Anti-interference copper liquid oxygen determination instrument

Abstract

The application discloses an anti-interference copper liquid oxygen determination instrument and belongs to the technical field of non-ferrous metallurgy smelting furnace front molten metal detection equipment. A double-channel acquisition front-end module is provided with two mutually independent floating ground acquisition branches of temperature and oxygen potential, and a common ground crosstalk path is cut off from a hardware level. A multi-copper alloy differentiation thermodynamic solution model of a Cu-Cu2O balance system is built in the instrument, and dedicated dynamic compensation coefficients are called for different copper alloy grades, so that the detection precision in a low oxygen range is greatly improved. A composite adaptive anti-interference conditioning module dynamically switches the filtering strength according to the harmonic amplitude of the power grid, and the signal response speed and stability are taken into account. A full-dimension fault diagnosis unit monitors the state of a probe, a cable and an acquisition circuit in real time and outputs a fault code. A multi-protocol isolation communication unit supports synchronous visual display of multiple terminals at a furnace front, outdoors and in central control, and realizes centralized management and control of a whole copper smelting process.

Description

Technical Field

[0001] This invention relates to the field of copper smelting technology, and in particular to an anti-interference copper liquid oxygen analyzer. Background Technology

[0002] In the copper smelting process, the oxygen content of the molten metal directly determines the conductivity and hot / cold working plasticity of the copper material. High-precision real-time monitoring of the oxygen activity in the molten copper is necessary throughout the entire process, from anode furnace reduction to copper molten transfer. Currently, in the non-ferrous metallurgical industry, online detection of dissolved oxygen in molten metal commonly employs solid electrolyte concentration cell oxygen sensors. These sensors operate on the principle of generating a concentration potential based on the difference in oxygen partial pressure across a solid electrolyte, and the oxygen content is determined by measuring the electrode potential signal. These sensors typically consist of an oxygen probe, a thermocouple, and signal acquisition and processing instruments, and are widely used in the steelmaking industry for oxygen determination in molten steel. However, all existing commercial oxygen determination equipment is developed based on the Fe-O equilibrium system of molten steel. Its Nernst equation calibration parameters, standard equilibrium constants, and high-temperature compensation coefficients are all designed for the iron-oxygen reaction system, resulting in numerous unresolved technical defects when directly applied to copper smelting scenarios.

[0003] First, molten copper follows a Cu-Cu₂O oxidation equilibrium, which is significantly different from the Fe-O equilibrium system of molten steel in terms of thermodynamics. Copper has a lower melting point (1083℃), and the copper smelting temperature range (800–1400℃) differs from that of molten steel (1500–1700℃). Their standard equilibrium constants and temperature compensation coefficients also differ by orders of magnitude. When existing equipment directly reuses the molten steel oxygen determination algorithm, the measurement error in the low oxygen range of 1–50 ppm in molten copper exceeds 30%, and the measured values ​​drift over a long period, making it impossible to support the refined deoxidation process control of the anode furnace. Second, the copper smelting production line is equipped with high-power anode furnace rectifier power supplies, high-voltage frequency converters for continuous casting mills, and other strong electromagnetic interference sources. The plant's power grid also experiences extremely strong harmonics and alternating magnetic fields. Traditional oxygen analyzers share a common grounding reference point for both the temperature and oxygen potential acquisition circuits. These two weak millivolt-level signals are highly susceptible to potential coupling and crosstalk in the strong electromagnetic environment of the field. This frequently results in typical faults where thermocouple temperature readings and oxygen potential signal amplitudes are normal, but a complete and continuous deoxidation detection curve cannot be output, completely compromising the furnace-side process guidance capability. Furthermore, in copper melts with different compositions, such as crude copper, oxygen-free pure copper, brass, and aluminum-iron bronze, solute elements significantly alter the oxygen activity coefficient of the copper melt. Existing equipment uses a single calibration parameter to calculate the oxygen activity of all types of copper melts, leading to extremely poor repeatability in high-alloy copper melt detection. The start-up and shutdown of smelting equipment and the high-power closing of the overhead crane generate instantaneous electromagnetic disturbances. Traditional fixed-parameter filtering schemes cannot balance filtering accuracy and signal response speed, resulting in frequent jumps and breaks in the oxygen potential curve, failing to fully record the entire deoxidation process of the entire furnace of copper melt. Furthermore, the existing equipment has weak fault diagnosis capabilities. Conditions such as aging of the probe's ceramic electrolyte, loose connections in the gun body wiring, and damage from erosion of the protective sleeve cannot be automatically identified. Maintenance personnel must check the hardware circuits segment by segment, resulting in lengthy production line downtime for repairs. The original process data storage capacity is limited, and oxygen content data from multiple furnaces of molten copper cannot be retained long-term, making process traceability difficult. Simultaneously, the original equipment is only equipped with small local displays, resulting in poor visibility in the high-temperature, dusty environment in front of the furnace. The central control and dispatch terminal cannot simultaneously obtain real-time oxygen content parameters of the molten copper, making centralized management of the entire smelting process difficult to implement.

[0004] Therefore, there is an urgent need in this field to develop a dedicated copper liquid oxygen meter that is applicable to all copper smelting scenarios, has Cu-Cu2O-specific thermodynamic calculation capabilities, can effectively suppress strong electromagnetic interference in smelting plants, adapts to differentiated compensation for multiple copper alloys, and has full-link fault diagnosis and multi-terminal remote visualization functions, so as to solve the long-standing technical shortcomings of existing general steel oxygen metering equipment in copper smelting applications. Summary of the Invention

