A safe control method for automatic steel tapping in converter

Abstract

The invention discloses a safe control method for automatic steel tapping of a converter. When the converter is automatically tapping steel, various faults of a tilting encoder of the converter and a laser rangefinder of a ladle car are judged by a controller, including not only the faults of the tilting encoder and the laser rangefinder body, but also the faults are judged by the cooperation of the rotation speed calculation deviation of the tilting frequency converter of the converter and the frequency converter of the ladle car. The invention can ensure that the whole system exits the automatic steel tapping state of the converter safely, timely and accurately, and has obvious effect. The invention is suitable for the design and application of similar automatic steel tapping control systems for converters. At the same time, the invention ensures the quality of molten steel tapped, reduces the labor intensity of related operators, obtains parameters of automatic steel tapping of the converter and equipment control parameters by multiple detection methods, can automatically handle partial faults such as output value jump caused by blocking of the laser rangefinder, and improves the efficiency of automatic steel tapping of the converter and the safety performance of automatic steel tapping of the converter.

Description

Technical Field

[0001] The invention relates to the field of metallurgical steelmaking automatic control, and in particular to a converter automatic steel tapping safety control method. Background Art

[0002] Automatic steel-tapping technology refers to all equipment related to converter steel-tapping, including the converter body, ladle car, alloy chute, slag retaining mechanism, etc., which are linked in a predetermined logical order to achieve fully automatic control of the steel-tapping process. At present, large-scale steel mills around the world have basically achieved automatic smelting and steel-tapping in converters, which has effectively improved the smelting success rate, shortened the smelting cycle, increased output and quality, while reducing raw material consumption and costs, greatly reducing the labor intensity of operators, and only manual monitoring is required during the automatic steel-tapping process.

[0003] However, due to the harsh working environment of the converter and ladle cars, the laser rangefinder used to locate the ladle car is prone to disconnection or power outages. At the same time, foreign objects passing through the ladle car's running track or smoke will also hinder the laser rangefinder from continuous measurement, resulting in errors in the automatic travel control of the ladle car. In severe cases, the ladle car may break the control cable and the ladle car may shift the steel connection position. If the automatic steel tapping of the converter is not stopped in time, serious production safety accidents such as steel spillage will occur. In addition, the tilt encoder cable of the converter may also be melted by high temperature during long-term work, resulting in errors in the automatic steel tapping control of the converter and production safety accidents such as converter overturning and steel overflow from the furnace mouth. These problems have seriously affected the reliability of automatic steel tapping, making it difficult to ensure production safety during the automatic steel tapping process.

[0004] At the same time, if the laser rangefinder is frequently blocked during the automatic steel tapping process, causing the output value to jump, or the speed of the ladle car is lower than the control system's expectation due to track obstruction, it will affect the controller's control of the automatic steel tapping process, making the controller unable to complete the automatic steel tapping process according to the predetermined program, thereby reducing the production efficiency of automatic steel tapping. Summary of the invention

[0005] The purpose of the present invention is to provide a converter automatic steel tapping safety control method in view of the problems existing in the prior art.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A converter automatic steel tapping safety control method comprises the following steps:

[0008] S1: When the ladle car moves automatically, two laser rangefinders are used to measure the distance. When the value measured by any of the laser rangefinders exceeds the maximum value, the controller will alarm. When the difference between the distances measured by the two laser rangefinders is greater than the first threshold, the controller will also alarm.

[0009] S2: The controller calculates the theoretical distance L of the ladle car according to the rotation speed of the ladle car inverter, and subtracts L from the actual distance measured by the laser rangefinder and takes the absolute value to obtain the first error distance L1. When L1 is greater than the second threshold, the ladle car will continue to move for 0.1m or 0.5s. If L1 is still greater than the second threshold, the controller will alarm.

[0010] S3: The ladle car moves to the steel receiving position, and the controller subtracts the distance the ladle car reached the steel receiving position when the steel was discharged last time from the current moving distance and takes the absolute value to obtain a second error distance L2. When L2 is greater than the third threshold, the controller will alarm. If the difference between the current moving distance and the expected moving distance exceeds the seventh threshold, the controller will also alarm.

