A method and system for controlling the residual molten steel in a continuous casting ladle

Abstract

The application discloses a control method and system for remaining molten steel in a continuous casting ladle, in which a computer system collects empty ladle weight obtained by a weighing device on a travelling crane and crane meter weight after a refining process, and also collects input material weight obtained by a weighing device on a material bin, and calculates ladle slag weight in a steel process and refining slag weight in a refining process according to a set material yield; after the ladle is placed on a ladle rotary table, the computer system collects rotary table meter weight obtained by a weighing device on the ladle rotary table according to a preset period, and calculates remaining molten steel quality in the ladle in combination with the other collected data, and the computer system also real-time displays the calculation result of the remaining molten steel quality on a target post display screen. The method provided by the application can better control the remaining molten steel quality in the ladle, thereby improving the quality of the cast slab and ensuring smooth production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of continuous casting in metallurgical production, and particularly relates to a control method and system for residual molten steel in a ladle for continuous casting. BACKGROUND

[0002] In the process of continuous casting, the control of residual molten steel in a ladle is a key link in production technology. Currently, workers generally determine the timing of closing the nozzle according to experience by visually observing the site. However, the error is large due to different people, which is very disadvantageous to production. If the liquid level of molten steel in the ladle is high, the amount of residual molten steel is high, which reduces the metal yield and affects the production efficiency. If the liquid level of molten steel in the ladle is low, the slag under the nozzle will significantly increase, the alloy elements in the steel will be lost, and the inclusions will be generated, which affects the cleanliness of the molten steel and deteriorates the quality of the molten steel, and is not conducive to the production of clean steel. At the same time, the slag in the ladle enters the tundish, causing the accumulation of molten slag in the tundish, which has a bad influence on the continuous casting process, the castability of the molten steel is poor, the nozzle is blocked, production accidents occur, and the production is affected. Therefore, how to better control the amount of residual molten steel in the ladle to improve the quality of the casting blank and ensure the smooth production has become a technical problem to be solved by those skilled in the art. SUMMARY

[0003] In one aspect, the present application provides the following technical solutions:

[0004] A control method for residual molten steel in a ladle for continuous casting, comprising:

[0005] In the process of hoisting the empty ladle by the crane to the preliminary refining furnace, the computer system collects the weight G 空包 of the empty ladle obtained by the weighing device on the crane.

[0006] In the process of tapping in the preliminary refining furnace, the computer system collects the weight of the materials input in the process of tapping obtained by the weighing device on the material bin, and calculates the weight g BOF渣 of the ladle slag according to the set material yield.

[0007] In the process of refining in the ladle, the computer system collects the weight of the materials input in the process of refining obtained by the weighing device on the material bin, and calculates the weight g LF渣 of the refining slag according to the set material yield.

[0008] In the process of hoisting the ladle after the refining process by the crane to the ladle rotary table of the continuous casting machine, the computer system collects the weight G 行总 of the ladle obtained by the weighing device on the crane.

[0009] After the ladle is placed on the ladle rotary table, the computer system collects the weight G 回总and the remaining molten steel quality g in ladle casting is calculated according to the following formula 浇余 Meanwhile, the computer system calculates g 浇余 and puts it into the target post display screen in real time, 浇余 = G 回总 - g 空包 - (g BOF渣 + g LF渣 )(1+α).

[0010] In the formula, α is the difference ratio, α=(G 初始回总 - g 行总 ) / G 初始回总 , and G 初始回总 is the initial value of the rotary table metering weight G 回总 collected by the computer system after the ladle is placed on the rotary table.

[0011] Optionally, in the control method, when the difference ratio α is greater than 1%, the computer system sends an alarm message to the target post display screen.

[0012] Optionally, in the control method, during the process of hoisting the empty ladle to the preliminary refining furnace by the crane, the computer system collects the furnace number information of the preliminary refining furnace, the ladle number information of the ladle, and the weighing time information.

[0013] Optionally, in the control method, the preset period is 1s-2s.

