Horseshoe sensor with signal compensation coil

Abstract

The present application belongs to the field of ladle slag detection, and particularly relates to a horseshoe-shaped sensor with a signal compensation coil, which comprises an excitation coil, a detection coil and a compensation coil wound in a horseshoe shape, the compensation coil is connected with one common end of the detection coil, and the other common end is configured as an output end; the detection coil has a central axis, the parallel projection of the detection coil on a projection plane is not completely overlapped with the parallel projection of the compensation coil on the projection plane; the central axis is parallel to the projection line, and both are perpendicular to the projection plane. The present application introduces the compensation coil, the voltage generated by the compensation coil is used to offset the part of the detection coil that does not change, so that the remaining output voltage is the changed part due to the steel slag, the smaller changed part output voltage can be amplified by using an amplifier with a larger amplification factor, so that the voltage signal reaching the signal processing end can be effectively identified, and the detection accuracy is also improved.

Description

Technical Field

[0001] This application belongs to the field of slag detection in steel ladles, specifically relating to a horseshoe-shaped sensor with a signal compensation coil. Background Technology

[0002] Existing horseshoe-shaped sensors typically consist of a sensor housing and a coil housed within it. The coil employs a dual-core structure within a single housing, including an excitation coil and a detection coil. These coils are stacked and wound in a horseshoe shape within the housing, forming two C-shaped outer and inner coils. The horseshoe-shaped sensor is installed robotically, semi-enclosed by a ring around the ladle nozzle. The excitation coil generates a magnetic field in the molten steel. Initially, the molten steel flowing out is almost entirely pure. Towards the end of the pouring process, slag mixes in, causing a decrease in fluid conductivity and thus affecting the magnetic field. This change in the magnetic field is reflected in the output voltage of the detection coil, which is amplified and displayed as the amount of slag content. In practical applications, we have found that when changes in the amount of slag in the molten steel cause changes in the magnetic field, the voltage change in the detection coil is very small. After attenuation and interference, the voltage signal is difficult to effectively detect at the signal processing end. An excessively small signal also affects the accuracy of the detection. Summary of the Invention

[0003] This application provides a horseshoe-shaped sensor with a signal compensation coil to solve the problem of insufficient output voltage change of the detection coil.

[0004] This application provides a horseshoe-shaped sensor with a signal compensation coil, comprising: The excitation coil is wound in a horseshoe shape; The detection coil is wound in a horseshoe shape. The compensation coil is wound in a horseshoe shape. The compensation coil is connected to one end of the detection coil, and the other end is configured as the output terminal. The detection coil has a central axis. The parallel projection of the detection coil on the projection plane does not completely overlap with the parallel projection of the compensation coil on the projection plane. The central axis is parallel to the projection line and perpendicular to the projection plane.

[0005] In one embodiment, the inner portion of the compensation coil is attached to the inner portion of the detection coil, and the outer portion of the compensation coil is located between the inner and outer portions of the detection coil.

[0006] In one embodiment, the outer portion of the compensation coil is attached to the outer portion of the detection coil, and the inner portion of the compensation coil is located between the inner and outer portions of the detection coil.

[0007] In one embodiment, the output voltage of the compensation coil is configured such that the difference between the output voltage of the compensation coil and the output voltage of the detection coil is less than 20 millivolts when pure molten steel flows through the long nozzle.

[0008] In one embodiment, the output voltage of the compensation coil is configured to be the same as the output voltage of the detection coil when pure molten steel flows through the long nozzle.

[0009] In one embodiment, the parallel projection of the detection coil on the projection plane completely overlaps with the parallel projection of the excitation coil on the projection plane.

[0010] In one embodiment, the inner portion of the compensation coil is attached to the inner portion of the detection coil, and the outer portion of the compensation coil is located at the midpoint between the inner and outer portions of the detection coil.

[0011] In one embodiment, the excitation coil has 10 turns and a wire diameter of 0.55mm. The input excitation current is alternating current with a current of 1000mA and a frequency of 500Hz. The detection coil has 8 turns and a wire diameter of 0.55mm. The compensation coil has 20 turns and a wire diameter of 0.55mm.

[0012] In one embodiment, the output terminal is connected to the input terminal of the amplifier.

[0013] In one embodiment, the horseshoe-shaped sensor with signal compensation coil further includes a housing configured in a horseshoe shape, and the excitation coil, detection coil, and compensation coil are all placed inside the housing.

