CN114107609A

CN114107609A - Gas injection process model for ladle refining

Info

Publication number: CN114107609A
Application number: CN202111402722.6A
Authority: CN
Inventors: 陈超; 范冰; 赵舸; 王杰
Original assignee: Central Iron and Steel Research Institute; Jiangsu Shagang Group Co Ltd; Zhangjiagang Hongchang Steel Plate Co Ltd
Current assignee: Central Iron and Steel Research Institute; Jiangsu Shagang Group Co Ltd; Zhangjiagang Hongchang Steel Plate Co Ltd
Priority date: 2021-11-24
Filing date: 2021-11-24
Publication date: 2022-03-01

Abstract

The invention belongs to the technical field of automation, and particularly discloses a gas injection process model for ladle refining, which is characterized in that a bottom blowing automatic gas supply model and a smelting process signal point are designed according to a smelting process, the automatic switching of model flow is realized by matching the bottom blowing automatic gas supply model with the smelting process signal point, and the automatic identification and adjustment of bottom blowing flow and bottom blowing signals in each stage of the ladle refining process are finally realized; the designed bottom blowing automatic air supply model is divided into two stages of paths, the first stage of path is used for judging the ventilation condition of a bottom blowing air supply element according to air supply pressure so as to select a process flow mode and determine the adjustment range of process flow, and the second stage of path is used for automatically adjusting the process flow within the adjustment range according to the judgment time zone of a smelting process signal point according to steel grades. The process model of the invention ensures that the bottom blowing gas supply control is more scientific and reasonable, reduces the extra energy waste of operators, increases the smelting stability and is beneficial to the realization of the automatic refining process.

Description

Gas injection process model for ladle refining

Technical Field

The invention belongs to the technical field of automation, and particularly relates to a gas injection process model for ladle refining.

Background

At present, strict requirements on the cleanliness of molten steel are required for high-quality steel, and in order to improve the cleanliness of the molten steel, a new technology is continuously adopted in actual production, wherein argon blowing stirring is a commonly adopted production process, and the argon blowing technology is adopted in all links from tapping of a converter, external refining to a continuous casting tundish. After smelting, the molten steel is poured into a ladle, various alloys are added into the molten steel, and inert gas-argon gas is blown into the molten steel through a porous air brick at the bottom of the ladle to stir the molten steel so as to adjust and homogenize the components of the molten steel and accelerate the floating of impurities in the molten steel.

The prior operation control method of the converter ladle bottom argon blowing system has the following defects: 1) for the same steel type, different operators have different timing choices for switching argon blowing pressure setting, argon blowing flow setting and argon blowing pressure flow setting values due to different personal operation experiences, and the ladle bottom argon blowing operation is difficult to standardize; 2) in the semi-automatic operation mode, in the tapping process of a furnace of molten steel, an operator still needs to contact a mouse and a keyboard for multiple times to open an argon gas stop valve, set and adjust the argon blowing pressure and the argon blowing flow set value, close the argon gas stop valve and the like.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a gas injection process model for ladle refining, which is used for changing the automatic identification and adjustment of bottom blowing flow and bottom blowing signals in each stage in the ladle refining process.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a gas injection process model for ladle refining is characterized in that a bottom blowing automatic gas supply model and a smelting process signal point are designed according to a smelting process, model flow automatic switching is achieved by matching the bottom blowing automatic gas supply model with the smelting process signal point, and finally automatic identification and adjustment of bottom blowing flow and bottom blowing signals in each stage of the ladle refining process are achieved.

The improvement is that the designed bottom blowing automatic air supply model is divided into two stages of paths, wherein the first stage of path is used for judging the ventilation condition of a bottom blowing air supply element according to air supply pressure so as to select a process flow mode and determine the adjustment range of process flow; the second-stage path is that the process flow is automatically adjusted within the adjusting range according to the signal point discrimination time zone of the smelting process according to the steel grade.

The improvement is that the air supply pressure in the first-stage path is delta P-P0, wherein P is the actual air supply pressure, and P0 is the model matching theoretical air supply pressure; if delta P is more than 0.3MPa, selecting a high-pressure mode, if 0.3MPa is more than delta P is more than-0.3 MPa, selecting a normal mode, and if delta P is less than-0.3 MPa, selecting a low-pressure mode; the process flow regulating range of the normal mode is Q, the process flow regulating range of the high-pressure mode is Q1-PQ/P0, and the process flow regulating range of the low-pressure mode is Q2-0.1-0.6Q.

As an improvement, the model matching theoretical pressure P0 and the normal mode process flow adjusting range Q are determined according to the steel type by referring to a steel type process card.

The improvement is that the smelting process signal points comprise a lifting signal, a ladle signal, an alloy signal, a slag signal, a power-on signal, a temperature measurement/sampling signal and a steel tapping signal; the steel tapping method comprises the steps that an operation time zone is formed between the transportation adjusting signal and the seat bag signal, the seat bag time zone is formed within 1-3 min after the seat bag signal starts, an electrifying time zone is formed between the electrifying signal and the temperature measuring/sampling signal, the alloy signal and the slag material signal are located in the electrifying time zone, the temperature measuring/sampling signal comprises electrode lifting, temperature measuring and electrode descending and belongs to the temperature measuring/sampling time zone, and the steel tapping signal comprises electrode lifting and steel tapping and belongs to the steel tapping time zone.