[0014] Optionally, in the control method, when the remaining molten steel quality g 浇余 displayed on the target post display screen drops below a first preset value, the casting speed is reduced; and when the remaining molten steel quality g 浇余 displayed on the target post display screen drops below a second preset value, the ladle nozzle is closed; wherein the second preset value is less than the first preset value.

[0015] Optionally, in the control method, during the process of hoisting the empty ladle to the preliminary refining furnace by the crane, the crane is stationary at the target position for a preset time, and the computer system collects the empty ladle weight G 空包 every m seconds after the crane is stationary for 5 seconds, a total of n times, and the average of the n collection values is taken as the final collection result of the empty ladle weight G 空包 .

[0016] Optionally, in the control method, the m seconds are not less than 5 seconds, and the n times are not less than 5 times.

[0017] Optionally, in the control method, the computer system takes the average of X collection values of the rotary table metering weight G 回总 before the start of casting as the initial value G 初始回总Any two of the X acquisition values are separated by at least Y seconds.

[0018] Optionally, in the control method described above, the X is not less than 3, and the Y seconds is not less than 5 seconds.

[0019] A control system of a continuous casting ladle residual molten steel, comprising:

[0020] A first weighing device is arranged on a crane for hoisting the ladle;

[0021] A second weighing device is arranged on a first material bin for feeding materials during tapping in an initial refining furnace;

[0022] A third weighing device is arranged on a second material bin for feeding materials during ladle refining;

[0023] A fourth weighing device is arranged on a ladle turret of a continuous casting machine;

[0024] A computer system is signal connected with the first weighing device, the second weighing device, the third weighing device and the fourth weighing device;

[0025] A post display screen is used for displaying information fed by the computer system.

[0026] The control method of the continuous casting ladle residual molten steel provided in the application has the following beneficial effects:

[0027] During the process of pouring the molten steel from the ladle to a tundish, the computer system calculates the current molten steel quality (i.e. weight) in the ladle and feeds the calculation result to the target post display screen in real time, so as to guide the pouring personnel to produce, i.e. the operator can understand the dynamic change of the molten steel weight in the ladle in time through the information on the post display screen, thereby controlling the pouring speed and the ladle nozzle closing time accurately, which is beneficial to reducing the nozzle slag amount, improving the molten steel cleanliness, improving the steel quality, reducing accidents, reducing the molten steel loss on the production line and improving the production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description only constitute the embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0029] Figure 1 is the principle diagram of the control system of the continuous casting ladle residual molten steel provided in the embodiments of the application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0031] Referring to Figure 1 In the steelmaking continuous casting production process, molten steel successively experiences three links of preliminary smelting, refining and continuous casting. The preliminary smelting is performed in a preliminary smelting furnace (for example, a converter or an electric furnace), and after the preliminary smelting, molten steel is tapped into a ladle (i.e., a continuous casting ladle). The refining mode is external refining, i.e., ladle refining, that is, the molten steel completes refining in the ladle. After the refining, the ladle is placed on a ladle tundish, and when the molten steel is poured into a tundish, a part of the molten steel remains in the ladle, which is referred to as ladle residual molten steel. In the above process, the ladle is transferred by a crane, that is, the ladle is transferred from a standby position to a tapping position of the preliminary smelting furnace, from the tapping position of the preliminary smelting furnace to a refining process position, and from the refining process position to a ladle tundish position, which are all achieved by hoisting the ladle by the crane. At the same time of tapping the preliminary smelting furnace, material needs to be put into the ladle, and therefore a first material bin corresponding to this link is configured. In the process of ladle refining, material also needs to be put into the ladle, and therefore a second material bin corresponding to this link is configured. It needs to be noted that the first material bin and the second material bin can be the same material bin or different material bins. For example, a material bin includes multiple material chambers and contains different materials, and the material bin serves both the preliminary smelting furnace tapping link and the ladle refining link. According to the different materials required by different links, the material bin opens the corresponding material chamber to complete material feeding.