[0011] S4: When the converter rotates, when the value measured by the tilt encoder exceeds the preset range, the controller will alarm. When the controller reads that the converter tilt electrical speed is greater than 0, if the value measured by the tilt encoder does not change within a limited time, the controller will also alarm.

[0012] S5: During the process of the converter tilting toward the rear, when the value measured by the tilt encoder of the converter is greater than the fourth threshold value, the proximity switch located on one side of the converter will be triggered to send a confirmation signal to the controller. If the tilt encoder does not receive the confirmation signal, the controller will alarm.

[0013] When the value measured by the laser rangefinder in step S1 exceeds the maximum value, an alarm is sent to the controller to prevent the control cable of the ladle car from being broken due to a long travel distance;

[0014] Step S2 can handle the problem that the output value of the laser rangefinder is suddenly blocked by pedestrians or vehicles, causing a jump in value, and can also identify and handle the problem that the output value of the laser rangefinder remains unchanged during the operation of the ladle car due to being blocked by an object for a long time;

[0015] Step S3 is a protective measure taken to prevent the position setting value of the ladle car from being accidentally reset or the seat tank position of the ladle car from being changed;

[0016] Step S4 can identify the failure of the tilt encoder itself to respond, and avoid problems caused by errors in the operation of the control system;

[0017] Step S5 is prepared to prevent the measurement result of the tilt encoder from being inaccurate, so as to avoid the converter being unable to turn to the designated position during the automatic steel tapping process;

[0018] The present invention uses the controller to judge various faults of the tilt encoder of the converter and the laser rangefinder of the ladle car, including not only the faults of the tilt encoder and the laser rangefinder body, but also the faults are judged by the rotation speed calculation deviation of the tilt frequency converter of the converter and the frequency converter of the ladle car, so as to ensure that the whole system exits the automatic steel-tapping state of the converter safely, timely and accurately, and has obvious effect, and is suitable for the design and application of the automatic steel-tapping control system of the similar converter;

[0019] At the same time, the present invention ensures the quality of molten steel during steel tapping, obtains parameters of automatic steel tapping of the converter and equipment control parameters through a variety of detection methods, and can automatically handle partial faults such as output value jumps caused by the laser rangefinder being blocked, thereby improving the efficiency of automatic steel tapping and also improving the safety performance of automatic steel tapping.

[0020] Preferably, the two laser rangefinders are divided into a main rangefinder and a secondary rangefinder. The controller preferentially uses the value of the main rangefinder as the actual distance. When the value measured by the main rangefinder is less than 0.1m, the controller will determine that the main rangefinder is disconnected or powered off, and the controller will use the value of the secondary rangefinder as the actual distance. When the values ​​measured by the two laser rangefinders are both less than 0.1m, the controller will determine that both laser rangefinders are disconnected or powered off, and the controller will alarm.

[0021] Preferably, when the value measured by the main rangefinder or the auxiliary rangefinder is less than 0.1 m, the controller no longer calculates the difference between the distances measured by the two laser rangefinders.

[0022] When the measurement result of the laser rangefinder is less than 0.1m, it means that the laser rangefinder is disconnected or powered off, and the influence of the faulty laser rangefinder needs to be eliminated so that the automatic steel tapping of the converter can continue.

[0023] Preferably, the controller records at least two consecutive values ​​sent by each of the laser rangefinders. If the difference between the two consecutive values ​​sent by the main rangefinder is greater than a fifth threshold, the controller determines that the value of the main rangefinder jumps significantly, and the controller uses the value of the auxiliary rangefinder as the actual distance. When the distance measurement values ​​of the two laser rangefinders jump significantly, the controller will alarm.

[0024] Preferably, before the ladle car moves, when the difference in distance measured by the two laser rangefinders is greater than a sixth threshold, the controller will alarm and at the same time the controller will prohibit the converter from automatically tapping steel.

[0025] If the difference in distances measured by the two laser rangefinders before the converter starts automatic steel tapping is greater than the sixth threshold, it may be because the laser directions of the two laser rangefinders have been manually adjusted and changed, resulting in the laser not irradiating the target object, or one of the laser rangefinders is blocked. Therefore, it is necessary to eliminate the fault in advance to avoid another fault after the converter starts automatic steel tapping, affecting the production process.

