Automatic steel charging system of pusher-type heating furnace

Abstract

The embodiment of the invention provides a pusher-type heating furnace automatic steel charging system which comprises a first laser range finder, a pressure sensor, a second laser range finder, a controller, an automatic steel charging control system, a pusher, a stokehole roller way and a heating furnace. The pusher is positioned on the right side of the advancing direction of the stokehole roller way; the heating furnace is located on the left side of the advancing direction of the stokehold roller way and right faces the steel pushing machine. The first laser range finder is located on the right side of the advancing direction of the stokehold roller way and located on the downstream of the steel pusher in the advancing direction of the stokehold roller way. The pressure sensor is arranged on the steel pushing machine; the second laser range finder is arranged at the rear end of a steel pushing arm of the steel pushing machine, and an irradiation point is the rear end of the steel pushing arm; the controller is in signal connection with the first laser range finder, the pressure sensor and the second laser range finder; and the automatic steel charging control system is in signal connection with the controller, the steel pusher and the stokehole roller way.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgical machinery, and particularly to an automatic steel charging system for a pusher-type reheating furnace. Background Art

[0002] There are mainly the following several modes for realizing automatic steel charging in today's hot rolling reheating furnaces: (1) realizing automatic positioning of slabs by matching the laser rangefinder with the speed of the furnace inlet roller table; (2) realizing automatic positioning of slabs by matching a single or multiple metal detectors or photoelectric sensors with the speed of the furnace inlet roller table; (3) realizing automatic positioning of slabs by matching limit switches with the speed of the furnace inlet roller table. After completing the above slab positioning, the displacement of the walking beam is used to calculate whether there is a steel charging vacancy, and then the width of the slab is associated to complete the final calculation of the pusher stroke. For a pusher-type reheating furnace with weak equipment foundation, manual operation is frequent, the automation efficiency of steel charging and discharging is not high, the control accuracy is lacking, the positioning of the furnace inlet slab and pusher mainly rely on manual operation, the control process is cumbersome, the functions are scattered, the efficiency is low, the proficiency requirement for operators is high, and there is a risk of over-pushing the slab, which may cause production safety accidents and affect the tapping plan time and production rhythm.

[0003] In the process of realizing the present invention, the applicant found that there are at least the following problems in the prior art:

[0004] The traditional technology does not completely cover the method for accurately positioning the furnace inlet slab and pusher, and cannot realize automatic steel charging in the case of mixed charging of slabs with different widths. Summary of the Invention

[0005] An embodiment of the present invention provides an automatic steel charging system for a pusher-type reheating furnace to solve the technical problem that the traditional technology does not completely cover the method for accurately positioning the furnace inlet slab and pusher and cannot realize automatic steel charging in the case of mixed charging of slabs with different widths.

[0006] To achieve the above object, on the one hand, an embodiment of the present invention provides an automatic steel charging system for a pusher-type reheating furnace, including: a first laser rangefinder, a pressure sensor, a second laser rangefinder, a controller and an automatic steel charging control system, a pusher, a furnace front roller table and a reheating furnace;

[0007] The pusher is located on the right side of the advancing direction of the furnace front roller table;

[0008] The reheating furnace is located on the left side of the advancing direction of the furnace front roller table and is directly opposite to the pusher;

[0009] The first laser rangefinder is located on the right side of the advancing direction of the furnace front roller table and is downstream of the pusher along the advancing direction of the furnace front roller table;

[0010] The pressure sensor is arranged on the pusher;

[0011] The second laser rangefinder is arranged at the rear end of the pusher arm of the pusher, and the irradiation point is the rear end head of the pusher arm;

[0012] The controller is signal-connected to the first laser rangefinder, the pressure sensor, and the second laser rangefinder;

[0013] The automatic steel loading control system is signal-connected to the controller, the pusher, and the front-of-furnace roller table.

[0014] Further, the laser ray emitted by the first laser rangefinder is parallel to the track surface of the front-of-furnace roller table, and the incident angle formed with the running direction of the front-of-furnace roller table is less than the maximum incident angle;

[0015] The maximum incident angle is determined according to the following formula (1):

[0016]

[0017] where θ max is the maximum incident angle, in degrees, which is the acute angle between the virtual straight line formed by connecting the first limit steel detection point and the second limit steel detection point and the advancing direction of the front-of-furnace roller table; W0 is the minimum width of the slab, in millimeters; W R is the width of the front-of-furnace roller table, in millimeters; L B is the deceleration distance of the slab, in millimeters.

[0018] Further, the automatic steel loading control system includes: a head stop position distance determination module, a deceleration position distance determination module, a distance comparison module, a deceleration control module, and a positioning stop module;

[0019] The head stop position distance determination module is used to project the straight-line distance from the first laser rangefinder to the head of the slab to be charged into the furnace onto the advancing direction of the front-of-furnace roller table as the head stop position distance of the slab to be charged into the furnace when the center of the slab to be charged into the furnace stops on the front-of-furnace roller table in a manner aligned with the center of the furnace door;

[0020] The head deceleration position distance determination module is used to superimpose the deceleration distance of the slab on the head stop position distance of the slab to be charged into the furnace to obtain the head deceleration position distance of the slab to be charged into the furnace;

[0021] The distance comparison module is used to compare the laser ranging data with the head deceleration position distance and the head stop position distance in real time;

[0022] The slab deceleration control module is used to maintain the running speed of the front-of-furnace roller table at 10% of the original speed during the period when the laser ranging data is less than the head deceleration position distance and greater than the head stop position distance, so as to convey the slab to be charged into the furnace at a low speed;

[0023] The slab positioning stop module is used to stop the running of the front-of-furnace roller table and set the slab positioning completion flag when the deviation value between the laser ranging data and the head stop position distance is less than 10 mm.

[0024] Furthermore, the automatic steel charging control system further includes: a full-furnace pusher starting point identification module, a pusher stroke margin determination module, a tapping translation distance determination module, an expected pusher stroke determination module, a pusher-in-place identification module, and a pusher-in-place stop module;

[0025] The full-furnace pusher starting point identification module is used to obtain the pusher pressure data from the controller in real time during the pusher pushing process, and take the actual pusher distance of the pusher monitored in real time as the first pusher distance when the pusher pressure data is greater than or equal to the preset pressure processing limit value;

[0026] The pusher stroke margin determination module is used to take the difference between the rated maximum pusher stroke and the first pusher distance as the pusher stroke margin;

[0027] The tapping translation distance determination module is used to take the value obtained by dividing the sum of the width of the first slab on the tapping side and the width of the previous tapped slab on the tapping side by 2 as the center line distance between the first slab on the tapping side and the previous tapped slab on the tapping side;

[0028] The expected pusher stroke determination module is used to determine the expected pusher stroke of the pusher during the pushing of the slab to be charged into the furnace according to the pusher stroke margin and the center line distance;

[0029] The pusher-in-place control module is used to set the pusher's proportional valve setting to zero during the pusher pushing process when it is determined in real time that the deviation between the actual pusher distance and the expected pusher stroke is within the preset pusher-in-place deviation range, so as to stop the pusher from pushing and control the pusher to return to the initial position.

[0030] Furthermore, the expected pusher stroke determination module is used to judge the magnitudes of the pusher stroke margin and the center line distance in real time; if the pusher stroke margin is greater than or equal to the center line distance, reset the pusher stroke insufficient flag bit, and set the expected pusher stroke of the pusher during the pushing of the slab to be charged into the furnace as the sum value of the first pusher distance and the center line distance; otherwise, set the pusher stroke insufficient flag bit, and set the maximum pusher stroke of the pusher during the pushing of the slab to be charged into the furnace as the minimum safe pusher stroke.

[0031] Furthermore, the automatic steel loading control system further includes:

[0032] A pusher steel in-place response module, configured to, when it is monitored that the pusher steel pressure data is less than the preset pressure processing limit value, take the actual pusher steel distance of the pusher steel machine monitored in real time as the second pusher steel distance; and when the second pusher steel distance is greater than the minimum safe travel of the pusher steel, reset the in-feed steel prohibition flag of the front-of-furnace roller table, otherwise set the in-feed steel prohibition flag of the front-of-furnace roller table.

[0033] Furthermore, the automatic steel loading control system further includes a reset module, and the reset module is configured to: when the pusher steel machine retreats to the initial position, set the pusher steel completion signal for 5 seconds, and at the same time send this signal to the rolling line L2 system, and reset the pusher steel completion signal after 5 seconds.

