High Pressure Nitrogen
High Pressure Nitrogen
(OP)
What exactly is the trick to getting high pressure to work correctly. I can't seem to get my pressure any higher than 1.05 mega pascals. The book calls for a 3.0 nozzle but I can't get anywhere close to the pressure required with that nozzle(book calls for roughly 1.5 MpA). I have to switch down to a 1.4 nozzle in order to get as high as the book says. Do I need to adjust the HP regulator coming in to the laser?
I am currently making an attempt at 3/8 SS. Running an Amada FO-3015 with a 160i control
I am currently making an attempt at 3/8 SS. Running an Amada FO-3015 with a 160i control





RE: High Pressure Nitrogen
I'm having the same problem has you, but i don't even get a cut straight. Always with tons of gross. But i'm using a 2,5mm with 1,5 MPa.
I have a 3kw Rosin Laser and with Percitec laser
What is the Focus you are using?
RE: High Pressure Nitrogen
RE: High Pressure Nitrogen
I've found this https://books.google.pt/books?id=pRah71xUxbMC&..., give it a look too, it seems a good book.
RE: High Pressure Nitrogen
RE: High Pressure Nitrogen
RE: High Pressure Nitrogen
RE: High Pressure Nitrogen
RE: High Pressure Nitrogen
Regarding gas settings and nozzle. Keep in mind that both gas pressure AND volume have to be considered. Larger nozzles equal less pressure and more volume. Think of a garden hose.... no restriction on end of hose equals high volume (gallons/minute flow rate) but low pressure and velocity. The water will only go a few inches out the end of the hose. Put a nozzle with a smaller opening on the end of the hose and the volume or flow rate will decrease but the pressure and velocity will increase shooting the water several feet. The nitrogen reacts in a similar fashion.
Also consider the diameter of the nozzle in relation to kerf (cut width). 3.0mm (0.12 inches) vs. 0.3mm (0.012 inches. This is why the pressure will increase as you reduce the nozzle gap creating a back pressure. The smaller the nozzle gap the more concentrated the gas flow will be into the kerf. I have cut 0.375 stainless nicely with a 2.5mm nozzle but think that the 3.0mm nozzle would be better if you have pressure and volume needed.
The liquid nitrogen tanks that you are using can also be an issue. Are you drawing off the gas outlet? Are you turning on the ppressure building valve? Have someone watch the regulator while you are trying to cut to see just how much pressure is available while cutting not just when no gas is being used.
Good luck! Hopefully this will help you understand the process. Attached is a cutting condition from Amada for your review.
RE: High Pressure Nitrogen
RE: High Pressure Nitrogen
1. the gas companies do not maintain their liquid dewars and many have trouble building pressure
2. you need high pressure dewars that put out at least 300psi
3. don't use a regulator, the dewar controls the delivery pressure, a regulator is just an unnecessary flow restriction. Protect the machine with blow off valves, not regulators.
4. you need to take liquid from the dewar, not gas. Run the liquid into an evaporator. Don't size the evaporator for your worst case cut scenario, size it for your worst case failure scenario. If an N2 leak develops you can draw a lot more than what a specific nozzle size and specific pressure will draw. Just like the blow off vale, the evaporator is key to protecting the machine.
5. run a large diameter line from the evaporator to the machine. I don't care what size the inlet is into the machine, run a fat line. The machines have a pressure drop through them, don't add to it.
6. If you go to a bulk tank, the same rules apply.
Chris
Chris Krug http://krugtech.com/
Maximum Up-time, Minimum BS
RE: High Pressure Nitrogen
RE: High Pressure Nitrogen
RE: High Pressure Nitrogen