[0026] Preferably, the current moving distance in step S3 adopts the actual distance.

[0027] Preferably, when the controller alarms, the controller will stop the converter from automatically tapping steel.

[0028] When a fault is found, the controller can remind the operator responsible for monitoring and stop the converter from automatically tapping steel in time, thereby avoiding production safety accidents.

[0029] Preferably, the controller is preset with the expected moving distance of the ladle car within a specified time. When the automatic moving time of the ladle car reaches the specified time, the controller will compare the actual distance with the expected moving distance. When the difference between the actual distance and the expected moving distance exceeds the seventh threshold, the controller will alarm.

[0030] When the controller timing exceeds the theoretical time, it can be found that the ladle car is stuck on the track or the laser of the laser rangefinder does not irradiate the ladle car, which provides a reference for subsequent maintenance.

[0031] Preferably, the controller adopts a PLC controller, and when the controller alarms, it will send fault information to the human-machine interface of the main operating room. The laser irradiation directions of the two laser rangefinders are set parallel to the moving direction of the ladle car.

[0032] Preferably, when the converter rotates to the steel tapping angle, the controller will record the moving distance of the ladle car, and at this time the ladle car should have arrived at the steel receiving position.

[0033] The converter starts to tap steel after it rotates to the tapping angle, at which time the ladle car is in the first position for receiving molten steel.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The present invention uses a controller to judge various faults of the tilt encoder of the converter and the laser rangefinder of the ladle car, including not only the faults of the tilt encoder and the laser rangefinder body, but also the faults are judged by the rotation speed calculation deviation of the tilt inverter of the converter and the inverter of the ladle car. The safety control method can ensure that the whole system exits the automatic steel-tapping state of the converter safely, timely and accurately, and the effect is obvious. It is suitable for the design and application of similar converter automatic steel-tapping control systems.

[0036] (2) The present invention ensures the quality of molten steel during steel tapping, obtains the parameters of automatic steel tapping of the converter and the equipment control parameters through a variety of detection methods, and can automatically handle some faults such as output value jumps caused by the blocking of the laser rangefinder, thereby improving the efficiency of automatic steel tapping and also improving the safety performance of automatic steel tapping. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the process of the present invention;

[0038] Figure 2 It is a schematic diagram of the process of judging whether the laser rangefinder itself is faulty in the present invention;

[0039] Figure 3 It is a schematic diagram of the process of comparing the deviations of two laser rangefinders in the present invention;

[0040] Figure 4 It is a schematic diagram of the process of judging whether the value of the laser rangefinder jumps in the present invention;

[0041] Figure 5 It is a schematic diagram of the process of comparing the steel connection positions in the present invention;

[0042] Figure 6 It is a schematic diagram of a flow chart for judging whether the position of a ladle car is within a restricted range in the present invention;

[0043] Figure 7 A schematic diagram of a flow chart for determining whether the inclination encoder is accurate in the present invention;

[0044] Figure 8 It is a schematic diagram of the process of judging whether the converter inclination angle exceeds the limit in the present invention. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "middle", "upper", "lower", "left", "right", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0047] like Figures 1 to 8 As shown, the specific scheme of the embodiment is as follows: Specifically, each difference in the method takes an absolute value for comparison when compared with each threshold value. In this embodiment, the first threshold value is 5m, the second threshold value, the fifth threshold value and the seventh threshold value are all 0.1m, the third threshold value is 0.2m, the limited time is 0.2s, the sixth threshold value is 0.7m, and the steel tapping angle is -78°.

[0048] A converter automatic steel tapping safety control method comprises the following steps:

[0049] S1: When the ladle car moves automatically, two laser rangefinders measure the distance. When the value measured by any laser rangefinder exceeds the maximum value, the controller will alarm. When the difference between the distances measured by the two laser rangefinders is greater than 5m, the controller will also alarm.

[0050] S2: The controller calculates the theoretical distance L of the ladle car according to the speed of the ladle car inverter. The controller subtracts L from the actual distance measured by the laser rangefinder and takes the absolute value to obtain the first error distance L1. When L1 is greater than 0.1m, the ladle car will continue to move for 0.1m or 0.5s. If L1 is still greater than 0.1m, the controller will alarm.