[0005] The purpose of this invention is to provide an anti-interference copper liquid oxygen analyzer to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides an anti-interference copper liquid oxygen analyzer, comprising an industrial shielded chassis, a wide-range isolated power supply unit, a dual-channel electrically isolated acquisition front-end module, an MCU main control and computing unit, a copper alloy thermodynamic parameter storage unit, a composite adaptive anti-interference conditioning module, a furnace front human-machine interaction unit, a full-dimensional fault diagnosis and data storage unit, and a multi-protocol isolated external communication unit. The dual-channel electrically isolated data acquisition front-end module is equipped with a thermocouple temperature acquisition branch and an oxygen potential acquisition branch. The input terminal of the composite adaptive anti-interference conditioning module is connected to the output terminal of the dual-channel electrically isolated acquisition front-end module, and the output terminal of the composite adaptive anti-interference conditioning module is connected to the input terminal of the MCU main control and processing unit. The composite adaptive anti-interference conditioning module integrates a hardware RC passive low-pass filter circuit and a moving average digital filter algorithm with dynamically adjustable window width, and has built-in power grid disturbance identification logic. The MCU main control computing unit is bidirectionally electrically connected to the copper alloy thermodynamic parameter storage unit. The copper alloy thermodynamic parameter storage unit pre-stores oxygen activity calculation compensation parameters for the Cu-Cu2O system corresponding to crude copper, pure copper, brass, and aluminum-iron bronze. The MCU main control computing unit adapts to the following formula to complete the calculation of the oxygen content in the copper liquid: ; in, The gas constant is The thermodynamic temperature of molten copper. It is Faraday's constant. The oxygen partial pressure on the reference electrode side. The oxygen partial pressure inside the molten copper. This is the dynamic compensation coefficient for the corresponding copper alloy; The full-dimensional fault diagnosis and data storage unit is bidirectionally connected to the MCU main control and computing unit; The multi-protocol isolated external communication unit is connected to the output of the MCU main control and computing unit, and is configured with an isolated RS-485 interface, a gigabit Ethernet interface and an HDMI video output interface.

[0007] Preferably, the industrial shielded enclosure is equipped with a strong and weak current separation compartment, the panel is equipped with explosion-proof and temperature-resistant aviation signal connectors, the aviation signal connectors are equipped with alumina ceramic heat insulation bushings, and the side walls of the enclosure are arranged with active heat dissipation air ducts.

[0008] Preferably, the wide-range isolated power supply unit is adapted to a wide voltage input of AC85-264V and outputs multiple electrically isolated DC power supply branches, which provide independent power to the dual-channel electrically completely isolated acquisition front-end module, the MCU main control and computing unit, the furnace front human-machine interaction unit, and the multi-protocol isolated external communication unit.

[0009] Preferably, the MCU main control computing unit has a built-in automatic smelting condition identification program, which can automatically identify the conditions of anode furnace refining, copper liquid transfer in the flow channel, and continuous casting heat preservation based on the copper liquid temperature and oxygen potential change trends, and adaptively retrieve the corresponding smelting parameter range.

[0010] Preferably, the thermocouple temperature acquisition branch has a built-in cold junction compensation unit, is compatible with B, K, and S type thermocouples, and covers a temperature measurement range of 800℃ to 1400℃; the oxygen potential acquisition branch has a range of 0 to 1200mV and a sampling resolution of not less than 0.001mV.

[0011] Preferably, the furnace front human-machine interaction unit is equipped with an industrial touch screen display, which has a quick selection menu for operating conditions, a one-click switching menu for thermocouple index numbers, a selection menu for copper alloy materials, and a setting menu for process alarm thresholds. The instrument is equipped with an audible and visual alarm module, which outputs audible and visual alarm signals when the oxygen content exceeds the limit or the equipment malfunctions.

[0012] Preferably, the data transmission delay of the multi-protocol isolated external communication unit is less than 100ms, and a single instrument synchronously drives the explosion-proof touch screen in front of the furnace, the outdoor high-brightness LED display screen, and the central control splicing screen.

[0013] This invention also provides a method for measuring oxygen in copper liquid, using the aforementioned anti-interference copper liquid oxygen analyzer, comprising the following steps: S1. Immerse the oxygen-determining probe in the molten copper and activate the dual-channel electrically isolated acquisition front-end module. The thermocouple temperature acquisition branch acquires the thermoelectric potential signal output by the thermocouple, and after cold junction compensation, obtains the thermodynamic temperature of the molten copper. The oxygen potential acquisition branch acquires the oxygen potential signal output by the solid electrolyte concentration cell of the oxygen-fixing probe. ; S2. The composite adaptive anti-interference conditioning module sequentially performs hardware RC passive low-pass filtering and variable window moving average digital filtering on the acquired temperature signal and oxygen potential signal, and detects the total harmonic distortion rate of the on-site voltage in real time. and the start-up and shutdown status of high-power smelting equipment, when If the filter strength is >5% or a high-power device is detected to be running, switch to the high filter strength setting. When the temperature is less than 3% and no high-power equipment is starting or stopping, switch to the low filter intensity setting and output the filtered temperature signal. With oxygen potential signal ; S3, the MCU main control unit calculates the filtered temperature signal. The true value of the thermodynamic temperature of the copper liquid is obtained by inverse calculation using the thermocouple calibration polynomial specified in the International Temperature Scale ITS-90: ; in, Thermoelectric electromotive force output from the thermocouple acquisition branch. These are the polynomial fitting coefficients for the corresponding degree sign. Let be the order of the polynomial. This is the cold junction compensation value; S4. The MCU main control unit calculates the oxygen potential signal based on the filtered oxygen potential signal. and the temperature obtained in step S3 Substituting into the Nernst equation for the Cu-Cu₂O equilibrium system, calculate the oxygen partial pressure inside the molten copper: ; in, The oxygen partial pressure on the reference electrode side. This is an electromotive force offset correction term introduced for the non-isothermal effect of thermocouples. It is Faraday's constant. It is the ideal gas constant; S5. The MCU main control computing unit retrieves the corresponding activity interaction coefficient from the copper alloy thermodynamic parameter storage unit according to the currently selected copper alloy grade. and dynamic compensation coefficient Calculate the oxygen activity coefficient in this copper alloy: ; in, is the activity coefficient of oxygen in the copper alloy. Solute element mole fraction; Then convert to oxygen concentration in parts per million (ppm): ; in, Where is the molar mass of oxygen. The molar mass of copper, This represents the standard state oxygen partial pressure. S6. The full-dimensional fault diagnosis and data storage unit monitors the thermocouple heating rate, oxygen potential change slope, acquisition circuit impedance and cable insulation resistance in real time. When any parameter exceeds the preset threshold, it outputs the corresponding fault code and drives the audible and visual alarm. S7. The MCU main control computing unit calculates the copper liquid temperature. Oxygen content The deoxidation trend curve is simultaneously sent to the furnace front human-machine interaction unit for local display, the full-dimensional fault diagnosis and data storage unit for archiving, and the multi-protocol isolated external communication unit for remote terminal output.

