Vacuum circulation degassing of steel liquid
Steel deoxidization and desulphurization often requires a quick and effective removal of oxygen and sulfur from the steel.This process is known as degassing.At present,the most widely used degassing method for steel-making is vacuum circulation degassing.Vacuum circulation degassing refers to the process of circulating molten steel in a vacuum environment to remove various gases.This method features rapid deoxidation,low energy consumption, simple operation, less secondary pollution, safe and reliable operation and so on.
The main equipment used in vacuum circulation degassing of steel liquid is vacuum degassing tank.Vacuum degassing tank is a container with certain parameters and a certain degree of vacuum which is used to deoxidate,remove sulfur,remove hydrogen and other gases in steel liquid.The vacuum degassing tank is composed of vacuum chamber,feeding device, stirring device, sealing device, oil cooling device, exhaust device, vacuum detection system, vacuum system and other parts.
The degassing process of molten steel is mainly heated to the required temperature and then added to the vacuum degassing tank.When the molten steel is put into the tank,the stirring device inside the tank will stir the molten steel evenly.At the same time,the vacuum system starts to reduce the pressure in the tank.After the pressure drops to a certain preset value,the stirring device will adjust its revolution according to the pre-set parameters and make the molten steel fully contact with the atmosphere inside the tank.In the low-pressure state,bubbles will be generated due to the evaporation of the existing nitrogen and hydrogen in the molten steel.At the same time,the oxygen and hydrogen of the molten steel will evaporate.The oxides produced during degassing will be removed from the tank through the exhaust device inside the tank.
Vacuum circulation degassing of steel liquid has many advantages.The first advantage is its low energy consumption.The stirring device adopts a low-power frequency converter to reduce the energy consumption during stirring.In addition,it can also reduce the labor intensity and improve the working environment of workers.Finally,the whole degassing process contains no waste residue,which greatly reduces the pollution to the environment.
In the production of steel,vacuum circulation degassing of steel liquid has been widely used.In order to ensure the effect of degassing and the safety of production of steel liquid,the parameters of pressure and temperature are frequently monitored and adjusted during the whole degassing process.Therefore,the operators should pay attention to the vacuum system and the overall control of degassing process,so as to make sure its stability and efficiency.
