In the heat treatment furnace, the temperature may get to 1000℃. The subjects been disposed in the furnace are vulnerable to oxygen, even small amount oxygen will damage them or harm the surfaces due to oxidization. High purity nitrogen is used in the heat treatment furnaces as a protecting atmosphere. Normally the purity is 99.99% or higher, by PSA directly or PSA and hydrogenation purification to get 99.999% purity.
For one of the biggest steel manufacturer of China, Shougang Group, supplied one PSA and hydrogenation purification system as nitrogen source for its refractory brick furnace. Before using nitrogen system, daily consumption of the furnace on nitrogen was around 100 cylinders of nitrogen. Despite of money spending, the process was much complicated. Just imagine 100 cylinders to be fitted to the nozzles and removed after using up.
Now with nitrogen system, the job becomes much simpler: just push the buttons. The system is made up of one PSA nitrogen generator and one ammonia cracker. Ammonia is divided into hydrogen and nitrogen by the cracker. Hydrogen then mixes with PSA nitrogen and removes the oxygen contained in nitrogen gas under heating. The product nitrogen purity is 99.999%. The 400L ammonia tank is replaced every 150 hours of working.
Industry application cases