[0014] Preferably, in step S2, the moving average window width N=32 and the filtering order m=4 for the high filtering intensity level, and the moving average window width N=8 and the filtering order m=2 for the low filtering intensity level.

[0015] Preferably, in step S6, the normal range of the thermocouple heating rate is 5℃ / s to 20℃ / s, the normal range of the oxygen potential change slope is within ±2mV / s, the normal range of the acquisition circuit impedance is less than 1kΩ, and the normal range of the cable insulation resistance is greater than 100MΩ.

[0016] The present invention achieves the following beneficial technical effects compared to the prior art: This invention provides an anti-interference copper liquid oxygen analyzer, characterized by high measurement accuracy, strong anti-interference capability, convenient operation and maintenance, and wide adaptability to various working conditions. Specifically, by setting up a dual-channel, fully floating ground electrically isolated acquisition architecture, the power supply and reference ground of the temperature and oxygen potential acquisition circuits are completely isolated, effectively cutting off the common ground crosstalk path of the two weak signals in the strong electromagnetic environment of the smelting plant from the hardware level, thus solving the industry-wide problem of abrupt changes in the copper liquid detection curve. Furthermore, by incorporating a multi-copper alloy differentiated thermodynamic calculation model adapted to the Cu-Cu2O equilibrium system, and designing exclusive dynamic compensation coefficients for different grades of copper melt, the measurement error is controlled within ±3ppm in the 1–50ppm low oxygen range, fundamentally solving the problem of copper... Addressing the pain point of liquid metal detection value drift; by incorporating a smelting harmonic adaptive composite filter module, the filter intensity can be dynamically adjusted according to on-site power grid disturbances, balancing signal response speed and measurement stability; equipped with a full-link fault diagnosis system, it achieves complete fault inspection and automatic fault coding output from the oxygen probe and oxygen lance cable to the instrument's internal acquisition circuit, significantly shortening the maintenance time of on-site smelting equipment; by configuring multi-protocol isolated communication and video output interfaces, it supports synchronous visual display of copper smelting parameters on multiple terminals including furnace front, outdoor, and central control, realizing centralized control of the entire copper smelting process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the anti-interference copper liquid oxygen analyzer provided by the present invention; Figure 2 This is a schematic diagram of the electrical connections of the anti-interference copper liquid oxygen analyzer provided by the present invention. Detailed Implementation

[0019] Unless otherwise specified, the terms "connection" and "linkage" used in this application include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and do not 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 invention.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The purpose of this invention is to provide an anti-interference copper liquid oxygen analyzer to solve the problems existing in the prior art.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] This invention provides an anti-interference copper liquid oxygen analyzer, the overall structure of which is as follows: Figure 1 and Figure 2As shown, it includes an industrial shielded enclosure 1, a wide-range isolated power supply unit 2, a dual-channel electrically isolated acquisition front-end module 3, an MCU main control and computing unit 4, a copper alloy thermodynamic parameter storage unit 5, a composite adaptive anti-interference conditioning module 6, a furnace front human-machine interaction unit 7, a full-dimensional fault diagnosis and data storage unit 8, and a multi-protocol isolated external communication unit 9.

[0025] The industrial shielded enclosure 1 employs a double-layer electromagnetic shielding sheet metal shell, with a nano-conductive shielding coating sprayed onto the inner wall to enhance the overall shielding effectiveness against the strong electromagnetic fields of the smelting plant area. The enclosure features independent strong and weak current compartments, physically isolating the strong current circuits from the weak current signal circuits to prevent electromagnetic radiation from the strong current circuits from interfering with the weak current signals. The enclosure panel is equipped with explosion-proof and temperature-resistant aviation signal connectors 10, used to connect the signal cables of the external oxygen lance. The aviation signal connectors 10 have an internal alumina ceramic heat-insulating bushing. Alumina ceramic has excellent high-temperature resistance and electrical insulation properties, effectively blocking the high-temperature radiation from the furnace opening from being conducted to the terminals, avoiding the risk of terminal oxidation and poor connection. Active cooling ducts are arranged on the side walls of the enclosure, and cooling fans can be installed within these ducts to promptly dissipate the heat generated by the various functional units inside the enclosure, ensuring long-term stable operation of the instrument in the extreme working environment of the smelting workshop with high temperature, high dust, and high flue gas. The industrial shielded enclosure 1 can be wall-mounted and fixed inside the control cabinet next to the furnace, or it can be installed at a suitable position in front of the furnace using a floor-standing bracket.

[0026] The wide-range isolation power supply unit 2 is compatible with a wide range of industrial grid voltages from AC 85V to 264V. This voltage range covers the fluctuation range of the power grid voltage in the smelting plant area, ensuring stable output even during significant voltage fluctuations. Internally, the wide-range isolation power supply unit 2 contains multiple independent switching power supply modules, outputting multiple independent and electrically isolated DC power supply branches. These DC power supply branches independently power the thermocouple temperature acquisition branch and oxygen potential acquisition branch in the dual-channel electrically isolated acquisition front-end module 3, the MCU main control unit 4, the furnace front human-machine interface unit 7, and the multi-protocol isolated external communication unit 9. There is no electrical conduction path between the power supply branches, effectively cutting off interference conduction paths between different circuits from the power supply side.