[0051] S3: The ladle car moves to the steel receiving position. The controller subtracts the distance the ladle car reached the steel receiving position when the steel was discharged last time from the current moving distance and takes the absolute value to obtain the second error distance L2. When L2 is greater than 0.2m, the controller will alarm. If the difference between the current moving distance and the expected moving distance exceeds the seventh threshold, the controller will also alarm.

[0052] S4: When the converter is rotating, if the value measured by the tilt encoder exceeds the preset range, the controller will alarm. When the controller reads that the converter tilt electrical speed is greater than 0, if the value measured by the tilt encoder does not change within 0.2s, the controller will also alarm.

[0053] S5: During the process of the converter tilting toward the rear, when the value measured by the converter's tilt encoder is greater than the fourth threshold, the proximity switch located on one side of the converter will be triggered to send a confirmation signal to the controller. If the tilt encoder does not receive the confirmation signal, the controller will alarm.

[0054] Specifically, the ladle car moves along the track, the laser rangefinder is arranged parallel to the track, the laser irradiation directions of the two laser rangefinders are parallel to the moving direction of the ladle car, and the lasers emitted by the two laser rangefinders can irradiate the ladle car.

[0055] Specifically, the proximity switch is a switch-type sensor, which has the characteristics of a travel switch and a micro switch, and also has sensing performance. When the converter approaches the sensing area of ​​the switch-type sensor, the proximity switch can send electrical instructions to the controller quickly without contact, pressure or sparks, and accurately reflect the position and stroke of the converter's motion mechanism. The sensing range of the proximity switch used in this embodiment is -65°±0.1°, so the fourth threshold is -65°-0.1°.

[0056] Specifically, the maximum value of the laser rangefinder is 50 m, and the preset range of the tilt encoder is less than or equal to 30° and greater than or equal to -105°.

[0057] Specifically, the two laser rangefinders are divided into a main rangefinder and a secondary rangefinder. The controller gives priority to using the value of the main rangefinder as the actual distance. When the value measured by the main rangefinder is less than 0.1m, the controller will determine that the main rangefinder is disconnected or powered off, and the controller will use the value of the secondary rangefinder as the actual distance. When the values ​​measured by both laser rangefinders are less than 0.1m, the controller will determine that both laser rangefinders are disconnected or powered off, and the controller will alarm.

[0058] Specifically, when the value measured by the primary rangefinder or the secondary rangefinder is less than 0.1 m, the controller no longer calculates the difference between the distances measured by the two laser rangefinders.

[0059] Specifically, the controller records at least two consecutive values ​​sent by each laser rangefinder. If the difference between the two consecutive values ​​sent by the main rangefinder is greater than 0.1m, the controller determines that the value of the main rangefinder jumps significantly, and the controller will use the value of the auxiliary rangefinder as the actual distance. When the distance measurement values ​​of the two laser rangefinders jump significantly, the controller will alarm; even if the value of the main rangefinder or the auxiliary rangefinder jumps significantly, it will not affect the execution of step S1. As long as the difference in the distances measured by the two laser rangefinders is less than 5m, the automatic movement of the ladle car will continue to proceed normally.

[0060] Specifically, before the ladle car moves, when the difference in distance measured by the two laser rangefinders is greater than 0.7m, the controller will alarm, and at the same time the controller will prohibit the ladle car from moving automatically and prohibit the converter from automatically tapping steel.

[0061] Specifically, the controller converts the running speed of the ladle car according to the rotation speed of the ladle car inverter, and then estimates L according to the running time of the ladle car recorded by the controller.

[0062] Specifically, the current moving distance in step S3 adopts the actual distance.

[0063] Specifically, when the controller alarms, the controller will simultaneously stop the automatic movement of the ladle car and the automatic steel tapping of the converter.

[0064] Specifically, the controller is preset with the expected moving distance of the ladle car within the specified time. When the automatic moving time of the ladle car reaches the specified time, the controller will compare the actual distance measured by the laser rangefinder with the expected moving distance. When the difference between the actual distance and the expected moving distance exceeds 0.1m, the controller will alarm.

