According to the specification and smelting level of converter, the total oxygen consumption of steel can be calculated and converted to the oxygen consumption of each hour. The low and peak oxygen consumption is balanced by ball irrigation or liquid vaporization. The gas pressure of peripheral comprehensive pipe network is higher than the pressure of final gas consumption point. It is sent to the user through the pressure regulating station as oxygen enriched coal injection of blast furnace, which is basically the average consumption, It is the basis for the selection of small air separation unit.
At present, the formation process of gas and oxygen products in small air separation unit is mainly divided into internal compression and external compression. Due to the lack of liquid and gas sales channels and sales experience in newly-built iron and steel enterprises, the liquid volume of air separation unit products is very small, at this time, the general external compression process is more. Iron and steel enterprises with existing air separation units have generally felt the benefits of gas and liquid sales, so new air separation units are considered to bring a large amount of liquid. In this case, there will be a variety of process options.
Iron and steel enterprises generally overhaul once a year, while the overhaul period of small air separation unit is generally more than two years. During the overhaul period, the gas will be vented. Although the amount of venting can be reduced by adjusting the oxygen consumption of oxygen enriched coal injection, the requirements for small air separation unit still have a certain capacity of variable load.
The production of iron and steel enterprises has the characteristics of continuity, and it is not allowed to stop production at ordinary times, so the air separation unit is required to be reliable, stable and safe for a long time.
With the improvement of product grade and technical unit of iron and steel enterprises, the requirement of gas quality is higher and higher. When the purity of oxygen is less than 99.2%, oxygen can not be delivered, while the purity of nitrogen used for blast furnace protection is required to be more than 99.99%. As for argon, it plays an important role in the quality of steel, especially high carbon steel. Therefore, the high quality requirements of DEAR Air Separation will give full play to its role in the air separation industry and gas industry.
