A multi-stage temperature measurement device and method for self-baking electrodes

Abstract

The present invention provides a multi-section temperature measurement device and method for a self-baking electrode, comprising a sensing rod, a transducer and an operation control device; a plurality of grooves or protrusions are arranged on the temperature measurement portion of the sensing rod corresponding to the baking section of the electrode, for reflecting ultrasonic waves; the transducer is installed on the upper end face or side of the sensing rod, for transmitting ultrasonic waves, and the ultrasonic waves are transmitted along the sensing rod; the operation control device is electrically and signal-connected to the transducer, for obtaining the reception time of the reflected wave of the ultrasonic wave through the transducer, and calculating the transmission speed of the ultrasonic wave in the sensing rod, and then obtaining the temperature of the sensing rod according to the corresponding relationship between the sound velocity and the temperature of the sensing rod material, so as to realize the temperature measurement of the baking section of the electrode. The multi-section temperature measurement device for the self-baking electrode of the present invention obtains the temperature of the baking section of the electrode in the ore-fired furnace, thereby providing a data basis for controlling the electrode baking, and achieving the purpose of optimizing the electrode pressing and releasing operation and reducing safety risks.

Description

Technical Field

[0001] The invention relates to the technical field of electrode temperature measurement, in particular to a multi-stage temperature measurement device and method for a self-baking electrode. Background Art

[0002] Submerged arc furnace is a huge industrial electric furnace, which transmits electric energy to the furnace through self-baking electrodes to smelt ore. The main raw material for generating electrodes is block electrode paste, which is a block object made of solid carbon (anthracite, coke and graphite) and binder (asphalt and coal tar) in a certain proportion. The electrode is made by self-baking electrode paste. During the working process, the electrode paste is continuously consumed and replenished. The electrode paste in the electrode is made under the combined action of arc conduction heat and electrode resistance heating. The electrode paste is baked in the electrode through three stages: the first stage: softening stage, the electrode paste temperature rises from room temperature to 200℃, and the electrode paste gradually softens into liquid; the second stage: volatilization stage, the electrode paste temperature rises from 200℃ to 650℃, the binder in the liquid electrode paste continuously decomposes and gasifies, and gradually becomes solid; the third stage: sintering stage, the polarization temperature gradually increases from 650℃ to 800℃, the residual volatiles in the electrode paste gradually volatilize, and the electrode paste is transformed into a hard solid.

[0003] If the electrode is not baked properly, it will lead to accidents such as over-burning and under-burning of the electrode, resulting in equipment loss and casualties. Properly controlling the temperature of the electrode sintering section can effectively prevent the problem of over-sintering and under-sintering of the electrode.

[0004] Since the electrode baking section is located in an electric furnace, the surrounding environment is extremely harsh, with the surrounding gas temperature of 300-500℃, and can reach 800-900℃ in a short time. There is extremely strong thermal radiation, explosive gas, high smoke and dust, and strong electromagnetic interference, so it is difficult for general measuring equipment sensors to work for a long time.

[0005] At present, the following methods are mainly used to measure the temperature of the electrodes of the submerged arc furnace:

[0006] (1) Platinum resistance temperature measurement:

[0007] Platinum resistance is placed in a ceramic protection tube, and the ceramic protection tube with platinum resistance is close to the electrode tube at the copper tile outside the electrode for measurement. The shielding effect of the ceramic protection tube causes the temperature measurement to follow slowly. At the same time, the strong electromagnetic of the electrode will generate eddy currents, causing abnormal temperature rise of the platinum resistance. The strong electromagnetic interference also interferes with the current of the measuring wire, resulting in inaccurate measurement. For example, the temperature measurement device of the self-baking electrode of the electric arc furnace with patent number (application publication number): ZL 201110426953.0.

[0008] (2) Thermal imaging temperature measurement

[0009] The temperature of the roasting section is measured by a thermal imaging probe. This method is difficult to work for a long time in the dusty and high temperature environment of the submerged arc furnace, and is easily damaged under strong electromagnetic interference. The electrode temperature measured is only the temperature of the electrode surface, which is greatly affected by the gas temperature in the furnace, resulting in inaccurate temperature measurement. For example, the patent number (application publication number): CN 110736343 A is a submerged arc furnace with a self-baking electrode roasting degree measuring device.

[0010] (3) Use multiple thermistors to bury in a steel pipe and insert into the electrode to measure the temperature. The surrounding magnetic field affects the measurement accuracy, and the multiple thermistor wires make the temperature measuring device thicker, which affects the deposition of electrode paste and easily forms voids. For example, a multi-point temperature measurement device ZL 201210576698.2.

[0011] The above methods all fail to meet the requirements of ease of use, accuracy and effectiveness of electrode temperature measurement, and lose the purpose of monitoring the operating temperature status of the electrode. Summary of the invention

[0012] In order to solve the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a multi-segment temperature measuring device and method for self-baking electrodes to obtain the temperature of the electrode baking section of the electric arc furnace, thereby providing a data basis for controlling the electrode baking, thereby achieving the purpose of optimizing the electrode pressing and releasing operation and reducing safety risks, so as to overcome the defects in the prior art.

