little something about electrically charged mists http://www.popsci.c...t%20charge%20energyJust so you know it can be done. [Vernon, Jan 03 2014] Actifryer review http://doesthisshit...ry-without-the-oil/It's not as "active" as a sustained air-vortex, but I think the "hot-oil fog" principle is used in one of these things. [Zeuxis, Jan 06 2014] Nathan Myhrvold http://www.amazon.c...oking/dp/0982761007Actually not sure if he is a real person... [4whom, Jan 06 2014] [+] crunchy.-- FlyingToaster, Jan 03 2014 To cause [xenzag] to begin frothing at the mouth, we make the main chamber of this cooking device both transparent and globular....-- Vernon, Jan 03 2014 //The particles of oil are so fine that they are barely able to "wet" any surface they touch, much less "soak" it//
Why? Surely they will wet and soak into the surface as easily as bulk oil?-- MaxwellBuchanan, Jan 03 2014 [MaxwellBuchanan], I should not have needed to remind you of "surface tension" and how it is stronger in relation to small droplets, than it is in relation to large droplets. Or, is the surface tension of oil droplets SO much less than that of water that that is the reason for your post???-- Vernon, Jan 03 2014 //"surface tension"//
That was exactly my point and no, you don't need to remind me about surface tension since a lot of my work at the moment involves trying to generate micron-sized water droplets in oil, inside a structure which is variable wetted by oil and by water. I know more than I want to about surface tension.
The surface tension which causes oil to wet a solid in bulk will have the same effect in droplets (in fact, it will be slightly worse in droplets - think of the vectors of the surface tension).
Try spray-painting something - you'll find that it works jolly well.-- MaxwellBuchanan, Jan 03 2014 [bigsleep], Good Point. I had neglected to think of that. Obviously we need to remove the oxygen from the system before introducing the oil. Hmmmm...a magnesium "getter"?
[MaxwellBuchanan], having encountered a number of fogs of water over the years, it is my observation that the tiny water droplets don't easily "wet" the fabric on which they set. If my assumption that oil droplets would behave similarly is mistaken, OK. That just becomes a way in which this Idea is Half-Baked!-- Vernon, Jan 03 2014 As long as you don't add a spark it should be simply a matter of keeping the temperature under the oil's flash point.-- FlyingToaster, Jan 03 2014 //tiny water droplets don't easily "wet" the fabric on which they set// That's usually because the fibres are either synthetic, or have a certain amount of natural oils on them.
Also, fibres are small and rough. Roughening a surface exaggerates its hydrophilicity or hydrophobicity: a roughened hydrophilic surface is even more hydrophilic; a roughened hydrophobic surface is even more hydrophobic. I think the same will apply to oil (ie, its affinity for the chip's surface will be affected by the chip's roughness, not by the format in which the oil is delivered).
Coming back to chips, there's another important factor. When chips are immersed in very hot oil, their water content boils. This creates bubbles which, in turn, drive the oil away and stop it soaking in. With your oil mist, I don't think the chip's water will be vaporized quickly enough to do this.-- MaxwellBuchanan, Jan 03 2014 Afterburner fries.-- FlyingToaster, Jan 03 2014 // Why is [8th] not here to bun this idea many times over ? //
We already did ...
//static- electric charge to the oil drops // // Now where could a vortex of air and superheated oil mist go wrong ? //
Mmmmm, carburettor, spark ignition, nice ...-- 8th of 7, Jan 04 2014 [MaxwellBuchanan], thanks for the info. There still remains a sort of "permeation speed" issue. When dunked into oil, any oil that permeates into the body of a potato-piece can be immediately replaced by more oil. That density of oil is not present here!
Also, keep in mind that hot air will be doing a significant part of the cooking (and in theory we could add a microwave-oven component to this device, too!). So we have a kind of "race" between the rate at which oil from the fog can permeate the potato, and the time it takes it to cook.
Experimentation seems to be in order!-- Vernon, Jan 04 2014 //microwave oven// I was thinking that as stream heater: the oil would heat up and, being so fine, quickly distribute the heat to the air, hopefully before it caught fire when you didn't want it to.-- FlyingToaster, Jan 04 2014 There are already implementations of super efficient fryers that use a combination of (I think) steam and a tiny amount of oil to cook with minimal greasage - I'm sure there's a link out there somewhere.-- Zeuxis, Jan 06 2014 There's also the fact that deep frying works because it produces extremely rapid heat transfer into the object, resulting in a crispy exterior with a cooked, but not over cooked interior.
This approach, due to the much more limited amount of oil in contact at any one time, will have a much slower cooking rate, producing, at best, something similar to pan frying.-- MechE, Jan 06 2014 How about soaking the chips in a strong alkali, then dunking them into strong acid? The local heating would cook the exterior and, if everything were timed right, you'd have neutral chips.-- MaxwellBuchanan, Jan 06 2014 Impingement ovens work with superheated, super desiccated air, relying on the oils on the foods stuffs to created the flavours associated with frying. As [MechE] says, more akin to pan or oven roast than deep frying. Pizzas work especially well in impingement ovens, and this method is commonly used in fast food pizza. Of course adding a vortex that suspends the food is a must, so definite bun. Personally I would not suspend fine particles of fat, or oil, in this superheated vortex. I am going to assume a certain amount of work has been done to avoid the towering firenado of fuel and oxygen that will take place in version 1 thru 3.5 of this device.
Firstly, the oils, as small spheres with large surface area, and a high temperature, will deteriorate from their original esters way before any interaction with the desired food product. Now this will be a complicated set of reactions, depending on what you oil you put in and at what temp, and how much water still remains in your "air". Regardless of the above the result will inevitably be a fine coating of carbon soot and aldehydes, maybe in a crunchy form, but nonetheless unpalatable.
My suggestion would be to suspend your food product in an impingement vortex, let the natural oils of the food do the rest.
NB: calculations only work for perfectly spherical foods, in a vacuum...-- 4whom, Jan 06 2014 [Max...] Have contacted Nathan Myhrvold, he is very interested in your above method, in the most basic sense. Having a bit of a problem with the //soaking in strong alkali// bit. By all accounts this might caustic to the pan. Nonetheless he will give it a shot. What's he got to lose? Life's a pH.-- 4whom, Jan 06 2014 //Have contacted Nathan Myhrvold// Is he a real person? He sounds more like an anagram.-- MaxwellBuchanan, Jan 06 2014 Before baking, pretzels are dipped in or sprayed with an alkali solution[*], so doing the same thing with potato sticks could potentially result in yummieness.
However, I do not see the point of the oil. If your fries are levitating due to high speed upward moving air, the rate of heat transfer should be very high, just as if the fries were immersed in oil.
Remember, it's that high rate of heat transfer which allows the outside of the fry to become crisp and brown, without dehydrating the interior.
The fact that the heat transfer medium is typcailly oil, is not relevant to the crispyness.-- goldbb, Jan 09 2014 this is a good way of making rancid, oxidized fats.-- bs0u0155, Jan 09 2014 Centrifuge. There needs to be a centrifuge.-- RayfordSteele, Jan 10 2014 random, halfbakery