[0032] The embodiment of the present application provides a control system for ladle residual molten steel in continuous casting, comprising: a first weighing device arranged on a crane for hoisting a ladle; a second weighing device arranged on a first material bin for feeding material during tapping of a preliminary smelting furnace; a third weighing device arranged on a second material bin for feeding material during ladle refining; a fourth weighing device arranged on a ladle tundish of a continuous casting machine; a computer system connected with the first weighing device, the second weighing device, the third weighing device and the fourth weighing device; and a post display screen for displaying information fed by the computer system. Figure 1As shown, the first weighing device is arranged on the travelling crane, the second weighing device is arranged on the first material bin, the third weighing device is arranged on the second material bin, and the fourth weighing device is arranged on the ladle rotary table. The first weighing device, the second weighing device, the third weighing device and the fourth weighing device are all signal-connected with the computer system, so that the computer system can collect the weight values obtained by the weighing devices. It should be understood that, if the first material bin and the second material bin are the same material bin, the second weighing device and the third weighing device are the same weighing device. The post display screen is used to display production information to the post staff, for example, displaying the current furnace information on the electronic screen.

[0033] The embodiment of the present application provides a control method for residual molten steel in a continuous casting ladle, comprising the following steps:

[0034] In step S1, during the process of hoisting the empty ladle to the preliminary refining furnace by the travelling crane, the computer system collects the empty ladle weight G 空包 obtained by the weighing device on the travelling crane.

[0035] It should be understood that the weighing of the travelling crane must be in a stationary state, that is, the travelling crane does not move forward and backward, and the hoisted object does not ascend and descend. In a preferred embodiment, the travelling crane is stationary at the target position for a preset time, and the computer system completes the collection of the empty ladle weight G 空包 within the preset time. Specifically, the computer system can collect the empty ladle weight G 空包 every m seconds after the travelling crane is stationary for 5 seconds, a total of n times, and the average value of the n collection values is taken as the final collection result of the empty ladle weight G 空包 . The final collection result is used in the formula for calculating the residual molten steel quality of the ladle described below. Preferably, the above-mentioned m seconds is not less than 5 seconds, and the above-mentioned n times is not less than 5 times. For example, after the travelling crane hoists the empty ladle, it needs to be stationary for 5 seconds first, and then the computer system collects the weight every 6 seconds within 35 seconds of the stationary travelling crane, a total of 5 numbers, and the average number is taken as the actual weighing quality of the empty ladle.

[0036] In order to facilitate production management, the computer system can collect the furnace number information of the preliminary refining furnace, the ladle number information of the ladle and the weighing time information in step S1.

[0037] In step S2, during the tapping process of the preliminary refining furnace, the computer system collects the material weight input during the tapping process obtained by the weighing device on the material bin, and calculates the ladle slag weight g BOF渣 according to the set material yield.

[0038] It should be noted that material yield refers to the ratio of the dissolved portion of a material after it has been added to the molten steel to the total amount added. That is, the weight of the ladle slag formed after a certain material is added to the molten steel is equal to the product of 1 minus the material yield and the weight of that material added. The material yield is preset in the computer system by staff based on the actual conditions of different materials. Specifically, the computer system calculates the weight (in grams) of the ladle slag formed from each material by summing the results. BOF渣 It can correctly match the corresponding material yield for different materials.

[0039] Step S3: During the ladle refining process, the computer system collects the weight of the materials input during the refining process from the weighing device on the material silo, and calculates the weight (g) of the refining slag based on the set material yield. LF渣 .

[0040] Calculate the weight of refining slag (g) LF渣 The process and calculation of ladle slag weight (g) BOF渣 The process is similar and will not be repeated here.

[0041] Step S4: During the process of the overhead crane transporting the ladle after the refining process to the ladle turret of the continuous casting machine, the computer system collects the crane's weighing weight G obtained by the weighing device on the overhead crane. 行总 .

