Pure nitrogen preparation device and process

Abstract

The invention discloses a pure nitrogen preparation device. The device comprises a filter, a turbine air compressor, an air pre-cooling unit, alternatively used molecular sieve adsorbers, an electricheater, a supercharged aftercooler, a main heat exchanger, an expansion machine, a first rectifying tower, a second rectifying tower, a first condensation evaporator, a second condensation evaporator,a subcooler, a liquid nitrogen pump and a cold box. According to the device, the cold flow needed by the device is prepared through expansion of pressured air, the air enters the second rectifying tower to participate in rectification after being expanded to a certain pressure, the extraction rate is high, and the energy consumption is low; or the air is expanded to the normal pressure, the pressure ratio is high, the refrigerating capacity efficiency is high, the refrigerating capacity is large, the starting time of the device can be shortened, the electricity consumption is saved, the extraction rate is higher, the energy consumption is lower, the high-pressure nitrogen is discharged out of the cold box after being reheated, the dirty nitrogen in the mixed part is used for air regeneration of alternatively used molecular sieve adsorbers, the oxygen content in the regenerated dirty nitrogen is reduced, and the service life of the electric heater is effectively prolonged.

Description

technical field [0001] The invention relates to the technical field of air separation, in particular to a pure nitrogen preparation device and process. Background technique [0002] With the technological development and innovation of chemical industry, electronics, new materials, porcelain steel industry, glass and other industries, the demand for nitrogen has increased rapidly, and at the same time, higher requirements have been put forward for the purity of nitrogen. [0003] The commonly used pure nitrogen equipment on the market is divided into two types: single-tower nitrogen production and double-tower nitrogen production. The single-tower nitrogen production can produce a certain pressure of product nitrogen directly for users to use. Although the structure of this process is simple, However, the extraction rate of the device is low, and the unit consumption of the product is high, which is not suitable for the large-scale use of nitrogen; the double-tower nitrogen p...

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Problems solved by technology

[0003] The commonly used pure nitrogen equipment on the market is divided into two types: single-tower nitrogen production and double-tower nitrogen production. The single-tower nitrogen production is smooth and can produce a certain pressure of product nitrogen for direct use by users. Although this type of process is simple in structure, However, the extraction rate of the device is low, and the unit consumption of the product is high, which is not suitable for the large-scale use of nitrogen; the double-tower nitrogen production can produce nitrogen at atmospheric pressure or low-pressure nitrogen with a pressure of 0.1-0.2MpaG, and the extraction rate of the device is high. Energy consumption It is lower than single tower nitrogen production, but due to the lower product pressure, the product nitrogen needs to be compressed by a nitrogen compressor to meet the user's requirements for nitrogen pressure

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