[0014] Compared with the prior art, this application includes at least the following beneficial effects: The horseshoe-shaped sensor with signal compensation coil introduces a compensation coil, which is connected to one end of the detection coil of the same name, and the other end of the detection coil of the same name is the output terminal. The voltage generated by the compensation coil is used to compensate for the unchanging part of the detection coil, so that most of the remaining output voltage is the part of the change caused by the steel slag. The output voltage value is relatively small. The smaller output voltage can use an amplifier with a larger amplification factor to amplify the change part, so that the voltage signal reaching the signal processing terminal can be effectively identified, and the detection accuracy is improved.

[0015] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0016] The accompanying drawings in this application are for illustrating preferred embodiments and to facilitate a clear understanding by those skilled in the art of various other advantages and benefits, and should not be construed as limiting the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0017] Figure 1 This is a schematic diagram of a horseshoe-shaped sensor with a signal compensation coil in one embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the detection coil in one embodiment of this application. Figure 1 .

[0019] Figure 3 This is a schematic diagram of the detection coil in one embodiment of this application. Figure 2 .

[0020] Figure 4 This is a schematic diagram of the detection coil in one embodiment of this application. Figure 3 .

[0021] Figure 5 This is a schematic diagram of the detection coil in one embodiment of this application. Figure 4 .

[0022] Figure 6 This is a schematic diagram of the connection between the detection coil and the compensation coil in one embodiment of this application.

[0023] Explanation of icon numbers: 10. Housing; 230. Excitation coil and detection coil; 20. Excitation coil; 30. Detection coil; 31. Output terminal; 40. Compensation coil. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0027] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0028] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," "fixing," and "coupling" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0029] Figure 1 An exploded schematic diagram of a horseshoe-shaped sensor with a signal compensation coil is shown. Figure 1 A schematic diagram showing the positional relationship between the compensation coil 40 and the detection coil 30 is provided. Please refer to [link / reference]. Figure 1 and Figure 6One embodiment of this application provides a horseshoe-shaped sensor with a signal compensation coil. This horseshoe-shaped sensor includes a horseshoe-shaped excitation coil and a detection coil 230, as well as a horseshoe-shaped compensation coil 40. The excitation coil 20 is supplied with alternating current of a certain frequency. The compensation coil 40 is electrically connected to the first terminal of the detection coil 30, and the second terminal is the output terminal 31 of the induced voltage, used for connection to an amplifier. The parallel projection of the detection coil 30 on the projection plane does not completely overlap with the parallel projection of the compensation coil 40 on the projection plane, and the projection line is perpendicular to the projection plane. The horseshoe-shaped sensor with a signal compensation coil introduced above introduces a compensation coil 40. The compensation coil 40 is connected to one end of the detection coil 30 with the same name, and the other end with the same name is the output terminal. The voltage generated by the compensation coil 40 compensates for the unchanged part of the detection coil 30, so that most of the output voltage that is retained is the part of the change caused by the steel slag. The output voltage value is relatively small. The smaller output voltage can use an amplifier with a larger amplification factor to amplify the change part, so that the voltage signal reaching the signal processing terminal can be effectively identified, and the detection accuracy is improved.

[0030] Figure 2 A schematic diagram is shown when the excitation coil 20 is energized with an alternating current of a certain frequency. The arrows in the diagram indicate the direction of the current at a certain instant. Figure 3 A schematic diagram of the detection coil 30 is shown, with the arrows indicating the direction of the induced electromotive force at a given instant. See also... Figure 2 In a typical horseshoe-shaped sensor, the alternating current in the excitation coil 20 generates an alternating magnetic field in the circled area (corresponding to the steel passage area of ​​the long nozzle) in the diagram. Since the instantaneous currents in the inner and outer parts of the excitation coil 20 are spatially opposite, the magnetic field lines of the alternating magnetic fields generated by them are also opposite in direction. The instantaneous magnetic field lines are shown within the circled area in the diagram. Here, ⊕ represents the instantaneous magnetic field lines generated by the instantaneous current in the inner part of the excitation coil 20 in the circled area, and W represents the instantaneous magnetic field lines generated by the instantaneous current in the outer part of the excitation coil 20 in the circled area. Because the inner part of the excitation coil 20 is closer to the center of the circled area, the number of ⊕ is greater than the number of W. After the two cancel each other out, the remaining number of ⊕ in the circled area is as follows: Figure 3 As shown, the remaining ⊕ can generate an induced electromotive force in the detection coil 30.