[0013] In order to achieve the above-mentioned purpose, the present invention provides a multi-segment temperature measuring device for a self-baking electrode, the multi-segment temperature measuring device comprising a sensing rod, a transducer and an operation control device; wherein, a plurality of grooves or protrusions are arranged on the temperature measuring portion of the sensing rod corresponding to the baking section of the electrode, for reflecting ultrasonic waves, thereby obtaining the average temperature of the plurality of sections at the same time; the transducer is installed on the upper end face or side face of the sensing rod, for transmitting ultrasonic waves, and the ultrasonic waves are transmitted along the sensing rod; the operation control device is electrically and signally connected to the transducer, for obtaining the receiving time of the reflected wave of the ultrasonic wave through the transducer, and calculating the transmission speed of the ultrasonic wave in the sensing rod, and then obtaining the temperature of the sensing rod according to the corresponding relationship between the sound velocity and the temperature of the sensing rod material, so as to realize the temperature measurement of the baking section of the electrode.

[0014] Through the above technical scheme, by reasonably placing the sensor rod inside the electrode, using the characteristic that the ultrasonic guided wave emitted by the transducer is reflected by the groove or protrusion on the sensor rod, by measuring the time of the reflected wave at the end of the ultrasonic guided wave, according to the distance difference between adjacent grooves or protrusions, the operation control device calculates the transmission speed of the ultrasonic guided wave along the sensor rod, and the temperature of each temperature measurement section can be known according to the corresponding relationship between the sound velocity and temperature of the sensor rod material, and the temperature of the electrode roasting section of the ore-fired furnace is obtained, thereby providing a data basis for controlling the electrode roasting, and achieving the purpose of optimizing the electrode pressing and releasing operation and reducing safety risks. The corresponding relationship between the material sound velocity and the temperature of the sensor rod can be obtained through experiments. Due to the particularity of the sensor rod, this sensor rod using ultrasonic temperature measurement can survive in an environment with high dust, strong thermal radiation, and strong electromagnetic interference. The other parts of the measuring equipment can be arranged in a place with a good environment away from the ore-fired furnace to avoid the influence of the environment on the equipment, thereby achieving the purpose of measuring temperature in this harsh environment.

[0015] As a further description of the multi-stage temperature measuring device of the self-baking electrode described in the present invention, preferably, the operation control device includes an operation control module; wherein the operation control module is electrically connected and signal-connected to the high-power ultrasonic excitation module, so that the operation control module sends a signal to the high-power ultrasonic excitation module to generate a trigger signal; the high-power ultrasonic excitation module is electrically connected and signal-connected to the sensor matching circuit, and the sensor matching circuit is electrically connected and signal-connected to the transducer and the band-pass filter circuit respectively, so that the trigger signal acts on the transducer through the sensor matching circuit, and the transducer converts the first electrical signal into an ultrasonic signal, and the ultrasonic signal is transmitted to the lower end surface through the sensor rod to generate a reflected echo, and the transducer converts the reflected echo into a second electrical signal and transmits it to the band-pass filter through the sensor matching circuit. The band-pass filtering circuit is electrically connected and signal-connected with the gain adjustment circuit, so that the second electrical signal is transmitted to the digital acquisition circuit for filtering and amplification after passing through the gain adjustment circuit; the gain adjustment circuit is electrically connected and signal-connected with the digital acquisition circuit, and the digital acquisition circuit is electrically connected and signal-connected with the operation control module, so that the second electrical signal is then uploaded to the operation control module through the digital acquisition circuit, and the operation control module uses an ultrasonic temperature measurement algorithm to process the temperature data according to the speed and distance constants; the operation control module is electrically connected and signal-connected with the communication module, and the communication module is electrically connected and signal-connected with the remote human-computer interaction module and / or the local human-computer interaction module, so that the temperature data is transmitted to the remote human-computer interaction module and the local human-computer interaction module through the communication module.

[0016] As a further explanation of the multi-stage temperature measuring device of the self-baking electrode described in the present invention, preferably, the sensing rod is placed in the electrode, and a protective tube is provided outside the sensing rod. The protective tube and the sensing rod are pre-buried in the electrode paste of the electrode to directly measure the internal temperature of the electrode paste; cylindrical insulation cotton is placed in the protection tube to isolate the gas flow, and the insulation cotton presses the temperature measuring part of the sensing rod so that it contacts the wall of the protection tube.

[0017] As a further explanation of the multi-stage temperature measuring device of the self-baking electrode described in the present invention, preferably, the protection tube is one or more of metal materials, graphite and / or ceramic materials, and the ceramic material is a monomer or a mixture of aluminum oxide, zirconium oxide, magnesium oxide, silicon carbide, and molybdenum silicide; the shape of the protection tube is a square tube or a round tube.

[0018] Through the above technical solution, the protection tube is made of steel, graphite tube and ceramic material, wherein the graphite tube can be used to support the lower end of the protection tube, keep it smooth at high temperature, and prevent the molten metal tube from blocking the protection tube. The ceramic material can be used to prevent the chemical reaction between the sensor rod and graphite at high temperature, resulting in premature melting.

