Process flow of nitrogen generator

rocess flow of nitrogen generator

The source and low cost of nitrogen is air, and the main components in the air are oxygen and nitrogen. They account for about 22% and 78% respectively. Of course, there are carbon dioxide, water vapor and a small amount of inert gases. Therefore, the nitrogen generator is essentially an "air separation" device, as long as oxygen and nitrogen are separated.

The nitrogen generator shall be selected according to its nitrogen purity. If the purity requirement is not high, molecular sieve nitrogen generator can be used. If the purity requirement is high, the refrigeration oxygen generator can be selected.

The refrigeration nitrogen generator uses different boiling points of oxygen and nitrogen (the boiling point of oxygen is - ° C, and the boiling point of nitrogen is - ° C). Compounds and other gases and dust and other impurities), which are then compressed and cooled to liquid air. Then, using the boiling point difference between oxygen and nitrogen, liquid air is evaporated and condensed in the distillation column for many times, and oxygen and nitrogen are separated to obtain pure oxygen (purity up to 99,6%) and pure nitrogen (purity up to 99,9%). If some additional devices are added, a small amount of rare inert gases such as argon, neon, helium, krypton and xenon can be extracted from the air. The oxygen generated by the air separation unit is compressed by the compressor, and finally the compressed nitrogen is put into the high-pressure steel cylinder for storage. Using this method to produce nitrogen requires large-scale complete sets of equipment and strict safe operation technology, but the output is high. It can produce several dry, 10000 cubic meters of oxygen and nitrogen per hour, and the raw materials consumed are only idle. There is no need to purchase, transport or store air in the warehouse, so this oxygen generation method has been widely used since the low-temperature air separation nitrogen (oxygen) generator was developed in 2010.

Molecular sieve oxygen generation method (adsorption method): oxygen enters the adsorber. When the oxygen in the adsorber reaches a certain amount (pressure reaches a certain level), the oxygen outlet valve can be opened to release oxygen. After a period of time, the nitrogen adsorbed by molecular sieve gradually increased, the adsorption capacity weakened, and the purity of oxygen decreased. It is necessary to pump out the nitrogen adsorbed on the molecular sieve with a vacuum pump, and then repeat the above process. This method of producing oxygen is also called adsorption. Recently, a small oxygen generator using adsorption to produce oxygen has been developed, which is convenient for home use. Of course, this is also a nitrogen generator.

It uses the characteristic that nitrogen molecules are larger than oxygen molecules, and uses special molecular sieves to separate oxygen from the air. First, the dry air is forced by the compressor to enter the vacuum adsorber through the molecular sieve, and the nitrogen molecules in the air are adsorbed by the molecular sieve. Air separation oxygen generation system includes air compressor system, air cooling system, water cooling system, molecular sieve purification system, booster expander system, distillation column system, pressurized gasification system, oxygen generation system, oxygen compressor system, pressure regulating station system oxygen generation in air separation distillation column and nitrogen oxygen separation principle of oxygen generation system: distillation column is a method to separate components by distillation. Equipment for obtaining high purity ingredients.

The air is cooled to a temperature close to the liquefaction temperature and sent to the lower column of the distillation column. Air and cryogenic reflux liquid

Fully contact the heat transfer from bottom to top to condense part of the air into liquid. Because oxygen is a non-volatile component and nitrogen is a volatile component, oxygen condenses more than nitrogen in the condensation process, thereby improving the purity of nitrogen in the gas. At the same time, the latent heat of condensation is released when the gas condenses, so that part of the reflux liquid is gasified. Because nitrogen is a volatile component. Therefore, nitrogen evaporates more than oxygen, thereby improving the purity of oxygen in the liquid. In this way, the gas and the reflux liquid on each tray conduct heat and mass transfer from bottom to top, and the purity of nitrogen in the gas phase increases once each tray passes. When the gas reaches the top of the lower tower, most of the oxygen has been condensed into liquid, so that the purity of nitrogen in the gas phase reaches 99%. Part of the nitrogen enters the condenser evaporator and condenses into liquid nitrogen. As reflux of lower tower. At the same time, the liquid oxygen at the bottom of the upper tower is vaporized and used as the rising gas of the upper tower to participate in the distillation of the upper tower.