[0031] Figure 4 and 5 Schematic diagrams of the detection coil 30 are shown for molten steel and slag passing through the circular area, respectively. (See attached diagram) Figure 4 and 5When molten steel or slag passes through the steel flow area, eddy currents are generated in the flow area. The magnetic field generated by these eddy currents is opposite in direction to the magnetic field generated by the excitation coil 20 in the flow area, thus weakening the magnetic field in the flow area. Since the conductivity of slag is much smaller than that of molten steel, only one-thousandth of that of molten steel, the eddy currents generated by slag are also significantly smaller than those generated by molten steel. Therefore, the canceling effect on the magnetic field in the flow area is much smaller than that of molten steel. Consequently, the magnetic field strength is greater when slag passes through the flow area and smaller when molten steel passes through it. When slag appears in the steel flow, the change in magnetic field strength can be detected by the change in the induced electromotive force generated by the detection coil 30.

[0032] Based on experimental data: when the excitation coil 20 has 5 turns and is supplied with 1000mA, 500Hz AC current, the output of the detection coil 30 is 212.8mV when the entire steel flow area is molten steel; and 213.1mV when the entire steel flow area is slag. The output change between all steel and all slag is 0.3mV. This change is very small, and since the steel flow often only contains some slag, the change will be even smaller. Therefore, this change must be amplified before it can be processed by subsequent equipment. For this purpose, an amplifier is installed at the output of the detection coil 30. Due to the voltage limitations of electronic components, the output of this amplifier cannot exceed 10V. Based on the above parameters, the amplification factor k of this amplifier can only be set to 40. After amplification, the voltage of all steel is 8512mV, and the voltage of all slag is 8524mV, with a change of 12mV between all steel and all slag. Furthermore, since the amplifier is often far from the main control room, the signal is attenuated and interfered with, making it difficult for the signal processor to effectively identify it when it reaches the signal processor, thus affecting the accuracy of the detection.

[0033] With 5 turns of excitation coil 20 and a 1000mA, 500Hz AC current applied, the output of compensation coil 40 is 225.4mV when the entire steel passage area is filled with molten steel and 225.9mV when the entire steel passage area is filled with slag. The output change is 0.5mV between all steel and all slag. By connecting the first corresponding terminals of detection coil 30 and compensation coil 40, and using the second corresponding terminal as the signal output terminal, the induced electromotive forces of detection coil 30 and compensation coil 40 are in opposite directions and cancel each other out. The signal output is 12.6mV for all steel and 12.8mV for all slag. The amplifier's amplification factor k can be set to 700 times. After amplification, the voltage of the all-steel is 12.6mV*700=8820mV, and the voltage of the all-slag is 12.8mV*700=8960mV. The change between the all-steel and all-slag is 140mV, which greatly improves the signal amplitude. The signal processor can effectively identify the signal and improve the detection accuracy.

[0034] It should be noted that, please continue to refer to... Figure 1 and Figure 6 A central axis is defined at the center point of the vertical detection coil 30's projection area. The parallel projection of the detection coil 30 onto the projection plane does not completely overlap with the parallel projection of the compensation coil 40 onto the projection plane; the projection lines are parallel to the central axis and perpendicular to the projection plane. This means that the compensation coil 40 and the detection coil 30 cannot be identical, preventing proportional changes in their output voltages. Therefore, the purpose of introducing the compensation coil 40 is to significantly reduce the sensor's output voltage while minimizing or minimizing the voltage change, thus greatly increasing the ratio of the voltage change to the total sensor output voltage.

[0035] In some embodiments, please continue to see Figure 6 When designing the compensation coil 40, it can be made smaller than the detection coil 30. The inner portion of the compensation coil 40 fits against the inner portion of the detection coil 30, and the outer portion of the compensation coil 40 is located between the inner and outer portions of the detection coil 30. Specifically, the outer portion of the compensation coil 40 can be located at the midpoint between the inner and outer portions of the detection coil 30. Designing the compensation coil 40 to be smaller saves space and materials and facilitates assembly.

[0036] The following data obtained from multiple experiments are used to illustrate this application: Experiment 1 When the excitation coil has 10 turns out of 20, the wire diameter is 0.55mm, the input AC current is 950mA, and the AC frequency is 500HZ; The detection coil has 8 turns out of 30, and the wire diameter is 0.55mm. The induced voltage is 275.8mV when the steel is molten, and 276.3mV when the slag is molten, with a change of 0.5mV. The amplifier's amplification factor K=30. After amplification, the induced voltage is 8274mV when the steel is molten and 8289mV when the slag is molten, with a change of 15mV.