[0034] Furthermore, the controller reads the straight-line distance from the head of the slab to be charged into the furnace to the first laser rangefinder, and calculates the laser ranging data according to the following formula (2):

[0035] S0 = L1 * cosθ (2)

[0036] Wherein, S0 is the laser ranging data, in millimeters; L1 is the straight-line distance from the head of the slab to be charged into the furnace measured by the first laser rangefinder, in millimeters; θ is the incident angle of the first laser rangefinder, in degrees.

[0037] The above technical solution has the following beneficial effects: determining the incident angle of the first laser rangefinder according to the minimum width and maximum length of all slabs, so that the first laser rangefinder arranged on the side of the front-of-furnace roller table can monitor the real-time positions of all slabs with a width greater than the minimum width and less than the width of the front-of-furnace roller table on the front-of-furnace roller table, thereby realizing the automatic positioning in front of the furnace for different-width slabs appearing on the same production line. It improves the degree of automation control of slab charging into the furnace, reduces manual operation, reduces the requirement for the proficiency of operators, improves the steel loading efficiency, enables the heating furnace area to operate more stably and efficiently, reduces the risk of over-pushing the slab, and reduces the occurrence of production safety accidents. Description of the Drawings

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1It is the architecture diagram of an automatic steel charging system for a pusher-type reheating furnace according to one embodiment of the present invention;

[0040] Figure 2 It is the schematic diagram of the incident angle of the first laser rangefinder according to one embodiment of the present invention;

[0041] Figure 3 It is the schematic diagram of the pusher pushing the steel according to one embodiment of the present invention;

[0042] Figure 4 It is the time sequence diagram of the pushing pressure of the pusher according to one embodiment of the present invention.

[0043] The reference numerals are represented as: 1, the first laser rangefinder; 2, the pressure sensor; 3, the second laser rangefinder; 4, the controller; 5, the automatic steel charging control system; 6, the pusher; 7, the front furnace roller table; 8, the reheating furnace; 9, the slab to be charged into the furnace. Detailed implementation manners

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] On the one hand, as Figure 1 shown, the embodiment of the present invention provides an automatic steel charging system for a pusher-type reheating furnace, including: the first laser rangefinder 1, the pressure sensor 2, the second laser rangefinder 3, the controller 4, the automatic steel charging control system 5, the pusher 6, the front furnace roller table 7 and the reheating furnace 8;

[0046] The pusher 6 is located on the right side of the advancing direction of the front furnace roller table 7;

[0047] The reheating furnace 8 is located on the left side of the advancing direction of the front furnace roller table 7 and is directly opposite to the pusher 6;

[0048] The first laser rangefinder 1 is located on the right side of the advancing direction of the front furnace roller table 7 and is downstream of the pusher 6 along the advancing direction of the front furnace roller table 7;

[0049] The pressure sensor 2 is arranged on the pusher 6;

[0050] The second laser rangefinder 3 is arranged at the rear end of the pushing arm of the pusher 6 and the irradiation point is the rear end head of the pushing arm;

[0051] The controller 4 is signal-connected to the first laser rangefinder 1, the pressure sensor 2 and the second laser rangefinder 3;

[0052] The automatic steel loading control system 5 is signal-connected to the controller 4, the pusher 6, and the front-furnace roller table 7.

[0053] In some embodiments, the first laser rangefinder 1 is disposed downstream of the pusher 6 and is on the same side of the front-furnace roller table 7 as the pusher 6. The acute angle between the laser ray of the first laser rangefinder 1 and the running direction of the front-furnace roller table 7 forms an incident angle θ, which is pre-determined according to the minimum width and maximum length of all the slabs to be successively pushed into the heating furnace 8 during production.

[0054] The first laser rangefinder 1 is used to monitor in real time the laser ranging signal of the head end face of the slab 9 to be charged into the furnace on the front-furnace roller table 7.

[0055] The pressure sensor 2 is disposed on the pusher 6 and is used to monitor the pusher pressure signal in the pusher arm of the pusher 6.

[0056] The second laser rangefinder 3 is disposed at the rear end of the pusher arm of the pusher 6 and the irradiation point is the rear end head of the pusher arm, and is used to monitor in real time the actual pusher distance signal of the pusher 6.

[0057] The controller 4 is signal-connected to the first laser rangefinder 1, the pressure sensor 2, and the second laser rangefinder 3, and is used to collect the laser ranging signal of the first laser rangefinder 1 and convert it into laser ranging data, collect the pusher pressure signal of the pressure sensor 2 and convert it into pusher pressure data, and collect the actual pusher distance signal of the second laser rangefinder 3 and convert it into the actual pusher distance.

[0058] The automatic steel loading control system 5 is deployed in the hot-rolled strip automation system (or hot-rolled strip computer control system or hot-rolled strip information management and control system) in the existing computers in the steel mill. The hot-rolled strip automation system includes: a basic automation system (rolling line L1 system) and a process automation system (rolling line L2 system); the automatic steel loading control system 5 is specifically deployed in the basic automation system. And it is signal-connected to the controller 4, obtains the laser ranging data, pusher pressure data, and actual pusher distance from the controller 4, and controls the slab to be charged into the furnace to stop on the front-furnace roller table 7 in a manner that the center line of the slab to be charged into the furnace is aligned with the center line of the furnace door of the heating furnace 8, and controls the pusher 6 to complete the automatic steel loading of the slab 9 to be charged into the furnace; the slab charging method of the pusher-type heating furnace adopts a direct-pushing charging method, and the steel discharging method adopts a side-pushing steel discharging method; the slab 9 to be charged into the furnace is one of multiple slabs with different or the same widths that need to be successively pushed into the heating furnace.

[0059] The first laser rangefinder 1 for positioning the slab on the front furnace roller table cannot be installed at a position directly facing the running direction of the front furnace roller table 7, and can only be installed on the side of the front furnace roller table 7. At this time, the first laser rangefinder needs to irradiate the slab 9 to be charged into the furnace on the front furnace roller table 7 at an incident angle θ with the running direction of the front furnace roller table 7. In order to ensure that the first laser rangefinder 1 can correctly monitor the slabs 9 to be charged into the furnace with different widths, it is necessary to pre-determine the incident angle θ of the first laser rangefinder 1 according to the minimum width and maximum length of all slabs that need to be pushed into the heating furnace in sequence during production, and install the first laser rangefinder 1 on the side of the front furnace roller table 7 according to the incident angle θ.

[0060] The laser ray of the first laser rangefinder irradiates on the head end face of the slab to be charged into the furnace, and converts the linear distance information from the first laser rangefinder to the head end face of the slab to be charged into the furnace into a 4 - 20 mA current signal, and then transmits it to the (PLC) controller 4. After being logically quantified by the controller 4, it is the linear distance from the first laser rangefinder to the head end face of the slab to be charged into the furnace. Combining with the incident angle θ and according to the trigonometric function relationship, the vertical distance from the first laser rangefinder to the head end face of the slab to be charged into the furnace, that is, the laser ranging data, can be obtained;

[0061] For the second laser rangefinder, to prevent the instrument from being interfered by the complex environment, its installation position needs to be at the rear end of the pusher arm of the pusher, and the irradiation point is the rear end head of the pusher arm. The second laser rangefinder needs to convert the pusher position information into a 4 - 20 mA current signal, and then transmit it to the (PLC) controller, and after being logically quantified, it is the distance between the pusher head and the preset logical zero position (the extreme backward limit position of the pusher); for the pressure sensor, taking advantage of the characteristic that the pressure in the hydraulic cylinder of the pusher will change suddenly when pushing all the slabs in the furnace, and combining with the data of the second laser rangefinder to judge the position of the pusher and its forward distance at the moment of sudden pressure increase. The pressure sensor also needs to connect the current signal to the (PLC) controller. To prevent the pressure fluctuation from affecting the logical judgment, it is necessary to filter the pressure signal. The controller 4 includes a PLC.

[0062] The embodiments of the present invention have the following technical effects: By determining the incident angle of the first laser rangefinder according to the minimum width and maximum length of all slabs, the first laser rangefinder set on the side of the front furnace roller table can monitor the real-time positions of all slabs with a width greater than the minimum width and less than the width of the front furnace roller table on the front furnace roller table, so as to realize the automatic positioning of slabs with different widths that appear on the same production line in front of the furnace. It improves the degree of automatic control of slab charging into the furnace, reduces manual operation, reduces the requirement for the proficiency of operators, improves the steel charging efficiency, enables the heating furnace area to operate more stably and efficiently, reduces the risk of over-pushing slabs, and reduces the occurrence of production safety accidents.

