The application of nitrogen in stainless steel laser cutting machines is mainly used as an auxiliary gas in two ways:
1) As an inert gas to prevent oxidation in laser cutting. Maintaining the metallic luster (shiny) of the cut surface of stainless steel products.
2) Blow down the melted part with the pressure of nitrogen to form a cutting seam.
For laser cutting, the nitrogen gas need to meet several requirements:
1) Purity should be required not less than 99.9%. In practice,99.99% purity is better.
2) Depending on the thickness of cut plate, nitrogen pressure is generally 1.0 Mpa for thickness below 10 mm. If 20 mm thickness stainless steel plate is to be cut, the pressure of nitrogen is generally 2 Mpa or higher.
3) Nitrogen flow rate depends on the diameter and pressure of cutting nozzle. Normally the flow rate is 20 Nm3/hr,40 Nm3/hr,60 Nm3/hr,80 Nm3/hr,etc.
Traditionally, to supply nitrogen gas for laser cutting machine, liquid nitrogen tank, vaporizer, pressure regulators,etc are installed at site. After using up one tank of liquid nitrogen, it need to be refilled or replaced. Some customers uses cylinder nitrogen too.
With the development of PSA (pressure swing adsorption) technology, nowadays on-site nitrogen generator supplying gaseous nitrogen is popular. Compared with liquid nitrogen system, on-site gaseous nitrogen generator has obvious advantages such as:
On-site nitrogen generator is normally skid assembly. When machine is sent to site, simply put on flat ground, no need for site base preparation,etc.
As nitrogen generator is factory assembled and tested, when machine reaches site, after electricity connection, with a simple touch on touch screen, within 15 minutes, the machine starts to produce high purity, high pressure nitrogen.
This is the biggest advantage. On-site nitrogen generator only consumes electricity during operation, getting 1.0 m3 gaseous nitrogen with 99.99% purity and 2.0 MPa pressure, the cost is only 0.6-0.8 kw electricity.
Using on-site nitrogen generator, the only maintenance is replacing the three filter elements after one year or after 8000 hours operation, and rate of operation is more than 95%, many customers just stop it for one day during one year.
Because of these advantages, on-site nitrogen generators are installed by many laser cutting machine users. Should you have any questions, welcome to contact us.