SU392301A1 - 5Shi? GshO = 'T [H1ShNAYA - Google Patents

Description

one

The invention relates to a technique for low-temperature gas separation, for the production of inert gases, such as krypton, and can be widely applied in air separation plants.

A known method for producing raw krypton by the method of low-temperature rectification, in which the primary krypton concentrate in liquid form is pumped into the upper part of a two-stage distillation coloinm.

In the process of rectification, phlegm is freed from oxygen and methane. From the top of the column, oxygen mixed with methane along with steam from the bottom of the primary krypton concentrate production column is fed to the separation column to wash the krypton from the reflux oil obtained in the top condenser. This reflux is returned to the bottom of the primary concentration column, and dry krypton mixed with heavy hydrocarbons is taken from the bottom of the two-stage column.

However, in a known method, there is a high concentration of hydrocarbons in the resulting product, a deteriorated rectification in a two-stage column as a result of the precipitation of hydrocarbon crystals and a high methane content.

The purpose of the invention is to obtain raw krypton purified from hydrocarbons, to improve the process of rectification and to increase explosion-proof operation.

This is achieved in that the methane fraction is taken from the zone of maximum methane content in a pair along the height of the concentration column, and the purification of hydrocarbons having a boiling point higher than xenon is performed during the distillation process in a separate separation column.

The liquid washed in the concentrating column 1 from oxygen and methane is completely exhausted in the evaporator, where coolant is used as a coolant in connection with a large temperature difference between the boiling points of various hydrocarbons and krypton.

The drawing shows a schematic diagram for the implementation of the proposed method. Primary krypton concentrate from the plant (not shown in the drawing) without untreated cleaning from hydrocarbons is poured into the middle part of the column / through pipeline 2. Liquid oxygen with a low content of krypton and xenon yanrvat Ute but the pipeline

3 to the top of the column 1. The stack in the column, the reflux is enriched with krypton, xenon and hydrocarbons, and is freed from oxygen. From the bottom of the column / liquid through the pipeline 4 is fed to the evaporator

5, where it is evaporated in cells. From the vaporizer 5

the gas through pipeline 6 is introduced into the collar 7, where it is divided into crude krypton and hydrocarbons. Crude cryptopes are removed from the upper part of the colope 7. A smaller part of it is taken as product through line 8, and most part by line 9 is fed to column 1 to create an explosion-free zone between areas with a high concentration of heavy hydrocarbons and oxygen. Methane fraction is withdrawn from the section of column 1 with the highest methane content in the steam, it is supplied via conduit 10 to the column // for washing from krypton and xenon and removed from the installation via conduit 12. The reflux for the rectification process in columns 7 and 11 is obtained in the upper capacitors 13 and 14. From

columns C kapton diffuse phlegm

pipeline 10 return. in the column.

Hydrocarbons from the installation are derived by

pipeline 15, and oxygen washed from krypton through pipeline 16.

Iredmet invention

The method of obtaining raw krypton: the method of low-temperature rectifying; without

pre-purification of the primary ... rypton concentrate from hydrocarbons,; so that, in order to increase the reliability and reduce the explosion hazard of the process, purification of the separated mixture from hydrocarbons,

having a boiling point higher than xenon, is produced during the rectification process.

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