Half a croissant, on a plate, with a sign in front of it saying '50c'
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Magnetic can squishing

Recycle Aluminum cans after radial pinching
  (+10, -2)(+10, -2)
(+10, -2)
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It seems more people would recycle aluminum cans if there were an easy way of reducing the space required. Stomping on cans is an acquired talent, and not suitable for those of us who do not tend to wear boots around.

But as our research into fusion reactors has shown, a theta-pinch device can squish those Al cans very effectively with about 1/2 a kiloJoule of energy (2.5 uF, 20kV.) Simply charge up the high-voltage capacitor, then discharge through an ignitron (mercury-vapor based high current switch) and a coil of wire suitable to conduct the large (10 kA) current for a few milliseconds.

After discharge, your Al can will consist of a radially scrunched (1/2") cylinder and a normal-sized can lid, neatly separated for easy recycling.

The loud discharge should be muffled by bags of lead pellets placed over the device, or at least firing range ear protectors.

This could be automated to allow the firing to be switched as the can is dropped through a Lexan tube of the correct size. Drop in a full sized can, out comes a miniaturized tube!

csea, Jul 04 2006

Ignitron http://en.wikipedia.org/wiki/Ignitron
High voltage / current mercury switch [csea, Jul 04 2006]

Mechanical Can Crushers http://housewares.h...s.aspx?LID=13196919
Old, non-fun technology [csea, Jul 05 2006]

What a can would look like. http://en.wikipedia...ed_Bennett_Relation
[Ling, Jul 05 2006]

the aforementioned vacuum version Vacuum_20Can_20Crusher
The vacuum can crusher [jhomrighaus, Jul 05 2006]

[link]






       I can only assume that you know what you're talking about. [+]
wagster, Jul 04 2006
  

       As funky as it does sound, would this really aid the recycling process? I assume the aluminium would need to be melted down later on, which would be easier with the larger surface area of the thin metal - as it was pre-scrunch.
fridge duck, Jul 04 2006
  

       and you can you fit all that into a shoe?
xenzag, Jul 04 2006
  

       :) Apart from the ludicrous current needed here; you would need to ensure the can didn't reach 1500C as the can would oxidise (burn?). Probably.
monojohnny, Jul 04 2006
  

       erm...what physical effect is actually being used here?   

       Some sort of magnetic induction to shrink the can ?   

       I might still bun this (despite the problem I mentioned above)....
monojohnny, Jul 04 2006
  

       Would a vacuum pump do the same job - with less chance of fires, burst ear drums etc ? (less fun I agree)...
monojohnny, Jul 04 2006
  

       Huge currents - check
Potential fires - check
Obscure technical stuff - check
Loud noises - check
Recycling - check
Link to wikipedia - check
Croissant - check
  

       We're good to go, Ma'am.
methinksnot, Jul 04 2006
  

       "Theta Pinch" = A fusion device in which the magnetic field runs parallel to the plasma column. It is a long cylindrical tube enclosed in a one-turn magnet coil.   

       Discharging a capacitor through the coil sets up a magnetic field, which in turn induces a current in the Al. cylinder. This induced current generates a magnetic field which neatly opposes the original radial field, and the result is a uniform mechanical force, radially inward, forcing the cylinder to reduce it's radial dimension.   

       The heat generated need not be large, nor sufficient to melt the aluminum, due to the very short discharge time.   

       Yes, a vacuum pump could be used, but as you say, less fun. If you're looking for baked means of squishing cans, there is a lever based one that has been around for a long time and seems to work. But that's not the point, afterall...
csea, Jul 05 2006
  

       Not thinking it will work. But have fun!
DrCurry, Jul 05 2006
  

       Yes, it does work, but not as a common household item: link.
Ling, Jul 05 2006
  

       Why?
5th Earth, Jul 05 2006
  

       It wouldn't match the decor.
Ling, Jul 05 2006
  

       Thanks, [Ling] for the reference. I've actually got a beer can (Coors - made with rocky mountain spring water!) that was made back in about 1972 with a 200J capacitor, and sports 2 narrow pinches.   

       I suppose "common household item" varies with the household ;)
csea, Jul 05 2006
  

       Thanks for the explanation [csea] - would this interfere with the telly ?   

