Method for preventing material blockage of converter blanking elephant trunk

Abstract

The invention relates to the technical field of ferrous metallurgy, in particular to a method for preventing material blockage of a discharging chute of a converter, which comprises the following steps of: blowing oxygen into a smoke hood of the converter to melt molten slag after smelting is finished; the method has the beneficial effects that the situation that the slag adheres to the discharging chute of the converter and blocks the site is avoided, the situation that the slag adheres to the discharging chute of the converter and falls off from the high altitude is avoided, and the safety risk is reduced; and the cleaning time is shortened by adopting a blowing and cleaning mode of bonded slag, the labor intensity of workers is reduced, and the slag cleaning treatment danger is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel metallurgy, and particularly relates to a method for preventing blockage of a tundish of a converter. BACKGROUND

[0002] The tundish of a converter flue is a device for conveying bulk materials and alloy materials in the process of steelmaking, and is installed on both sides of a first-stage flue of a converter and is a water-cooled structural member. Since the tundish is subjected to the roasting of high-temperature flames and the adhesion of splashes such as slag and liquid during smelting, and is also subjected to the impact and friction of bulk materials, the working condition of the tundish is very poor.

[0003] The smelting temperature of a converter is as high as 1600 DEG C or above, and a large amount of dross is generated in the blowing process of the converter. The dross is splashed everywhere under the action of high-pressure oxygen and is easily attached to the surface of the inner sleeve of the tundish, which can cause blockage. The blockage of the tundish of the converter is difficult to be found in the blowing process. Since the tundish is blocked, a large amount of bulk materials is not added into the furnace, which can cause a high-temperature molten pool and cause great damage to the furnace lining. In addition, the blockage of the tundish is difficult to clean, a large amount of adhered slag falls off, and high-altitude falling objects can cause great safety hazards to production. SUMMARY

[0004] In order to overcome the defects of the prior art, the present application provides a method for preventing blockage of a tundish of a converter. The method comprises the following steps: after smelting is completed, oxygen is blown into a smoke hood of the converter to melt the slag on the tundish, and nitrogen is blown into the smoke hood of the converter after tapping to clean the adhered slag on the tundish. The method can improve the melting rate of the slag, reduce the splashing amount of the slag, and reduce the content of the molten slag in the converter after the molten steel is tapped, so that the blockage of the tundish is avoided.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0006] The method for preventing blockage of a tundish of a converter comprises the following steps: after smelting is completed, oxygen is blown into a smoke hood of the converter to melt the slag on the tundish, and nitrogen is blown into the smoke hood of the converter after tapping to clean the adhered slag on the tundish.

[0007] S1, after smelting of the converter is completed

[0008] The blowing mode of the converter is selected to be a blowing mode, the rotational speed of a primary air blower of the converter is 1200-1350 rpm, and the rotational speed of a secondary air blower of the converter is 600-700 rpm.

[0009] Oxygen is blown by an oxygen lance, and the oxygen supply intensity of the oxygen lance is adjusted to 2.2-2.8 Nm 3 / t·min.

[0010] The oxygen flow reflection position is adjusted between -10° and 10° of the tilting converter angle, sparks appear at the position of the smoke cover downpipe, the converter angle is fixed, the oxygen lance is moved up and down between 0-200mm above the waiting point, the oxygen blowing time is controlled within 2-3min, and normal tapping operation is realized;

[0011] S2, after the converter tapping is finished

[0012] The converter blowing mode is selected as the slag splashing mode, the primary air fan speed of the converter is 500-800rpm, and the secondary air fan speed is 600-700rpm;

[0013] The oxygen lance sprays nitrogen, and the nitrogen supply intensity of the oxygen lance is adjusted to 2.0-2.5Nm 3 / t·min; the oxygen lance is moved up and down between 0-200mm below the waiting point, the nitrogen blowing time is controlled within 2-3min, and normal slag splashing operation is realized.

[0014] Further, in steps S1 and S2, the oxygen lance nitrogen sealing valve and the auxiliary lance nitrogen sealing valve are all opened.

[0015] Further, in steps S1 and S2, the oxygen lance fast switching valve is opened during the oxygen lance spraying process.

[0016] Further, in step S1, the oxygen flow reflection position is adjusted to be at the downpipe.

[0017] Further, in step S2, the converter is fixed at the zero position.

[0018] Compared with the prior art, the method has the following beneficial effects:

[0019] 1. The method solves the problem of slag sticking to the downpipe of the converter after blowing and tapping, avoids the situation that the slag condenses into blocks and falls from a high altitude, reduces the safety risk, and shortens the cleaning time, reduces the labor intensity of workers and reduces the danger of slag cleaning.

[0020] 2. After the blowing is finished, the oxygen lance sprays oxygen and nitrogen, and the downpipe in the converter is blown and cleaned, so that the slag sticking situation is reduced, and the downpipe of the converter is prevented from being blocked. DETAILED DESCRIPTION

[0021] The specific embodiment of the application is further described below:

[0022] A method for preventing the downpipe of the converter from being blocked, which sprays oxygen into the smoke cover of the converter after smelting to melt the molten slag, sprays nitrogen into the smoke cover of the converter after tapping to clean the molten slag adhered to the downpipe in the smoke cover of the converter, and specifically includes the following contents:

[0023] S1, after the converter smelting is ended

[0024] Converter blowing mode is selected blowing mode, the converter primary air fan speed is 1200-1350 rpm, the secondary air fan speed is 600-700 rpm; the oxygen lance nitrogen seal valve, the vice gun nitrogen seal valve is all opened, the oxygen lance sprays oxygen, the oxygen lance oxygen supply intensity is adjusted to 2.2-2.8 Nm 3 / t·min, the oxygen lance fast cutting valve is opened;

[0025] The converter initial inclination is located at zero position, the reflection position is determined by small range swing furnace observation method, the inclination converter angle is adjusted between -10°-10°, the oxygen flow reflection position is located at the discharge port, the smoke cover discharge chute position has spark, the converter angle is fixed, the oxygen lance is moved up and down between 0-200 mm above the waiting point; the oxygen blowing time is controlled to be 2-3 min, and the normal tapping is realized.