[0027] The dual-channel, electrically isolated data acquisition front-end module 3 features two independent floating ground acquisition branches: a thermocouple temperature acquisition branch and an oxygen potential acquisition branch. These two branches are physically independent, each with its own signal conditioning circuitry, signal amplification circuitry, and reference ground. There is no common reference ground connection between the two branches, and the power frequency isolation withstand voltage is no less than 2500VAC. This design ensures complete electrical isolation between the two acquisition branches, eliminating the possibility of crosstalk between two weak signals at the hardware level.

[0028] The thermocouple temperature acquisition branch is equipped with a magnetically isolated signal amplification circuit at its front end. Magnetic isolation technology uses magnetic field coupling to transmit signals, rather than through electrical conductivity, thus achieving electrical isolation between input and output. This branch incorporates a high-precision cold junction compensation chip, which measures the temperature of the thermocouple reference junction in real time and outputs a compensation value to eliminate the impact of reference junction temperature variations on measurement accuracy. This branch is compatible with three mainstream thermocouple types: Type B, Type K, and Type S. Operators can switch between types of thermocouples using a single click via a human-machine interface. The thermocouple temperature acquisition branch has a measurement range covering 800℃ to 1400℃, fully covering the temperature range of all copper smelting processes, including copper smelting, copper liquid transfer, and copper alloy continuous casting.

[0029] The oxygen potential acquisition branch employs a two-stage high-precision, low-drift instrumentation operational amplifier. The first-stage amplifier acts as a pre-buffer amplifier, featuring extremely high input impedance and extremely low input bias current. The second-stage amplifier serves as the main amplification stage, providing stable voltage gain. The front end of the oxygen potential acquisition branch is equipped with an ultra-high impedance floating-ground isolation conditioning circuit with an input impedance of no less than 10Ω. 12 With an input impedance of Ω, this high impedance minimizes the loss of the weak potential signal from the copper liquid oxygen probe, ensuring that the weak oxygen potential signal is not distorted or attenuated during transmission and conditioning. This branch has a range of 0 to 1200 mV and a sampling resolution of 0.001 mV, enabling precise capture of minute oxygen potential fluctuations in the low-oxygen range of copper liquid.

[0030] The input terminal of the composite adaptive anti-interference conditioning module 6 is connected to the output terminal of the dual-channel electrically isolated acquisition front-end module 3, and the output terminal of the composite adaptive anti-interference conditioning module 6 is connected to the input terminal of the MCU main control and processing unit 4. At the hardware level, the composite adaptive anti-interference conditioning module 6 employs an RC passive low-pass filter circuit, composed of resistors and capacitors. Utilizing the bypass effect of the capacitor on high-frequency signals and the attenuation effect of the resistor, it achieves preliminary suppression of the 50Hz power frequency and its integer multiples of harmonics at the smelting site. At the software level, the composite adaptive anti-interference conditioning module 6 incorporates a variable window moving average digital filtering algorithm. This algorithm integrates power grid disturbance identification logic and collects the total harmonic distortion rate of the on-site voltage in real time. And the start / stop status of high-power smelting equipment, and dynamically adjust the window width N and filter order m of the moving average filter based on this information. When the total voltage harmonic distortion rate... When the voltage harmonic distortion exceeds 5% or high-power equipment such as the rectifier cabinet of an anode furnace or the frequency converter of a continuous casting mill is detected to be in operation, the composite adaptive anti-interference conditioning module 6 automatically switches to the high filtering intensity level. At this time, the sliding average window width N is set to 32 and the filtering order m is set to 4 to effectively suppress data jumps caused by electromagnetic shocks. When the oxygen potential is less than 3% and no high-power equipment is started or stopped, the composite adaptive anti-interference conditioning module 6 automatically adjusts to a low filtering intensity level. At this time, the sliding average window width N is 8 and the filtering order m is 2 to ensure the dynamic response speed of the oxygen potential signal, while taking into account both signal stability and dynamic detection accuracy.

[0031] The MCU main control unit 4 uses a 32-bit high-performance industrial-grade microcontroller with a built-in floating-point unit, enabling efficient execution of complex mathematical operations. The MCU main control unit 4 incorporates a core for calculating the oxygen activity in liquid copper, responsible for all numerical calculations related to oxygen activity in liquid copper. The MCU main control unit 4 and the copper alloy thermodynamic parameter storage unit 5 are connected bidirectionally via a bidirectional data bus. The copper alloy thermodynamic parameter storage unit 5 internally stores independent Cu-Cu2O system thermodynamic databases for four types of copper melts: crude copper, pure copper, brass, and aluminum-iron bronze. This database includes standard equilibrium constants, temperature compensation coefficients, and activity interaction coefficients of solute elements with oxygen for each copper alloy grade. and exclusive dynamic compensation coefficient When performing oxygen activity calculation, the MCU main control unit 4 adaptively retrieves the corresponding dynamic compensation coefficient from the copper alloy thermodynamic parameter storage unit 5 according to the currently selected copper alloy grade. And complete the high-precision conversion of oxygen content in liquid copper according to the following formula: ; in, The oxygen potential signal output by the oxygen probe. Let be the ideal gas constant. The thermodynamic temperature of molten copper. It is Faraday's constant. The oxygen partial pressure on the reference electrode side. The oxygen partial pressure inside the molten copper. This is a dynamic compensation coefficient that is adaptively retrieved based on the currently selected copper alloy grade.

[0032] The MCU main control unit 4 also has a built-in automatic smelting condition identification program. This program can automatically match the current smelting condition based on the collected copper liquid temperature change rate and oxygen potential change rate. When the temperature change rate is gradual and the oxygen potential decreases in a stepwise manner, the program automatically identifies it as an anode furnace refining condition and retrieves the thermodynamic compensation parameters corresponding to crude copper and a higher data sampling and holding period. When the temperature decreases slowly and the oxygen potential is relatively stable but accompanied by low-frequency disturbances, the program automatically identifies it as a flow channel transfer condition and retrieves the compensation parameters corresponding to pure copper and appropriately increases the filtering intensity. When the temperature is basically constant and the oxygen potential needs to be continuously monitored for a long time, the program automatically identifies it as a continuous casting holding condition, retrieves the compensation parameters corresponding to the copper alloy grade, and enables a low-power continuous acquisition mode. Through the above automatic identification and parameter adaptive matching, operators do not need to perform complex parameter calibration, reducing the threshold for furnace operation.

