Metallurgical slag thickness online measuring device and method and application

Abstract

The invention relates to a metallurgical slag thickness online measuring device and method and application, and belongs to the field of ferrous metallurgy process detection. The device comprises a support, a driving mechanism, a rigid probe, a torque and displacement sensor and a data processor. The driving mechanism drives the rigid probe to vertically pass through air, slag and a molten steel layer at a constant speed; the sensor synchronously collects torque and displacement signals in real time; and the data processor constructs a torque-displacement curve according to the torque-displacement curve, and automatically calculates the thickness of the slag by identifying two torque sudden change points (corresponding to an air-slag interface and a slag-molten steel interface) on the curve. The method realizes automatic online measurement based on the device. The device is mounted on a metallurgical container such as a steel ladle, a converter or an electric arc furnace to realize in-situ measurement. The device performs measurement based on a direct physical resistance principle, has the advantages of good real-time performance, strong anti-interference capability, high precision, good environmental adaptability, compact structure, high safety and the like, and can provide data support for intelligent control in the smelting process.

Description

Technical Field

[0001] This invention belongs to the field of detection technology in the iron and steel metallurgical process, specifically relating to an online measurement device, method and application for metallurgical slag thickness. Background Technology

[0002] In the iron and steel metallurgical process, slag thickness is a key parameter for measuring the smelting state, controlling the composition of molten steel, and ensuring steel quality. Accurately determining slag thickness and adjusting the smelting process accordingly can effectively reduce the oxidizability of molten steel, decrease alloy consumption, and improve the steel yield. Currently, slag thickness measurement techniques mainly include manual sampling, ultrasonic measurement, radiographic measurement, and electromagnetic induction.

[0003] The manual sampling method involves inserting a sampling rod during the smelting interval and determining the slag thickness based on the slag layer marks adhering to the rod. This method suffers from significant lag, failing to reflect real-time changes in slag thickness, and is also accompanied by safety risks such as high temperatures and splashing during operation.

[0004] Ultrasonic measurement utilizes the difference in the propagation speed of ultrasonic waves in different media to achieve measurement. However, slag is characterized by high temperature, multiphase, strong corrosion, and non-uniformity. Ultrasonic waves are severely attenuated in the slag layer, and the measurement accuracy is easily affected by factors such as slag composition and bubble content, resulting in large errors under complex smelting conditions.

[0005] X-ray measurement is based on the difference in intensity attenuation of rays after penetrating different media. Although it has high accuracy, rays are radioactive and require complex protective devices. The equipment is expensive and poses potential health risks to operators, making it difficult to widely apply in small and medium-sized steel enterprises.

[0006] The electromagnetic induction method is greatly affected by the temperature, composition and magnetic field of molten steel, resulting in insufficient measurement stability and making it difficult to meet the requirements of high-precision measurement.

[0007] In summary, existing slag thickness measurement technologies suffer from problems such as poor real-time performance, insufficient accuracy, low safety, or high cost, making it difficult to meet the requirements of efficient, accurate, and safe production in the iron and steel metallurgical process. Therefore, a new type of online slag thickness measurement technology is urgently needed. Summary of the Invention

[0008] The purpose of this invention is to provide an online measurement device, method, and application for metallurgical slag thickness, in order to overcome the above-mentioned technical defects.

[0009] To address the aforementioned technical problems, one aspect of this application provides an online metallurgical slag thickness measurement device, comprising:

[0010] support; The drive mechanism is mounted on the bracket; A rigid probe is connected to the power output end of the drive mechanism and is driven by the drive mechanism to perform uniform linear motion in the vertical direction. It is used to pass through the air zone, slag layer and molten steel layer in sequence during the measurement process. A torque sensor is used to detect in real time the output torque generated by the drive mechanism during the motion of the rigid probe. A displacement sensor is used to detect the vertical displacement of the rigid probe in real time. A data processor, connected to the torque sensor and the displacement sensor, is used to receive and process real-time signals of the output torque and the displacement. Based on the real-time signals, a torque-displacement relationship curve reflecting the change of the output torque with the displacement is constructed. By analyzing the torque-displacement relationship curve, the first torque abrupt change point corresponding to the rigid probe entering the slag layer from the air zone and the second torque abrupt change point corresponding to the entry of the rigid probe into the molten steel layer from the slag layer are identified. The thickness of the slag layer is calculated based on the displacement values ​​corresponding to the first torque abrupt change point and the second torque abrupt change point.

[0011] According to an online metallurgical slag thickness measuring device, the driving mechanism includes: Servo motor; A speed reducer, the input end of which is connected to the output shaft of the servo motor; A ball screw is arranged vertically, with its bottom end coaxially connected to the rigid probe, and the ball screw is constrained to move only along its axial direction by an anti-rotation mechanism set on the bracket; The gear nut, which is rotatably supported on the bracket by bearings and fitted onto the ball screw, forms a ball screw pair with the ball screw. The output end of the reducer meshes with the gear nut through a transmission mechanism to drive the gear nut to rotate around the axis of the ball screw. The rotational motion of the gear nut is converted into the vertical linear motion of the ball screw through the ball screw pair, thereby driving the rigid probe.

[0012] According to an online measurement device for metallurgical slag thickness, the transmission mechanism is a bevel gear pair.

[0013] According to an online measurement device for metallurgical slag thickness, the support is further provided with a guide mechanism, which is used to constrain the rigid probe to move only in the vertical direction.