[0019] As a further description of the multi-stage temperature measuring device for the self-baking electrode described in the present invention, preferably, the sensing rod is placed outside the electrode, the sensing rod contacts the electrode for temperature measurement, and the sensing rod is covered with strips of thermal insulation cotton to reduce heat conduction between the electrode and the environment.

[0020] As a further explanation of the multi-stage temperature measuring device of the self-baking electrode described in the present invention, preferably, a copper washer is provided on the outer ring of the electrode, and a holding tube is provided on the outer sleeve of the copper washer so that the electrode is coaxially arranged in the holding tube, the holding tube is connected to the bottom of the lower brake, one end of the synchronization rod is fixedly connected to the lower brake, and the other end of the synchronization rod is connected to the sensing rod. The relative position of the copper washer and the holding tube remains unchanged, and the relative distance between the holding tube and the lower brake remains unchanged, so that when the electrode moves up and down, the relative position of the sensing rod and the copper washer remains unchanged, thereby synchronously obtaining the temperature of the electrode baking section to achieve temperature measurement.

[0021] Through the above technical scheme, the sensing rod can be moved up a certain height when measuring temperature, that is, it can produce relative movement with the copper tile, and the temperature at that location can be recorded after the sound velocity stabilizes. By moving the sensing rod up multiple times to measure the temperature at different positions, the temperature gradient of the roasting section can be obtained, and more comprehensive information on the roasting state of the roasting section can be obtained.

[0022] As a further description of the multi-stage temperature measuring device of the self-baking electrode described in the present invention, preferably, the thermal insulation cotton is composed of ceramic fibers, and the ceramic fibers are one or more of aluminum silicate fibers, aluminum oxide fibers and / or zirconium oxide fibers.

[0023] As a further explanation of the multi-stage temperature measuring device of the self-baking electrode described in the present invention, preferably, the sensing rod is made of a non-ferromagnetic metal material, a graphite tube or a ceramic material with a high-temperature anti-oxidation coating on the surface, the non-ferromagnetic metal material is a monomer or a mixture of iron alloy, tungsten, molybdenum, rhenium, iridium, and lanthanum, and the ceramic material is a monomer or a mixture of aluminum oxide, zirconium oxide, magnesium oxide, silicon carbide, and molybdenum silicide; the shape of the sensing rod is filamentous or strip-shaped, and the cross-section of the sensing rod is circular or square, so that the sensing rod will not induce current under an alternating magnetic field, and is used to transmit ultrasonic waves.

[0024] Through the above technical solution, after many experiments and studies by the inventor, the material of the selected sensor rod can ensure that the sensor rod has good ultrasonic guided wave transmission and reflection performance, avoiding the problem that the sensor rod melts inside the electrode, thereby absorbing the ultrasonic guided wave and making it difficult to form a reflected wave.

[0025] As a further description of the multi-stage temperature measuring device for the self-baking electrode of the present invention, preferably, the shape of the groove or protrusion can be tooth-shaped, round, or square.

[0026] As a further illustration of the multi-stage temperature measuring device for the self-baking electrode of the present invention, preferably, the transducer is an electroacoustic converter, which converts an electrical pulse signal into an ultrasonic signal as a transmitter and converts an ultrasonic signal into an electrical pulse signal as a receiver.

[0027] In order to achieve another object of the present invention, the present invention also provides a method for using the multi-stage temperature measuring device of the self-baking electrode, the method comprising the following steps:

[0028] Step S1): two grooves or protrusions with a spacing of L are arranged at a distance D at the softening section, volatilization section and sintering section of the corresponding electrode on the sensing rod to reflect ultrasonic waves;

[0029] Step S2): the operation control device controls the transducer to emit ultrasonic waves, so that the ultrasonic waves are transmitted along the sensor rod, and the transducer receives the reflected waves to obtain the ultrasonic reflection wave time T between each section of grooves or protrusions, where T is in seconds (s);

[0030] Step S3): The operation control device calculates the average sound velocity of the first temperature measurement section according to the distance difference L between adjacent grooves or protrusions: The average sound velocity in the second temperature measurement section is The average sound velocity in the third temperature measurement section is The unit is meter / second (m / s); the unit of L1, L2, L3 is meter (m); the unit of T1, T2, T3 is second (s);

[0031] Step 4): According to the corresponding relationship between the sound velocity and temperature of the sensing rod material, the average temperature of the softening section, volatilization section and sintering section of the electrode can be obtained.

[0032] Here, the length of the temperature measuring section can be determined according to the length of the electrode roasting section, and the distance of each temperature measuring section can be determined according to different measurement environments. The temperature of each temperature measuring section can be known according to the corresponding relationship between the sound velocity and the temperature of the sensing rod material. The sensing rod can also have multiple temperature measuring sections, and the temperature of multiple areas can be obtained. Preferably, when measuring the temperature, the sensing rod is moved up to produce relative motion with the copper tile, and the temperature value after the sound velocity stabilizes is recorded. Specifically, the sensing rod can be moved up to a certain height when measuring the temperature, that is, it produces relative motion with the copper tile, and the temperature at that place is recorded after the sound velocity stabilizes. After the temperature at different positions is measured by moving the sensing rod up multiple times, the temperature gradient of the roasting section can be obtained, and more comprehensive information about the roasting state of the roasting section can be obtained. For example, each time it is moved up 5cm, and the temperature at that place is measured after standing for more than one minute, the temperature gradient at intervals of 5cm can be obtained.

