Help with a watery knife idea

[edispilff]

Alright... We've got nice carbon blades with firesteels, and that pretty much almost covers the basics.. The only thing missing is a way to get some clean water without having to:
1. start a fire, boild water, wait to cool (or use hot;tea etc.)
2. wait a half an hour for the purification tablets to take effect
3. wear out your arm pumping for 10 minutes to get a pint of water or waiting for a prefilter to run through a drip sack

So, the proposal is to make a knife handle or sheath or, somehow, a combination of the two that incorporates a series of UV LED bulbs to provide a quick (less than 90 seconds) way of purifying substantial amounts of water in the least amount of time using the least amount of energy. Breathe.

I've got 100 365nm 10000mcd UV LEDs that are waiting to be exploited for this purpose. After Looking at some of the other UV sterilization products on the market, It's SAFE to say that 10 of these LEDs wired in series at 3 volts lithium will provide enough light to sterilize 1 pint in 60-90 seconds.

As to how to incorporate a switch without using moving parts (no rattles, shakes or parts to wear out), keeping the entire housing water proof to a submersible depth of no more than .35 m, and what type of battery's to use for this.

cr2032 button cell battery (the kind that keeps the time on you computer up to date when it's off) put out 3v at .2mA... which is enough to power at least 20 of these guys for maybe 10 hours... and they're pretty small at 20mm x 3.2mm.

What are your thoughts on this?

Is this the right location to post this?

Are there any electroManiacs on this forum who can help with this?

Is this worth doing?

Insight, comments, diagrams, and most of all HELP are greatly appreciated.

 

[Chips]

Although I don't know much about UV sterilisation, will you not need to strain your water first so it is clear?

Waterproofing it should be pretty easy. But I don't know if your idea will work.

365nm is almost the same as violet light, I am not a biologist, but I am not sure if this will kill bacteria etc.

Apparently, light of 254 nm is used to commercially steralise things, your wavelength may not be low enough to do it fast. Are you planning to market this commercially? If so, you will be liable if anyone gets poisoned by water that your product does not disinfect sufficiently.

 

[jungle_re]

like the idea of a DIY steri tool. Would want it located in my knife handle or sheath though as it would get more exposesure and likelyhood of damage

 

[Jared]

Chips is correct, you need 240nm - 290nm to sterilise.

http://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradiation

 

[edispilff]

Yes gentlemen, just looked into that and i see that 254nm is where the sterilization process starts... hmmm, wonder if LEDs are made in that short wavelength at all?.. Yep, some german company has them for...

... are you ready for this?

380$ @ 265 nm.... thats going to put a world of hurting on the pocketbook and my eyes :yikes:

There is another company that offers the same 365 for 33$... still too high for cost of multiples. :aargh4: The LEDs that i have are good for identifying counterfeit money, sterilizing toothbrushes, and causing cataracts and subsequent blindness. Not sure if thats really gonna be a hit with the northern community

i can however get the steripen flourescent UV mini lamps from a suppplier for 32$ a piece. They are 2"x3/4"dia. and work off of 6 volts... but that is way to big and energy consuming for this application...

hmmm, back to the drawing board

Thanks for the heads up guys... i'm changing my forum name to blindscandi now :togo:

 

[Shambling Shaman]

I do like the idea, but we are heading to the old argument of
"If you have one tool for every thing and lose it?"

That said I still like the idea/thought process behind it.

 

[korvin karbon]

try the steripen. Problem with UV is it does not have a great range so small container and then stick the LEDS in, swirl it about. Also the issue of particles which will hide microbes and viruses.

 

[Ogri the trog]

While not my ideal combiniation,
It's probably one worth investigating. With a knife / steriliser combo, you'd still need a vessel for water treatment or storage, which might mean that you've compromised the integrity of your knife for little overall gain. If you are carrying a vessel, it might make more sense to couple those two items (steriliser / vessel) as are alreay available, together. We're often told that a knife is your most important survival tool, so I'd be tempted not to weaken it unnecessarily.
Building on your idea though, our house water gets pumped from the well, filtered and then passed through a UV chamber (rated at 15 Watts) before going into the cold water tank in the attic - so I recon its workeable, even if not personally practical.

Let us know if you go ahead with it.

Ogri the trog

 

[leon-1]

If I was you I would also look into the degradation of epoxy resins under UV light. It's only a thought, but I still think it worth looking into.

 

[Jared]

The problem with this I suspect is going to be testing to ensure its actually working. Which would require laboratories, samples of the nasties, and verifying they've been sterilised afterwards.

Just wondering why the Guyot Designs Firefly idea hasn't been adapted to use UV light.

 

[edispilff]

Yeah guys all you say is true...
- the water will have to have a fair amount of prefiltering to ensure that the large particles don't act like asteroids hiding microbes
- The glass laminates i can get are UV stabilized so thats not the biggest problem
- I'm in pretty tight with the forest service so water testing/research isn't the biggest problem

putting all your eggs in one basket is a good point. Was simply trying to figure out a way to kill more than one bird with one stone - so to speak.

The concept is there, but the biggest leap seems to be the manufacture of LEDs, in that wavelength, are ridiculously expensive. I did a little research this morning on the present availability of UV based LEDs and found that the wavelength ratings given to the LEDs are only peak ratings. Short UV-C still exist within the LED UV ranges with Peaks of up to 380nm. The only problem is the efficiency and concentration of the UV. It's less than 3% at 365nm! This would take quite a while to hammer out 16 oz. of clear fluid.
After looking into a little further, The mercury vapor (MV) lamps are also housed in quartz/synthetic quartz housing that lets 100% of the UV-C through to the outside liquid. Quartz isn't exactly an indestructable item . Also, the MV lamps operate at only 35% UV-C (@6 watts for testing) efficiency at any wattage range.

There appears to be so much energy waste, that it's almost pointless to continueu in this venture. I hate waste

..and then there was a slight diversion towards sonic sterilization... as long as we can come up with a way to make a portable nuclear reactor to power it

Thanks for the comments amigos. This one is gonna get canned for the time being. I'm going fishing ... and will probably drink right out of the stream anyway.

 

[Shambling Shaman]

and will probably drink right out of the stream anyway.

Filter it through your beard like a true Bushcrafter.....(if you have one)

 

[korvin karbon]

Filter it through your beard like a true Bushcrafter.....(if you have one)

or like the more mature members do, take their false teeth out and use them to filter (runs farrrrrrrrrrrr away very quickly)

 

[Glen]

Just wondering why the Guyot Designs Firefly idea hasn't been adapted to use UV light.

Tha Aquastar is pretty close to that idea http://www.uvaquastar.com/

The new ( in re-design ) mÜV is looking very interesting too

 

[Jared]

Tha Aquastar is pretty close to that idea http://www.uvaquastar.com/

The new ( in re-design ) mÜV is looking very interesting too

Yes, that mÜV does look interesting. The fact can power it with various batteries especially.