[0014] According to an online metallurgical slag thickness measuring device, the guiding mechanism includes: A linear guide or guide sleeve is used in conjunction with the rigid probe or the ball screw.

[0015] According to an online measurement device for metallurgical slag thickness, it also includes: A signal acquisition unit is connected between the torque sensor, the displacement sensor, and the data processor, and is used to condition and convert the sensor signals from analog to digital.

[0016] According to an online metallurgical slag thickness measurement device, the data processor is further configured to: calculate the volume and / or mass of the slag layer based on the calculated thickness of the slag layer and the cross-sectional area of ​​the metallurgical container.

[0017] According to an online measurement device for metallurgical slag thickness, the rigid probe is made of a material that is resistant to high temperatures and melt erosion, the material including high-temperature alloys or ceramic materials; and / or, the front end of the rigid probe is tapered.

[0018] On the other hand, the embodiments of this application provide a method for using an online metallurgical slag thickness measurement device, including the following steps: The drive mechanism is activated, driving the rigid probe to descend vertically at a constant speed, so that it passes through the air zone, the slag layer, and the molten steel layer in sequence. The torque sensor and the displacement sensor are used to synchronously collect the output torque value of the drive mechanism and the displacement value of the rigid probe in real time. The acquired torque and displacement signals are transmitted to the data processor. The data processor constructs a torque-displacement relationship curve based on the torque signal and the displacement signal. The data processor analyzes the torque-displacement relationship curve to identify the first torque abrupt change point corresponding to the rigid probe entering the slag layer from the air zone, and the second torque abrupt change point corresponding to the probe entering the molten steel layer from the slag layer. The thickness of the slag layer is calculated based on the displacement values ​​corresponding to the first torque mutation point and the second torque mutation point.

[0019] On the other hand, the present application provides an application of an online metallurgical slag thickness measuring device, characterized in that the online metallurgical slag thickness measuring device is installed in a metallurgical container, so that the measuring path of the rigid probe passes through the internal space of the metallurgical container, for online measurement of the slag layer thickness above the melt in the metallurgical container; The metallurgical container is a ladle, converter, or electric arc furnace.

[0020] The beneficial effects of this invention are as follows: (1) By actively and uniformly passing through the slag layer through a rigid probe controlled by a drive mechanism, and by using sensors to collect torque and displacement signals in real time during the movement, a complete measurement cycle can be completed within a few seconds to tens of seconds, and the measurement results are fed back in real time. This completely overcomes the problems of lag, safety risks and labor intensity of traditional manual sampling methods, and can provide real-time data support for the dynamic control of the smelting process.

[0021] (2) Based on the direct physical principle that there are significant differences between the viscous resistance and density resistance generated by different media (air, slag, molten steel) on the motion probe, the interface position is determined by identifying characteristic abrupt change points on the torque-displacement curve. This principle is not significantly affected by complex working conditions such as slag composition, bubble content, and temperature field distribution, nor does it rely on the propagation characteristics of acoustic, ray, or electromagnetic waves in complex molten media. This avoids the technical bottlenecks of large signal attenuation in ultrasonic methods, high protection requirements in ray methods, and susceptibility to interference in electromagnetic induction methods. It exhibits excellent stability and measurement accuracy in high-temperature, multiphase, and highly corrosive metallurgical environments.

[0022] (3) The measuring device mainly consists of a mechanical transmission unit, a standard sensor, and a general data processing unit, without the need for complex waveguides, radiation sources, or high-precision transceivers. In particular, it adopts an integrated transmission design of "gear and nut rotation driving anti-rotation screw linear motion", which is compact in structure, has good transmission rigidity, and high reliability. The overall device manufacturing cost and subsequent maintenance cost are significantly lower than those of X-ray method and high-end ultrasonic method, making it easier to promote and apply in various steel enterprises (including small and medium-sized enterprises).

[0023] (4) This invention not only outputs the direct parameter of slag thickness, but its data processing unit can also automatically calculate the volume and mass of slag by combining the known geometric dimensions of the metallurgical container. This provides direct and quantitative input for subsequent refined smelting operations such as slag material control, alloy addition optimization, and steel oxidation control, and strongly supports the intelligent and precise upgrading of the iron and steel smelting process.

[0024] (5) The device and method of the present invention do not rely on the principle limitations of specific metallurgical containers. Through adaptable installation, they can be widely used in various metallurgical containers such as converters (sub-lance system), electric arc furnaces (furnace walls), ladles (refining process) and molten iron ladles, to realize online monitoring of slag thickness in different smelting processes. They have high versatility and flexibility.

[0025] To make the above description of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of an online metallurgical slag thickness measurement device.

[0027] Explanation of reference numerals in the attached figures: 1. Servo motor; 2. Reducer; 3. Ball screw; 4. Transmission device; 5. Rigid probe; 6. Ladle; 7. Molten steel layer; 8. Slag layer; 9. Air zone; 10. Data processor; 11. Signal acquisition device. Detailed Implementation

[0028] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0029] It should be noted that, in this invention, the upper, lower, left, and right in the figure are considered to be the upper, lower, left, and right of the online metallurgical slag thickness measuring device described in this specification.

[0030] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0031] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0032] This embodiment relates to an online measurement device for metallurgical slag thickness (hereinafter referred to as the device). Please refer to... Figure 1 As shown, it includes a bracket (not shown), a drive mechanism, a rigid probe 5, a torque sensor (not shown), a displacement sensor (not shown), and a data processor 10.