       [+] for such a high-tech ,power hungry sledgehammer of a solution to crack this walnut of a problem !
monojohnny, Jul 05 2006
  

       Can we get some more specific information on here:   

       For instance:   

       1. An estimate of charge time for the capacitor - assuming its being charged from the mains (for both 110V and 240 V - and any other standards).   

       2. Physical size of the device.   

       3. Whether this might violate any international arms treaties or not.   

       I think this would be make for a fine diagram to show this idea - way beyond my abilities - anyone?
monojohnny, Jul 05 2006
  

       Link to the aforementioned Vacuum can crusher attached.   

       As to the idea. After viewing the link would this pinch the can all the way down as you describe?   

       As to shape or surface are of aluminum for recycling, I dont think it matters as I believe an arc furnace is used to melt the Aluminum.
jhomrighaus, Jul 05 2006
  

       Based on the picture on the wiki entry, I'd think there was more mileage in selling the warped cans as art, than marketing the machine for home use. You can charge a lot more for art.   

       Btw, if it's in wiki, is this actually an original idea?
DrCurry, Jul 05 2006
  

       The wiki would indicate a certain amount of bakeness about the idea unfortunately.
monojohnny, Jul 05 2006
  

       1 kJ = 1000 Watt-seconds, so theoretical charge time from 125V, 20A circuit is a 0.025 seconds. I'm not familiar with current spcs on 240V mains (30A?) If so, about 6.9ms. Realistically, at high voltage (for high energy, fast discharge) one might charge up in a few seconds, and discharge in a few 10s of microseconds. Certainly the cycle time is faster than the can load/ unload time.   

       Physical size: a 20kv, 2.5uF (oil filled) capacitor is typically about 1 cubic foot. The power supply might be 1/4 that size, or smaller if longer charge time is acceptable. Ignitrons are about the size of beer cans. So the whole thing is smaller than a trash compactor (albeit more specialized!)   

       I don't think there are international laws governing the charge/discharge of high energy capacitors. Clearly anything above 50J can be lethal. Do not try this at home unless you are trained in safety techniques for high voltage / energy systems!   

       Interference: Yes, possible interference with any RF system should be considered, but placing the entire apparatus in a Faraday cage should reduce this to acceptable levels.   

       While the wiki does show a degree of bakedness, I presumed the technique was not "widely known," and suits the spirit of the HB.
csea, Jul 05 2006
  

       "22 megawatts of electricity, enough to kill 250 people"   

       88 KW per exposure: there's a metric I can sleep on.
reensure, Jul 05 2006
  

       Reassuringly expensive [+]
AbsintheWithoutLeave, Jul 05 2006
  

       How would the cans be baled if they ended up that shape? It's hard enough when they've been crushed along their axes. I suppose they could always be melted together.
Could it be combined with a linear induction motor? That way, the crusher could draw on a hopper of cans and shoot the crushed forms out the other end at amazing speed.
nineteenthly, Jul 05 2006
  

       Superb. So I think a walk-in sized Faraday's cage would do the trick - all in all then, maybe the whole product would be about the size of a large fridge.   

       Would you care to speculate on what would happen if a full can of beer was placed in the Magno-Squisher ? (or would we need a bigger capacitor)
monojohnny, Jul 05 2006
  

       /Would you care to speculate on what would happen if a full can of beer was placed in the Magno-Squisher   

       This might be a high tech way to shotgun a beer!
bungston, Jul 05 2006
  

       [reensure],   

       It's not power [watts] that kill, it's energy [Joules, or Watt-seconds]   

       22 MW implies continuous power (infinite duration).   

       Energy lethality is around 50 Joules, or 50 Watt-seconds, delivered across the heart muscle. This could be 100W for 1/2 second, 500 watts for 1/10 second, or 5 Watts for 10 seconds.   

       The limiting factor, of course, is the impedance of the body (how much energy can be delivered in what time?) which depends on applied voltage.   

       The reference imples that 250 people all holding hands could be killed by applying a source which could deliver 220MW to the string. The 88kW/person would need to be applied for no more than a millisecond and still be lethal. 88kW for a whole second would likely cause a good deal of vaporization.   

       re. beer and other contaminates - aren't we a bit far from the original idea?
csea, Jul 06 2006
  
      
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