[0042] Similar to the process of weighing empty packages, the overhead crane must be stationary during weighing; that is, the crane must not move back and forth, and the load must not be raised or lowered. In a preferred embodiment, the computer system completes the weighing of the overhead crane G within a preset time during which the crane is stationary. 行总 The data is collected. Specifically, the computer system can collect the weight G of the empty package every p seconds after the vehicle has been stationary for 5 seconds. 空包 A total of q data points were collected, and the average value of the q collected values ​​was taken as the vehicle's metering weight G. 行总 The final acquisition result is used in the formula for calculating the difference ratio α, which will be described later. Preferably, the p seconds is no less than 5 seconds, and the q times is no less than 5 times.

[0043] Step S5: After the large bag is placed on the large bag turntable, the computer system collects the turntable weighing weight G obtained by the weighing device on the large bag turntable according to a preset cycle. 回总 And calculate the mass (g) of the remaining molten steel after the ladle pouring according to the following formula. 浇余 At the same time, the computer system will g 浇余 Real-time projection onto the target job display screen, g 浇余 =G 回总 -G 空包 -(g BOF渣 +g LF渣 (1+α).

[0044] wherein, a is the difference ratio, a = (G 初始回总 -G 行总 ) / G 初始回总 , G 初始回总 is the initial value of the measured weight G 回总 of the tundish rotary table collected by the computer system after the tundish is placed on the tundish rotary table.

[0045] Specifically, the above-mentioned preset period can be 0.5s-2s, for example, the computer system collects the measured weight G 回总 of the tundish rotary table every 1s after the tundish is placed on the tundish rotary table. The initial value G 初始回总 may be the first value collected in step S5, or the average of several values collected before the pouring starts, for example, the computer system takes the average of X values of the measured weight G 回总 of the tundish rotary table before the pouring starts as the initial value G 初始回总 , and the collection time of any two of the X values is at least Y seconds apart. Preferably, the above-mentioned X is not less than 3, and the above-mentioned Y is not less than 5 seconds.

[0046] In a preferred embodiment, when the difference ratio a is greater than 1%, the computer system sends an alarm message to the target post display screen. After the post staff sees the alarm message, the post staff will promptly calibrate the crane and / or the weighing device on the tundish rotary table.

[0047] After the pouring starts, the molten steel in the tundish gradually decreases, so the measured weight G 回总 of the tundish rotary table gradually decreases over time, and g 浇余 = G 回总 -G 空包 -(g BOF渣 +g LF渣 )(1+α) shows that the value of g 浇余 gradually decreases. In a preferred embodiment, when the remaining molten steel mass g 浇余 of the tundish displayed on the target post display screen decreases to below a first preset value, the pouring speed is reduced; when the remaining molten steel mass g 浇余 of the tundish displayed on the target post display screen decreases to below a second preset value, the tundish nozzle is closed; wherein the second preset value is less than the first preset value. For example, the tundish tapping capacity of a certain production line is 120 tons, when the remaining molten steel mass g 浇余 of the tundish decreases to 17 tons, the operator will control the pouring speed, prevent nozzle slagging in advance, and control the amount of nozzle slagging, when the remaining molten steel mass g 浇余 of the tundish decreases to 0.35 tons, the tundish nozzle is closed, and the pouring is completed.

[0048] In a preferred embodiment, the computer system automatically records the stop pouring time and the ladle pouring remaining molten steel mass g 浇余 to the production control information platform, facilitating statistics, analysis, management of the return of the remaining molten steel, and guiding production control. After the ladle completes pouring, the remaining molten steel and top slag in the ladle are poured into a slag tank and transported to a slag plant with environmental qualifications for treatment. After processes such as natural cooling, water pulverization, cast iron hammering, and magnetic separation of large steel slag, the molten steel is returned to the steel plant for recycling. In the traditional management mode, in order to reduce the loss of slag steel and ensure that all remaining molten steel is returned, a dedicated person needs to be assigned to supervise the operation during the transportation of the remaining molten steel to the slag plant, which undoubtedly increases personnel and management costs. The computer system automatically records the stop pouring time and the ladle pouring remaining molten steel mass g 浇余 to the production control information platform, facilitating statistics, analysis, management of the return of the remaining molten steel, and guiding production control. After the ladle completes pouring, the remaining molten steel and top slag in the ladle are poured into a slag tank and transported to a slag plant with environmental qualifications for treatment. After processes such as natural cooling, water pulverization, cast iron hammering, and magnetic separation of large steel slag, the molten steel is returned to the steel plant for recycling. In the traditional management mode, in order to reduce the loss of slag steel and ensure that all remaining molten steel is returned, a dedicated person needs to be assigned to supervise the operation during the transportation of the remaining molten steel to the slag plant, which undoubtedly increases personnel and management costs. The computer system automatically records the stop pouring time and the ladle pouring remaining molten steel mass g