[0033] The support frame serves as the mechanical foundation and load-bearing structure of the entire device, providing a stable installation platform. It needs to possess sufficient structural strength and rigidity to withstand the harsh environment of the metallurgical site, such as high-temperature radiation and vibration, and to ensure that all components installed on it maintain precise relative positions.

[0034] The drive mechanism is the actuator that provides vertical power to the probe. Its function is to generate a controllable, uniform linear driving force, ensuring that the rigid probe 5 can be smoothly inserted into the melt at a preset constant speed. This uniform motion is a prerequisite for subsequently constructing an accurate torque-displacement curve and identifying abrupt changes at the medium interface.

[0035] The rigid probe 5 is connected to the power output end of the drive mechanism and is driven by the drive mechanism to perform uniform linear motion in the vertical direction. It is used to sequentially pass through the air zone 9, the slag layer 8, and the molten steel layer 7 during the measurement process. Specifically, the rigid probe 5 is the detection component that directly contacts the measured medium. Its "rigidity" ensures that the probe itself will not undergo elastic deformation when passing through media of different densities and viscosities, thus ensuring that the displacement detected by the displacement sensor accurately reflects the position of the probe tip. The sequential passage of the rigid probe 5 through the three media layers of air, slag, and molten steel is a direct physical process that triggers two step-like changes (abrupt changes) in the driving load (torque).

[0036] The torque sensor is used to detect in real time the output torque generated by the drive mechanism during the movement of the rigid probe 5. Specifically, the torque sensor is one of the signal sensing elements. Its function is to convert the resistance encountered by the rigid probe 5 when it passes through different media (manifested as the load torque of the drive mechanism) into a measurable electrical signal in real time and with high precision. The resistance encountered by the rigid probe 5 when it moves through air, slag, and molten steel is completely different, resulting in significant differences in the torque signal. These differences are the basis for identifying the medium interface.

[0037] In some embodiments, the torque sensor is directly connected in series between the output shaft of the servo motor 1 and the input shaft of the reducer 2, or integrated into the servo motor 1 as a built-in function. Its function is to directly measure the actual torque output required by the motor drive system to overcome the external load (i.e., the resistance encountered by the rigid probe 5 as it moves in the medium).

[0038] A displacement sensor is used to detect the vertical displacement of the rigid probe 5 in real time. Specifically, the displacement sensor is another signal sensing element, typically employing a high-precision encoder. Its function is to synchronize with the moving parts of the drive mechanism (such as a lead screw) to measure and output the real-time position (depth) of the rigid probe 5. The displacement signal and torque signal are strictly synchronized in time, together forming a two-dimensional data pair describing the "resistance-position" relationship.

[0039] In some embodiments, the displacement sensor is typically a rotary encoder, which is coaxially connected to the lead screw shaft of the ball screw 3 (e.g., mounted on the upper end of the lead screw shaft). Its function is to indirectly calculate the linear displacement of the rigid probe 5 by measuring the rotation angle of the lead screw shaft. Working principle: The lead of the ball screw 3 is a fixed, known value. Therefore, after the rotary encoder measures the rotation angle or number of rotations of the lead screw shaft, the data processor 10 can calculate the linear displacement of the rigid probe 5 using the formula (displacement = number of rotations × lead).

[0040] The data processor 10 is connected to the torque sensor and the displacement sensor to receive and process real-time signals of output torque and displacement. Based on the real-time signals, a torque-displacement relationship curve reflecting the change of output torque with displacement is constructed. By analyzing the torque-displacement relationship curve, the first torque abrupt change point corresponding to the rigid probe 5 entering the slag layer 8 from the air zone 9 and the second torque abrupt change point corresponding to the rigid probe 5 entering the molten steel layer 7 from the slag layer 8 are identified. The thickness of the slag layer 8 is calculated based on the displacement values ​​corresponding to the first torque abrupt change point and the second torque abrupt change point.

[0041] Specifically, the data processor 10 first receives and synchronizes real-time signal streams from the torque sensor and displacement sensor. Then, the data processor 10 maps the torque values ​​to the displacement values ​​one-to-one, plotting a characteristic curve (torque-displacement curve) showing the change in torque with the downward depth of the rigid probe 5. By analyzing the slope and amplitude changes of this characteristic curve, or by performing mathematical difference processing, the data processor 10 can automatically and accurately locate two distinct torque jump points: the first point (corresponding to displacement value L1) marks the transition of the rigid probe 5 from low-resistance air to high-resistance viscous slag; the second point (corresponding to displacement value L2) marks the transition of the rigid probe 5 from slag to molten steel with different density and viscosity characteristics. Finally, the data processor 10 calculates the displacement difference between these two characteristic points (ΔL = L2 - L1) to directly determine the actual physical thickness of the slag layer. The entire processing is automated, achieving a rapid and reliable conversion from the raw signal to the final thickness value.

[0042] In some embodiments, the data processor 10 is an industrial computer or a PLC.

[0043] In some embodiments, the drive mechanism includes a servo motor 1, a reducer 2, and a gear nut 4.

[0044] Servo motor 1 is the power source for the entire drive mechanism. Its function is to provide rotational motion and torque output. By receiving commands from the controller (usually coordinated by data processor 10), servo motor 1 can operate at a preset constant speed, ensuring the stability of the input speed of subsequent transmission links. This is the fundamental guarantee for achieving uniform linear motion of the rigid probe 5. Its high responsiveness and good speed-torque characteristics enable it to sensitively adapt to changes in resistance encountered by the rigid probe 5 in different media.