[0033] The all-dimensional fault diagnosis and data storage unit 8 is bidirectionally connected to the MCU main control and processing unit 4. The all-dimensional fault diagnosis and data storage unit 8 is equipped with a complete equipment health diagnosis subroutine, which monitors multiple parameters in real time. Specifically, the all-dimensional fault diagnosis and data storage unit 8 monitors the thermocouple heating rate in real time, with a normal range of 5℃ / s to 20℃ / s. If the thermocouple heating rate exceeds this range, it is judged as an abnormal probe insertion or a broken thermocouple. The all-dimensional fault diagnosis and data storage unit 8 monitors the oxygen potential change slope in real time, with a normal range within ±2mV / s. If the oxygen potential change slope exceeds this range, it is judged as a cracked probe electrolyte or an aging reference electrode. The all-dimensional fault diagnosis and data storage unit 8 monitors the acquisition circuit impedance in real time, with a normal range of less than 1kΩ. If the acquisition circuit impedance is greater than or equal to 1kΩ, it is judged as a loose connection in the gun body circuit or oxidation of the terminals. The all-dimensional fault diagnosis and data storage unit 8 monitors the cable insulation resistance in real time. The normal range is greater than 100MΩ. If the cable insulation resistance is lower than 100MΩ, it is judged as erosion damage to the protective sleeve. When any parameter exceeds the preset threshold range, the all-dimensional fault diagnosis and data storage unit 8 immediately outputs the corresponding unique fault code. For example, E01 represents probe electrolyte cracking, E02 represents a loose connection, E03 represents reference electrode aging, E04 represents erosion damage to the protective sleeve, and E05 represents high-temperature oxidation of the terminal. The all-dimensional fault diagnosis and data storage unit 8 simultaneously drives the audible and visual alarm component of the furnace front human-machine interaction unit 7 to issue audible and visual alarm signals. The all-dimensional fault diagnosis and data storage unit 8 has a large-capacity non-volatile memory, which supports the permanent storage of at least 10,000 complete temperature and oxygen measurement full curves. The original data collected during all fault periods are synchronously retained. Complete smelting history data can be exported offline through the local USB interface, supporting copper smelting process traceability and smelting parameter optimization.

[0034] The furnace-front human-machine interface unit 7 is equipped with an industrial touch screen display. This display is dustproof, waterproof, and vibration-resistant, adapting to the harsh working environment in front of the furnace. The industrial touch screen interface has four main functional modules: a quick selection menu for process conditions, a one-click switching menu for thermocouple calibration numbers, a copper alloy material selection menu, and a process alarm threshold setting menu. The display interface is divided into independent zones, simultaneously displaying the real-time temperature of the molten copper, the oxygen content in ppm, a complete deoxidation trend curve, the remaining probe lifespan, and the current operating status of the equipment. The furnace-front human-machine interface unit 7 also features an audible and visual alarm component. When the oxygen content exceeds the upper or lower limits of the process, the probe performance deteriorates, or a fault occurs in the acquisition circuit, the audible and visual alarm component outputs an audible and visual alarm signal to alert on-site operators for timely handling.

[0035] The multi-protocol isolated external communication unit 9 is connected to the output of the MCU main control and processing unit 4. The multi-protocol isolated external communication unit 9 integrates multiple electrically isolated external communication interfaces, specifically including an isolated RS-485 interface supporting the Modbus RTU industrial bus protocol; a gigabit industrial Ethernet interface supporting the Modbus TCP protocol; and an HDMI industrial video output interface. All communication interfaces are electrically isolated to ensure there is no electrical continuity between the internal circuitry of the instrument and external devices. The data transmission delay of the multi-protocol isolated external communication unit 9 is less than 100ms, supporting a single instrument to synchronously drive three types of display terminals: a furnace-front explosion-proof touchscreen, an outdoor high-brightness LED display, and a central control splicing screen. The instrument synchronously sends smelting parameters to various display terminals through the above interfaces, enabling a single instrument to drive multiple terminals for synchronous display. The central control room host computer supports remotely sending smelting process parameters, modifying alarm thresholds, and retrieving historical detection curves through the isolated RS-485 interface or gigabit industrial Ethernet interface, completing centralized control of the entire copper smelting process.

[0036] The copper liquid oxygen determination method provided by this invention will be described in detail below with reference to specific measurement steps.

[0037] The first step involves connecting an immersion oxygen lance equipped with a calcium-stabilized β″ alumina oxygen lance probe and a thermocouple to the instrument front end via aviation signal connector 10. The oxygen lance is then inserted into molten copper. The dual-channel electrically isolated acquisition front-end module 3 is activated, and the thermocouple temperature acquisition branch picks up the thermoelectric potential signal generated by the thermocouple through a magnetically isolated signal amplification circuit. It has a built-in high-precision cold junction compensation chip that simultaneously measures the temperature of the thermocouple reference junction and outputs the cold junction compensation value. The oxygen potential acquisition branch picks up the oxygen potential signal generated by the solid electrolyte concentration cell of the oxygen probe through an ultra-high impedance floating ground isolation conditioning circuit. The signal is conditioned and amplified by two stages of high-precision, low-drift instrumentation amplifiers. The power supply and signal reference ground of the two acquisition branches are completely isolated, with a power frequency isolation withstand voltage of not less than 2500VAC, thus completely cutting off the common ground coupling crosstalk path between the two weak signals at the hardware level.

