nitrox stik

[fredk]

looking for some opinions. has anyone heard of, used or seen a product called the nitrox stik? they claim it's the easiest, cheapest way to blend nitrox up to a 40% mix.
you can see it and read about it on the following website.
www.envirodive.com

 

[MikeFerrara]

Global sells a similar device, may even be the same one. We will be getting one this summer. PP blending alone is just too slow and wasts too much gas.

 

[holly]

I saw this machine for making Nitrox on the internet. Has anyone seen one?
http://www.machine-designs.com

 

[Uncle Pug]

I saw this machine for making Nitrox & Trimix in my garage...

 

[jetblast00]

Originally posted by Uncle Pug
I saw this machine for making Nitrox & Trimix in my garage...

yea, yea, everyone knows they sell those over at diveinn.com...
It's just the shipping that stinks... you know what it takes to UPS a whole garage!

 

[neil]

Fred,
I am very familiar with the O2 stick as we installed one in the last (and I mean LAST) dive shop I worked in. It's very simple: an O2 bottle (K or similar size) is hooked up to what is basically a PV mixing chamber, the O2 mixes with the air and then goes into your compressor. So you are actually compressing nitrox. The mix reading is taken at the bottom of the mix tube before it enters the compressor. The process is finicky at first, and it takes practice to get the exact mix you want. We banked 40% and mixed from there. We were usually within 1% of our 40% goal when filling the banks after some practice. It requires constant monitoring of the O2 meter.
It's safer than PP and you don't need an O2 clean compressor. It comes with a good O2 meter, O2 regulator and the mixing tube. Other than that, I don't know a damn thing about it. Oh, yeah, it comes in a couple of sizes based on how big a compressor you have.

Neil

 

[Drew Sailbum]

Nitrox Stik is relatively simple, and does have a few advantages over partial pressure blending. You can empty the oxygen tank and there is much less oxygen cleaning required.

As with any blending system, practice makes almost perfect. After a few blends, you'll be better at getting the precise blend you want every time.

 

[Uncle Pug]

The Nitrox Stik is fairly expensive...
I was going to make one out of PVC but a friend of mine said,
"Nah, let me build you one out of S.S."
I said, "OK."

Simple Simple Simple

I analyze post compression (Omar does too but has been fiddling with pre-compression analysis as well)

It is a piece of cake to get spot on mixes...
Not only with Nitrox but Trimix too...
Course Trimix requires the purchase of a Helium analyzer...
And if you don't spend so much on the blender then you can buy one of those

Here is a picture of the blender itself... this is before I hooked up the helium inlet on the other side...

The gas goes into a venturi and then is blended by several delrin baffels inside the S.S. tube.

You could do the same thing with PVC pipe and some inserts with holes in them...

 

[NINman]

All I have to say is wow. When I grow up I want t o be like UP and have a setup like that in my gorage. Maybe some day.

 

[omar]

The first preblending set up was by Morgan Wells (NOAA) using a coiled garden hose on the inlet of an oil-free compressor. The coiled garden hose used the coriolis effect to mix the gases.

There are better ways than using a garden hose and if I put together a blending setup again I would get some readily available inline static mixing tubes. A lot cheaper and a lot easier than fabricating something. You can get PVC inline static mixing tubes for $75. SS ones are available but are for greater flows (you would need to have a bigger compressor to use these). I would use 2 of these to preblend EANx/Tmix prior to the compressor.

As with any breathing mix make sure that you have the proper filtration on the outlet side.

omar