Inscrit le: 20 Juil 2015
|Posté le: Dim 24 Jan 2016, 22:16 Sujet du message: canon "douchette"
|Nickel tu m'as convaincu d'en acheter !
D'ailleur j'ai trouvé un article de Goofy pour résoudre le problème nucs qui gèlent !
je le met ici (ne sachant pas ou le mettre ><) au cas ou quelqu'un aurait le même problème
|Now for my very very long-winded explanation of what solved my nuc nozzle freeze up problems: |
For starters, I now have 6 small 12 volt light bulbs on the nuc nozzle. They are automotive lights used for a car's side marker lights, or lighting up the license plate, etc. However, they have very little to do with the answer. I'm sure they help, but it turns out that heat (or lack there of) was not my problem.
It always puzzled me why I has so much trouble with nuc nozzle freeze ups, while all these other people ran their combo guns fine. I can understand why the t-guns don't freeze, because they are running so rich the water keeps things 'warm', and aren't really a nuc nozzle anyway. But why don't combo guns have my problems?
Well, it is all about pressure. The total amount of pressure doesn't matter: "It's not how big it is, but it is how you use it" Laugh
For starters you need constant pressure for both your air and your water. This means that the air source feeding the nuc nozzle has to stay constant, and the water source feeding the nuc nozzle has to stay constant. If you have a well, then put a pressure regulator somewhere before you gun. But this wasn't really my problem either. I had regulator on both for some time.
Ok, enough suspense, lets get to the good stuff. Your nuc nozzle's mixture is controlled by the difference in pressure between your air source and your water source. Either one can be easily made richer by simply increasing the pressure of its supply.
Freeze-ups start to happen all the time. On a good reliably working setup, you don't really notice them because they fix themselves. This is what was wrong will all my previous setups. They didn't fix themselves. They actually made themselves much worse when even a little freeze up started to happen.
When the nuc nozzle starts to freeze up, the ice causes the size of the nozzle's orifice to get smaller. Because both the air and the water are fighting to get out a single hole, the one with the higher pressure will get richer, at the expense of the other.
Here are the three possible scenarios:
1. Your water and air pressure are perfectly balanced. Well, at the current ratio of air and water, things have already started to freeze up. Keeping the same ratio will simply allow the freezing to continue until everything stops.
2. Your air pressure is higher than your water pressure. This is the really bad situation. When things start to freeze, the air will get richer, and the water leaner. This will lead to certain freeze ups, and fast.
3. Your water pressure is higher than your air pressure. This is the holy grail. When things start to freeze, the water will get richer, the air leaner, and the nozzle will dethaw itself Smile
Hang in there. Just two areas left to cover:
What I was doing wrong:
I had my compressor's regulator set higher than the pressure my nozzle normally ran at. I have a small compressor and want to use every last bit of air that I can. So, I always have it open up all the way, and (logically I thought) wasn't limiting the air pressure. After all, it always ran at a constant pressure set like that. This was my first big mistake. When the nozzle starts to freeze, less air can get out. However with my regulator set the way it was, the air pressure was allowed to get higher and higher, because I wasn't really limiting it. The higher air pressure would then beat out the constant water pressure and start to make the mixture leaner. This just make it freeze up more/faster.
Lesson number 1: ALWAYS SET YOUR AIR PRESSURE REGULATOR TO A LITTLE BELOW WHAT THE NOZZLE IS CAPABLE OF USING!!!
The other thing I was doing wrong:
In order to get the right nuc mixture, you always need a little less water pressure than air pressure, or it will be too rich. Right? WRONG!!!
What you want is less water, but not at less pressure. Remember the holy grail above. You want more water pressure than air pressure so the nuc nozzle will fix itself if it starts to freeze. But how is this done. Well for those of you 'in the know', you are probably just saying 'Duh goofy!' For those of you running high pressure combo guns, you are already doing what I am about to explain, and probably just don't realize it. For the rest of us (myself include until just a couple of days ago), especially those with low pressure setups, here is the trick. You need to control both the water pressure, and the water flow, but separately. I had only been controlling the pressure, or only controlling the flow. So, here's the trick:
1. Make sure you have a constant water pressure. I use a small air pressure regulator on my nuc's water feed to do this.
2. Make sure your water pressure is higher than your air pressure (the bigger the difference the better). I am currently running about 30-40 psi higher water pressure than air pressure. With high pressure combo guns this is kind of a given. But with low pressure setups, it is common to more or less match them. Don't!
3. Use a controlling valve AFTER the pressure regulator. Choose your weapon: gate valve, needle valve, pressure snubber, etc.
Number 3 is really the key. When running normally, the high pressure before the valve is reduce by the restricted flow due to the small opening in the valve, resulting in a much lower pressure on the outlet side. However, think about what would happen if you blocked the nuc nozzle's orifice. That small flow of water would have nowhere to go and just fill up behind the nuc nozzle's blockage. When that's all full, the water isn't going to stop flowing in, because there is still a very high pressure on the other side of the valve, forcing more water through. If the blockage didn't give way, in a relatively short period of time, the pressure after the valve would build up to equal the pressure before the valve. For you combo gun guys, that would mean that the nuc nozzle would be being fed around 1000 psi of water, at that point.
Well it is safe to say that the blockage (the freeze up in this case) isn't going to hang around too long with that much pressure. But it usually doesn't get to that point because as the pressure starts to grow, more water is forced out the nuc nozzle, making the mixture richer, and dethawing it. Although not as drastic in low pressure setups, it still works just as well, making the water mixture richer and fixing the freeze up.
Well I said it would be long winded. If you made it all the way through, then you deserve a Thumbs up
Hope this helps someone. Also hope it isn't completely wrong Smile