[0045] The input end of the reducer 2 is connected to the output shaft of the servo motor 1. Specifically, the reducer 2 has two main functions: first, it converts the high speed and low torque output of the servo motor 1 into a low speed and high torque suitable for driving the subsequent ball screw pair, so as to meet the working condition requirements of overcoming the large resistance when the rigid probe 5 is inserted into the melt; second, it serves as a connection and transition component between the servo motor 1 and the subsequent transmission mechanism, thereby enhancing the rigidity and load-bearing capacity of the entire transmission system.

[0046] The ball screw 3 is vertically oriented, with its bottom end coaxially connected to the rigid probe 5. The ball screw 3 is constrained by an anti-rotation mechanism mounted on a support, allowing it to move only along its axial direction. Specifically, the ball screw 3 is the component that enables the conversion of motion (rotational to linear). Its "screw shaft" (or lead screw) is rigidly connected coaxially to the rigid probe 5, and the two move as a single unit. This screw shaft is constrained by an "anti-rotation mechanism" (e.g., a linear guide, guide key, or spline pair). This anti-rotation mechanism is fixed to the support, allowing the screw shaft to slide freely along its axis (vertical direction) but strictly preventing it from rotating about its own axis. This constraint state of "allowing only axial movement and not rotation" is the structural prerequisite for converting the rotational motion of the subsequent gear nut 4 into the pure linear motion of the screw shaft (and the rigid probe 5).

[0047] When the anti-rotation mechanism is a guide key, it specifically refers to machining one or more raised elongated ridges (i.e., "keys") axially on the outer cylindrical surface of the ball screw shaft 3, while simultaneously machining matching grooves (i.e., "keyways") on the inner wall of the bracket or fixed guide sleeve. Then, the "key" on the screw shaft is inserted into the "keyway" of the fixed sleeve. The "key" can slide freely up and down within the "keyway" (achieving axial movement), but the side of the "key" is tightly fitted against the side wall of the "keyway," completely preventing the screw shaft from rotating relative to the fixed sleeve.

[0048] When the anti-rotation mechanism is a splined pair, it specifically refers to machining an external cylindrical surface (called "external spline") with multiple evenly distributed axial teeth on the lead screw shaft of the ball screw 3, and simultaneously machining an internal cylindrical surface (called "internal spline") with multiple internal teeth in the inner hole of the sleeve fixed on the bracket to mesh with it. Then, the "external spline" part of the lead screw shaft is installed into the "internal spline" hole of the fixed sleeve, forming a multi-tooth meshing. The meshing of numerous spline teeth allows the two to slide relative to each other along the axial direction. At the same time, because the sides of the teeth are in close contact, the rotational freedom of the lead screw shaft around the axis is greatly restricted, and it can withstand greater torque.

[0049] In some embodiments, the rigid probe 5 is removable and replaceable.

[0050] The gear nut 4 is rotatably supported on the bracket by bearings and is fitted onto the ball screw 3, forming a ball screw pair with the ball screw 3. The output end of the reducer 2 meshes with the gear nut 4 through the transmission mechanism to drive the gear nut 4 to rotate around the axis of the ball screw 3, and converts the rotational motion of the gear nut 4 into the vertical linear motion of the ball screw 3 through the ball screw pair, thereby driving the rigid probe 5.

[0051] The gear nut 4 is a ball screw nut with integrated transmission teeth and is the final actuator of the drive mechanism. Its functions are as follows: (1) It is mounted on the bracket by a pair of bearings (usually angular contact ball bearings). This mounting method allows the gear nut 4 to rotate freely and smoothly around the axis of the ball screw 3, while bearing axial and radial loads. (2) Its interior is the nut part of the ball screw pair, which meshes with the screw shaft of the ball screw 3 through circulating balls to form a high-precision and high-efficiency transmission pair. (3) Its outer cylindrical surface or end face is machined with gear teeth (i.e., the driven part of the "transmission mechanism"). These gear teeth mesh with the driving gear (i.e., the driving part of the "transmission mechanism") from the output end of the reducer 2. When the reducer 2 outputs power, it drives the gear nut 4 to rotate. (4) When the gear nut 4 is driven to rotate, the screw shaft of the ball screw 3 that it is paired with is locked by the anti-rotation mechanism and cannot rotate. According to the working principle of the ball screw pair, the rotating gear nut 4 will force the anti-rotation screw shaft to produce a linear motion along the axis. This linear motion is directly and equally transmitted to the rigid probe 5 that is coaxially connected with it, thereby realizing the drive probe 5 to perform a strictly vertical uniform linear lifting and lowering motion.

[0052] In some embodiments, the transmission mechanism is a bevel gear pair. A bevel gear pair, also known as a conical gear pair, is a pair of gears used to transmit rotational motion between intersecting shafts (typically at a 90-degree angle). In this device, the bevel gear pair specifically includes a driving bevel gear and a driven bevel gear. The driving bevel gear is fixedly mounted on the output shaft of the reducer 2, and its axis of rotation coincides with the axis of rotation of the output shaft of the reducer 2, typically in a horizontal direction. The driven bevel gear is a ring of bevel teeth directly machined on the outer circumference or end face of the gear nut 4, and its axis of rotation coincides with the axis of rotation of the ball screw 3, in a vertical direction. The tooth surfaces of the two bevel gears mesh with each other at a 90-degree angle in space.