[0063] Further, the laser ray emitted by the first laser rangefinder 1 is parallel to the track surface of the front furnace roller table 7, and the incident angle θ formed between the laser ray and the running direction of the front furnace roller table 7 is less than the maximum incident angle θ max ;

[0064] The maximum incident angle θ max is determined according to formula (1):

[0065]

[0066] where θ max is the maximum incident angle, in degrees, which is the acute angle between the virtual straight line formed by connecting the first limit steel detection point and the second limit steel detection point and the advancing direction of the front furnace roller table; W0 is the minimum width of the slab, in millimeters; W R is the width of the front furnace roller table, in millimeters; L B is the deceleration distance of the slab, in millimeters.

[0067] The first limit steel detection point is the position of the lower endpoint of the head end face of the slab with the minimum width and maximum length when the upper edge of the slab with the minimum width and maximum length is aligned with the upper edge of the front furnace roller table, and the head end face of the slab with the minimum width and maximum length is located at the head deceleration position of the slab with the minimum width and maximum length;

[0068] The second limit steel detection point is the position of the upper endpoint of the head end face of the slab with the minimum width and maximum length determined when the lower edge of the slab with the minimum width and maximum length is aligned with the lower edge of the front furnace roller table, and the center line of the slab with the minimum width and maximum length is aligned with the center line of the furnace door;

[0069] where the lower edge of the slab is the edge of the slab on the furnace door side, and the lower edge of the front furnace roller table is the edge of the front furnace roller table on the furnace door side; the upper edge of the slab is the edge of the slab on the pusher side, and the upper edge of the front furnace roller table is the edge of the front furnace roller table on the pusher side; the head deceleration position of the slab with the minimum width and maximum length is on the side where the slab comes from the second limit steel detection point, and the distance to the second limit steel detection point is the deceleration distance of the slab; the deceleration distance of the slab is the distance obtained by integrating the speed of the front furnace roller table during the period when the speed of the front furnace roller table decelerates to 0 while keeping no relative sliding between the slab and the track surface of the front furnace roller table, which is the minimum distance required for the slab to decelerate, and the reserved deceleration distance for the slab cannot be less than this deceleration distance of the slab.

[0070] In some embodiments, according to the installation space on the production line site, with the center point of the line connecting the first extreme steel inspection point and the second extreme steel inspection point as the axis, rotate the virtual straight line to obtain a new virtual straight line, and determine the incident angle of the first laser rangefinder; wherein, the incident angle of the first laser rangefinder is less than or equal to the maximum incident angle of the first laser rangefinder, which is the acute angle formed between the laser ray of the first laser rangefinder and the running direction of the front-of-furnace roller table; under the constraint that the straight-line distance from the first laser rangefinder to the first extreme steel inspection point is less than the measurement range of the first laser rangefinder, set the first laser rangefinder along the new virtual straight line at the installation space on one side of the upper edge of the front-of-furnace roller table according to the incident angle.

[0071] Before starting production, the first laser rangefinder needs to be set on the side of the front-of-furnace roller table, specifically on the side where the pusher of the front-of-furnace roller table is located, and on the downstream side of the pusher. The forward direction of the front-of-furnace roller table is defined as the downstream, and the incoming direction of the front-of-furnace roller table is defined as the upstream. In order for the positioned first laser rangefinder to perform front-of-furnace positioning for slabs with various different widths and lengths, the embodiments of the present invention use a slab with a hypothetical minimum width and maximum length as a reference to determine the maximum incident angle θ of the first laser rangefinder. max , the second extreme steel inspection point is Figure 2 point B in Figure 2 , the first extreme steel inspection point is max point A in

[0072] Now consider the positioning situation when the width of the slab entering the furnace is the narrowest. When the slab enters the charging roller table (front-of-furnace roller table) in the extreme posture, it is divided into two cases: One is when the edge of the slab is close to the edge of the roller table pusher side, the ray of the first laser rangefinder first irradiates the edge of the head end face of the slab close to the furnace door side. At this time, the detection position is the first extreme steel detection point A of the first laser rangefinder, and the distance from the first extreme steel detection point A of the first laser rangefinder to the stop position of the slab head should be greater than or equal to the deceleration distance of the slab, otherwise, the slab positioning cannot be accurately completed; The other is when the edge of the slab is close to the edge of the roller table furnace door side, before the slab positioning stops, the irradiation point of the ray of the first laser rangefinder should always be on the cross-section of the slab. When the slab positioning is completed, the edge of the head end face of the slab close to the pusher side is the second extreme steel detection point B. Given the extreme irradiation positions of the first laser rangefinder for charging in two extreme postures, combining the two can analyze the maximum irradiation angle of the laser rangefinder. The maximum incident angle θ that ensures the normal positioning of the slab can be calculated using formula (1) when the width of the slab is greater than or equal to the minimum width defined by W0. max .

[0073] Among them, W0 is the minimum width of the slab, in millimeters; W R is the width of the front-of-furnace roller table, in millimeters; L B is the deceleration distance of the slab, in millimeters. The calculation method of L B is as follows: First, without relative sliding between the slab and the roller table surface, during the process of decelerating the roller table speed to 0, the deceleration distance is calculated by integrating the roller table speed. In practice, if the roller table decelerates too fast, relative displacement will occur between the slab and the roller table. In practical applications, some calculation errors can also be added to the obtained deceleration distance. After obtaining the maximum incident angle, when actually deploying the first laser rangefinder in the production line, the available installation space near the production line also needs to be considered. Preferably, when the installation space permits, the first laser rangefinder is deployed along the straight line connecting points A and B on the outside of the edge of the front-of-furnace roller table close to the pusher side, and the incident angle is set to the maximum incident angle. In some cases, due to the limitation of the installation space near the production line, it is impossible to deploy the first laser rangefinder along the straight line connecting points A and B. Then, the virtual straight line of points A and B can be rotated around the center point of line segment AB to obtain a new virtual straight line. The incident angle corresponding to the new virtual straight line is less than the maximum incident angle. The first laser rangefinder is deployed along the new virtual straight line, with the incident angle corresponding to the new virtual straight line (i.e., the included angle between the new virtual straight line and the advancing direction of the front-of-furnace roller table), in the available installation space on the outside of the edge of the front-of-furnace roller table close to the pusher side.

[0074] The embodiments of the present invention have the following technical effects: The incident angle of the first laser rangefinder is determined according to the minimum width and maximum length of all slabs, so that the first laser rangefinder arranged on the side of the front furnace roller table can monitor the real-time positions of all slabs with a width greater than the minimum width and less than the width of the front furnace roller table on the front furnace roller table, thereby realizing the automatic positioning of slabs with different widths appearing on the same production line in front of the furnace. Moreover, for slabs with a width greater than the minimum width, they can be irradiated by the first laser rangefinder at any offset position in the width direction of the front furnace roller table. This improves the degree of automatic control of slab charging into the furnace, reduces manual operations, lowers the requirements for the proficiency of operators, improves the steel charging efficiency, enables the heating furnace area to operate more stably and efficiently, reduces the risk of over-pushing slabs, and reduces the occurrence of production safety accidents.

[0075] Further, the automatic steel charging control system 5 is used to monitor in real time the laser ranging data of the head end face of the slab to be charged into the furnace on the front furnace roller table; according to the laser ranging data and the length of the slab to be charged into the furnace, control the front furnace roller table to decelerate and position the slab to be charged into the furnace, so that when the slab to be charged into the furnace stops in front of the furnace, the center of the slab to be charged into the furnace is aligned with the center of the furnace door; monitor in real time the actual pushing distance and pushing pressure data of the pusher, and according to the actual pushing distance, pushing pressure data, the width of the first slab on the tapping side currently and the width of the slab tapped on the tapping side last time, control the pusher's sequence to complete the automatic steel charging of the slab to be charged into the furnace.

[0076] In some embodiments, the first laser rangefinder for positioning the slab on the front furnace roller table cannot be installed at a position directly facing the running direction of the front furnace roller table and can only be installed on the side of the front furnace roller table. At this time, the first laser rangefinder needs to irradiate the slab on the front furnace roller table at an incident angle with a certain angle to the running direction of the front furnace roller table. In order to ensure that the first laser rangefinder can correctly monitor slabs with different widths, it is necessary to pre-determine the incident angle of the first laser rangefinder according to the minimum width and maximum length of all slabs that need to be pushed into the heating furnace in sequence during production, and install the first laser rangefinder on the side of the front furnace roller table according to the incident angle.

