A soft blowing method and control device for argon blowing at the bottom of a continuous casting ladle rotary table

A technology of turret and continuous steel casting, which is applied in the field of steelmaking in iron and steel metallurgy. It can solve the problems of easy blockage of breathable bricks, unreasonable adjustment of argon gas flow, and increased cost of refractory materials for ladle lining, so as to reduce the consumption of oxygen for cleaning. and nitrogen consumption, the improvement of non-burning oxygen purge rate, and the effect of reducing slab quality defects

CN111644584BActive Publication Date: 2022-04-22LAIWU STEEL YINSHAN SECTION CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2022-04-22

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Abstract

The present invention provides a method and a control device for blowing argon at the bottom of a continuous casting ladle turret, which transfers part or all of the soft blowing in the late stage of LF refining in the prior art from the LF refining treatment position to the continuous casting ladle turret. The position to be poured on the ladle turret is left still for manual ventilating brick blowing and soft blowing. During the pouring process at the pouring position, the automatic soft blowing mode and automatic blowing plugging are selected, and different automatic soft blowing modes are selected according to the different requirements for the control of inclusions in the steel. Blowing mode, in different automatic soft blowing modes, the proportion of molten steel pouring to the total molten steel in the ladle is different, and the types of breathable bricks selected are different. Compared with the soft blowing method in the later stage of LF refining in the prior art, the soft blowing time of the LF refining treatment position is saved by 3 to 8 minutes, and the average temperature drop of molten steel in the ladle is reduced by more than 0.12°C / min compared with the same period last year. The weight of electrolytic inclusions in continuous casting slab samples decreased by 7% to 20% year-on-year, and the qualified rate of casting slab quality increased by 0.01% year-on-year.
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Description

technical field

[0001] The invention relates to a control device and a soft blowing method for blowing argon at the bottom of a rotary table of a continuous casting ladle, and belongs to the technical field of steelmaking process in iron and steel metallurgy. Background technique

[0002] In the prior art, after the ladle is refined from the LF refining position, it is hoisted to the pouring position of the continuous casting ladle turret, and then enters the pouring position for casting. Bottom blowing argon in the LF refining ladle is a simple and efficient refining technology outside the furnace. It is generally divided into two stages: large flow argon blowing, stirring and mixing in the early stage and soft blowing with low flow rate to remove inclusions in the later stage. At present, domestic LF refining ladles of more than 100 tons generally use two bottom-blowing permeable bricks. The processing time of high-quality steel is generally more than 40 minutes, and the s...

Examples

Embodiment 1

[0096] A control device for blowing argon at the bottom of a continuous casting ladle turret, such as figure 1 , figure 2 As shown, it includes a gas circuit control cabinet 1 and an electrical control cabinet 3. The electrical control cabinet 3 is equipped with a signal light 4, a touch screen 5, a programmable logic controller PLC 6 and a switch button 7, and the gas circuit control cabinet 1 is equipped with a gas circuit control unit. 2. There are first manual ball valve 8a, second manual ball valve 8b, The third manual ball valve 8c connects the gas source inlet to the gas source, and the gas source outlet 1# and the gas source outlet 2# communicate with the ventilation brick 1# and the ventilation brick 2# through the quick joint 9 respectively.

[0097] The signal light 4 is used for prompting or alarming, including a red light 4a, a yellow light 4b and a blue light 4c, wherein, the red light 4a-an alarm for blockage of the ventilation brick or low pipeline pressure, ...

Embodiment 2

[0143] As described in Example 1, a soft blowing method and control device for argon blowing at the bottom of a continuous casting ladle turret, the difference is:

[0144] It is used for 130tLF refining ladle casting to produce low carbon steel SPHD, and the soft blowing time in the post-stage of LF refining in the prior art is 10min

[0145] (1) Select the automatic soft blowing mode, select the type of breathable brick: SPHD is a middle-end steel grade with inclusion control requirements, choose automatic soft blowing mode B: shorten 50% of the soft blowing time in the late stage of LF refining in the existing technology, that is, 5min , transferred to the continuous casting ladle turret for soft blowing. When the amount of molten steel pouring reaches 40% of the total amount of molten steel in the ladle, that is, 130t×40%=52t, stop argon blowing. The change of the net weight of the molten steel is linearly adjusted, the soft blowing value of the molten steel pouring proces...

Embodiment 3

[0155] As described in Example 1, a control device and soft blowing method for argon blowing at the bottom of a continuous casting ladle turret, the difference is:

[0156] It is used for 130tLF refining ladle casting to produce ultra-low carbon steel DC04, and the soft blowing time of the existing technology LF refining stage is 12min

[0157] (1) Select the automatic soft blowing mode, select the type of breathable brick: DC04 is a high-end steel grade with strict inclusion control, select the automatic soft blowing mode C: shorten the soft blowing time of the existing technology LF refining stage by 25%, that is, 3min, transfer Go to the continuous casting ladle turret for soft blowing. When the molten steel casting volume reaches 50% of the total molten steel in the ladle, that is, 130t×50%=65t, stop argon blowing. The change of the net weight is adjusted linearly, the soft blowing value of the molten steel pouring process = the net weight of the remaining molten steel in ...