[0065] Specifically, when the converter rotates to -78°, the controller will record the moving distance of the ladle car. At this time, the ladle car should have arrived at the steel receiving position, which refers to the preset position where the ladle car receives molten steel.

[0066] Specifically, the controller uses S7-400PLC controller. When the controller alarms, it will send fault information to the human-machine interface of the main operating room. The converter tilting system is S120 system. The power of the converter tilting motor is 160kW, and the power of the converter tilting motor brake is 0.45kW. The tilt encoder is installed on the side of the converter tilting motor to detect the tilting angle of the converter. The detection accuracy is 0.1°. The tilt encoder has been connected to the controller; the ladle trolley travel system is controlled by the controller.

[0067] Specifically, the converter tapping port is provided with a slag detection device, which can detect slag inclusion during converter tapping, with a detection accuracy of more than 98%. The relevant signals of the slag detection device are connected to the control system.

[0068] Specifically, the steps of automatic steel tapping in the converter are as follows:

[0069] (1) After the oxygen lance blowing is completed, the control system confirms that the conditions for automatic steel tapping from the converter are met and issues a prompt for automatic steel tapping from the converter. After manual confirmation, the automatic steel tapping button for the converter is pressed;

[0070] (2) The steel tapping angle and the corresponding steel receiving position are calculated based on the converter molten iron loading amount and furnace type measurement results. The laser rangefinder is used to measure the actual position of the ladle car. The control system controls the ladle car to automatically move to the steel receiving position to receive the molten steel.

[0071] (3) The converter tilts toward the rear of the furnace, and the infrared detection device at the furnace mouth detects the state inside the furnace. Image recognition technology is used to determine whether there are abnormal conditions in the furnace, such as a large amount of foamy slag. If there are no abnormal conditions, the converter tilts to the steel tapping angle. Otherwise, the controller will alarm and stop the converter from automatically tapping steel.

[0072] (4) After the converter reaches the tapping angle, the tapping port is opened, molten steel flows out of the tapping port, and the tapping process begins. The preset value of the converter tilting angle is automatically set at the moment, and the preset value is fine-tuned according to the steel flow width and slag conditions detected by the slag detection and the slag conditions detected by the furnace mouth infrared detection device;

[0073] (5) The distance between the ladle car and the shaking furnace angle are coupled and controlled in a segmented manner. According to the dumping angle and the feedback data from the steel flow centering detection device, the distance between the ladle car and the ladle car is automatically adjusted to ensure that the molten steel flows smoothly into the ladle;

[0074] (6) Automatically adding alloy into the ladle;

[0075] (7) When the tilting angle reaches the end angle of steel tapping and the slag detection system detects that the slag content exceeds the preset value, the slag blocking system starts to work, quickly blocks the steel tapping port, and the tilting system quickly tilts the converter back to 0°;

[0076] (8) The ladle car leaves the steel tapping position and automatically moves to the argon blowing position, and the slag car moves to the slag tapping position;

[0077] (9) After the start of the slag pouring process is manually confirmed, the slag pouring operation is performed according to the preset slag pouring tilting angle. The slag car and the converter tilt in conjunction to ensure that the slag is smoothly poured from the furnace mouth into the slag pot;

[0078] (10) After the slag flow online detection device detects that there is no slag flowing out, the tilting system tilts the converter back to 0°.

[0079] Furthermore, the whole process of automatic steel tapping from the converter is realized mainly by controlling the automatic walking of the ladle car and controlling the automatic rotation of the converter. The following problems can be avoided by the automatic steel tapping safety control method of the converter of the present application:

[0080] A: In step 1 of the automatic steel tapping of the converter, the lasers emitted by the two laser rangefinders may not irradiate the target object, or one of the laser rangefinders may be blocked. At this time, the controller cannot obtain the accurate position of the ladle car, and cannot ensure that the ladle car can move safely after the automatic steel tapping of the converter begins. In this method, whether the above problem occurs is determined by determining whether the difference in the distances measured by the two laser rangefinders is greater than 0.7m, so as to ensure that the controller can obtain the accurate position of the ladle car;

