Air Separation Equipment
Production of air separation equipment in various forms. There are devices for producing gaseous oxygen and nitrogen, and there are also devices for producing liquid oxygen and nitrogen. But as far as basic processes are concerned, there are four main types, namely, high pressure, medium pressure, high pressure, and low-pressure processes. China’s air separation equipment production scale has been from the early production of only 20m3/h (oxygen) oxygen machine. To have the capacity to produce 20000 m3/h, 30000 m3/h, 50000 m3/h, and 60000m3/h large air separation equipment, and has completed the scientific research stage, will be able to manufacture 8000m3 /h super large air separation equipment.
The Basic System
Air separation equipment is a large complex system, mainly composed of the following subsystems: power system, purification system, refrigeration system, heat exchange system, distillation system, product transport system, liquid storage system and control system.
- Mainly refers to the raw air compressor. Air separation equipment through low-temperature separation to oxygen, nitrogen, and other products, is essentially through energy conversion to complete. And the energy of the device is mainly input by the raw air compressor. Correspondingly, most of the total energy consumption required by air separation is the energy consumption of the raw air compressor.
- It is composed of an air pre-cooling system (air cooling system) and a molecular sieve purification system (purification system). The compressed raw air has a higher temperature, and the air pre-cooling system reduces the temperature of the air through contact heat exchange and can wash the harmful impurities such as acid substances in the air. The molecular sieve purification system further removes moisture, carbon dioxide, acetylene, propylene, propane, nitrous oxide, and other substances harmful to the operation of air separation equipment.
- The heat balance of air separation equipment is accomplished by the refrigeration system and heat exchange system. With the development of technology, the plate-fin heat exchanger is mainly made of aluminum.
The core of air separation equipment is an important equipment for low temperature separation. High and low pressure two – stage rectification is usually adopted. As long as it consists of low pressure tower, medium pressure tower and condensing evaporator.
Large air separation equipment adopts a computer distributed control system, which can realize automatic control.
The air separation equipment can be divided into five basic systems in terms of process flow:
In the equipment of oxygen production using the principle of low-temperature distillation, in order to ensure the normal operation of air distillation separation in the low-temperature area, the air must be pretreated with filtration, precooling and purification in the room temperature area.
There is a large amount of dust in the air. In the long and high-speed operation of the air turbine compressor (air compressor for short), dust will cause the wear, corrosion, and scaling of the impeller, blade, and other parts inside the machine, which will shorten the service life of the machine. Therefore, it is necessary to set the raw air filter to remove the dust in the air.
After being compressed by the air turbine compressor, the air temperature rises to more than 80 degrees, resulting in the failure of subsequent adsorption and heat transfer. By setting the air pre-cooling system, the air temperature entering the air separation equipment can be effectively reduced.