[0049] The above description of disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of controlling the residual molten steel in a continuous casting ladle, characterized by, The application relates to a control system for controlling the remaining molten steel of a continuous casting ladle, and a control method thereof. During the process of transporting the empty ladle to the preliminary smelting furnace by the crane, the computer system collects the weight of the empty ladle obtained by the weighing device on the crane ; In the tapping process of the preliminary refining furnace, the computer system collects the weight of the materials input in the tapping process obtained by the weighing device on the first material bin, and calculates the weight of the ladle slag according to the set material yield ; In the ladle refining process, the computer system collects the weight of the material input in the refining process obtained by the weighing device on the second material bin, and calculates the refining slag weight according to the set material yield ; In the process of ladle from travelling crane to ladle rotary table of continuous casting machine after ladle lifting and transferring process, computer system collects the weighing weight of travelling crane obtained by weighing device on travelling crane ; After the ladle is placed on the ladle turret, the computer system collects the turret metered weight obtained by the weighing device on the ladle turret according to a preset period , and calculates the remaining molten steel mass of the ladle pouring according to the following formula , and the computer system simultaneously casts the target post display screen in real time, ; In the formula, is the difference ratio, , is the initial value of the measured weight of the rotary table after the ladle is placed on the rotary table and is acquired by the computer system. is the initial value of the measured weight of the rotary table after the ladle is placed on the rotary table and is acquired by the computer system.

2. The control method according to claim 1, characterized by, When the difference ratio is greater than 1%, the computer system sends an alarm message to the target post display screen.

3. The control method according to claim 1, characterized by, During the process of hoisting the ladle to a preliminary refining furnace by a travelling crane, the computer system collects the furnace number information of the preliminary refining furnace, the ladle number information of the ladle and the weighing time information.

4. The control method according to claim 1, characterized by, The preset period is 1-2 seconds.

5. The control method according to claim 1, characterized by, When the remaining steel water quality of the ladle shown on the target post display screen falls below a first preset value the pouring speed is reduced; when the remaining steel water quality of the ladle shown on the target post display screen falls below a second preset value the ladle nozzle is closed; wherein the second preset value is less than the first preset value.

6. The control method according to any one of claims 1 to 5, characterized by, In the process of hoisting the empty ladle to the preliminary refining furnace by the crane, the crane is stationary at the target position for a preset time, and the computer system collects the weight of the empty ladle every m seconds after the crane is stationary for 5 seconds , a total of n times, and the average value of the n collection values is taken as the final collection result of the weight of the empty ladle .

7. The control method according to claim 6, characterized by The m seconds are not less than 5 seconds, and the n times are not less than 5 times.

8. The control method according to claim 6, characterized by, Computer system to weigh a turntable averaging X number of acquisitions taken at least Y seconds apart prior to the start of the pour as the initial value averaging X number of acquisitions taken at least Y seconds apart prior to the start of the pour as the initial value 9. The control method according to claim 8, characterized by, The X is not less than 3, and the Y seconds are not less than 5 seconds.

10. A control system for pouring residual molten steel into a continuous casting ladle, characterized in that, The control system comprises: A first weighing device arranged on a travelling crane for hoisting the ladle; A second weighing device arranged on a first material bin for feeding materials during the tapping process of the preliminary refining furnace; A third weighing device arranged on a second material bin for feeding materials during the ladle refining process; A fourth weighing device arranged on a ladle rotating platform of a continuous casting machine; A computer system connected with the first, second, third and fourth weighing devices; A post display screen for displaying the information fed by the computer system.

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