Uv/Germicial light Questions

Here is a little project that I was thinking about.

You can run a Diesel on waste vegetable oil (greasecar.com).
I haven't done this yet but was thinking of getting into it. Diesel and waste vegetable oil can have algae/bacteria growth. This will clog filters and ruin injection pumps.

There are air quality filters, medical sterization equipment and water purifiers that use UV light. So I wanted to install a UV light inside the fuel tank because it wouldn't hurt the environment like a biocide additive would.

1. Does anyone know of a somewhat compact germical light fixture that would fit into a fuel tank and handle 170 degrees
2. Should be long lasting 2-3 years
3. Run of 12 volts
4. It could be led, incadescent, fluorescent
5. It has to be Waterproof
6. Is there a Germicial LED that emits at around 254nm

If anyone could post links or information it would be helpful.

-Thanks

first thought: is it necessary, since the fuel gets used and replaced?

second thought: spark in the fuel tank sounds undesirable

isn't there normal diesel fuel additives to clean the injectors or maybe absorb water in the lines that is poisonous to algae/bacteria?

Well let's sort out the the things that can be done from the things that cannot.
1). I doubt that it wll be possible to build 254nm LED. The technical challenges in making an emitter that puts out photons with energies that high are considerable. YOu also need to put a pretty hefty amount of energy to reliably kill organism, so it would take a lot of LED's, even if they existed, and relative to Fluorescents, LED's aren't very efficient.
2). 2-3 year lifetime, not in the cards either. Today these devices are almost exclusively Fluorescent tube devices. The GE lamp catalog quotes a life of about 7500 hours (8 months)(GE G8t5,g64t6,g15t8,g25t8,g30t8 are all designed with peak output at 254nm, and are classed as group 3 High Risk UV exposure devices. Exposure to skin or eyes WILL result in injury)

My own experience with UV Eprom erasers says that 7500 hours is probably optimistic (at least with the G8T5). It isn't that they lamps don't work, they just cease to generate enough energy in the right part of spectrum to erase Eproms, or kill bacteria.

LED and Long life pproaches aren't going to work, however there are UV sterilizers that are used as part of the filtration for Reverse Osmosis water systems, and similar devices for use in ponds/fountains (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=4329949317 is such a device on ebay). The essentially run a transparent pipe around the UV source at low flow rates to insure that sufficent energy is imparted to anything in the water to kill it. The source isn't water proof, but obviously the pipe or tubing carrying the water is. What you want to accomplish can probably be done by circulating the fuel through such a device assuming that the plumbing isn't damaged by the oil, located outside the tank. You would need an inverter to provide 120VAC needed, and a pump. The UV sterlizers run about $80. Most spec at least annual replacement of the lamp.
see http://www.waterfiltersonline.com/uv-systems.asp

A link to one of the manufacturers is http://www.r-can.com/sterilight/uv-2.asp. They may know how to build what you want.

UV sterilizers reqire a transparant medium. If your fuel is cloudy, things will survive the light by being shaded by dirt.

You may want to look into natural oils, such as Wild Oregano and Tea Tree. Very little would be needed. They aren't harmful to the environment, in fact the oregano is useful internally, too. Great for any infectious disease, including flu, and as a preventative.