[0077] The laser ranging data is the distance along the direction of the front furnace roller table between the head end face of the slab to be charged into the furnace and the first laser rangefinder, that is, the vertical distance between the head end face of the slab to be charged into the furnace and the first laser rangefinder. This distance can be calculated according to the straight-line distance between the first laser rangefinder and the head end face of the slab to be charged into the furnace measured by the first laser rangefinder and the incident angle.

[0078] The automatic steel loading control system 5 controls the front-of-furnace roller table to decelerate and position the slab to be charged into the furnace according to the laser ranging data and the length of the slab to be charged into the furnace, so that when the slab to be charged into the furnace stops in front of the furnace, the center of the slab to be charged into the furnace is aligned with the center of the furnace door. The automatic steel loading control system 5 monitors the actual steel pushing distance and steel pushing pressure data of the pusher in real time, and controls the pusher's steps to complete the automatic steel loading of the slab to be charged into the furnace according to the actual steel pushing distance, steel pushing pressure data, the width of the first slab on the tapping side currently and the width of the slab tapped on the tapping side last time. The steel pushing pressure data can be measured by a pressure sensor set on the pusher. According to the steel pushing pressure data, it can be detected whether the pusher is pushing all the slabs in the heating furnace, whether the pusher starts to retract, etc.; the actual steel pushing distance when the pusher is pushing all the slabs in the heating furnace can be controlled by the width of the first slab on the tapping side currently and the width of the slab tapped on the tapping side last time, as well as by the steel pushing pressure data, so as to complete the steel loading operation by controlling the pusher's steps.

[0079] The embodiment of the present invention has the following technical effects: determining the incident angle of the first laser rangefinder according to the minimum width and maximum length of all slabs, so that the first laser rangefinder set on the side of the front-of-furnace roller table can monitor the real-time positions of all slabs with a width greater than the minimum width and less than the width of the front-of-furnace roller table on the front-of-furnace roller table, thereby realizing the automatic positioning in front of the furnace of slabs with different widths appearing on the same production line. It improves the degree of automatic control of slab charging into the furnace, reduces manual operation, reduces the requirement for the proficiency of operators, improves the steel loading efficiency, enables the heating furnace area to operate more stably and efficiently, reduces the risk of over-pushing slabs, and reduces the occurrence of production safety accidents.

[0080] Further, the automatic steel loading control system 5 includes: a head stop position distance determination module, a deceleration position distance determination module, a distance comparison module, a deceleration control module, and a positioning stop module;

[0081] The head stop position distance determination module is used to take the projection distance of the straight-line distance from the first laser rangefinder to the head of the slab to be charged into the furnace in the advancing direction of the front-of-furnace roller table as the head stop position distance of the slab to be charged into the furnace in the case where the center of the slab to be charged into the furnace stops on the front-of-furnace roller table in a manner aligned with the center of the furnace door; the head stop position distance is calculated according to formula (3):

[0082]

[0083] where S1 is the head stop position distance, in millimeters; L2 is the projection distance of the straight-line distance from the center of the furnace door of the heating furnace to the first laser rangefinder in the advancing direction of the front-of-furnace roller table, in millimeters; L0 is the length of the slab to be charged into the furnace obtained from the production operation plan, in millimeters; l1 is a preset offset used to make up for the measurement error, in millimeters;

[0084] A head deceleration position distance determination module, configured to superimpose a slab deceleration distance on the head stop position distance of the slab to be charged into the furnace, so as to obtain the head deceleration position distance of the slab to be charged into the furnace;

[0085] A distance comparison module, configured to, during the process of the slab to be charged into the furnace running on the front furnace roller table, compare the laser ranging data with the head deceleration position distance and the head stop position distance in real time;

[0086] A slab deceleration control module, configured to, during the period when the laser ranging data is less than the head deceleration position distance and greater than the head stop position distance, maintain the running speed of the front furnace roller table at 10% of the original speed, so as to convey the slab to be charged into the furnace at a low speed; wherein, the original speed is the speed of the front furnace roller table during the period when the laser ranging data is greater than the head deceleration position distance;

[0087] A slab positioning stop module, configured to, when the deviation value between the laser ranging data and the head stop position distance is less than 10 millimeters, stop the running of the front furnace roller table and set the slab positioning completion flag; wherein, the slab positioning completion flag will be reset after the pusher slab sequence is completed;

[0088] Wherein, the slab deceleration distance is the distance obtained by integrating the speed of the front furnace roller table during the period when the speed of the front furnace roller table decelerates to 0 under the condition that no relative sliding occurs between the slab and the surface of the front furnace roller table; the laser ranging data is the projection distance of the straight-line distance from the first laser rangefinder to the head of the slab to be charged into the furnace in the advancing direction of the front furnace roller table.

[0089] In some embodiments, as Figure 2 shown, L2 is the vertical distance from the center line of the furnace door of the reheating furnace to the first laser rangefinder, that is, the projection distance of the straight-line distance from the center of the furnace door of the reheating furnace to the first laser rangefinder in the advancing direction of the front furnace roller table, in millimeters, and is known as a production line parameter when the installation of the first laser rangefinder is completed; L0 is the length of the slab to be charged into the furnace obtained from the production operation plan, in millimeters; l1 is a preset offset used to make up for the measurement error, in millimeters. S1 in formula (3) is the head stop position distance, which is the vertical distance from the head of the slab to the first laser rangefinder when the slab to be charged into the furnace stops on the front furnace roller table in an alignment manner with the center of the furnace door, in millimeters; To realize the automatic positioning of the slab to be charged into the furnace, it is necessary to request the length of the slab to be charged into the furnace from the MES system (or production work plan) before positioning on the charging roller table. After determining the slab length, select the slab to be charged into the furnace positioning method, including head positioning, intermediate positioning, and tail positioning. The embodiment of the present invention adopts intermediate positioning. Calculate the head stop position of the slab according to the slab length and the positioning method. During the high-speed transportation process of the slab, compare S0 (laser ranging data) with S1 (head stop position distance) plus L BThe value of (the slab deceleration distance), i.e., the head deceleration position distance, is continuously compared: when the laser ranging data S0 is less than the head deceleration position distance, the roller table speed is set to 10% of the low-speed steel feeding speed; when the difference between the laser ranging data S0 and the head stop position distance S1 is within 10 mm, the roller table stops running and the slab positioning completion flag bit is set. After the steel pushing step is completed, the slab positioning completion flag bit is reset.

[0090] The embodiment of the present invention has the following technical effects: by real-time monitoring the laser ranging data with the first laser rangefinder and comparing it with the head deceleration position distance, early deceleration is achieved, avoiding the problem that the speed of the slab to be charged is too high when it reaches the corresponding head stop position and suddenly stops and slides, thus avoiding the problem of inaccurate positioning and improving the positioning accuracy.

[0091] Further, the controller 4 is used to sample the pushing steel pressure data obtained by the pressure sensor 2 in real time, and sample the actual pushing steel distance obtained by the second laser rangefinder 3 in real time;

[0092] The automatic steel charging control system 5 further includes: a full furnace steel pushing starting point identification module, a steel pushing stroke margin determination module, a tapping translation distance determination module, an expected steel pushing stroke determination module, a steel pushing in place identification module, and a steel pushing in place stop module;

[0093] The full furnace steel pushing starting point identification module is used to, during the steel pushing process of the pusher, obtain the pushing steel pressure data from the controller in real time, and take the actual pushing steel distance of the pusher monitored in real time as the first pushing steel distance when the pushing steel pressure data is greater than or equal to the preset pressure processing limit value;

[0094] The steel pushing stroke margin determination module is used to take the difference between the rated maximum steel pushing stroke and the first pushing steel distance as the steel pushing machine stroke margin;

[0095] The tapping translation distance determination module is used to take the value obtained by dividing the sum of the width of the first slab on the tapping side and the width of the previous tapped slab on the tapping side by 2 as the center line distance between the first slab on the tapping side and the previous tapped slab on the tapping side;

[0096] The expected steel pushing stroke determination module is used to determine the expected steel pushing stroke of the pusher during the steel pushing of the slab to be charged according to the steel pushing machine stroke margin and the center line distance;

[0097] The steel pushing in place control module is used to, during the steel pushing process of the pusher, when it is determined in real time that the deviation between the actual pushing steel distance and the expected steel pushing stroke is within the preset steel pushing in place deviation range, set the proportional valve of the pusher to zero to stop the pusher from pushing steel and control the pusher to return to the initial position.