[0038] In the second step, the composite adaptive anti-interference conditioning module 6 sequentially performs hardware RC passive low-pass filtering and variable window moving average digital filtering on the acquired temperature signal and oxygen potential signal. And the start-up and shutdown status of high-power smelting equipment. When the total voltage harmonic distortion rate... When the voltage harmonic distortion exceeds 5% or high-power equipment is detected to be running, the composite adaptive anti-interference conditioning module 6 automatically switches to a high filtering intensity level. At this point, the sliding average window width N is set to 32 and the filtering order m to 4, to suppress data fluctuations caused by electromagnetic shocks. When the oxygen potential is less than 3% and no high-power equipment is starting or stopping, the composite adaptive anti-interference conditioning module 6 automatically adjusts to a low filtering intensity level. At this point, the moving average window width N is set to 8 and the filtering order m is set to 2 to ensure the dynamic response speed of the oxygen potential signal. After filtering, the composite adaptive anti-interference conditioning module 6 outputs the filtered temperature signal. With the filtered oxygen potential signal To the MCU main control and processing unit 4.

[0039] The third step is for the MCU main control processing unit 4 to process the filtered temperature signal. The true value of the thermodynamic temperature of the copper liquid is obtained by inverse operation using the thermocouple calibration polynomial specified in the International Temperature Scale (ITS-90). : ; in, Thermoelectric electromotive force output from the thermocouple acquisition branch. These are the polynomial fitting coefficients corresponding to the degree sign, where n is the polynomial order, with 8 for B-type, 9 for K-type, and 8 for S-type. This represents the reference junction temperature compensation value output by the cold junction compensation chip. (The following are the fitting coefficients.) The thermocouple number is retrieved from the read-only memory inside the MCU main control unit 4.

[0040] Fourth step, the MCU main control unit 4 calculates the oxygen potential signal based on the filtered oxygen potential signal. and the temperature obtained in the third step Substituting into the Nernst equation for the Cu-Cu₂O equilibrium system, calculate the oxygen partial pressure inside the molten copper. : ; in, The oxygen partial pressure on the reference electrode side is determined by the reference electrode material at a certain temperature. The equilibrium oxygen partial pressure is determined by the following. The electromotive force offset correction term introduced for the non-isothermal effect of the thermocouple is determined by the thermal shock response characteristics at the moment the probe is inserted into the copper liquid. It is Faraday's constant. is the ideal gas constant.

[0041] Fifth, the MCU main control unit 4 retrieves the corresponding activity interaction coefficient of the solute element with oxygen from the copper alloy thermodynamic parameter storage unit 5 based on the copper alloy grade selected by the current operator. and dynamic compensation coefficient Calculate the oxygen activity coefficient in this copper alloy. : ; in, is the activity coefficient of oxygen in a specific copper alloy, with an infinitely dilute solution as the reference state; Solute element The mole fraction is determined by the copper alloy grade; Dynamic compensation coefficients specific to copper alloy grades.

[0042] Then convert it to oxygen concentration in parts per million (ppm). : ; in, The molar mass of oxygen is 16.00 g / mol. The molar mass of copper is 63.55 g / mol. The standard oxygen partial pressure is taken as 1 atm.

[0043] Step 6: The all-dimensional fault diagnosis and data storage unit 8 monitors the thermocouple heating rate, oxygen potential change slope, acquisition circuit impedance, and cable insulation resistance in real time. When the thermocouple heating rate exceeds the normal range of 5℃ / s to 20℃ / s, or the oxygen potential change slope exceeds the normal range of ±2mV / s, or the acquisition circuit impedance is greater than or equal to 1kΩ, or the cable insulation resistance is less than 100MΩ, the all-dimensional fault diagnosis and data storage unit 8 immediately outputs the corresponding unique fault code and drives the audible and visual alarm component of the furnace front human-machine interaction unit 7 to issue an audible and visual alarm signal.

[0044] Step 7: The MCU main control computing unit 4 calculates the copper liquid temperature. Oxygen content The complete deoxidation trend curve is simultaneously transmitted to the furnace-front human-machine interface unit 7 for local real-time display, to the all-dimensional fault diagnosis and data storage unit 8 for long-term archiving, and to the furnace-front explosion-proof touch screen, outdoor high-brightness LED display, and central control room SCADA monitoring splicing screen via the multi-protocol isolated external communication unit 9 for remote terminal output. The central control room host computer can remotely transmit smelting process parameters, modify alarm thresholds, and retrieve historical detection curves through the multi-protocol isolated external communication unit 9.

[0045] The present invention will be further illustrated below through specific application examples.

[0046] Example 1: Copper Anode Furnace Brussels Refining Process. The copper liquid oxygen meter provided by this invention is installed in the control cabinet next to the anode furnace. The signal cable of the copper liquid oxygen metering gun is connected to the explosion-proof aviation socket at the front end of the meter. The operator selects the anode furnace brussels refining process from the quick selection menu of the process conditions on the industrial touch screen, and selects the brussels grade from the copper alloy material selection menu. The meter automatically retrieves the thermodynamic compensation parameters of the Cu-Cu2O system corresponding to the brussels, including the activity interaction coefficients of solute elements such as Fe and Ni in the brussels to oxygen and the specific dynamic compensation coefficients for brussels. The value equals 0.015, completing parameter initialization. The operator inserts the oxygen lance, equipped with a calcium-stabilized β″ alumina oxygen probe and a type B thermocouple, into the copper melt in the anode furnace. At this time, the typical temperature of the copper melt is 1200℃, or 1473K. The dual-channel isolated acquisition front-end module 3 simultaneously acquires the thermocouple thermoelectric potential signal and the oxygen potential signal. The composite adaptive anti-interference conditioning module 6 detects that the anode furnace rectifier power supply is in operation and the total voltage harmonic distortion rate is 6.8%, and automatically switches to the high filter intensity level. The MCU main control arithmetic unit 4 executes the temperature inverse operation, oxygen partial pressure calculation, and oxygen content conversion sequentially according to steps three to five. Under typical operating conditions, the thermoelectric potential measured by the type B thermocouple is... The voltage was 8.92mV, and the temperature was obtained through inverse calculation. The value is 1473K; measured in the oxygen potential branch. The value is 385.6 mV. Substituting this value into the Nernst equation yields the oxygen partial pressure inside the copper melt. 3.2×10 -8 atm; Substituting into the activity coefficient formula, we get The value is 0.132; the final calculated oxygen content is... The oxygen content was 8.6 ppm. The all-dimensional fault diagnosis unit 8 simultaneously monitored the thermocouple heating rate (12℃ / s), oxygen potential change slope (-0.8mV / s), circuit impedance (0.3kΩ), and insulation resistance (greater than 200MΩ), all within the normal range, with no fault codes output. The MCU main control unit 4 simultaneously transmitted the temperature (1473K), oxygen content (8.6ppm), oxygen potential (385.6mV), and complete deoxidation trend curve to local storage for archiving, real-time display on the furnace front touchscreen, and remote monitoring on the central control room SCADA splicing screen, completing a single copper liquid oxygen determination measurement. After the anode furnace completes the reduction operation, process personnel can retrieve historical furnace curves via the local USB interface to optimize deoxidation parameters for subsequent furnace operations.