Has the advantages that:

at present, the flow control of the ladle refining bottom blowing is limited to the flow of the process, and the function of automatically adjusting the proper flow according to the ventilation effect is not available, the adjustment of the specific numerical value of the flow of the ladle refining bottom blowing gas mostly depends on manual adjustment of an operator based on observation and experience, a lot of extra work is added to the originally nervous ladle refining operation process, the extra energy of the operator is wasted, and the instability of smelting is caused. The development of the process model of the invention increases the feedback and automatic adjustment functions of the flow, the bottom blowing flow in the ladle refining process can realize automatic adjustment based on automatic discrimination and automatic control, so that the bottom blowing gas supply control is more scientific and reasonable, the extra energy waste in the work of operators in tension is reduced, the smelting stability is increased, the modeling and control effects of the control unit are stabilized, the interference factors in the ladle refining process are further reduced, and the realization of the automatic refining process is facilitated.

Detailed Description

The present invention will be described in further detail with reference to examples. The reagents or instruments used are not indicated by manufacturers, and are regarded as conventional products which can be purchased in the market. Referring to a steel type process card, the steel type selected in the embodiment is 82B, the model matching theoretical air supply pressure P0 is 0.3-0.5 Mpa, and the process flow regulating range Q in a normal mode is 50-700 NL/min.

Example 1

When the actual air supply pressure P is 0.4-0.6 MPa, the delta P is 0.1-0.2 MPa, and 0.3MPa is larger than the delta P to 0.3MPa, the flow regulating range Q in a normal mode is 50-700 NL/min; according to the steel grade, the process flow is automatically adjusted within the adjusting range according to the signal points of the smelting process by judging the time zone, as shown in table 1, the automatic switching of the model flow is realized by matching the bottom blowing automatic gas supply model with the signal points of the smelting process, and finally, the automatic identification and adjustment of the bottom blowing flow and the bottom blowing signal in each stage of the ladle refining process are realized.

TABLE 1 Normal mode flow Meter

Example 2

When the actual air supply pressure P is 0.7-1.0 MPa, the delta P is 0.4-0.5 MPa, and the delta P is more than 0.3MPa, the flow regulating range Q1 in a high-pressure mode is selected to be (0.7-1.0)/(0.3-0.5) × (500-700) NL/min is approximately equal to 2 × (500-700) NL/min; according to the steel grade, the process flow is automatically adjusted within the adjusting range according to the signal points of the smelting process by judging the time zone, as shown in the table 2, the automatic switching of the model flow is realized by matching the bottom blowing automatic gas supply model with the signal points of the smelting process, and finally, the automatic identification and adjustment of the bottom blowing flow and the bottom blowing signal in each stage of the ladle refining process are realized.

TABLE 2 high pressure mode flowmeter

Example 3

When the actual air supply pressure P is 0.1-0.5 MPa, the delta P is (-0.2) — (-0.25) Mpa, and the delta P is less than-0.3 Mpa, the flow rate adjusting range Q2 in a low-pressure mode is 0.5 (500-700) NL/min (250-350) NL/min; according to the steel grade, the process flow is automatically adjusted within the adjusting range according to the signal points of the smelting process by judging the time zone, as shown in table 3, the automatic switching of the model flow is realized by matching the bottom blowing automatic gas supply model with the signal points of the smelting process, and finally, the automatic identification and adjustment of the bottom blowing flow and the bottom blowing signal in each stage of the ladle refining process are realized.

TABLE 3 Low pressure mode flowmeter

The protection of the present invention is not limited to the above embodiments. Variations and advantages that may occur to those skilled in the art may be incorporated into the invention without departing from the spirit and scope of the inventive concept and the scope of the appended claims is intended to be protected.

Claims

1. A gas injection process model for ladle refining is characterized in that: the method comprises the steps of designing a bottom blowing automatic gas supply model and a smelting process signal point according to a smelting process, realizing automatic model flow switching by matching the bottom blowing automatic gas supply model with the smelting process signal point, and finally realizing automatic identification and adjustment of bottom blowing flow and bottom blowing signals in each stage of a ladle refining process.

2. The gas injection process model for ladle refining as claimed in claim 1, wherein: the designed bottom blowing automatic air supply model is divided into two stages of paths, wherein the first stage of path is used for judging the ventilation condition of a bottom blowing air supply element according to air supply pressure so as to select a process flow mode and determine the adjustment range of process flow; the second-stage path is that the process flow is automatically adjusted within the adjusting range according to the signal point discrimination time zone of the smelting process according to the steel grade.

3. The gas injection process model for ladle refining as claimed in claim 2, wherein: the air supply pressure in the first-stage path is delta P = P-P0, wherein P is actual air supply pressure, and P0 is model matching theoretical air supply pressure; if delta P is more than 0.3MPa, selecting a high-pressure mode, if 0.3MPa is more than delta P is more than-0.3 MPa, selecting a normal mode, and if delta P is less than-0.3 MPa, selecting a low-pressure mode; the process flow regulating range of the normal mode is Q, the process flow regulating range of the high-pressure mode is Q1= PQ/P0, and the process flow regulating range of the low-pressure mode is Q2= 0.1-0.6Q.

4. The gas injection process model for ladle refining as claimed in claim 3, wherein: the model matching theoretical pressure P0 and the process flow adjusting range Q of the normal mode are determined according to the type of steel by referring to a steel type process card.

5. The gas injection process model for ladle refining as claimed in claim 1, wherein: the smelting process signal points comprise a lifting signal, a ladle signal, an alloy signal, a slag signal, an electrifying signal, a temperature measuring/sampling signal and a tapping signal; the steel tapping method comprises the steps that an operation time zone is formed between the transportation adjusting signal and the seat bag signal, the seat bag time zone is formed within 1-3 min after the seat bag signal starts, an electrifying time zone is formed between the electrifying signal and the temperature measuring/sampling signal, the alloy signal and the slag material signal are located in the electrifying time zone, the temperature measuring/sampling signal comprises electrode lifting, temperature measuring and electrode descending and belongs to the temperature measuring/sampling time zone, and the steel tapping signal comprises electrode lifting and steel tapping and belongs to the steel tapping time zone.