[0037] Experiment 2 When the excitation coil has 10 turns in 20 turns, a wire diameter of 0.55mm, an AC current of 1000mA, and an AC frequency of 500HZ; The detection coil has 8 turns out of 30, and the wire diameter is 0.55mm. The induced voltage is 289.2mV when the steel is molten, and 289.6mV when the slag is molten, with a change of 0.4mV. The amplifier's amplification factor K=30. After amplification, the induced voltage is 8676mV when the steel is molten and 8688mV when the slag is molten, with a change of 12mV.

[0038] Experiment 3 When the excitation coil has 10 turns in 20 turns, the wire diameter is 0.55mm, the AC current is 1050mA, and the AC frequency is 500HZ; The detection coil has 8 turns out of 30, and the wire diameter is 0.55mm. The induced voltage is 303.7mV when the steel is molten, and 304.1mV when the slag is molten, with a change of 0.4mV. The amplifier's amplification factor K=30. After amplification, the induced voltage is 9111mV when the steel is molten and 9123mV when the slag is molten, with a change of 12mV.

[0039] Experiment 4 When the excitation coil has 10 turns out of 20, the wire diameter is 0.55mm, the AC current is 950mA, and the AC frequency is 500HZ; The detection coil has 8 turns out of 30, and the wire diameter is 0.55mm. The induced voltage is 275.8mV when the steel is molten, and 276.3mV when the slag is molten, with a change of 0.5mV. The compensation coil has 20 turns out of 40, with a wire diameter of 0.55mm. The induced voltage is 263.1 mV when the steel is molten and 263.8 mV when the slag is molten, with a change of 0.7 mV. After the detection coil 30 and the compensation coil 40 are coupled at the same terminals: the induced voltage is 12.7 mV when the steel is molten and 12.5 mV when the slag is molten, with a change of 0.2 mV. The amplifier's amplification factor K=700. After amplification, the induced voltage is 8890 mV when the steel is molten and 8750 mV when the slag is molten, with a change of 140 mV.

[0040] Experiment 5 When the excitation coil has 10 turns in 20 turns, the wire diameter is 0.55mm, the AC current is 1000mA, and the AC frequency is 500HZ; The detection coil has 8 turns out of 30, and the wire diameter is 0.55mm. The induced voltage is 289.2mV when the steel is molten, and 289.6mV when the slag is molten, with a change of 0.4mV. The compensation coil has 20 turns out of 40, and the wire diameter is 0.55mm. The induced voltage is 275.9mV when the steel is molten, and 276.7mV when the slag is molten, with a change of 0.8mV. After the detection coil 30 and the compensation coil 40 are coupled at the same terminals: the induced voltage is 13.3mV when the steel is molten and 12.9mV when the slag is molten, with a change of 0.4mV. The amplifier's amplification factor K=700. After amplification, the induced voltage is 9310mV when the steel is molten and 9030mV when the slag is molten, with a change of 280 mV.

[0041] Experiment 6 When the excitation coil has 10 turns in 20 turns, the wire diameter is 0.55mm, the AC current is 1050mA, and the AC frequency is 500HZ; The detection coil has 8 turns out of 30, and the wire diameter is 0.55mm. The induced voltage is 303.7mV when the steel is molten, and 304.1mV when the slag is molten, with a change of 0.4mV. The compensation coil has 20 turns out of 40, with a wire diameter of 0.55mm. The induced voltage is 289.8mV when the steel is molten and 290.5mV when the slag is molten, with a change of 0.7mV. After the detection coil 30 and the compensation coil 40 are coupled at the same terminals: the induced voltage is 13.9 mV when the steel is molten and 13.6 mV when the slag is molten, with a change of 0.3 mV. The amplifier's amplification factor K=700. After amplification, the induced voltage is 9730 mV when the steel is molten and 9520 mV when the slag is molten, with a change of 210 mV.

[0042] Based on the experimental data above, it can be seen that in experiments 1-3, without the introduction of compensation coil 40, the amplified voltage signals were all in the tens of microvolts; while in experiments 4-6, with the introduction of compensation coil 40, the amplified voltage signals were all in the hundreds of microvolts, and the signal amplitude was greatly improved, so it could be effectively identified by the signal processor.

