Raw material air is drawn in from the suction tower and removed by air filters to remove dust and other mechanical impurities. After being filtered, the air is compressed to about 0.52 MPa in a centrifugal air compressor, precooled by an air cooling tower, and the cooling water is divided into cooling towers in sections, the lower section is circulating cooling water, and the upper section is low temperature chilled water. The air is cooled to about 10 ° C after cooling by the air cooling tower, and then enters the molecular sieve adsorber for switching, and carbon dioxide, hydrocarbons and residual water vapor in the air are adsorbed. The molecular sieve adsorber is used for two switching, one of which is regenerated in one operation, and the switching period of the purifier is 240 minutes.
After the air is purified, it is divided into two ways: most of the air in the main heat exchanger and the reflux gas (pure oxygen, pure nitrogen, nitrogen, etc.) heat exchange to reach the liquefaction temperature of about -173 ° C into the lower tower. The other air is cooled in the main heat exchanger by the returning cold gas to -105 ° C, and then taken out into the expander to expand and cool, and then enters the upper tower to participate in rectification while replenishing the cooling loss.
In the lower column, the air is initially separated into nitrogen and oxygen-containing 38-40% oxygen-rich liquid space (bottom of the lower column), and the nitrogen generated at the top is condensed into liquid nitrogen in the condensing evaporator, while the main cold low-pressure side liquid oxygen is vaporized. Part of the liquid nitrogen is used as the lower column reflux liquid, and another part of the liquid nitrogen is taken out from the top of the lower column, and after being subcooled in the cold, it is sent to the middle of the upper column as a reflux source and a cold source on the condensation side of the condenser of the crude argon column I through the throttling. The oxygen-enriched liquid at the bottom of the lower tower is taken out and sent to the upper tower by throttling and cooling to participate in the upper column rectification.
Oxygen is taken from the bottom of the upper tower and reheated in the main heat exchanger with the raw air, and then sent out to the cold box to be pressurized by the oxygen compressor and sent to the user.
The sewage nitrogen is taken out from the upper part of the tower and sent to the fractionation tower after being reheated in the subcooler and the main heat exchanger, and most of it is used as a regeneration gas of the molecular sieve (about 21000/h). A small portion enters the water cooling tower as a cold source to cool the circulating water.
Nitrogen is taken from the top of the upper tower, and the cold box is reheated in the subcooler and the main heat exchanger, and is pressurized by a nitrogen compressor and sent to the user.
The product liquid nitrogen is discharged from the main cold and sent to a liquid nitrogen tank for storage. The liquid oxygen discharged from the liquid nitrogen storage tank is pressurized by the liquid oxygen pump and then enters the liquefier, evaporated into oxygen and then sent to the oxygen pipe network for delivery to the user.
Contact: Will Shi
Add: No.20, Jinfeng Rd., Xiashi industrial Area, Anyuan Dist., 337000, Pingxiang City, Jiangxi, China