[0033] The beneficial effects of the present invention are as follows: the multi-section temperature measurement device and method of the self-baking electrode of the present invention, by reasonably placing the sensor rod inside the electrode, using the characteristic that the ultrasonic guided wave emitted by the transducer is reflected by the groove or protrusion on the sensor rod, by measuring the time of the reflected wave at the end of the ultrasonic guided wave, according to the distance difference between adjacent grooves or protrusions, the operation control device calculates the transmission speed of the ultrasonic guided wave along the sensor rod, and the temperature of each temperature measurement section can be known according to the corresponding relationship between the sound velocity and temperature of the sensor rod material, and the temperature of the baking section of the electrode of the ore-heating furnace is obtained, thereby providing a data basis for controlling the electrode baking, achieving the purpose of optimizing the electrode pressing and releasing operation and reducing safety risks, wherein the corresponding relationship between the sound velocity and temperature of the sensor rod material can be obtained through experiments, and due to the particularity of the sensor rod, the sensor rod using ultrasonic temperature measurement can survive in an environment with high dust, strong thermal radiation, and strong electromagnetic interference, and the other parts of the measuring equipment can be arranged in a place with a good environment away from the ore-heating furnace to avoid the influence of the environment on the equipment, thereby achieving the purpose of measuring temperature in this harsh environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The figure is a side view of the multi-stage temperature measuring device of the self-baking electrode of the present invention in a mineral arc furnace.

[0035] Figure 2 The figure is a top view of the multi-stage temperature measuring device of the self-baking electrode of the present invention in a mineral arc furnace.

[0036] Figure 3 This is a schematic diagram of the first structure of the multi-stage temperature measuring device for the self-baking electrode of the present invention.

[0037] Figure 4 This is a second structural schematic diagram of the multi-stage temperature measuring device for the self-baking electrode of the present invention.

[0038] Figure 5 This is a third structural schematic diagram of the multi-stage temperature measuring device for the self-baking electrode of the present invention.

[0039] Figure 6 Schematic diagram of the shape of the sensor rod of the present invention.

[0040] Figure 7 It is a schematic diagram of the structure of the operation control device of the present invention.

[0041] Figure 8 It is a schematic diagram of the installation relationship between the transducer and the sensor rod of the present invention.

[0042] Fig. 9 It is a cross-sectional schematic diagram of the sensing rod of the present invention. DETAILED DESCRIPTION

[0043] In order to further understand the structure, features and other purposes of the present invention, the preferred embodiments are described in detail with reference to the accompanying drawings as follows. The embodiments described in the drawings are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention.

[0044] The submerged arc furnace is a huge industrial electric furnace that relies on three or six self-baking electrodes to deliver energy to the furnace to melt the charge. The electrodes are formed by baking electrode paste, such as Figure 1 The three finished electrodes are evenly arranged in the furnace in the shape of a letter " ". Figure 2 As shown, Figure 2 Too Figure 1 AA sectional view of the furnace. The electrode 201, furnace body 202, and charge 203. The electrode is buried in the charge to release the arc to melt the charge.

[0045] The present invention provides a multi-segment temperature measuring device for a self-baking electrode, comprising a sensing rod 102, a transducer 103 and an operation control device; wherein a plurality of grooves or protrusions are arranged on the temperature measuring portion of the sensing rod 102 corresponding to the baking segment of the electrode 201, for reflecting ultrasonic waves, thereby obtaining the average temperature of the plurality of segments at the same time; the shape of the grooves or protrusions may be tooth-shaped, round, or square; the transducer 103 is installed on the upper end face or side face of the sensing rod 102, such as Figure 8 As shown, it is used to emit ultrasonic waves, which are transmitted along the sensor rod 102; the operation control device is electrically and signal-connected with the transducer 103, and is used to obtain the reception time of the reflected wave of the ultrasonic wave through the transducer 103, and calculate the transmission speed of the ultrasonic wave in the sensor rod 102, and then obtain the temperature of the sensor rod 102 according to the corresponding relationship between the sound velocity and the temperature of the sensor rod material, so as to realize the temperature measurement of the roasting section of the electrode.