[0098] In some embodiments, during slab pushing, first, the pusher will push the slab to be charged into the furnace from the front furnace roller table into the heating furnace. At this time, the pusher only pushes this one slab to be charged into the furnace, and the pusher pressure data is relatively small, and the pusher pressure data is less than the preset pressure processing limit value. When the pusher continues to push the slab, the slab to be charged into the furnace enters the heating furnace and contacts the original slabs in the heating furnace. Then, the pusher starts to push all the slabs in the heating furnace, including the slab to be charged into the furnace, towards the tapping side of the heating furnace. At this time, the pusher pressure data is greater than or equal to the preset pressure processing limit value. Since the widths of the slabs entering the heating furnace may be the same or different, it is necessary to set the expected pusher travel according to the width of the first slab on the tapping side and the width of the last tapped slab on the tapping side. When setting the expected pusher travel, it is also necessary to consider the limit of the maximum rated pusher travel that the pusher can reach. The expected pusher travel cannot be greater than the maximum rated pusher travel. By comparing the actual pusher distance with the expected pusher travel in real time, if the actual pusher distance is equal to the expected pusher travel, it means that the pushing is in place. In actual application, it is very difficult to achieve complete equality. Therefore, a preset pusher in-place deviation range is set to improve the success rate of identifying that the pushing is in place. The minimum value of the preset pusher in-place deviation range that can ensure the success rate of identifying that the pushing is in place can be obtained through multiple tests.

[0099] The embodiments of the present invention have the following technical effects: When determining the expected pusher travel, the widths of the first slab on the tapping side and the last tapped slab on the tapping side are taken into account, so as to adapt to the tapping of slabs with different widths mixed in the furnace. By monitoring the relationship between the actual pusher distance and the expected pusher travel in real time, automatic slab pushing is realized. The degree of automatic control of slab charging and discharging is improved, manual operation is reduced, and the requirement for the proficiency of operators is lowered. The charging and discharging efficiency is improved, and the heating furnace area operates more stably and efficiently. The risk of over-pushing the slab is reduced, and the occurrence of production safety accidents is decreased. It is ensured that the slabs discharged from the tapping side are within the normal tapping area, and the stable and smooth operation of the furnace condition is guaranteed.

[0100] Further, the expected pusher travel determination module is configured to determine in real time the magnitudes of the pusher travel margin and the center line distance; if the pusher travel margin is greater than or equal to the center line distance, the pusher travel shortage flag bit is reset, and the expected pusher travel of the pusher during the pushing of the slab to be charged into the furnace is set to the sum value of the first pusher distance and the center line distance; otherwise, the pusher travel shortage flag bit is set, and the maximum pusher travel of the pusher during the pushing of the slab to be charged into the furnace is set to the minimum safe pusher travel.

[0101] Wherein, the minimum safe pusher travel is the travel when the pusher just pushes the slab out of the front furnace roller table.

[0102] In some embodiments, when the pusher pressure data is greater than or equal to the preset pressure processing limit value, it indicates that at this time the pusher starts to push all the slabs in the heating furnace to move together towards the tapping side. At this time, the pusher already has a stroke of the first pusher distance. At this time, according to the width of the first slab on the tapping side and the width of the last tapped slab on the tapping side, the center line distance between the first slab on the tapping side and the last tapped slab on the tapping side is determined. This center line distance is the distance that the pusher needs to continue pushing, but the total pusher distance cannot exceed the rated maximum pusher stroke. Therefore, the rated maximum pusher stroke is subtracted from the first pusher distance to obtain the pusher stroke margin, and it is necessary to compare the pusher stroke margin with the center line distance. In the case where the pusher stroke margin is greater than or equal to the center line distance, the pusher can continue to push for a stroke length of the center line distance. Therefore, the expected pusher stroke is set to the sum of the first pusher distance and the center line distance;

[0103] As Figure 3 shown, L3 is the pusher limit stroke or the pusher rated maximum stroke; L4 is the stroke of the pusher head to the inner edge of the roller table; W2 is the width of the last slab out of the furnace; W3 is the width of the next slab out of the furnace; In the case where the pusher stroke margin is less than the center line distance, the pusher can no longer continue to push for a stroke length of the center line distance. At this time, the maximum pusher stroke during the pusher period of the slab to be charged into the furnace is set to the minimum safe pusher stroke, so that the pusher can just push the slab to be charged into the furnace out of the front roller table of the furnace, thereby vacating the front roller table of the furnace and avoiding affecting the entry of the next slab into the front roller table of the furnace.

[0104] As Figure 3As shown, the stroke allowance of the pusher is calculated using ΔS = L3 - S2, where ΔS is the stroke allowance of the pusher, L3 is the rated maximum stroke of the pusher, and S2 is the first pusher distance. The stroke allowance is compared with the distance required to push the slab to be discharged to the tapping position. The distance from the slab to be discharged to the tapping position is the distance between the centerlines of the previously tapped slab and the slab to be discharged. If the remaining distance of the pusher is greater than the distance required to push the slab to the tapping position, the pusher stroke insufficient flag is reset, and the expected pusher stroke for this pusher operation is set to S2 + (W2 + W3) / 2. Otherwise, the pusher stroke insufficient flag is set, and the expected pusher stroke for this pusher operation is set to the minimum safe stroke L4 of the pusher, so as not to affect the forward distance of the pusher for the next slab to enter. Until the next pusher operation, the pusher stroke is judged again. If the pusher stroke meets the normal pusher distance, the flag of insufficient pusher stroke is reset. When using the minimum safe distance for pushing, when a sharp increase in pressure is detected during the forward movement of the pusher, it indicates that the pusher is about to push the entire furnace of slabs. If the pusher stroke is greater than the safe stroke at this time, the pusher retraction sequence will be directly triggered. During this period, the slabs on the side of the tapping will not be displaced, nor will it affect the judgment of the next pusher distance.

[0105] The embodiment of the present invention has the following technical effects: When the stroke allowance of the pusher is insufficient, the slab to be charged is pushed out of the front furnace roller table, so as not to affect the entry of the next slab into the front furnace roller table and maintain the continuity of production.

[0106] Further, the automatic steel loading control system 5 further includes:

[0107] A pusher in-place response module, configured to use the actual pusher distance of the pusher currently monitored in real time as the second pusher distance when it is monitored that the pusher pressure data is less than the preset pressure processing limit value; and when the second pusher distance is greater than the minimum safe stroke of the pusher, reset the furnace front roller table steel feeding prohibition flag, otherwise set the furnace front roller table steel feeding prohibition flag.

[0108] Wherein, the minimum safe stroke of the pusher is the stroke when the pusher just pushes the slab out of the front furnace roller table.

[0109] In some embodiments, when the pusher pressure data is less than the preset pressure processing limit value, the pusher is just about to retract. Record the actual pusher distance at this time as the second pusher distance. If the second pusher distance is greater than the minimum safe stroke of the pusher, it means the front furnace roller table is idle, and the furnace front roller table steel feeding prohibition flag is reset to allow the next slab to enter the front furnace roller table. Otherwise, it means there is still a slab on the front furnace roller table that has not been completely pushed out of the front furnace roller table. At this time, the furnace front roller table steel feeding prohibition flag is set to prohibit the next slab from entering the front furnace roller table.

[0110] The embodiments of the present invention have the following technical effects: When the pusher is just about to retract, the actual pushing distance is recorded as the second pushing distance. By comparing the second pushing distance with the minimum safe pushing stroke, it is possible to automatically identify whether the front-of-furnace roller table is idle, so as to control whether the next slab can enter the front-of-furnace roller table and automatically control the timing of the next slab entering the front-of-furnace roller table, avoiding the steel piling accident on the front-of-furnace roller table.

[0111] Further, the automatic steel loading control system 5 further includes a reset module, and the reset module is used for: when the pusher retracts to the initial position, setting the pusher completion signal for 5 seconds, and at the same time sending this signal to the rolling line L2 system, and resetting the pusher completion signal after 5 seconds. In some embodiments, after the pusher retracts to the initial position, it is necessary to set the pusher completion signal for 5s, and at the same time send this signal to the rolling line secondary (L2) system for slab information tracking in the furnace. The width of the slab discharged on the tapping side this time can be recorded and used as the width of the slab discharged on the tapping side in the previous time for the pushing distance calculation of the next pusher.

[0112] Further, the controller 4 reads the straight-line distance from the head of the slab to be charged into the furnace to the first laser rangefinder 1, and calculates the laser ranging data according to formula (2):

[0113] S0 = L1 * cosθ (2)

[0114] Wherein, S0 is the laser ranging data, in millimeters; L1 is the straight-line distance from the head of the slab to be charged into the furnace measured by the first laser rangefinder, in millimeters; θ is the incident angle of the first laser rangefinder, in degrees.

