An air separation fractionation tower system and a process for preparing low-purity oxygen using the system

Abstract

The invention discloses an air separation fractionating tower system and a technology utilizing the air separation fractionating tower system to prepare low-purity oxygen. The pressure air is subject to heat exchange by a main heat exchanger and a liquid oxygen evaporator and is converted into partially liquefied air, then the air is separated into oxygen-rich liquid air and nitrogen in a lower tower of the fractionating tower, and the oxygen-rich liquid air enters an upper tower of the fractionating tower; the nitrogen is cooled into liquid nitrogen in the condensing evaporator, and is sent into the upper tower of the fractionating tower through an overcooler; each material in the upper tower of the fractionating tower is separated into low-purity liquid oxygen and nitrogen, and the low-purity liquid oxygen is subject to heat exchange and gasifying with the nitrogen at the lower part of the lower tower of the fractionating tower in the condensing evaporator, is subject to heat exchange by the condensing evaporator and the main heat exchanger, and is sent out as a product; the low-purity liquid oxygen is also subject to heat exchange by the liquid oxygen evaporator and the main heat exchanger, and is sent out as the product. The air separation fractionating tower system has the advantages that the low-purity oxygen and high-purity oxygen with different purities and pressures can be simultaneously produced, the operation pressure is low, the extraction rate is high, the energy consumption is little, the equipment investment is low, the requirements of low-purity oxygen and high-purity oxygen in multiple industries can be well met, and the air separation fractionating tower system is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of air separation devices, and in particular relates to an air fractionation tower system and a process for preparing low-purity oxygen by using the system. Background technique [0002] With the rise of my country's coal chemical industry, petrochemical industry, integrated gasification combined cycle power generation system (IGCC), non-ferrous smelting and other industries, many new demands have been put forward for air separation equipment. Safety and reliability, energy saving and emission reduction are the basic requirements and prerequisites for air separation equipment, the needs of building a resource-saving and environment-friendly society and scientific development, and the common expectation of air separation equipment users. Due to the rapid development of technology, the relationship between the air separation industry and these industries is no longer a simple relationship between supply and de...

AI Technical Summary

Problems solved by technology

[0007] It is not economical to dilute the high-purity oxygen (99.6%) produced by conventional cryogenic air separation equipment into low-purity oxygen, but the oxygen production of low-purity oxygen and energy-saving pressure swing adsorption oxygen production equipment is limited, the floor area is large, and Can not produce nitrogen and liquid products at the same time

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