[0046] In one embodiment of the present invention, preferably, Figure 7As shown, the operation control device includes an operation control module 110; wherein the operation control module 110 is electrically connected and signal-connected with the high-power ultrasonic excitation module 105, so that the operation control module 110 sends a signal to the high-power ultrasonic excitation module 105 to generate a trigger signal; the high-power ultrasonic excitation module 105 is electrically connected and signal-connected with the sensor matching circuit 104, and the sensor matching circuit 104 is electrically connected and signal-connected with the transducer 103 and the band-pass filter circuit 107 respectively, so that the trigger signal acts on the transducer 103 through the sensor matching circuit 104, and the transducer 103 converts the first electrical signal into an ultrasonic signal, and the ultrasonic signal propagates to the lower end surface through the sensor rod 102 to generate a reflected echo, and the transducer 103 converts the reflected echo into a second electrical signal and transmits it to the band-pass filter circuit 107 through the sensor matching circuit 104; the band-pass filter circuit 107 and the enhancer The gain adjustment circuit 108 is electrically connected and signal-connected, so that the second electrical signal is transmitted to the digital acquisition circuit 109 for filtering and amplification after passing through the gain adjustment circuit 108; the gain adjustment circuit 108 is electrically connected and signal-connected with the digital acquisition circuit 109, and the digital acquisition circuit 109 is electrically connected and signal-connected with the operation control module 110, so that the second electrical signal is then uploaded to the operation control module 110 through the digital acquisition circuit 109, and the operation control module 110 uses an ultrasonic temperature measurement algorithm to process according to the speed and distance constants to obtain temperature data; the operation control module 110 is electrically connected and signal-connected with the communication module 111, and the communication module 111 is electrically connected and signal-connected with the remote human-computer interaction module 112 and / or the local human-computer interaction module 113, so that the temperature data is transmitted to the remote human-computer interaction module 112 and the local human-computer interaction module 113 through the communication module 111. The remote human-computer interaction module 112 and the local human-computer interaction module 113 can transmit the set speed and distance constants to the operation control module 110, change the constants in the operation control module 110, and facilitate the operation control module 110 to calculate the speed and thereby obtain temperature data.

[0047] Another embodiment of the present invention, as Figure 3 and Figure 4 As shown, the sensing rod 102 can be placed in the electrode 201, wherein a protective tube 101 is provided on the outer shell of the sensing rod 102, and the protective tube 101 and the sensing rod 102 are pre-buried in the electrode paste of the electrode 201 to directly measure the internal temperature of the electrode paste; a cylindrical heat-insulating cotton 114 is placed in the protection tube 101 to isolate the gas flow, and the heat-insulating cotton 114 presses the temperature-measuring part of the sensing rod 102 to make it contact with the wall of the protection tube 101. Preferably, as Figure 3As shown, the outer ring of the electrode 201 is provided with a copper tile 204, and the outer sleeve of the copper tile 204 is provided with a holding tube 205, so that the electrode 201 is coaxially arranged in the holding tube 205, and the holding tube 205 is connected to the bottom of the lower brake 206, and one end of the synchronization rod 115 is fixedly connected to the lower brake 206, and the other end of the synchronization rod 115 is connected to the sensing rod 102. The relative position of the copper tile 204 and the holding tube 205 remains unchanged, and the relative distance between the holding tube 205 and the lower brake 206 remains unchanged, so that when the electrode 201 moves up and down, the relative position of the sensing rod 102 and the copper tile 204 remains unchanged, and then the temperature of the baking section of the electrode 201 is synchronously obtained to achieve temperature measurement. In this way, the sensing rod can move up a certain height when measuring temperature, that is, it produces relative movement with the copper tile, and the temperature at that location is recorded after the sound velocity is stable. After the sensing rod is moved up multiple times to measure the temperature at different positions, the temperature gradient of the baking section can be obtained, and more comprehensive information on the baking state of the baking section can be obtained. The copper sheet 204 is used to provide the electrode with a function, and the electrode paste is heated and baked by utilizing the heat conducted by the electric furnace and the resistance heat generated by the current flowing through the electrode. The lower brake 206 is used to press and release the electrode to achieve the up and down movement of the electrode. More preferably, Figure 4 As shown, the synchronization rod 115 can be connected to one end of the synchronization hinge 119, the synchronization hinge 119 is wound on the synchronization pulley 118, the other end of the synchronization hinge 119 is connected to the counterweight 116, and the synchronization pulley 118 is fixed on the bracket 117 to realize the up and down movement of the synchronization rod 115.

[0048] Another embodiment of the present invention, as Figure 5 As shown, the sensing rod 102 can also be placed outside the electrode 201. The sensing rod 102 contacts the electrode 201 to measure the temperature, measure the temperature of each calcination section of the electrode 201, and then infer the temperature of the electrode paste. The sensing rod 102 is covered with a strip of heat-insulating cotton 114 to reduce the heat conduction between the electrode 201 and the environment. Preferably, as Figure 5 As shown, the outer ring of the electrode 201 is provided with a copper washer 204, and the sensing rod 102 is placed between the copper washer 204 outside the electrode 201. The outer sleeve of the copper washer 204 is provided with a holding tube 205, so that the electrode 201 is coaxially arranged in the holding tube 205, and the holding tube 205 is connected to the bottom of the lower brake 206. One end of the synchronization rod 115 is fixedly connected to the lower brake 206, and the other end of the synchronization rod 115 is connected to the sensing rod 102. The relative position of the copper washer 204 and the holding tube 205 remains unchanged, and the relative distance between the holding tube 205 and the lower brake 206 remains unchanged, so that when the electrode 201 moves up and down, the relative position of the sensing rod 102 and the copper washer 204 remains unchanged, and then the temperature of the roasting section of the electrode 201 is synchronously acquired to achieve temperature measurement. In this way, the sensing rod can be moved up a certain height when measuring temperature, that is, it can produce relative movement with the copper tile. After the sound velocity stabilizes, the temperature at that location is recorded. By moving the sensing rod up multiple times to measure the temperatures at different locations, the temperature gradient of the roasting section can be obtained, and more comprehensive information on the roasting state of the roasting section can be obtained.