[0115] In some embodiments, as Figure 2 shown, S0 is the laser ranging data, in millimeters, which is the perpendicular distance from the first laser rangefinder to the head end face of the slab to be charged into the furnace, that is, the projection distance of the straight-line distance from the first laser rangefinder to the head of the slab to be charged into the furnace in the advancing direction of the front-of-furnace roller table; L1 is the straight-line distance from the head of the slab to be charged into the furnace directly measured by the first laser rangefinder, in millimeters; θ is the incident angle of the first laser rangefinder, in degrees; L1 is directly measured in real time by the first laser rangefinder. The incident angle of the first laser rangefinder has been determined and is known when the first laser rangefinder is installed before the start of production. According to the trigonometric function relationship, the laser ranging data can be determined.

[0116] The above technical solutions of the embodiments of the present invention will be described in detail below in combination with specific application examples. For technical details not introduced during the implementation process, reference can be made to the relevant descriptions above.

[0117] An embodiment of the present invention is an automatic steel loading system for a pusher-type reheating furnace that uses a detection device to accurately position the slab entering the furnace and the pusher. The embodiment of the present invention is based on a pusher-type reheating furnace with a straight pusher entry method for the slab entering the furnace, a side pusher for the steel discharging method, and a single slab is entered into the furnace each time. The specification length of the slab entering the furnace is 9 - 10m, and the width range is 600mm - 770mm. The embodiment of the present invention first selects a suitable positioning method according to the length of the slab, and calculates the head position during slab positioning through the first laser rangefinder, so as to realize the positioning of the slab entering the furnace on the front roller table of the furnace; after the slab positioning is completed, the pusher distance is automatically calculated through the width of the slab scheduled by the linked MES system, and then combined with the pressure mutation of the second laser rangefinder and the pressure sensor on the pusher during pusher operation, to complete the judgment of the automatic pusher sequence, and finally realize the complete process of automatic steel loading.

[0118] Detect the relevant data of the first laser rangefinder in the actual positioning of the slab entering the furnace: For the positioning of the front roller table of the slab, due to the limitations of the position of the roller table entering the furnace and the mechanical structure of the pusher head, and the complexity of the slab condition during actual production, it is necessary to use the first laser rangefinder to monitor the head section position of the slab in real time, and compare it with the preset stop position to control the deceleration and stop of the roller table, so as to realize the positioning of the slab. The installation position of the detection instrument is as Figure 2 shown. Figure 2 In which, L0 is the length of the slab entering the furnace; L1 is the actually measured distance by the laser rangefinder; L2 is the distance between the laser rangefinder and the center line of the furnace door; S0 is the distance obtained by converting the laser rangefinder data into the same direction as the roller table direction; θ max is the maximum incident angle of the laser rangefinder; W0 is the width of the slab entering the furnace; W R is the width of the roller table; A is the limit irradiation point when detecting the steel by the laser rangefinder, that is, the first limit steel detection point; B is the limit irradiation point when the laser rangefinder stops, that is, the second limit steel detection point;

[0119] Determine the vertical distance from the head of the slab to the first laser rangefinder according to formula (2), where S0 is the laser rangefinder data, which is the vertical distance from the head of the slab to the first laser rangefinder, in millimeters; L1 is the straight-line distance from the head of the slab to the first laser rangefinder, in millimeters; θ is the incident angle of the first laser rangefinder, in degrees.

[0120] According to formula (3), with the aim of aligning the center of the slab with the center of the furnace mouth when the slab stops in front of the furnace, the stop position of the slab head is determined. Here, S1 is the distance of the stop position of the slab head, which is the vertical distance from the head of the slab to the first laser rangefinder when the head of the slab stops at the stop position of the slab head, with the unit of millimeters; L2 is the vertical distance from the center line of the furnace door of the heating furnace to the first laser rangefinder, with the unit of millimeters; L0 is the length of the slab, with the unit of millimeters, which can be obtained from the production operation plan; l1 is a preset offset, with the unit of millimeters, used to compensate for measurement errors.

[0121] The incident angle of the first laser rangefinder is related to the measurement range of the first laser rangefinder, the cross-sectional width W0 of the slab, the attitude of the slab during positioning, and the deceleration distance of the slab. Now consider the positioning situation when the width of the slab entering the furnace is the narrowest. When the slab enters the charging roller table in the extreme attitude, it is divided into two cases: One is when the edge of the slab is close to the edge of the roller table pusher side, the ray of the first laser rangefinder first irradiates the edge of the head section of the slab close to the furnace door side. At this time, the detection position is the first limit steel detection point A of the first laser rangefinder, and the distance from the first limit steel detection point A of the first laser rangefinder to the stop position of the slab head at this time should be greater than or equal to the deceleration distance of the slab, otherwise the slab positioning cannot be accurately completed;

[0122] The other is when the edge of the slab is close to the edge of the roller table furnace door side. Before the slab positioning stops, the irradiation point of the ray of the first laser rangefinder needs to be always on the cross-section of the slab. When the slab positioning is completed, the edge of the head section of the slab close to the pusher side is the second limit steel detection point B. Given the limit irradiation positions of the first laser rangefinder for charging in two extreme attitudes, by combining the two and analyzing, the maximum irradiation angle of the laser rangefinder can be obtained. The maximum incident angle θ that ensures the slab can be normally positioned in the case where the width of the slab is greater than or equal to the minimum width defined by W0 can be calculated using the following formula max , and θ is determined according to formula (1) max , preferably, the maximum incident angle can be used as the incident angle of the first laser rangefinder. Here, W0 is the minimum width of the slab, with the unit of millimeters; W R is the width of the roller table in front of the furnace, with the unit of millimeters; L B is the deceleration distance of the slab, with the unit of millimeters. The calculation method of L B is to first calculate the deceleration distance by integrating the roller table speed during the period when the roller table speed is decelerated to 0 without relative sliding between the slab and the roller table surface. In practice, if the roller table decelerates too fast, there will be relative displacement between the slab and the roller table. In practical applications, some calculation errors can also be added to the obtained deceleration distance.

[0123] Logical judgment for realizing automatic slab positioning: To realize the automatic positioning of the slab entering the furnace, it is necessary to request the length of the slab entering the furnace from the MES system (or production work plan) before positioning on the furnace roller table. After determining the slab length, select the positioning method for the slab entering the furnace, including head positioning, middle positioning, and tail positioning. Calculate the stop position of the slab head according to the slab length and positioning method. During the high-speed transportation of the slab, continuously compare the value of S0 (laser ranging data) with the sum of S1 (distance to the head stop position) and L B (deceleration distance) (i.e., the distance to the head deceleration position): When the laser ranging data S0 is less than the distance to the head deceleration position, the roller table speed is set to 10% of the low-speed steel feeding speed; when the difference between the laser ranging data S0 and the head stop position S1 is within 10 millimeters, the roller table stops running and the slab positioning completion flag bit is set. After the steel pushing step is completed, the slab positioning completion flag bit is reset.

[0124] Explanation of slab mixed loading: When slab mixed loading occurs, with the change of the width of the slab to be fed into the furnace, it will have different impacts on the steel pushing distance of the pusher. For different situations of the width of the slab entering the furnace and the width of the slab leaving the furnace, the following are the impacts on the steel pushing distance of the pusher:

[0125] (1) The width of the slab entering the furnace is equal to the width of the slab leaving the furnace

[0126] When the width of the slab entering the furnace is equal to the width of the slab leaving the furnace, it belongs to equal-distance steel pushing. After each steel discharging is completed, a fixed distance equal to the width of the discharged slab will be left on the discharging side. When each slab enters the furnace, the pusher only needs to advance a fixed distance so that the next slab on the discharging side can reach the specified discharging position.

[0127] (2) The width of the slab entering the furnace is less than the width of the slab leaving the furnace

[0128] When the width of the slab entering the furnace is less than the width of the slab leaving the furnace, it belongs to increased-distance steel pushing. Since the slab entering the furnace is narrower than the discharged slab, after the slab leaves the furnace, the remaining distance on the discharging side will be greater than the width of the slab entering the furnace. When each slab enters the furnace, the pusher needs to increase the stroke to make up for the width difference between the slab entering and leaving the furnace. After that, the stroke needs to be increased every time a narrow slab is pushed into the furnace.

