It should be 25.500 cubic in inches not 255.000
Hmm? I dont understand.... Did I get the wrong number for the cubic inches? Thanks, JR
Originally Posted by Jaakko Fagerlund
The problems you had is not with the light but the coolant. It is fluorescent, meaning the UV light was being converted to visible light and the lamp could not do it's job.
Originally Posted by Mcgyver
Originally Posted by Mcgyver
Did you do a write up on this with more details? As I am wanting to build one myself. I see some commercial ones recoup the coolant accidentally caught up with the oil off the skimmer.
Ah, sorry, my bad. I promise I won't do calculations when I'm sober
Originally Posted by JRouche
Dave my plan was always to do a write up, but its also an experiment....I need to get it more refined. I've also got a half done scheme for returning coolant without hoses across the floor. Everything overhead and blown back with air....need to get that singing as well. btw the saw blade is temporary, was a disk the right size...it sort of worked however I've purchase a proper disk which has the property of the oil liking to cling to it. Overall it's a work in progress although it is usable
Originally Posted by Davo J
I don't understand that - its fluorescent?
Originally Posted by macona
the 'its crap' referred more its physique, it was just horribly made, press together plastics parts that would fall apart if you looked at it, very week pump etc. If never worked long enough to assess its effectiveness with bacteria.
Current think is something a little more heavy duty - the pond unit, or res water unit and using the beefy main pump to circulate.
Mcgyver, the problem with "commercial" UV units, whether for aquariums, homes or whatever, is that they are constructed to a price point. This rarely coincides with optimum effectiveness.
First, you must use a "germicidal" lamp. I forget the wavelength of the output but I know that Phillips makes them, in the same approximate wattages as flourescent lamps. Match it to a quality ballast. The lamp must run in air to reach a reliable operating temperature. That means slipping it in a fairly close-fitting tube of UV-transparent material. Many commercial units use a pastic, but I forget what kind. It does not really matter; the BEST material is fused quartz. You can probably get it from Fisher Scientific and it wont be cheap, but it IS worth it.
The liquid to be treated must be clean; no lumps that create shadows where bacteria can hide from the radiation. It must also be reasonably transparent to UV radiation. Example:- for CLEAN water, maximum effective penetration is about one centimeter. ( Researchers have determined the effective UV energy dose in microwatts/cc and they then use a 1 cm depth water depth.)
On the basis of the 1 cm depth, and the annular volume between the quartz tube and its outer jacket, you instal a flow regulator such as a Dole valve to ensure that the energy/unit volume is reached.
You now have a WORKABLE UV sterilizer.
The jacket for the quartz tube can be ordinary pipe, PVC, aluminum, or stainless steel. The inlet and outlet are just close nipples. The ends of the jacket should be EASILY removeable but, since pressure is low, simple O-ring fittings will work.
Now for the BAD news. FIRST UV light reacts with all sorts of stuff. Most importantly, it oxidizes soluble iron, (which WILL be in your coolant,) to the insoluble form, which deposits on the quartz tube. This effectively blinds off the tube to UV radiation, even in a thin layer. Depending upon the rate at which it builds up it must be chemically removed. No big deal; a quick wash in either hydrochloric or oxalic acid cleans it right up. BUT, this is maintenance.
SECOND, this is NOT clean water; even after filtration, there is still the dispersed oil as well as that lovely flourescent colourant, (which I suspect is a dye of the same family as is used in antifreeze.) These both may absorb UV energy disproportionately, lowering the bactiricidal effectiveness.
If I were going to build a UV reactor for this application, I would cut the liquid DEPTH to about 5 mm, and DOUBLE the energy input, (by cutting the flow rate through reactor.) I think that I would design around a 20 watt germicidal lamp, which is about the same length as a 20 watt T8. For a lamp source, I would try a lighting specialist. Here in Ottawa, there is a firm, Buchannan Electric, and ALL they sell is light bulbs and ballasts. Otherwise, ask a biology laboratory where they buy theirs.
Any questions, PM me.
Duffy, Gatineau, Quebec
UV in-line sterilizers
For info, parts, etc., see: http://www.aquanetics.com/ or http://www.lifegardaquatics.com/prod...oduct.php?id=5
Had the Aquanetics 60w unit for many years. Other than changing the tubes every other year, no problems. Examined the Rainbow/Lifeguard filter UV unit first hand as well. Quality construction and the advantage of single ended UV bulbs and a test tube like quartz enclosures for the bulb.
Last edited by Rosco-P; 05-09-2012 at 11:14 AM.