[0053] The drive mechanism (the rotary-linear conversion mechanism consisting of servo motor 1, reducer 2, ball screw 3, and gear nut 4) in the aforementioned embodiments can be directly replaced by a linear drive mechanism. For example, a hydraulic cylinder or pneumatic cylinder can be used as the drive mechanism. The cylinder body of the hydraulic cylinder or pneumatic cylinder is fixedly mounted on the bracket, and the end of its piston rod is directly connected to the rigid probe 5 or connected through a connector. By controlling the flow and pressure of the hydraulic or pneumatic system, the piston rod can be driven to move the rigid probe 5 in a uniform linear motion in the vertical direction. This solution has a simpler and more direct structure and is suitable for applications where the requirements for motion accuracy are relatively relaxed but the driving force is large.

[0054] In some embodiments, the support is further provided with a guide mechanism, which is used to constrain the rigid probe 5 to move only in the vertical direction. The guide mechanism is an independent mechanical constraint system attached to the drive mechanism, and its function is to provide radial positioning and attitude stability for the entire long stroke movement of the rigid probe 5, ensuring that its movement trajectory is an absolutely vertical straight line.

[0055] The guiding mechanism provides additional intermediate support for the long cantilever rigid probe 5 or the slender ball screw 3, greatly improving the rigidity of the entire motion system. This not only reduces the impact of stress deformation on measurement accuracy, but also effectively reduces the radial load and bending moment acting on transmission components such as the ball screw pair and gear nut 4, extending their service life and improving the system's reliability under harsh working conditions.

[0056] As one example of its application, the guiding mechanism includes a linear guide pair or guide sleeve, which mates with a rigid probe 5 or a ball screw 3.

[0057] When the guiding mechanism is a linear guide pair, the linear guide pair, through the circulation of internal balls or rollers, allows the slider to move linearly along the guide rail with extremely low friction. Its function is to withstand radial forces from all directions and a certain overturning moment. When the rigid probe 5 is long or subjected to lateral forces while passing through uneven slag, the linear guide pair effectively suppresses any lateral offset, bending, or vibration that the rigid probe 5 may produce, forcing its movement trajectory strictly constrained to the vertical straight line defined by the guide rail. This complements the anti-rotation mechanism (constraining rotation), together achieving complete constraint on the rigid probe 5 in space, allowing it to move "only in one direction (vertically)."

[0058] When the guiding mechanism is a guide sleeve, it typically consists of a wear-resistant sleeve fixed to a bracket and a smooth guide post connected to a rigid probe 5 or a ball screw 3. Its principle is to constrain radial movement through a small clearance fit. Although its accuracy, rigidity, and lifespan are generally lower than those of linear guide pairs, it is less expensive and suitable for applications with shorter strokes, lighter loads, or slightly lower accuracy requirements. Its function is the same as that of a linear guide pair, namely, constraining the probe 5 to move only in the vertical direction.

[0059] In a preferred embodiment of the invention, the guiding mechanism for ensuring the motion accuracy of the rigid probe 5 and the anti-rotation mechanism for realizing the motion conversion of the ball screw 3 can be physically related or even integrated into the same functional component, thereby simplifying the structure, improving rigidity, and reducing costs. The function of the guiding mechanism is to constrain the radial degree of freedom of the rigid probe 5 (or the ball screw 3 coaxially connected to it), preventing its lateral offset and bending. The function of the anti-rotation mechanism is to constrain the rotational degree of freedom of the ball screw 3 about its own axis. Together, they ultimately constrain the motion of the rigid probe 5 in space to retain only one vertical linear motion degree of freedom. Therefore, they are highly consistent and complementary in their functional objectives.

[0060] For example, when a linear guide pair is used as the guiding mechanism: the linear guide is firmly mounted on the bracket, and the slider is fixed to the lead screw shaft of the ball screw 3 (or a component rigidly connected to the lead screw shaft) through a rigid connecting block with no rotational capability (e.g., a connecting block with a square inner hole or keyway). The precise fit between the slider and the guide rail itself strictly restricts the rotation of the connecting block (and the lead screw shaft connected to it) in any direction, thus achieving the "anti-rotation" requirement. At the same time, the slider can slide freely along the guide rail, achieving precise "linear guidance". Therefore, in this scheme, a set of linear guide pairs simultaneously completes the two constraint functions of "guidance" and "anti-rotation".

[0061] For example, a spline pair is used: an external spline is machined on the screw shaft of the ball screw 3, and a fixed spline sleeve with an internal spline (as a guide sleeve) is mounted on the bracket and meshes with the external spline of the screw shaft. The meshing of the spline teeth strictly prevents the rotation of the screw shaft (achieving anti-rotation). At the same time, the spline pair allows the screw shaft to slide freely along the axial direction under the guidance of the spline teeth (achieving linear guidance). Therefore, a spline pair element integrates the anti-torsional constraint necessary for "anti-rotation" and the radial constraint and linear sliding function necessary for "guidance".

[0062] This embodiment also includes a signal acquisition unit 11, which is connected between the torque sensor, the displacement sensor and the data processor 10, and is used to condition (such as filter, amplify) and convert the sensor signals from analog to digital.

[0063] The signal acquisition unit 11 acts as a bridge and preprocessing unit between the raw signals from the sensors and the central data processor 10. Its task is to receive the raw analog electrical signals from the torque sensor and the displacement sensor and convert them into digital signals that the digital processor 10 can directly recognize and process.