[0047] Example 2: Continuous casting and rolling production line operation for copper rods. The copper melt oxygen meter provided by this invention is connected to the oxygen lance in the copper melt tundish of the continuous casting production line. The operator selects the continuous casting condition for copper on the industrial touch screen and loads a thermodynamic correction model specific to pure copper. The start-up and shutdown of the mill frequency converter generates instantaneous electromagnetic shocks. The composite adaptive anti-interference conditioning module 6 detects the instantaneous changes in the total harmonic distortion rate of the voltage in real time and dynamically adjusts the filter parameters to a suitable filter intensity level, ensuring that the oxygen potential curve does not experience interruptions or jumps. The meter uploads real-time copper melt parameters to the central control room's large splicing screen via a gigabit industrial Ethernet interface. The central control operator remotely monitors the oxygen content of the copper melt in each flow channel, completing the pre-control of billet quality. During long-term operation of the continuous casting production line, the all-dimensional fault diagnosis and data storage unit 8 automatically records complete test data for each casting, supporting subsequent quality traceability of copper rod products.

[0048] Example 3: Long-term online monitoring of copper molten metal in a closed flow channel. An oxygen-controlling probe is fixedly installed on the side wall of the copper molten metal conveying flow channel. The copper molten metal oxygen-controlling instrument provided by this invention is in continuous online monitoring mode. Multiple smelting equipment on the smelting site start and stop synchronously. The automatic condition identification program built into the MCU main control unit 4 automatically switches parameters to adapt to the flow channel transport conditions based on the characteristics of a slow decrease in copper molten metal temperature, relatively stable oxygen potential, and low-frequency disturbances, and appropriately increases the filtering intensity. The dual-layer isolation acquisition architecture isolates interference from the magnetic field of the flowing copper molten metal and the electromagnetic field of high-power equipment, providing a stable long-term output of continuous change curves of copper molten metal oxygen content and temperature. The multi-protocol isolated external communication unit 9 pushes core process parameters to a high-brightness outdoor screen in the flow channel via an HDMI industrial video output interface, allowing personnel at the crane and feeding stations to remotely monitor the operating conditions.

[0049] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] It should be noted that the components mentioned in the above embodiments are all general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0051] This invention has illustrated its principles and implementation methods using specific examples. The descriptions of these embodiments are merely illustrative of the method and its core ideas; furthermore, those skilled in the art will recognize that modifications may be made to the specific implementation methods and application scope based on the principles of this invention. Therefore, the content of this specification should not be construed as limiting the invention.

Claims

1. An anti-interference copper liquid oxygen analyzer, characterized in that, It includes an industrial shielded enclosure (1), a wide-range isolated power supply unit (2), a dual-channel electrically completely isolated acquisition front-end module (3), an MCU main control and computing unit (4), a copper alloy thermodynamic parameter storage unit (5), a composite adaptive anti-interference conditioning module (6), a furnace front human-machine interaction unit (7), a full-dimensional fault diagnosis and data storage unit (8), and a multi-protocol isolated external communication unit (9). The dual-channel electrically isolated acquisition front-end module (3) is equipped with a thermocouple temperature acquisition branch and an oxygen potential acquisition branch; The input terminal of the composite adaptive anti-interference conditioning module (6) is connected to the output terminal of the dual-channel electrically isolated acquisition front-end module (3), and the output terminal of the composite adaptive anti-interference conditioning module (6) is connected to the input terminal of the MCU main control and operation unit (4); the composite adaptive anti-interference conditioning module (6) integrates a hardware RC passive low-pass filter circuit and a moving average digital filter algorithm with dynamically adjustable window width, and has built-in power grid disturbance identification logic; The MCU main control computing unit (4) is bidirectionally electrically connected to the copper alloy thermodynamic parameter storage unit (5). The copper alloy thermodynamic parameter storage unit (5) pre-stores the oxygen activity calculation compensation parameters of the Cu-Cu2O system corresponding to crude copper, pure copper, brass, and aluminum-iron bronze. The MCU main control computing unit (4) adapts to the following formula to complete the calculation of the oxygen content of copper liquid: ； in, The gas constant is The thermodynamic temperature of molten copper. It is Faraday's constant. The oxygen partial pressure on the reference electrode side. The oxygen partial pressure inside the molten copper. This is the dynamic compensation coefficient for the corresponding copper alloy; The full-dimensional fault diagnosis and data storage unit (8) is bidirectionally connected to the MCU main control and computing unit (4); The multi-protocol isolated external communication unit (9) is connected to the output of the MCU main control and operation unit (4) and is configured with an isolated RS-485 interface, a gigabit Ethernet interface and an HDMI video output interface.