[0081] B: In steps 2, 5 and 8 of automatic steel tapping from the converter, the laser rangefinder is prone to disconnection or power failure. At this time, the value sent to the controller by the disconnected or powered-off laser rangefinder will be less than 0.1m. At the same time, the laser rangefinder is also easily blocked by foreign objects or smoke passing through the running track of the ladle car, causing the measured value to jump. The present method adopts a one-in-one-standby mode, in which the controller identifies the failed or jumping laser rangefinder, and activates another standby laser rangefinder to continue to provide the controller with the accurate position of the ladle car, and performs supplementary correction through step S2 to prevent the standby laser rangefinder from being blocked by foreign objects or smoke passing through the running track of the ladle car and being unable to measure continuously. This ensures that the automatic steel tapping from the converter can continue while also ensuring production safety.

[0082] C: In steps 2, 5 and 8 of automatic steel tapping from the converter, the ladle car may have a problem of breaking the cable connected to it due to a long travel distance. The method can prevent the position of the ladle car from exceeding the specified range through step S1;

[0083] D: In steps 2, 5 and 8 of automatic steel tapping from the converter, the laser rangefinder may be blocked by an object for a long time, resulting in the output value of the ladle car remaining unchanged during operation. The method can determine whether the above problem occurs through step S2. After confirming the occurrence of the above problem, the method uses the theoretical distance L for short-time or short-distance control. If the deviation between the estimated value and the measured value returns to a reasonable range within a short time or short distance, the laser rangefinder can be used to control the ladle car, thereby avoiding the normal movement of the ladle car being affected by the jump of the laser rangefinder value. At the same time, since the laser rangefinder is set parallel to the track of the ladle car, if the deviation between the estimated value and the measured value still exceeds the reasonable range within a short time or short distance, it is very likely that someone or a foreign object is parked on the track of the ladle car. The controller will alarm and stop the ladle car to avoid safety accidents.

[0084] E: In steps 2, 5 and 8 of automatic steel tapping from the converter, the ladle car position setting value stored in the controller may be accidentally reset. There is also a problem that the ladle car seat position changes while the ladle car position stored in the controller does not change. At this time, it is very easy to cause steel splashing when the converter is automatically tapped. The method can determine whether such a problem occurs through step S3, and prevent the converter from continuing to tap steel after the problem occurs, thereby avoiding the occurrence of steel splashing;

[0085] F: In steps 2, 5 and 8 of automatic steel tapping from the converter, the ladle car cannot reach the set position within the specified time due to uneven tracks or insufficient output of the ladle car motor, which affects the efficiency of automatic steel tapping from the converter. At the same time, due to the above problems, step S3 may cause the steel receiving position stored in the controller to approach the same direction each time after multiple executions, resulting in cumulative errors. This method identifies whether the above problems occur by comparing the actual distance measured by the laser rangefinder with the expected moving distance of the ladle car. If a problem occurs, the controller can stop the automatic steel tapping from the converter and remind the operator to perform maintenance, and reset the steel receiving position stored in the controller, thereby preventing safety accidents and avoiding the long-term operation of the ladle car with faults that affects the efficiency of automatic steel tapping from the converter;

[0086] G: In steps 3, 4, 5, 7, 9 and 10 of automatic steel tapping in the converter, the measurement result of the tilt encoder is likely to be inaccurate and deviate from the actual situation. When the problem is serious, it will lead to serious accidents such as converter overturning and steel overflow at the furnace mouth. The method can determine whether the above problem occurs through step S5 to prevent the above problem from causing safety accidents, and can calibrate the tilt encoder through the proximity switch;

[0087] H: In steps 3, 4, 5, 7, 9 and 10 of automatic steel tapping of the converter, the tilt encoder may be unresponsive due to cable fusing or faults. The method can determine whether the above problem occurs through step S4, and stop the automatic steel tapping of the converter in time to prevent the converter from losing control due to failure to obtain the rotation angle of the converter.

[0088] I: In steps 3, 4, 5, 7, 9 and 10 of automatic steel tapping from the converter, the control system may be wrong or the system-set converter running direction may be opposite to the actual running direction and other system problems. The above problems may easily cause the tilt encoder measurement value to exceed the limit. The method can determine whether the above problems occur through step S4, and stop the automatic steel tapping from the converter in time to avoid safety accidents.