[0064] The functionality of the signal processing unit (data processor 10 and / or signal acquisition unit 11) can be further expanded. For example, a wireless transmission module (such as a Wi-Fi, 4G / 5G, Zigbee, or LoRa module) can be integrated into it. This wireless transmission module can transmit the processed slag thickness, calculated volume / mass data, and possible temperature profile data to a remote monitoring center, cloud server, or mobile terminal in real time. This enables remote monitoring, historical storage, networked analysis, and centralized management of data, facilitating the construction of a plant-wide intelligent monitoring system for the smelting process.

[0065] The data processor 10 is also configured to perform the following extended calculation function: calculate the volume and / or mass of the slag layer 8 based on the calculated thickness of the slag layer 8 and the cross-sectional area of ​​the metallurgical container.

[0066] The real-time thickness H (in meters) of the slag layer 8, and the horizontal cross-sectional area S (in square meters) of the corresponding metallurgical vessel (such as a ladle or converter) at the measurement location. The area S is a fixed or known quantity that can be calculated from parameters such as liquid level and tilt angle, and is usually pre-stored in the memory of the data processor 10 or given by the host system.

[0067] Data processor 10 performs geometric calculations: volume V = thickness H × cross-sectional area S.

[0068] The previous step yielded the slag volume V and the slag density ρ (unit: tons / cubic meter). Slag density ρ is a physical property parameter that can be estimated using empirical formulas based on the main slag system composition of the current furnace (such as CaO-SiO2-Al2O3 system), or by taking a typical average value and storing it in the processor.

[0069] Data processor 10 performs physical calculations: mass M = volume V × density ρ.

[0070] In some embodiments, the rigid probe 5 is made of a material that is resistant to high temperatures and melt erosion, including high-temperature alloys or ceramic materials.

[0071] If the probe material is severely corroded or undergoes a chemical reaction, its surface state and shape will change, leading to alterations in the resistance characteristics it encounters when passing through the medium, which may interfere with the stability and repeatability of the torque signal. Corrosion-resistant materials can maintain the relative stability of the probe surface state, ensuring that the torque signal accurately reflects the physical properties (viscosity, density) of the medium itself, rather than changes in the probe's own state.

[0072] In some embodiments, the front end of the rigid probe 5 is designed to be tapered, meaning that its end cross-section gradually narrows from the shaft to the tip, forming a sharp or blunt cone.

[0073] When the rigid probe 5 enters the viscous slag layer 8 from the air zone 9, the conical front end can "pierce" the slag layer more smoothly than the flat head, effectively dispersing and reducing the impact force at the moment of contact, avoiding large vibration and resistance peaks, making the sudden change of torque signal at the interface (the first torque change point) clearer and easier to identify, while reducing the instantaneous load on the drive mechanism.

[0074] The conical structure helps to push away the melt during the movement of the rigid probe 5, reducing eddies and slag entrapment, and lowering the dynamic resistance fluctuations that the rigid probe 5 may experience when passing through the molten steel layer 7. At the same time, the smooth conical surface also facilitates the easier sliding off of any small amount of slag or molten steel adhering to the rigid probe 5 as it is lifted, reducing residue and preparing it for the next measurement, thus improving the independence and accuracy of the measurement.

[0075] The rigid probe 5 can be functionally expanded. For example, the rigid probe 5 can adopt a hollow tubular structure, with one or more thermocouples arranged in its internal cavity. The temperature sensing points of these thermocouples can be distributed at different heights along the probe axis. When the rigid probe 5 performs thickness measurement and passes through different media layers, the internal thermocouples can simultaneously and in-situ measure the temperature in the air, slag, and molten steel, thereby obtaining a vertical temperature profile of the molten pool. This temperature information can be transmitted to the data processor 10 along with the thickness data, providing more comprehensive online data for temperature control in the smelting process.

[0076] It should be noted that the rigid probe 5 is located above the ladle 6.

[0077] This embodiment provides a method for using an online metallurgical slag thickness measurement device, including the following steps: Step 1: Start the measurement process.

[0078] Start the drive mechanism to drive the rigid probe 5 to descend at a constant speed in the vertical direction, so that it passes through the air zone 9, the slag layer 8 and the molten steel layer 7 in sequence.

[0079] This step is the physical execution phase of the entire measurement. The drive mechanism provides constant power to ensure that the rigid probe 5 is inserted vertically into the melt at a preset constant speed. Uniform motion is a prerequisite for ensuring the synchronicity of subsequent data acquisition and the accuracy of analysis. The rigid probe 5 successively passes through three media layers with vastly different physical properties: air, viscous slag, and molten steel with a higher density. This is the direct physical process that triggers two step changes in the driving load.

[0080] Step 2: Real-time data synchronization and collection.

[0081] The output torque value of the drive mechanism and the displacement value of the rigid probe 5 are collected in real time and synchronously through torque sensor and displacement sensor.

[0082] This step is the signal sensing and digitization stage. The torque sensor captures in real-time the changes in resistance that the rigid probe 5 needs to overcome to move. This resistance directly reflects the characteristics of the medium in which the rigid probe 5 is located (air resistance is minimal, slag resistance increases significantly due to viscosity, and molten steel resistance changes abruptly again due to density differences). A displacement sensor (such as an encoder) simultaneously measures the real-time depth of the rigid probe 5. The strict synchronous acquisition of these two signals provides accurate data pairs for subsequently constructing a one-to-one "resistance-position" relationship.

[0083] Step 3, signal transmission.

[0084] The acquired torque and displacement signals are transmitted to the data processor 10.

