Nitrogen Purity Grades: 95%, 99.9% or 99.999%
Engineering Background
The oxygen content drives the application. Food modified atmosphere packaging generally runs between 98% and 99.9% nitrogen, because the objective is to displace oxygen from the headspace, not to create an inert atmosphere at trace levels. Laser cutting of stainless steel needs 99.99% or better at high pressure, because residual oxygen causes oxidation on the cut face and destroys the edge quality. Electronics soldering and semiconductor processes require 99.999% or above, where even 20 ppm of oxygen affects reflow and yield. Chemical and petrochemical tank blanketing typically sits at 97% to 99.5%, where the goal is maintaining a non-flammable atmosphere outside the flammability envelope rather than absolute inertness. Pharmaceutical and medical applications add a documentation requirement on top of the purity number: the gas must be traceable to a validated specification.
Design and Application
The engineering consequence of high purity is not just a larger sieve bed. Higher purity shortens the adsorption cycle, which means more frequent valve switching, faster sieve attrition and a larger share of product gas consumed for regeneration. Practical rules keep projects on budget. First, write the specification in ppm of oxygen, not in nines, because 99.99% and 99.995% are a factor of two apart in oxygen terms. Second, check whether the process needs the purity at the point of use or only inside the vessel, because in-line polishing at the point of use is often cheaper than generating the whole stream at that grade. Third, confirm pressure and purity together; a generator that holds 10 ppm at 0.5 MPa may not hold it at 0.8 MPa without a second stage.
Key Specifications
|
Parameter |
Value |
|
Nitrogen purity |
95% / 99% / 99.9% / 99.99% / 99.999% |
|
Residual oxygen |
50,000 / 10,000 / 1,000 / 100 / 10 ppm |
|
Flow rate |
1 - 3,000 Nm3/h |
|
Outlet pressure |
0.1 - 1.0 MPa, booster up to 30 MPa |
|
Pressure dew point |
-40 to -70°C |
|
Typical application |
Blanketing / packaging / laser / electronics |
|
Adsorbent |
Carbon molecular sieve |
|
Control system |
PLC with purity trend logging |
|
Purity monitoring |
In-line oxygen analyser, 0 - 1,000 ppm |
|
Alarm |
High oxygen deviation, auto switch to standby |
What HUAYAN Delivers
HUAYAN treats purity as a contractual number rather than a brochure claim. Each generator is factory tested against the agreed specification with a calibrated oxygen analyser, and the test record ships with the equipment. Where a plant needs one purity for bulk use and another for a critical point, we split the design into a base generator plus a point-of-use polishing unit instead of over-specifying the whole stream, which routinely cuts both capital and power cost. Our engineering team has specified nitrogen systems from 95% blanketing gas to 99.999% electronics grade across more than fifty countries.
FAQ
Q: What is 99.999% nitrogen in ppm of oxygen?
A: 10 ppm. Each additional nine reduces residual oxygen by a factor of ten, so 99.99% is 100 ppm and 99.9% is 1,000 ppm.
Q: Can one generator deliver two purity grades?
A: Yes. A split design with a base stream and a downstream polishing stage is common, and it is usually cheaper than generating the full flow at the higher grade.
Contact HUAYAN
Not sure which grade your process needs? Send the application details to Mail@huayangas.com or call +86 151 5000 6570 and we will recommend the lowest purity that meets the requirement.