[0026] S2, after the converter tapping is ended

[0027] Converter blowing mode is selected slag splashing mode, the converter is located at zero position fixed; the converter primary air fan speed is 500-800 rpm, the secondary air fan speed is 600-700 rpm; the oxygen lance nitrogen seal valve, the vice gun nitrogen seal valve is all opened, the oxygen lance sprays nitrogen, the oxygen lance nitrogen supply intensity is adjusted to 2.0-2.5 Nm 3 / t·min, the oxygen lance fast cutting valve is opened;Adjust the oxygen lance to move up and down between 0-200 mm below the waiting point;The nitrogen blowing time is controlled to be 2-3 min, and the normal slag splashing is realized.

[0028] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art, according to the technical scheme and the concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

[0029] The following examples are implemented on the premise of the technical scheme of the present application, and the detailed implementation mode and specific operation process are given, but the protection scope of the present application is not limited to the following examples. The methods used in the following examples are all conventional methods unless otherwise specified.

[0030] Example:

[0031] The converter specification is 260 t, the converter blowing end lifts the lance, and the converter is at zero position. In the converter primary operation picture, the oxygen lance operation mode is selected manual operation mode. The converter blowing mode is selected blowing; the converter primary air fan speed is set to 1200 rpm, and the secondary air fan speed is set to 650 rpm; the oxygen lance nitrogen seal and the vice gun nitrogen seal valve are manually opened.

[0032] The oxygen lance oxygen supply flow is adjusted to 40000 Nm 3 / h, oxygen lance stop in the waiting point position, manual opening oxygen lance fast switch valve.

[0033] Converter zero position, angle of tilting converter between -10° ~ 10°, through tilting converter to adjust the reflection position of oxygen flow, observe the spark appearing in the position of smoke cover and down pipe, at this time, fix the angle of converter, adjust the oxygen lance position, move up and down between 0 ~ 200mm above the waiting point; oxygen blowing time control in 2.5min, close oxygen and raise lance, organize tapping.

[0034] After tapping, converter zero position; select manual operation mode in the converter first stage operation picture, converter blowing mode select splashing slag.

[0035] Converter primary air fan speed set to 800rpm, secondary air fan speed set to 650rpm; open nitrogen seal valve of oxygen lance and secondary lance manually.

[0036] Oxygen lance nitrogen supply flow adjustment to 35000Nm 3 / h, oxygen lance stop in the waiting point position, manual opening oxygen lance fast switch valve. Adjust the oxygen lance position, move up and down between 0 ~ 200mm above the waiting point. Nitrogen blowing time control in 3min, then organize normal splashing slag.

[0037] Through blowing, oxygen lance spraying oxygen to reduce the content of molten slag in the converter, reduce the slag sticking of down pipe, after tapping, oxygen lance spraying nitrogen to blow the slag on the down pipe and in the converter, reduce the content of molten slag in the converter, reduce the slag sticking of down pipe in the process of converter blowing, prevent the down pipe from blocking.

Claims

1. A method for preventing blockage of the converter feed chute, characterized in that, The method for preventing blockage of the converter charging chute involves injecting oxygen into the converter fume hood to melt the steel slag after smelting, and injecting nitrogen into the converter fume hood to clean the steel slag adhering to the charging chute after tapping. Specifically, it includes the following steps: S1, After converter smelting is completed Select the blowing mode for the converter, with the primary air fan speed at 1200-1350 rpm and the secondary air fan speed at 600-700 rpm; Oxygen is injected through the oxygen lance, and the oxygen supply intensity is adjusted to 2.2–2.8 Nm. 3 / t·min; Adjust the oxygen stream reflection position by tilting the converter angle between -10° and 10°. Sparks appear at the position of the hood discharge chute. Fix the converter angle and move the oxygen lance up and down between 0 and 200 mm above the waiting point. Control the oxygen blowing time to 2 to 3 minutes and perform normal steel tapping operations. S2, After the converter tapping is completed The converter blowing mode is selected as the slag splashing mode; the primary air fan speed is 500-800 rpm, and the secondary air fan speed is 600-700 rpm; Nitrogen gas is injected through the oxygen lance, and the nitrogen supply intensity of the oxygen lance is adjusted to 2.0–2.5 Nm. 3 / t·min; Adjust the oxygen lance to move up and down between 0 and 200 mm below the waiting point; Control the nitrogen blowing time to 2 to 3 minutes for normal slag splashing operation.

2. The method for preventing blockage of the converter feed chute according to claim 1, characterized in that, In steps S1 and S2, the nitrogen sealing valve of the oxygen lance and the nitrogen sealing valve of the auxiliary lance are both opened.

3. The method for preventing blockage of the converter feed chute according to claim 1, characterized in that, In steps S1 and S2, the quick-cut valve of the oxygen lance is opened during the oxygen lance blowing process.

4. The method for preventing blockage of the converter feed chute according to claim 1, characterized in that, In step S1, the oxygen stream reflection position is adjusted to be located at the feed inlet.

5. A method for preventing blockage of the converter feed chute according to claim 1, characterized in that, In step S2, the converter is fixed at the zero position.