[0085] This step completes the collection of raw measurement data from the sensor to the central processing unit. The signal is usually conditioned (amplified, filtered) and converted from analog to digital by the signal acquisition unit 11, and then transmitted to the data processor 10 at high speed and reliably through wired or wireless communication links, preparing for subsequent intelligent analysis.

[0086] Step 4: Construct the characteristic curve.

[0087] The data processor 10 constructs a torque-displacement relationship curve based on the torque signal and the displacement signal.

[0088] This step is preparation for data visualization and feature extraction. The data processor 10 correlates and plots the received discrete torque and displacement values ​​in a coordinate system with displacement as the horizontal axis and torque as the vertical axis, or reassembles the data to form a complete characteristic curve of torque versus displacement. This curve visually shows the change in resistance experienced by the rigid probe 5 throughout its entire stroke, and is used to transform the physical process into an analyzable mathematical graph.

[0089] Step 5: Intelligent identification of the media interface.

[0090] The data processor 10 analyzes the torque-displacement relationship curve to identify the first torque abrupt change point corresponding to the rigid probe 5 entering the slag layer 8 from the air zone 9, and the second torque abrupt change point corresponding to the rigid probe 5 entering the molten steel layer 7 from the slag layer 8.

[0091] This step is where the intelligence of the method lies. Data processor 10 performs mathematical analysis on the curve constructed in step four. It automatically locates two points on the curve where the torque increases significantly by a step. The first point marks the precise instant when the tip of rigid probe 5 enters the high-resistance slag from the low-resistance air (the first torque abrupt change point); the second point marks the precise instant when rigid probe 5 enters the molten steel layer with different physical properties from the slag layer (the second torque abrupt change point). This step achieves automatic, objective, and precise identification from continuous signals to key feature points.

[0092] Step six: Calculate the final result.

[0093] The thickness of the slag layer 8 is calculated based on the displacement values ​​corresponding to the first and second torque mutation points.

[0094] This step is crucial for obtaining the final measurement results. Data processor 10 reads and records the coordinates of the two abrupt change points identified in step five on the displacement axis: the depth L1 when the rigid probe 5 reaches the air-slag interface, and the depth L2 when it reaches the slag-molten steel interface. A simple arithmetic operation is performed: slag thickness H = L2 - L1. This calculated result, H, represents the real-time physical thickness of the slag layer within the current metallurgical vessel. The entire process is automated, achieving a rapid and accurate conversion from physical insertion to digital results.

[0095] This embodiment provides an application of an online metallurgical slag thickness measurement device. The device is installed in a metallurgical container, and the measurement path of the rigid probe 5 passes through the internal space of the metallurgical container to measure the thickness of the slag layer 8 above the melt inside the metallurgical container online.

[0096] Metallurgical containers include steel ladles, converters, or electric arc furnaces.

[0097] Specifically, metallurgical containers are high-temperature equipment used in the steel smelting process, such as ladles, converters, or electric arc furnaces, to hold molten steel and slag.

[0098] This application physically integrates and spatially aligns the measuring device with the target metallurgical vessel. Specifically, the device's support is securely mounted or fixed to a specific structure of the metallurgical vessel (such as a furnace flange, furnace wall mounting base, furnace cover, or near the auxiliary lance insertion hole). Mechanical adjustments are then made to ensure that the vertical axis of the rigid probe 5 is precisely aligned with the internal space of the vessel, allowing it to pass unimpeded through the air zone 9, slag layer 8, and molten steel layer 7 throughout its descent and ascent. This "in-situ" installation method makes the measurement an embedded, non-invasive (relative to manual sampling) automated step in the smelting vessel operation process.

[0099] By permanently or semi-permanently integrating the device into the metallurgical vessel, measurements can be initiated instantly at any desired moment during the smelting or refining process, without interrupting production, opening the furnace lid, or requiring close operator intervention. The rigid probe 5 is inserted directly into the molten pool from the top of the vessel, measuring the actual state of the melt under the current process conditions. The data is highly real-time, truly achieving "online" monitoring synchronized with the production process.

[0100] The measurement path of rigid probe 5 passes directly through the actual space of the molten pool, and the measured thickness is the true physical thickness of the slag layer at that location. By reasonably selecting the installation point (such as avoiding areas of intense agitation or slag holes), measurement results that are representative of the process can be obtained. This overcomes the errors caused by sampling location and cooling solidification in offline sampling methods, and also avoids the systematic errors caused by vessel wall structure, dust interference, or model simplification in some non-contact measurement methods (such as X-rays, some radar methods).

[0101] This application transforms the high-temperature, hazardous manual operations at the furnace into remotely controlled automated operations. Operators are no longer exposed to the dangerous environments of high-temperature radiation, molten steel splashes, and harmful fumes, greatly improving operational safety. Simultaneously, the automated measurement data can be directly connected to the plant's process control system or manufacturing execution system, providing key input variables for the automated closed-loop control of the smelting process (such as automatic slag feeding and automatic slag removal), thus driving the intelligent upgrading of the production process.

[0102] Specific application scenarios: metallurgical containers include steel ladles, converters, or electric arc furnaces.

[0103] Application in steel ladles 6: During the waiting process before steel refining (such as LF furnace, RH vacuum treatment) or casting, the thickness of refining slag or covering agent in the ladle can be monitored online to control slag condition, evaluate refining effect, prevent slag entrapment, and optimize subsequent processes.

[0104] Applications in converters: Typically installed on the converter's auxiliary lance system or at dedicated measuring ports. During the later stages of blowing or before the final stage, it allows for rapid measurement of the slag layer thickness within the furnace, providing real-time data for dynamically adjusting the slag-forming process, controlling the final phosphorus and sulfur content, and determining the timing of slag removal.

