Table of Contents

1. Introduction
2. Principles of Air Separation
3. Main Components of a Liquid air separation unit
4. Operational Process
5. Parameters and Efficiency
6. Tewincryo Company Solutions
7. References

Introduction

Liquid air separation units (ASUs) are vital in producing high-purity gases such as oxygen, nitrogen, and argon. These units operate by separating atmospheric air into its primary components through various processes involving cooling, liquefaction, and distillation.

Principles of Air Separation

Air separation is based on the differences in boiling points of the constituents of air: nitrogen (-196°C), oxygen (-183°C), and argon (-186°C). By cooling the air to below the boiling points of these elements, they can be separated via fractional distillation.

Main Components of a Liquid Air Separation Unit

Air Compression System

An air compressor increases the pressure of incoming air to between 5 and 10 bar, which is crucial for driving the subsequent cooling and distillation processes.

Pre-Cooling Unit

Pre-cooling reduces the air temperature to approximately 5°C, often using a combination of water and refrigeration cycles.

Purification Unit

Impurities such as water vapor and carbon dioxide are removed to prevent blockages in the cryogenic cold box. This process typically involves molecular sieves.

Heat Exchange System

Cold air exits the distillation column and absorbs heat from the incoming compressed air, achieving temperatures near the liquefaction point of -170°C.

Distillation Column

The core of the process, where liquefied air separates into nitrogen, oxygen, and argon through fractional distillation.

Operational Process

The air separation operation begins with air intake, purification, and compression. Next, the air is cooled down to cryogenic temperatures in a series of heat exchangers. In the distillation column, air components are separated by boiling point differences, with nitrogen being extracted at the top and oxygen collected at the bottom.

Parameters and Efficiency

Key parameters include the distillation column pressure (5-7 bar), temperature gradients (-170°C to -196°C), and purity levels (up to 99.9% for industrial gases). Efficiency can be enhanced by optimizing compressor pressure and minimizing heat exchange losses.

Tewincryo Company Solutions

Tewincryo provides state-of-the-art air separation systems, offering customized units with advanced heat management and energy recovery. Their designs focus on minimizing operational costs through innovation in molecular sieve technology and highly efficient compressors.

References

1. Smith, J., & Johnson, L. (2016). Cryogenic Air Separation: An Overview. Industrial Gas Journal.
2. Peters, G. (2020). Advances in Air Separation Technologies. Chemical Engineering Today.
3. Tewincryo Company Website. (2023). Air Separation Solutions. Retrieved from https://www.tewincryo.com