[0129] (3) The width of the slab entering the furnace is greater than the width of the slab leaving the furnace

[0130] When the width of the slab entering the furnace is greater than the width of the slab leaving the furnace, it belongs to decreased-distance steel pushing. Since the slab entering the furnace is wider than the discharged slab, after the slab leaves the furnace, the remaining distance on the discharging side will be less than the width of the slab entering the furnace. When each slab enters the furnace, the pusher needs to reduce the stroke to make up for the width difference between the slab entering and leaving the furnace. After that, the stroke needs to be reduced every time a wide slab is pushed into the furnace.

[0131] Realization of automatic slab pushing: Some necessary detection components need to be added, including a second laser rangefinder for detecting the real-time position of the slab pusher and a pressure sensor for detecting the change in oil pressure inside the hydraulic cylinder of the slab pusher. By using the second laser rangefinder to monitor the actual slab pushing distance in real time and the pressure sensor to automatically identify the pressure change from only pushing the slab to be charged into the furnace to pushing all the slabs in the furnace and the pressure change when the slab pusher just starts to retract, combined with the widths of the first slab on the tapping side and the last tapped slab, the impacts involved in the slab misloading description are solved, and the automatic slab pushing for slabs with different widths in misloading is realized.

[0132] Among them, for the second laser rangefinder, to prevent the instrument from being interfered by the complex environment it is in, its installation position needs to be at the rear end of the pushing arm of the slab pusher, and the irradiation point is the rear end head of the pushing arm. The second laser rangefinder needs to convert the position information of the slab pusher into a 4 - 20 mA current signal and then transmit it to the (PLC) controller, which is logically quantified into the distance between the pusher head of the slab pusher and the preset logical zero position (the extreme retraction limit position of the slab pusher); for the pressure sensor, taking advantage of the characteristic that the pressure inside the hydraulic cylinder of the slab pusher will change suddenly when pushing all the slabs in the furnace, combined with the data of the second laser rangefinder to judge the position of the slab pusher and its forward distance at the moment of sudden pressure increase. The pressure sensor also needs to connect the current signal to the PLC controller. To prevent the pressure fluctuation from affecting the logical judgment, it is necessary to filter the pressure signal.

[0133] The initial stroke of the slab pusher is the maximum stroke when the slab pusher pushes the slab in place, which is measured by the second laser rangefinder when the first slab pushing is completed manually. During the automatic slab pushing process, when there is no slab in the heating furnace, the slab pusher will push the slab with the maximum stroke. When the furnace is about to be filled with slabs, since there is no detection device at the furnace door position on the tapping side and it is impossible to judge the position of the first slab on the tapping side, the first slab on the tapping side needs to be pushed to the tapping position in manual mode. After manually judging that the slab pushing is in place, the slab pusher manually retracts to the initial position, and will automatically latch the maximum stroke when the slab pusher pushes the slab in place according to the change of the pressure sensor signal, which is used for calculating the slab pushing distance in the next slab pushing, so as to realize the automatic slab pushing of the next slab to be charged into the furnace.

[0134] Logic for realizing automatic slab pushing: When the slab to be charged is positioned on the charging roller table, the signal indicating that the slab in front of the furnace is positioned is set. After selecting the automatic mode of the slab pusher on the operation screen, if the furnace meets the slab charging conditions, the slab pusher will automatically start the slab pushing and charging sequence.

[0135] (1) First, when the automatic slab pushing starts, it is necessary to request the width of the tapped slab from the MES system first for calculating the maximum stroke of the slab pusher for this slab pushing. After the request is completed, the slab pusher automatically advances to push the slab.

[0136] (2) As Figure 4As shown in the figure, when the pressure value of the pressure sensor (pushing steel pressure data) is greater than or equal to the preset pressure processing limit value P5, the rising edge of this signal is used to latch the travel of the pusher. At this time, the travel S2 of the pusher is the travel when the pusher is about to push all the slabs in the furnace. At the same time, the given value of the proportional valve of the pusher is changed, and the pusher reduces the speed to push the steel, which is beneficial to the accurate positioning of the slabs and can also effectively avoid the resonance of the slabs in the furnace during pushing. Figure 4 In the figure, the horizontal axis is time in seconds, and the vertical axis is pressure in pascals; t1 is the period when the pusher advances without load at startup; p1 is the no-load pressure; t2 is the period when the pusher advances the slab on the front roller table of the furnace; p2 is the pressure for the pusher to push one slab; t3 is the period when the pusher advances all the slabs in the furnace; p3 is the pressure for the pusher to push all the slabs in the furnace; t4 is the period from when the pusher finishes pushing the steel to returning to the initial position; p4 is the pressure when the pusher retracts; p5 is the pressure processing critical value (preset pressure processing limit).

[0137] (3) As Figure 4 shown in the figure, the travel margin of the pusher is calculated using ΔS = L3 - S2, and the travel margin is compared with the distance that needs to be advanced when pushing the slab to be discharged to the tapping position. The distance from the slab to be discharged to the tapping position is the distance between the centerlines of the last tapped slab and the slab to be discharged. If the remaining distance of the pusher is greater than the distance to push the slab to the tapping position, the pusher travel shortage flag bit is reset, and the maximum travel of this steel pushing is set to S2 + (W2 + W3) / 2. Otherwise, the pusher travel shortage flag bit is set, and the maximum travel of this steel pushing by the pusher is set to the minimum safe travel L4, so as not to affect the advancing distance of the pusher for the next slab to be pushed into the furnace. Until the next steel pushing, the travel of the pusher is judged again. If the travel of the pusher meets the normal steel pushing distance, the flag bit of the pusher travel shortage is reset. When using the minimum safe distance to push the steel, when a sharp increase in pressure is detected during the forward movement of the pusher, it indicates that the pusher is about to push all the slabs in the furnace. If the travel of the pusher is greater than the safe travel at this time, the pusher retraction sequence will be directly triggered. During this period, the slabs on the tapping side will not be displaced, nor will it affect the judgment of the next steel pushing distance.

[0138] (4) The pusher continues to advance to push the steel, and at the same time judges whether the actual travel (actual steel pushing distance) of the pusher and the preset travel (desired steel pushing travel) are within the deviation range, that is, whether the tapped slab has reached the set travel. When the pusher advances to the position, the given value of the proportional valve of the pusher is set to zero, and the pusher stops. Otherwise, it continues to push the steel at a low speed.

[0139] (5) As Figure 4 shown in the figure, it is detected whether the pressure of the pressure sensor is less than the pressure processing limit value P5. When it is less than the limit value, the travel S3 of the pusher at this time is latched at the falling edge of the signal. At this time, the travel of the pusher is the travel when the pusher pushes the slab on the tapping side to the tapping position.

[0140] (6) As shown Figure 3 in the figure, it is judged whether the final stroke S3 of the pusher is greater than L4, that is, whether the pusher has pushed the slab on the front furnace roller table out of the edge of the roller table. If the condition is met, the steel feeding prohibition flag of the front furnace roller table is reset, and steel can be pushed normally; otherwise, this flag is set, and the next slab is prohibited from entering the front furnace roller table. When the pusher condition is met again, the pusher needs to complete a steel pushing operation without a newly incoming slab, and then judge the pusher stroke again. After the condition is met, the steel feeding prohibition flag of the front furnace roller table is reset. After this steel pushing operation is completed, the signal indicating the completion of steel charging sent to the rolling line L2 system needs to be blocked to prevent the furnace tracking information from being disordered.

[0141] (7) After the pusher returns to the initial position, the width of W3 is assigned to W2 for calculating the steel pushing distance of the pusher for the next time. The steel pushing completion signal needs to be set for 5 s, and at the same time, this signal is sent to the rolling line L2 system for tracking the slab information in the furnace.

[0142] The embodiments of the present invention have the following technical effects: By linking the length of the scheduled slab in the MES system and detecting the actual position of the slab entering the furnace, and comparing it with the preset stop position, the roller table is controlled to decelerate and stop, so as to realize slab positioning and complete automatic slab positioning. A second laser rangefinder for detecting the real-time position of the pusher and a pressure sensor for detecting the change in the oil pressure in the pusher hydraulic cylinder are added. The displacement and pressure changes are used to judge the steel pushing action and complete the steel pushing sequence. The degree of automatic control of slab charging is improved, manual operation is reduced, and the requirement for the proficiency of operators is lowered; the steel charging and discharging efficiency is improved, and the heating furnace area operates more stably and efficiently; the risk of over-pushing the slab is reduced, and the occurrence of production safety accidents is decreased; it is ensured that the slab discharged from the tapping side is in the normal tapping area, and the stable operation of the furnace condition is guaranteed.

[0143] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the present disclosure. The appended method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy.