[0043] In some embodiments, when designing the compensation coil 40, it can be designed to be smaller than the detection coil, with the outer portion of the compensation coil 40 fitting against the outer portion of the detection coil 30, and the inner portion of the compensation coil 40 located between the inner and outer portions of the detection coil 30. Designing the compensation coil to be smaller saves space and materials and facilitates assembly.

[0044] In some embodiments, when designing the compensation coil 40, the output voltage of the compensation coil 40 can be configured such that the difference between it and the output voltage of the detection coil 30 when pure molten steel flows through the long nozzle is less than 20 millivolts. The smaller the output voltage after coupling between the corresponding terminals of the detection coil 30 and the compensation coil 40 when pure molten steel flows through the long nozzle, the higher the ratio of voltage change to total output voltage can be. Furthermore, a larger amplifier gain can be selected, resulting in a larger voltage difference at the amplifier output terminals, making it easier to identify.

[0045] Furthermore, when designing the compensation coil 40, the output voltage of the compensation coil 40 can be configured to be the same as the output voltage of the detection coil 30 when pure molten steel flows through the long nozzle, which can further increase the ratio of voltage change to total output voltage.

[0046] In some embodiments, the parallel projection of the detection coil 30 on the projection surface completely overlaps with the parallel projection of the excitation coil 20 on the projection surface, which can save installation space and reduce the size of the sensor.

[0047] In some embodiments, the output terminal 31 of the detection coil 30 and the compensation coil 40 is directly connected to the input terminal of the amplifier, reducing the length of the wire and thus reducing the loss of output voltage.

[0048] In some embodiments, the excitation coil 20, the detection coil 30, and the compensation coil 40 can all be placed inside a horseshoe-shaped housing 10, and the housing can be used to fix and protect the excitation coil 20, the detection coil 30, and the compensation coil 40.

[0049] In summary, introducing a compensation coil 40 into the sensor can significantly reduce the sensor's output voltage while minimizing the change in voltage. This can greatly increase the ratio of voltage change to the total output voltage of the sensor, improve the amplifier's amplification factor, and ensure accurate identification by the signal processing end.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no contradiction or conflict, the various technical features mentioned in the various embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A horseshoe-shaped sensor with a signal compensation coil, characterized in that, include: The excitation coil is wound in a horseshoe shape; The detection coil is wound in a horseshoe shape. The compensation coil is wound in a horseshoe shape. The compensation coil is connected to one end of the detection coil, and the other end is configured as the output terminal. The detection coil has a central axis. The parallel projection of the detection coil on the projection plane does not completely overlap with the parallel projection of the compensation coil on the projection plane. The central axis is parallel to the projection line and perpendicular to the projection plane. The output voltage of the compensation coil is configured such that the difference between it and the output voltage of the detection coil is less than 20 millivolts when pure molten steel flows through the long nozzle; or, the output voltage of the compensation coil is configured such that it is the same as the output voltage of the detection coil when pure molten steel flows through the long nozzle. The inner portion of the compensation coil is in contact with the inner portion of the detection coil, and the outer portion of the compensation coil is located at the midpoint between the inner and outer portions of the detection coil.

2. The horseshoe-shaped sensor with signal compensation coil according to claim 1, characterized in that, The inner portion of the compensation coil is in contact with the inner portion of the detection coil, and the outer portion of the compensation coil is located between the inner and outer portions of the detection coil.

3. The horseshoe-shaped sensor with signal compensation coil according to claim 1, characterized in that, The outer portion of the compensation coil is in contact with the outer portion of the detection coil, and the inner portion of the compensation coil is located between the inner and outer portions of the detection coil.

4. The horseshoe-shaped sensor with signal compensation coil according to claim 1, characterized in that, The parallel projection of the detection coil on the projection plane completely overlaps with the parallel projection of the excitation coil on the projection plane.

5. The horseshoe-shaped sensor with signal compensation coil according to claim 4, characterized in that, The excitation coil has 10 turns and a wire diameter of 0.55mm. The input excitation current is AC, with a current of 1000mA and a frequency of 500Hz. The detection coil has 8 turns and a wire diameter of 0.55mm. The compensation coil has 20 turns and a wire diameter of 0.55mm.

6. The horseshoe-shaped sensor with signal compensation coil according to claim 1, characterized in that, The output terminal is connected to the input terminal of the amplifier.

7. The horseshoe-shaped sensor with signal compensation coil according to claim 1, characterized in that, The horseshoe-shaped sensor with signal compensation coil also includes a housing configured in a horseshoe shape, and the excitation coil, detection coil and compensation coil are all placed inside the housing.

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