Converter bottom blowing system capable of allowing multiple media to share bottom blowing lances and method for using same

A method for using a converter bottom blowing system capable of allowing multiple media to share bottom blowing lances, wherein the converter bottom blowing system comprises:

• a first gas source, wherein the first gas source is connected in parallel with a lime powder silo, a lime powder blowing tank and a first injector, the lime powder silo is connected with the lime powder blowing tank;
• the lime powder blowing tank is connected with the first injector;
• a lime powder silo stamping valve is provided between the first gas source and the lime powder silo, and a lime powder blowing tank stamping valve is provided between the first gas source and the lime powder blowing tank;
• and a first cut-off valve is provided between the lime powder blowing tank and the first injector;
• the first gas source comprises oxygen;
• a second gas source, wherein the second gas source is connected in parallel with a biochar powder silo, a biochar powder blowing tank and a second injector, and the biochar powder silo is connected with the biochar powder blowing tank;
• the biochar powder blowing tank is connected with the second injector;
• a biochar powder silo stamping valve is provided between the second gas source and the biochar powder silo, and a biochar powder blowing tank stamping valve is provided between the second gas source and the biochar powder blowing tank;
• and a second cut-off valve is provided between the biochar powder blowing tank and the second injector;
• the second gas source comprises nitrogen;
• and
• a converter, wherein a plurality of bottom blowing lances are arrayed at a bottom of a converter, and the bottom blowing lances are connected with the first injector and the second injector through a three-way valve, and a third cut-off valve is provided between the first injector and the three-way valve, and a fourth cut-off valve is provided between the second injector and the three-way valve;
• and
• the method comprises steps of:
• S1, air blowing to an empty furnace, which comprises sub-steps of:
• opening the fourth cut-off valve, closing the first cut-off valve, the first regulating valve, the second cut-off valve, the second regulating valve and the third cut-off valve, and blowing nitrogen from the second gas source to the bottom blowing lances at the bottom of the converter;
• S2, charging melted iron, which comprises sub-steps of:
• adding steel scrap and molten iron to the converter, opening the biochar powder blowing tank stamping valve and the lime powder blowing tank stamping valve, pressurizing the lime powder blowing tank to 1.3 MPa to 1.5 MPa by means of the first gas source, and pressurizing the biochar powder blowing tank to 1.3 MPa to 1.5 MPa by means of the second gas source;
• S3, biochar powder blowing, which comprises sub-steps of:
• after the steel scrap and the molten iron are added to the converter, opening the biochar powder silo stamping valve, the second cut-off valve and the second regulating valve, and blowing biochar powder and nitrogen simultaneously from the second gas source to the bottom blowing lances at the bottom of the converter;
• S4, when the steel scrap is completely melted, stopping the biochar powder blowing, and switching to the lime powder blowing, which comprises sub-steps of:
• S41, closing the second cut-off valve and the second regulating valve in sequence, and stopping the biochar powder blowing;
• continuing blowing nitrogen to the bottom blowing lances at the bottom of the converter by means of the second gas source continues;
• S42, opening the third cut-off valve, blowing oxygen from the first gas source to the bottom blowing lances at the bottom of the converter, and simultaneously controlling a flow rate of the nitrogen blown from the second gas source to the bottom blowing lances at the bottom of the converter to gradually decrease,
• when the nitrogen blowing from the second gas source to the bottom blowing lances at the bottom of the converter is completed, switching to the oxygen blowing from the first gas source to the bottom blowing lances at the bottom of the converter, and closing the fourth cut-off valve;
• and
• S43, opening the lime powder silo stamping valve, the first cut-off valve and the first regulating valve, and simultaneously blowing lime powder and oxygen from the first gas source to the bottom blowing lances at the bottom of the converter;
• and
• S5, air blowing, which comprises sub-steps of:
• closing the first cut-off valve and the first regulating valve, stopping the first gas source from blowing the lime powder to the bottom blowing lances at the bottom of the converter, and continuing blowing oxygen from the first gas source to the bottom blowing lances at the bottom of the converter.