Double-tower double-condensation backflow expansion nitrogen making machine and nitrogen making method thereof

Abstract

The invention discloses a double-tower double-condensation backflow expansion nitrogen making machine comprising an intake pretreatment device and a nitrogen making device which are connected through a pipeline. The intake pretreatment device comprises an air filter, an air compressor, a pre-cooling unit and a purifier. The nitrogen making device comprises a main heat exchanger used for heat exchange, a subcooler used for cooling, rectifying towers, a main condensation evaporator, an auxiliary condensation evaporator and an expansion machine. The rectifying towers comprise an upper tower and a lower tower. The lower tower is provided with an air inlet. The air inlet communicates with the purifier through the main heat exchanger by means of a pipeline. The invention further provides a nitrogen making method of the double-tower double-condensation backflow expansion nitrogen making machine. Oxygen-enriched liquid air is used for step-by-step evaporation in the main condensation evaporator and an auxiliary condensation evaporator, and under the condition of obtaining high-purity gas nitrogen products at the equal pressure, it is achieved that compared with a conventional double-tower single-condensation backflow expansion high-purity nitrogen making machine, the double-tower double-condensation backflow expansion nitrogen making machine can lower the discharge pressure of the air compressor, reduce the electricity consumption and reduce the processing air quantity, thereby reducing the comprehensive energy consumption.

Description

Technical field: [0001] The invention relates to the field of mechanical equipment, in particular to a double-tower double-condensation reflux expansion nitrogen generator and a nitrogen production method thereof. Background technique: [0002] With the development of the economy, scientific and technological research and development of civilian industries are inseparable from the gas industry and cryogenic technology. The economic growth of the world, especially China, makes the air separation market look promising and the situation is optimistic. The development of petrochemical, electronics, chemical fiber, polysilicon and other industries requires more and more high-purity nitrogen. Nitrogen-generating equipment belongs to the category of energy conservation and environmental protection encouraged by the state. [0003] The chemical nature of nitrogen is inactive, and it is very inert in the normal state, and it is not easy to chemically react with other substances. Th...

AI Technical Summary

Problems solved by technology

If the user needs a product with a nitrogen pressure of 3-4barg, an air compressor with a higher pressure is required, and the energy consumption of the air compressor will also increase accordingly, so the amount of processed air will increase, and the overall energy consumption will also increase.

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