Air separation device for large liquid amount preparation and method

Abstract

The invention relates to an air separation device for large liquid amount preparation and a method. The air separation device comprises an air filter, an air compressor, a purification unit, a supercharger, a high-low-temperature supercharged turbine expander and a cryogenic separation cold box unit. Compressed air directly undergoes heat exchange and then enters a lower tower partially, and undergoes supercharging by the supercharger and then is cooled and throttled to enter the lower tower partially, air pumping is carried out in the supercharger, the air undergoes double-supercharging double-expansion of the high-low-temperature supercharged turbine expander and then enters the lower tower, the product oxygen and the product nitrogen adopt a double-pump internal compression process, andan argon-making system adopts an oxygen-enriched liquid air total-reflux form. According to the disclosed method of the air separation device for large liquid amount preparation by cryogenic separation, the step of air pumping in the supercharger and the step of enabling the air to undergo double-supercharging double-expansion of the high-low-temperature supercharged turbine expander and then toenter the lower tower are adopted, the product oxygen and the product nitrogen adopt the double-pump internal compression process, and the argon-making system adopts the total-reflux form, so that therequirement of large liquid amount air separation large cooling capacity is well met, the circulation of the material flow is fully utilized, the equipment is reduced, the energy consumption is reduced, and the extraction rate is improved.

Description

technical field [0001] The invention relates to the technical field of air cryogenic separation, in particular to an air separation device and method for producing a large amount of liquid. Background technique [0002] With the rapid development of steel and chemical industries, the demand for industrial gases such as oxygen, nitrogen and argon has also increased greatly, especially the same user's demand for gaseous and liquid products in different production stages has risen together. Gaseous products have the advantages of convenient supply and rapid utilization, while liquid products have the advantages of easy storage and transportation. The conventional external compression air separation unit can produce up to 10% liquid products, and the conventional internal compression air separation unit can produce up to 20% liquid products. In the past two years, subject to the mandatory requirements of the government's ecological and environmental protection, the production c...

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Problems solved by technology

The low-pressure expansion into the upper tower process produces very little liquid, which cannot meet the requirements of a large liquid volume; the medium-pressure expansion into the lower tower process produces about 20% of the liquid, and a lot of air needs to be added to produce a large liquid amount, increasing the energy consumption of the device

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