[0049] The sensing rod 102 described in the present invention is made of non-ferromagnetic metal material, graphite tube or ceramic material with a high-temperature anti-oxidation coating on the surface. The non-ferromagnetic metal material is a single body or mixture of iron alloy, tungsten, molybdenum, rhenium, iridium, lanthanum, and the ceramic material is a single body or mixture of aluminum oxide, zirconium oxide, magnesium oxide, silicon carbide, molybdenum silicide. The shape of the sensing rod 102 is filamentous or strip-shaped, and it will not induce current under an alternating magnetic field, and is used to transmit ultrasonic waves. Figure 6 As shown, the cross section of the sensing rod 102 is circular or square.

[0050] The protection tube 101 described in the present invention is one or more of metal materials, graphite and / or ceramic materials, and the ceramic material is a single body or a mixture of aluminum oxide, zirconium oxide, magnesium oxide, silicon carbide, and molybdenum silicide. The shape of the protection tube 101 is a square tube or a round tube, and its function is to protect the sensing rod 102 from being wrapped by the electrode paste. The protection tube 101 is connected by bolts or welded, and is pre-buried in the self-baking electrode. As the electrode is consumed, the protection tube 101 is also consumed, and needs to be continuously replenished.

[0051] The thermal insulation cotton 114 described in the present invention is composed of ceramic fibers, which are but not limited to one or more of aluminum silicate fibers, aluminum oxide fibers and / or zirconium oxide fibers. The thermal insulation cotton 114 is pre-pressed into a cylindrical shape and placed in the protective tube 101, or made into a strip shape and attached to one side of the sensor rod 102.

[0052] The transducer 103 described in the present invention is an electroacoustic converter, which converts an electrical pulse signal into an ultrasonic signal as a transmitter, and converts an ultrasonic signal into an electrical pulse signal as a receiver. The transducer 103 generates ultrasonic waves, which are transmitted along the sensor rod 102. When the ultrasonic waves reach the groove or the bottom of the sensor rod, they are reflected. The reflected ultrasonic waves reach the transducer along the sensor rod. The average sound velocity is calculated using the time difference and distance between adjacent grooves, and then the average temperature is obtained.

[0053] The present invention also provides a method for using the multi-stage temperature measuring device of the self-baking electrode, the method comprising the following steps:

[0054] Step S1): Three temperature measuring sections are set on the sensing rod 102 corresponding to the softening section, volatilization section and sintering section of the electrode 201. The sensing rod 102 is provided with two grooves or protrusions at intervals of L at intervals of D for reflecting ultrasonic waves, such as Fig. 9 As shown;

[0055] Step S2): the operation control device controls the transducer 103 to emit ultrasonic waves, so that the ultrasonic waves are transmitted along the sensor rod 102, and the transducer 103 receives the reflected waves to obtain the ultrasonic reflection wave time T between each section of grooves or protrusions, where T is in seconds (s);

[0056] Step S3): The operation control device calculates the average sound velocity of the first temperature measurement section according to the distance difference L between adjacent grooves or protrusions: The average sound velocity in the second temperature measurement section is The average sound velocity in the third temperature measurement section is The unit is meter / second (m / s); the unit of L1, L2, L3 is meter (m); the unit of T1, T2, T3 is second (s);

[0057] Step 4): The average temperature of the softening section, volatilization section and sintering section of the electrode 201 can be obtained according to the corresponding relationship between the sound velocity and temperature of the sensing rod 102 material.

[0058] Among them, the length of the temperature measuring section can be determined according to the length of the electrode roasting section, and the distance of each temperature measuring section can be determined according to different measurement environments. The temperature of each temperature measuring section can be known according to the corresponding relationship between the sound velocity and temperature of the sensing rod material. The sensing rod can also have multiple temperature measuring sections, and the temperature of multiple areas can be obtained. Preferably, when measuring the temperature, the sensing rod is moved up to produce relative motion with the copper tile, and the temperature value after the sound velocity stabilizes is recorded. Specifically, the sensing rod can be moved up to a certain height when measuring the temperature, that is, it produces relative motion with the copper tile, and the temperature at that place is recorded after the sound velocity stabilizes. After the temperature of different positions is measured by moving the sensing rod up multiple times, the temperature gradient of the roasting section can be obtained, and more comprehensive information about the roasting state of the roasting section can be obtained. For example, each time it is moved up 5cm, and the temperature at that place is measured after standing for more than one minute, the temperature gradient at intervals of 5cm can be obtained.

