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Liquid Nitrogen Bug Spray

It makes 'em hold still long enough to be swatted/stomped.
  (+9, -2)
(+9, -2)
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This Idea requires an in-home air-separation and liquefaction system. Kind of expensive, but perhaps manageable on a small-enough scale.

What that device does is first separate nitrogen out of ordinary air (there are things already available in the prescription market that separate oxygen out of the air, and that means nitrogen could be separated, instead). Then the separated nitrogen is liquified, and fed into a Dewar Flask (designed to hold liquid gas with a low rate of heat transfer and boiling). There of course should be an arrangement to capture boiled-off nitrogen and to re-liquefy it.

The Dewar Flask is removeable from the unit. The cap for the Flask has a liquid-feed-in valve, an evaporation pressure-release valve, and also one other thing, a pump-action aerosol mist-sprayer.

One neat thing about a Dewar Flask is that even though it holds liquid nitrogen, you can hold the Flask in your bare hand. The Flask is double-walled, with a vacuum in between the walls. Your classic glass "Thermos" brand bottle was actually a Dewar Flask surrounded by a steel protective shell (which didn't often protect it enough, alas).

OK, so you see a bug you want to kill -- so grab the Flask and squirt! The nitrogen spray hits the air and immediately starts to warm up, on its way to the bug. Meanwhile, while IT warms up, a significant volume of air surrounding the spray is being cooled; it is giving its heat up to warm the nitrogen, of course.

A very cold blast of air surrounds the bug! Bugs are cold-blooded animals, so this makes it start to move kind of slowly. (Just the other day I saw a fly buzz into my refrigerator, so I closed the door. A little while later the bug was stiff with cold; it would have warmed up again and flown away if I had let it.)

So, for a bug sprayed with liquid nitrogen, the same thing will happen, and rather faster because the gas is MUCH colder than the insides of a refrigerator. Now you can more easily swat it with a flyswatter, or even step on it, before it gets away. Then all you have to do is trash the corpse and put the Dewar Flask back into the liquefaction unit.

Vernon, Oct 05 2006

Autumn Watch with Kate and B'lOddie http://www.bbc.co.u...ritain/autumnwatch/
look for moth magnet - although why they needed quite such a cauldron of wine and sugar, heaven only knows. [po, Oct 06 2006]


       Brilliant! And it never touches the actual bug so could be used for chilling martini glasses also. One IQF bun for you.
Galbinus_Caeli, Oct 05 2006

       [21 Quest] Yes, I know this can be dangerous. That's why it's HalfBaked!
Vernon, Oct 05 2006

       At an old job, the computer operators had those cans of compressed air for dusting. When you turned them upside down they sprayed out the propellant (a refrigerant). Any time a fly was discovered in the area, the place turned into a shooting gallery. This works as [Vernon] describes with flies, but beware its effectiveness when it comes to wasps. I trapped one between my screen and window. No amount of refrigerant could slow it at all.   

       Fun stuff. +
Shz, Oct 05 2006

       I agree, this sounds more useful for chilling drinks.
EdisonsTwin, Oct 05 2006

       [21 quest] Thats hillarious! I bet the frog was ticked.
MoreCowbell, Oct 05 2006

       I don't approve of the deliberate killing of anything. It is an action that brutalises and diminishes the perpetrators, reducing them to imitate the behaviour of the insects they hunt with such fervour. [-]
xenzag, Oct 05 2006

       Killing is not a requirement. You could just do with them as we did - put them in other people's desks.
Shz, Oct 05 2006

       A suggested re-write, if I may.   

       Title: Liquid Nitrogen Bug Spray   

       Summary: It makes 'em hold still long enough to be swatted/stomped.   

       Description: As above. A Dewar Flask is used for handheld transportation of the liquid nitrogen about the home.
Texticle, Oct 05 2006

       great stuff, Vernon.   

       amused me when thinking of my beloved B'lOddie last night on Autumn Watch (note to self - find link) who had chilled out some moths (in the fridge) that he had caught, to slow 'em up for the viewers to get a quick shufftie before he released them and if its good enough for B'lOddie...
po, Oct 06 2006


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