[0089] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A converter automatic steel tapping safety control method, characterized in that: The following steps are involved: S1: When the ladle car moves automatically, two laser rangefinders are used to measure the distance. When the value measured by any of the laser rangefinders exceeds the maximum value, the controller will alarm. When the difference between the distances measured by the two laser rangefinders is greater than the first threshold, the controller will also alarm. S2: The controller calculates the theoretical distance L of the ladle car according to the rotation speed of the ladle car inverter, and subtracts L from the actual distance measured by the laser rangefinder and takes the absolute value to obtain the first error distance L1. When L1 is greater than the second threshold, the ladle car will continue to move for 0.1m or 0.5s. If L1 is still greater than the second threshold, the controller will alarm. S3: The ladle car moves to the steel receiving position, and the controller subtracts the distance the ladle car reached the steel receiving position when the steel was discharged last time from the current moving distance and takes the absolute value to obtain a second error distance L2. When L2 is greater than the third threshold, the controller will alarm. If the difference between the current moving distance and the expected moving distance exceeds the seventh threshold, the controller will also alarm. S4: When the converter rotates, when the value measured by the tilt encoder exceeds the preset range, the controller will alarm. When the controller reads that the converter tilt electrical speed is greater than 0, if the value measured by the tilt encoder does not change within a limited time, the controller will also alarm. S5: During the process of the converter tilting toward the rear, when the value measured by the tilt encoder of the converter is greater than the fourth threshold, the proximity switch located at one side of the converter will be triggered to send a confirmation signal to the controller. If the tilt encoder does not receive the confirmation signal, the controller will alarm. When the controller alarms in the above steps, the controller will stop the converter from automatically tapping steel.

2. A converter automatic steel tapping safety control method according to claim 1, characterized in that: The two laser rangefinders are divided into a main rangefinder and a secondary rangefinder. The controller first uses the value of the main rangefinder as the actual distance. When the value measured by the main rangefinder is less than 0.1m, the controller will determine that the main rangefinder is disconnected or powered off. The controller will use the value of the secondary rangefinder as the actual distance. When the values ​​measured by the two laser rangefinders are both less than 0.1m, the controller will determine that both laser rangefinders are disconnected or powered off, and the controller will alarm.

3. A converter automatic steel tapping safety control method according to claim 2, characterized in that: When the value measured by the main rangefinder or the auxiliary rangefinder is less than 0.1 m, the controller no longer calculates the difference between the distances measured by the two laser rangefinders.

4. A converter automatic steel tapping safety control method according to claim 2, characterized in that: The controller records at least two consecutive values ​​sent by each of the laser rangefinders. If the difference between the two consecutive values ​​sent by the main rangefinder is greater than a fifth threshold, the controller determines that the value of the main rangefinder jumps significantly, and the controller uses the value of the auxiliary rangefinder as the actual distance. When the distance measurement values ​​of the two laser rangefinders jump significantly, the controller will alarm.

5. The automatic steel-tapping safety control method of a converter according to claim 1 is characterized in that: Before the ladle car moves, when the difference in distance measured by the two laser rangefinders is greater than a sixth threshold, the controller will alarm and simultaneously the controller will prohibit the converter from automatically tapping steel.

6. A converter automatic steel tapping safety control method according to claim 1, characterized in that: The current moving distance in step S3 adopts the actual distance.

7. A converter automatic steel tapping safety control method according to claim 1, characterized in that: The controller is preset with the expected moving distance of the ladle car within the specified time. When the automatic moving time of the ladle car reaches the specified time, the controller will compare the actual distance with the expected moving distance. When the difference between the actual distance and the expected moving distance exceeds the seventh threshold, the controller will alarm.

8. A converter automatic steel tapping safety control method according to claim 1, characterized in that: The controller adopts a PLC controller. When the controller alarms, it will send fault information to the human-machine interface of the main operating room. The laser irradiation directions of the two laser rangefinders are set parallel to the moving direction of the ladle car.

9. A converter automatic steel tapping safety control method according to claim 1, characterized in that: When the converter rotates to the steel tapping angle, the controller will record the moving distance of the ladle car. At this time, the ladle car should have arrived at the steel receiving position.

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