[0059] The corresponding relationship between the sound velocity and temperature of the selected sensor rod material can be obtained through experiments. Make a test rod, set a groove or protrusion at a distance of h = 5cm from the end of the test rod, and place the test rod in a constant temperature furnace. A platinum resistance sensor with an error of less than 1°C is placed in the constant temperature furnace in advance. The temperature measurement range is 100-1000°C. Set the temperature of the constant temperature furnace to 100°C. After 20 minutes, when the temperature in the furnace is stable, test the time t of the ultrasonic echo between the groove or protrusion and the end face. The speed of sound at that temperature can be obtained. Referring to this method, the temperature is increased by 10°C to further obtain the speed of sound at different temperatures. By gradually increasing the temperature in the constant temperature furnace, the speed of sound data at every 10°C from 100 to 1000°C can be obtained. The speed of sound-temperature curve is made based on these temperature and speed of sound data. The corresponding relationship between the speed of sound and temperature of the sensor rod material at 100-1000°C can be known.

[0060] Due to the particularity of the sensor rod, this sensor rod using ultrasonic temperature measurement can survive in environments with high dust, strong thermal radiation, and strong electromagnetic interference. The other parts of the measuring equipment can be arranged in a place with a good environment away from the electric arc furnace to avoid the impact of the environment on the equipment, thereby achieving the purpose of measuring temperature in such a harsh environment.

[0061] Example 1

[0062] An embodiment of the multi-stage temperature measuring device of the self-baking electrode of the present invention is as follows.

[0063] The whole device includes a protection tube 101, a sensor rod 102, a transducer 103, a sensor matching circuit 104, a high-power ultrasonic excitation module 105, a storage module 106, a bandpass filter circuit 107, a gain adjustment circuit 108, a digital acquisition circuit 109, an operation control module 110, a communication module 111, a remote human-computer interaction module 112, and a local human-computer interaction module 113.

[0064] Among them, a sensing rod is set between the copper tiles outside the self-baking electrode. The sensing rod is made of tungsten and is a cylinder with a diameter of 1 mm. Two grooves are set at the softening section, volatilization section and sintering section of the self-baking electrode corresponding to the sensing rod, and the longitudinal section of the groove is square. At the softening section, volatilization section and sintering section of the self-baking electrode corresponding to the sensing rod, the temperature is measured in contact with the electrode tube. The sensing rod is covered with thermal insulation cotton 114 to reduce the heat conduction between the electrode tube and the environment. The transducer is installed on the upper end face of the sensing rod.

[0065] The software in the operation control module 110 is used to send a signal through the high-power ultrasonic excitation module 105 to generate a trigger signal, which acts on the transducer 103 through the sensor matching circuit 104. The transducer 103 converts the electrical signal into an ultrasonic signal. The ultrasonic signal propagates to the lower end surface through the sensor rod 102 to generate a reflected echo. The transducer 103 converts the reflected echo into an electrical signal and transmits it to the bandpass filter circuit 107. After passing through the gain adjustment circuit 108, it is transmitted to the digital acquisition circuit 109 for filtering and amplification, and then the data is uploaded to the operation control module 110.

[0066] The operation control module 110 calculates the speed data based on the time data of the ultrasonic reflection data and the distance to obtain the temperature data by looking up the table, such as the receiving time difference Δt of the ultrasonic wave between the grooves of each segment of the sensor rod, combined with the corresponding distance L between the grooves of each segment of the sensor rod, and the average speed of the ultrasonic wave between the grooves of each segment according to the formula The average velocity of the ultrasonic wave between each groove segment is obtained.

[0067] According to the simulated fitting curve of the corresponding relationship between ultrasonic transmission speed and specific sensor rod temperature, the average temperature of each section of the sensor rod is obtained in the range of 100-1000°C, that is, the average temperature of the softening section, volatilization section and sintering section of the self-baking electrode.

[0068] The human-computer interaction modules 112 and 113 can transmit the set speed and distance constants to the operation control module, change the constants in the operation control module, and facilitate the calculation of time, temperature, etc. by the software in the operation control module.

[0069] Example 2

[0070] Another embodiment of the multi-stage temperature measuring device for the self-baking electrode of the present invention is as follows.

[0071] The whole device includes a protection tube 101, a sensor rod 102, a transducer 103, a sensor matching circuit 104, a high-power ultrasonic excitation module 105, a storage module 106, a bandpass filter circuit 107, a gain adjustment circuit 108, a digital acquisition circuit 109, an operation control module 110, a communication module 111, a remote human-computer interaction module 112, and a local human-computer interaction module 113.

[0072] Among them, the protection tube is pre-buried in the self-baking electrode. The material of the protection tube is graphite, and the side length is 30mm square tube; the material of the sensor rod is molybdenum, and the surface is made of molybdenum silicide high temperature anti-oxidation coating, a round solid column, placed in the protection tube. Two protrusions are set at the softening section, volatilization section and sintering section of the sensor rod corresponding to the self-baking electrode, and the longitudinal section of the protrusion is square. At the softening section, volatilization section and sintering section of the sensor rod corresponding to the self-baking electrode, alumina fiber insulation cotton is placed, made into a strip and attached to one side of the sensor rod, pressing the sensor rod to keep in contact with the protection tube. The transducer is installed on the upper end face of the sensor rod.

