Kaifeng Kaixing Air separation Equipment Company introduces the detailed process of air separation

The raw air is inhaled from the suction tower, and dust and other mechanical impurities are removed by the air filter.

After filtration, the air is compressed to about 0.52Mpa in the centrifugal air compressor, the air cooling tower, the cooling water enters the cooling tower in sections, the lower section is the circulating cooling water, the upper section is the low temperature chilled water, the air passes through the air cooling tower from bottom to bottom, and is cleaned at the same time.

After the air is cooled by the air cooling tower, the temperature drops to ~10 ° C, and then enters the molecular sieve adsorbers used for switching, and carbon dioxide, hydrocarbons and residual water vapor in the air are adsorbed. The molecular sieve adsorber is used by two, one of which works while the other regenerates.

The switching cycle of the purifier is 240 minutes, and the automatic switching is scheduled. After the air is purified, it is divided into two ways: most of the air goes directly into the fractionating tower, and the other way goes to the pressurized expansion machine and enters the fractionating tower. Most of the air in the main heat exchanger and backflow gas (pure oxygen, pure nitrogen, waste nitrogen, etc.) heat exchange to reach the air liquefaction temperature of about -173℃ into the lower tower. When the charged air is cooled to -105℃ by the reflux cold gas in the main heat exchange, it is pumped into the expansion machine to expand and refrigerate, and the expanded air enters the upper tower to participate in rectification after passing through the thermosiphon evaporator.

In the lower tower, the air is initially separated into nitrogen and oxygen-rich liquid air, the top nitrogen is condensed into a liquid in the condensing evaporator, and the low pressure side of the main cooling liquid oxygen is vaporized. Part of the liquid nitrogen is used as the reflux liquid of the lower tower, and the other part of the liquid nitrogen is drawn from the top of the lower tower, and is supercooled and throttled by nitrogen and waste nitrogen through the cooler, and then sent to the top of the upper tower and the condensing side of the fine argon tower. After the liquid air is cooled in the subcooler, it is sent to the middle of the upper tower through throttling to serve as the cold source of the reflux liquid and the condenser side of the crude argon tower I. Oxygen is drawn from the bottom of the upper tower, and is reheated in the main heat exchanger, and then out of the cold box into the oxygen compressor and pressurized to 3.0Mpa (G) to the user. The polluted nitrogen is drawn from the upper part of the upper tower, and is reheated in the subcooler and the main heat exchanger before being sent out of the fractionator, and some of it is used as the regeneration gas of molecular sieve adsorbers.

Nitrogen is drawn from the top of the upper tower, reheated in the subcooler and main heat exchanger, and then out of the cold box, part of it is sent out as product nitrogen, and sent to the user after the nitrogen compressor is pressurized, and the rest of the nitrogen enters the water cooling tower as a cold source to cool the outside water. The liquid oxygen of the product is discharged from the main cooling and sent to the liquid oxygen storage tank for preservation. The liquid oxygen is discharged from the liquid oxygen storage tank and pressurized to 15Mpa by the liquid oxygen pump. The pressurized liquid oxygen enters the carburetor, evaporates into oxygen, and then sends it to the bottle filling room to fill the bottle. At the same time, the equipment reserves the export of liquid oxygen products.