[0105] Applications in electric arc furnaces: Can be installed at appropriate locations on the furnace wall or lid. During the melting or oxidation phase, it is used to monitor the height of the foamy slag, which is crucial for optimizing the power supply system, improving thermal efficiency, protecting the furnace lining, and controlling splashing. It is an auxiliary means to achieve efficient and energy-saving smelting in electric arc furnaces.

[0106] The present invention provides an online measurement device, method and application for metallurgical slag thickness, which realizes automated, real-time and non-contact inference measurement of slag thickness, and has the advantages of strong anti-interference ability, good environmental adaptability and high accuracy.

[0107] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. An online measurement device for metallurgical slag thickness, characterized in that, include: support; The drive mechanism is mounted on the bracket; The rigid probe (5) is connected to the power output end of the drive mechanism and is driven by the drive mechanism to perform uniform linear motion in the vertical direction. It is used to pass through the air zone (9), slag layer (8) and molten steel layer (7) in sequence during the measurement process. A torque sensor is used to detect in real time the output torque generated by the drive mechanism during the motion of the rigid probe (5); A displacement sensor is used to detect the displacement of the rigid probe (5) in the vertical direction in real time; The data processor (10) is connected to the torque sensor and the displacement sensor to receive and process real-time signals of the output torque and the displacement. Based on the real-time signals, a torque-displacement relationship curve reflecting the change of the output torque with the displacement is constructed. The torque-displacement relationship curve is analyzed to identify the first torque abrupt change point corresponding to the rigid probe (5) entering the slag layer (8) from the air zone (9) and the second torque abrupt change point corresponding to the slag layer (8) entering the molten steel layer (7). The thickness of the slag layer (8) is calculated based on the displacement values ​​corresponding to the first torque abrupt change point and the second torque abrupt change point.

2. The online metallurgical slag thickness measuring device according to claim 1, characterized in that, The drive mechanism includes: Servo motor (1); The speed reducer (2) has its input end connected to the output shaft of the servo motor (1); The ball screw (3) is set in the vertical direction, and its bottom end is coaxially connected to the rigid probe (5). The ball screw (3) is constrained by an anti-rotation mechanism set on the bracket so that it can only move along its axial direction. The gear nut (4) is rotatably supported on the bracket by bearings and fitted onto the ball screw (3), forming a ball screw pair with the ball screw (3). The output end of the reducer (2) meshes with the gear nut (4) through a transmission mechanism to drive the gear nut (4) to rotate around the axis of the ball screw (3), and converts the rotational motion of the gear nut (4) into the vertical linear motion of the ball screw (3) through the ball screw pair, thereby driving the rigid probe (5).

3. The online metallurgical slag thickness measuring device according to claim 2, characterized in that, The transmission mechanism is a bevel gear pair.

4. The online metallurgical slag thickness measuring device according to claim 2, characterized in that, The bracket is also provided with a guide mechanism, which is used to constrain the rigid probe (5) to move only in the vertical direction.

5. The online metallurgical slag thickness measuring device according to claim 4, characterized in that, The guiding mechanism includes: A linear guide or guide sleeve is used in conjunction with the rigid probe (5) or the ball screw (3).

6. The online metallurgical slag thickness measuring device according to claim 2, characterized in that, Also includes: The signal acquisition unit (11) is connected between the torque sensor, the displacement sensor and the data processor (10) and is used to condition and convert the sensor signals from analog to digital.

7. The online metallurgical slag thickness measuring device according to claim 1, characterized in that, The data processor (10) is also configured to calculate the volume and / or mass of the slag layer (8) based on the calculated thickness of the slag layer (8) and the cross-sectional area of ​​the metallurgical container.

8. The online metallurgical slag thickness measuring device according to claim 1, characterized in that, The rigid probe (5) is made of a high-temperature resistant and melt-resistant material, including high-temperature alloys or ceramic materials; and / or, the front end of the rigid probe (5) is tapered.

9. A method using the online metallurgical slag thickness measuring device as described in any one of claims 1-8, characterized in that, Includes the following steps: Start the drive mechanism to drive the rigid probe (5) to descend at a constant speed in the vertical direction, so that it passes through the air zone (9), the slag layer (8) and the molten steel layer (7) in sequence. The torque sensor and the displacement sensor are used to synchronously collect the output torque value of the drive mechanism and the displacement value of the rigid probe (5) in real time. The collected torque and displacement signals are transmitted to the data processor (10). The data processor (10) constructs a torque-displacement relationship curve based on the torque signal and the displacement signal; The data processor (10) analyzes the torque-displacement relationship curve to identify the first torque abrupt change point corresponding to the rigid probe (5) entering the slag layer (8) from the air zone (9) and the second torque abrupt change point corresponding to the rigid probe (5) entering the molten steel layer (7) from the slag layer (8). The thickness of the slag layer (8) is calculated based on the displacement values ​​corresponding to the first torque mutation point and the second torque mutation point.

10. An application of an online measurement device for metallurgical slag thickness, characterized in that, The metallurgical slag thickness online measuring device according to any one of claims 1-8 is installed in a metallurgical container, so that the measuring path of the rigid probe (5) passes through the internal space of the metallurgical container, for online measurement of the thickness of the slag layer (8) above the melt in the metallurgical container; The metallurgical container is a steel ladle (6), a converter, or an electric arc furnace.

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