2. The anti-interference copper liquid oxygen analyzer according to claim 1, characterized in that: The industrial shielded enclosure (1) is equipped with a strong and weak current separation compartment, and the panel is equipped with an explosion-proof and heat-resistant aviation signal connector (10). The aviation signal connector (10) is equipped with an alumina ceramic heat insulation bushing, and the side wall of the enclosure is arranged with an active heat dissipation air duct.

3. The anti-interference copper liquid oxygen analyzer according to claim 1, characterized in that: The wide-range isolated power supply unit (2) is adapted to AC85-264V wide voltage input and outputs multiple electrically isolated DC power supply branches, which are independently powered by the dual-channel electrically completely isolated acquisition front-end module (3), the MCU main control and calculation unit (4), the furnace front human-machine interaction unit (7), and the multi-protocol isolated external communication unit (9).

4. The anti-interference copper liquid oxygen analyzer according to claim 1, characterized in that: The MCU main control computing unit (4) has a built-in automatic smelting condition identification program, which can automatically identify the conditions of anode furnace refining, copper liquid transfer in the flow channel and continuous casting heat preservation based on the copper liquid temperature and oxygen potential change trend, and adaptively retrieve the corresponding smelting parameter range.

5. The anti-interference copper liquid oxygen analyzer according to claim 1, characterized in that: The thermocouple temperature acquisition branch has a built-in cold junction compensation unit, is compatible with B, K, and S type thermocouples, and covers a temperature measurement range of 800℃ to 1400℃; the oxygen potential acquisition branch has a range of 0 to 1200mV and a sampling resolution of not less than 0.001mV.

6. The anti-interference copper liquid oxygen analyzer according to claim 1, characterized in that: The furnace front human-machine interaction unit (7) is equipped with an industrial touch screen, which has a quick selection menu for operating conditions, a one-click switching menu for thermocouple index numbers, a selection menu for copper alloy materials, and a setting menu for process alarm thresholds. The instrument is equipped with an audible and visual alarm module, which outputs audible and visual alarm signals when the oxygen content exceeds the limit or the equipment malfunctions.

7. The anti-interference copper liquid oxygen analyzer according to claim 1, characterized in that: The data transmission delay of the multi-protocol isolated external communication unit (9) is less than 100ms, and a single instrument synchronously drives the explosion-proof touch screen in front of the furnace, the outdoor high-brightness LED display screen, and the central control splicing screen.

8. A method for measuring oxygen in copper liquid, using the anti-interference copper liquid oxygen analyzer as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Immerse the oxygen probe in the molten copper and start the dual-channel electrically isolated acquisition front-end module (3). The thermocouple temperature acquisition branch acquires the thermoelectric potential signal output by the thermocouple and obtains the thermodynamic temperature of the molten copper after cold junction compensation. The oxygen potential acquisition branch acquires the oxygen potential signal output by the solid electrolyte concentration cell of the oxygen detector. ; S2. The composite adaptive anti-interference conditioning module (6) sequentially performs hardware RC passive low-pass filtering and variable window moving average digital filtering on the collected temperature signal and oxygen potential signal, and detects the total harmonic distortion rate of the field voltage in real time. and the start-up and shutdown status of high-power smelting equipment, when If the filter strength is >5% or a high-power device is detected to be running, switch to the high filter strength setting. When the temperature is less than 3% and no high-power equipment is starting or stopping, switch to the low filter intensity setting and output the filtered temperature signal. With oxygen potential signal ; S3, the MCU main control unit (4) calculates the filtered temperature signal. The true value of the thermodynamic temperature of the molten copper is obtained by inverse calculation using the thermocouple calibration polynomial specified in the International Temperature Scale (ITS-90): ； in, Thermoelectric electromotive force output from the thermocouple acquisition branch. These are the polynomial fitting coefficients for the corresponding degree sign. Let be the order of the polynomial. This is the cold junction compensation value; S4, the MCU main control unit (4) calculates the filtered oxygen potential signal. and the temperature obtained in step S3 Substituting into the Nernst equation for the Cu-Cu₂O equilibrium system, calculate the oxygen partial pressure inside the molten copper: ； in, The oxygen partial pressure on the reference electrode side. This is an electromotive force offset correction term introduced for the non-isothermal effect of thermocouples. It is Faraday's constant. It is the ideal gas constant; S5. The MCU main control unit (4) retrieves the corresponding activity interaction coefficient from the copper alloy thermodynamic parameter storage unit (5) according to the currently selected copper alloy grade. and dynamic compensation coefficient Calculate the oxygen activity coefficient in this copper alloy: ； in, is the activity coefficient of oxygen in the copper alloy. Solute element mole fraction; Then convert to oxygen concentration in parts per million (ppm): ； in, Where is the molar mass of oxygen. The molar mass of copper, This represents the standard state oxygen partial pressure. S6. The full-dimensional fault diagnosis and data storage unit (8) monitors the thermocouple heating rate, oxygen potential change slope, acquisition circuit impedance and cable insulation resistance in real time. When any parameter exceeds the preset threshold, it outputs the corresponding fault code and drives the audible and visual alarm. S7, the MCU main control computing unit (4) calculates the copper liquid temperature Oxygen content The deoxygenation trend curve is simultaneously sent to the furnace front human-machine interaction unit (7) for local display, the full-dimensional fault diagnosis and data storage unit (8) for archiving, and the multi-protocol isolated external communication unit (9) for remote terminal output.

9. The method for determining oxygen content in molten copper according to claim 8, characterized in that: In step S2, the moving average window width N=32 and the filtering order m=4 for the high filtering intensity level, and the moving average window width N=8 and the filtering order m=2 for the low filtering intensity level.

10. The method for determining oxygen content in molten copper according to claim 8, characterized in that: In step S6, the normal range of the thermocouple heating rate is 5℃ / s to 20℃ / s, the normal range of the oxygen potential change slope is within ±2mV / s, the normal range of the acquisition circuit impedance is less than 1kΩ, and the normal range of the cable insulation resistance is greater than 100MΩ.

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