[0144] In the foregoing detailed description, various features are combined in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the invention lies in less than all of the features of the single disclosed embodiment. Accordingly, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0145] The above-described embodiments are described to enable any person skilled in the art to make or use the present invention. For those skilled in the art, various modifications to these embodiments are obvious, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of the disclosure. Therefore, the disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0146] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but those of ordinary skill in the art should recognize that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the manner in which this term is encompassed is similar to the term "including". In addition, any use of the term "or" in the claims or specification is intended to mean "non-exclusive or".

[0147] Those skilled in the art will also appreciate that the various illustrative logical blocks, units, and steps listed in the embodiments of the present invention can be implemented by electronic hardware, computer software, or a combination of both. To clearly show the interchangeability of hardware and software, the various illustrative components, units, and steps have been generally described in terms of their functions. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the overall system. Those skilled in the art can implement the described functions in various ways for each specific application, but such implementation should not be construed as exceeding the scope of protection of the embodiments of the present invention.

[0148] In the embodiments of the present invention, the various illustrative logical blocks or units can be implemented or operate the described functions by a general-purpose processor, a digital signal processor, an application specific integrated circuit (ASIC), a field programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of the above designs. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0149] The steps of the methods or algorithms described in the embodiments of the present invention can be directly embedded in hardware, software modules executed by the processor, or a combination of the two. The software modules can be stored in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and the storage medium can be disposed in an ASIC, and the ASIC can be disposed in a user terminal. Optionally, the processor and the storage medium can also be disposed in different components of the user terminal.

[0150] In one or more exemplary designs, the functions described in the embodiments of the present invention may be implemented in hardware, software, firmware, or any combination of the three. If implemented in software, these functions may be stored on a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. A computer-readable medium includes both computer storage media and communication media that facilitate transfer of a computer program from one place to another. The storage media may be any available media that can be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store program code in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. In addition, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless means such as infrared, radio, and microwave, it is included in the definition of computer-readable medium. Disk and disc include compact disk, laser disk, optical disk, DVD, floppy disk, and Blu-ray disk, where disks usually reproduce data magnetically, while discs usually reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0151] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An automatic steel charging system for a pusher-type reheating furnace, characterized in that, Including: A first laser rangefinder (1), a pressure sensor (2), a second laser rangefinder (3), a controller (4), an automatic steel loading control system (5), a pusher (6), a front-furnace roller table (7), and a heating furnace (8); The pusher (6) is located on the right side of the advancing direction of the front-furnace roller table (7); The heating furnace (8) is located on the left side of the advancing direction of the front-furnace roller table (7) and is directly opposite to the pusher (6); The first laser rangefinder (1) is located on the right side of the advancing direction of the front-furnace roller table (7) and is downstream of the pusher (6) along the advancing direction of the front-furnace roller table (7); The pressure sensor (2) is arranged on the pusher (6); The second laser rangefinder (3) is arranged at the rear end of the pushing arm of the pusher (6) and the irradiation point is the rear end head of the pushing arm; The controller (4) is signal-connected to the first laser rangefinder (1), the pressure sensor (2), and the second laser rangefinder (3); The automatic steel loading control system (5) is signal-connected to the controller (4), the pusher (6), and the front-furnace roller table (7).

2. The automatic steel charging system for the pusher-type reheating furnace according to claim 1, wherein, The laser ray emitted by the first laser rangefinder (1) is parallel to the track surface of the front furnace roller table (7), and the incident angle (θ) formed between the laser ray and the running direction of the front furnace roller table (7) is less than the maximum incident angle (θ max ); The maximum incident angle (θ max ) is determined according to the following formula: where θ max is the maximum incident angle in degrees, which is the acute angle between the virtual straight line formed by connecting the first limit steel detection point and the second limit steel detection point and the advancing direction of the front furnace roller table; W0 is the minimum width of the slab in millimeters; W R is the width of the front furnace roller table in millimeters; L B is the deceleration distance of the slab in millimeters.

3. The pusher-type reheating furnace automatic steel charging system according to claim 1, characterized in that, The automatic steel loading control system (5) includes: a head stop position distance determination module, a deceleration position distance determination module, a distance comparison module, a deceleration control module, and a positioning stop module; The head stop position distance determination module is used to take the projected distance in the advancing direction of the front-furnace roller table of the straight-line distance from the first laser rangefinder to the head of the slab to be charged into the furnace as the head stop position distance of the slab to be charged into the furnace when the slab to be charged into the furnace stops on the front-furnace roller table in a manner that the center of the slab is aligned with the center of the furnace door; The head deceleration position distance determination module is used to obtain the head deceleration position distance of the slab to be charged into the furnace by adding the slab deceleration distance to the head stop position distance of the slab to be charged into the furnace; The distance comparison module is used to compare the laser ranging data with the head deceleration position distance and the head stop position distance in real time; The slab deceleration control module is used to keep the running speed of the front-furnace roller table at 10% of the original speed during the period when the laser ranging data is less than the head deceleration position distance and greater than the head stop position distance, so as to convey the slab to be charged into the furnace at a low speed; The slab positioning stop module is used to stop the running of the front-furnace roller table and set the slab positioning completion flag when the deviation value between the laser ranging data and the head stop position distance is less than 10 millimeters.

4. The pusher-type reheating furnace automatic steel charging system according to claim 3, wherein, The automatic steel loading control system (5) further includes: a full-furnace pusher starting point identification module, a pusher stroke margin determination module, a steel discharging translation distance determination module, an expected pusher stroke determination module, a pusher in-place identification module, and a pusher in-place stop module; The full-furnace pusher starting point identification module is used to obtain the pusher pressure data from the controller in real time during the pusher pushing process, and take the actual pusher distance monitored in real time as the first pusher distance when the pusher pressure data is greater than or equal to the preset pressure processing limit value; The pusher stroke margin determination module is used to take the difference between the rated maximum pusher stroke and the first pusher distance as the pusher stroke margin; The tapping translation distance determination module is used to take the value obtained by dividing the sum of the width of the current first slab on the tapping side and the width of the last tapped slab on the tapping side by 2 as the center line distance between the current first slab on the tapping side and the last tapped slab on the tapping side; The expected pusher travel determination module is used to determine the expected pusher travel of the pusher during the pushing of the slab to be charged into the furnace according to the pusher travel margin and the center line distance; The pusher in-place control module is used to, during the process of the pusher pushing the slab, when it is determined in real time that the deviation between the actual pushing distance and the expected pusher travel is within the preset pusher in-place deviation range, set the given value of the proportional valve of the pusher to zero, so as to stop the pusher from pushing the slab and control the pusher to return to the initial position.

5. The pusher-type reheating furnace automatic steel charging system according to claim 4, wherein, The expected pusher travel determination module is used to judge the magnitudes of the pusher travel margin and the center line distance in real time; if the pusher travel margin is greater than or equal to the center line distance, reset the pusher travel insufficient flag bit, and set the expected pusher travel of the pusher during the pushing of the slab to be charged into the furnace to the sum value of the first pushing distance and the center line distance; Otherwise, set the pusher travel insufficient flag bit, and set the maximum pusher travel of the pusher during the pushing of the slab to be charged into the furnace to the minimum safe pusher travel.

6. The pusher-type reheating furnace automatic steel charging system according to claim 4, characterized in that, The automatic steel charging control system (5) further includes: The pusher in-place response module is used to, when it is monitored that the pusher pressure data is less than the preset pressure processing limit value, take the actual pushing distance of the pusher monitored in real time as the second pushing distance; and when the second pushing distance is greater than the minimum safe pusher travel, reset the furnace front roller table steel feeding prohibition flag bit, otherwise set the furnace front roller table steel feeding prohibition flag bit.

7. The pusher-type reheating furnace automatic steel charging system according to claim 4, characterized in that The automatic steel charging control system (5) further includes a reset module, and the reset module is used to: when the pusher returns to the initial position, set the pusher completion signal for 5 seconds, and at the same time send this signal to the rolling line L2 system, and reset the pusher completion signal after 5 seconds.

8. The pusher-type reheating furnace automatic steel charging system according to claim 1, characterized in that, The controller (4) reads the distance from the head of the slab to be charged into the furnace to the first laser rangefinder (1) from the first laser rangefinder (1), and calculates the laser ranging data according to the following formula: S0 = L1 * cosθ Wherein, S0 is the laser ranging data, with the unit of millimeter; L1 is the straight-line distance from the head of the slab to be charged into the furnace measured by the first laser rangefinder to the first laser rangefinder, with the unit of millimeter; θ is the incident angle of the first laser rangefinder, with the unit of degree.

Images