[0073] The software in the operation control module 110 sends a signal to the high-power ultrasonic excitation module 105 to generate a trigger signal, which acts on the transducer 103 through the sensor matching circuit 104. The transducer 103 converts the electrical signal into an ultrasonic signal. The ultrasonic signal propagates to the lower end surface through the sensor rod 102 to generate a reflected echo. The transducer 103 converts the reflected echo into an electrical signal and transmits it to the bandpass filter circuit 107. After passing through the gain adjustment circuit 108, it is transmitted to the digital acquisition circuit 109 for filtering and amplification, and then the data is uploaded to the operation control module 110.

[0074] The operation control module 110 calculates the speed data based on the time data of the ultrasonic reflection data and the distance to obtain the temperature data by looking up the table, such as the receiving time difference Δt of the ultrasonic wave between the grooves of each segment of the sensor rod, combined with the corresponding distance L between the grooves of each segment of the sensor rod, and the average speed of the ultrasonic wave between the grooves of each segment according to the formula The average velocity of the ultrasonic wave between each groove segment is obtained.

[0075] According to the simulated fitting curve of the corresponding relationship between ultrasonic transmission speed and specific sensor rod temperature, the average temperature of each section of the sensor rod is obtained in the range of 100-1000°C, that is, the average temperature of the softening section, volatilization section and sintering section of the self-baking electrode.

[0076] The communication module 111 transmits the calculated time and distance, including the length of the sensing rod and the depth of the electrode in the furnace, to the local human-computer interaction module 113.

[0077] The human-computer interaction modules 112 and 113 can transmit the set speed and distance constants to the operation control module, change the constants in the operation control module, and facilitate the calculation of time, temperature, etc. by the software in the operation control module.

[0078] Example 3

[0079] Another implementation of the multi-stage temperature measurement method of the self-baking electrode of the present invention is as follows.

[0080] A protective tube is embedded in the self-baking electrode. The material of the protective tube is alumina. The protective tube is a regular round tube with an inner diameter of 30mm. The sensing rod is made of tungsten-rhenium alloy, and the cross-section diameter is a round solid column of 2mm, which is placed in the protective tube. In the softening section, volatilization section and sintering section of the sensing rod corresponding to the self-baking electrode, the thermal insulation cotton of aluminum silicate ceramic fiber is placed, which is pressed into a cylindrical shape in advance and placed in the protective tube, and the sensing rod is pressed to keep in contact with the protective tube. The transducer is installed on the upper end face of the sensing rod.

[0081] Two grooves are set at the softening section, volatilization section and sintering section of the sensor rod corresponding to the self-baking electrode, and the longitudinal section of the groove is a triangle. The lower end surface of the sensor rod corresponding to the sintering section is in the sintering section, which can be regarded as the lowest groove of the sensor rod in the sintering section, which is used to calculate the transmission time of the reflected wave of the ultrasonic wave. The distance between the grooves in the softening section and the volatilization section is 20cm and 10cm respectively, and the distance between the upper groove in the sintering section and the lowest end of the sensor rod is 5cm.

[0082] The ultrasonic wave is transmitted along the sensor rod by a transducer and reflected after reaching the bottom of the sensor rod. The transducer receives the reflected wave and converts it into an electrical pulse signal. The receiving time difference of the reflected wave between the grooves of each section of the ultrasonic wave is 85.26us, 43.11us, and 22.20us respectively.

[0083] According to the distance between each section of the groove, the average speed of ultrasonic wave transmitted on each section of the sensor rod is obtained as 4691.531m / s, 4639.295m / s, and 4504.505m / s.

[0084] According to the "sound velocity-temperature curve" of the sensor rod material at 100-1000°C, the average temperature of each section of the sensor rod can be obtained, that is, the average temperature of the softening section, volatilization section and sintering section of the self-baking electrode is 210°C, 410°C, and 790°C.

[0085] Example 4

[0086] Another implementation of the multi-stage temperature measurement method of the self-baking electrode of the present invention is as follows.

[0087] A sensing rod is set between the copper tiles outside the self-baking electrode. The sensing rod is made of tungsten-rhenium alloy, and is a rectangular solid column with a cross-section length of 5 mm and a width of 0.5 mm. The sensing rod contacts the electrode tube for temperature measurement at the softening section, volatilization section and sintering section of the self-baking electrode. The sensing rod is covered with thermal insulation cotton 114 to reduce heat conduction between the electrode tube and the environment. The transducer is installed on the side of the sensing rod.

[0088] A groove is set at each of the softening section, volatilization section and sintering section of the sensor rod corresponding to the self-baking electrode to reflect ultrasonic waves. The longitudinal section of the groove is semicircular. The transducer emits ultrasonic waves and transmits them along the sensor rod. After filtering out the secondary and above reflected waves, the maximum receiving time difference of the reflected waves between the grooves of each section of the ultrasonic wave is 106.32us, 64.278us, and 44.037us, respectively. The corresponding maximum distances between the grooves of each section are 25cm, 15cm, and 10cm, and the average speeds of ultrasonic waves transmitted on each section of the sensor rod are 4702.784m / s, 4667.227m / s, and 4541.635m / s, respectively. At the same time, the receiving time of other reflected waves between the grooves of each section and the corresponding distances between the grooves of each section can be obtained, and the corresponding average ultrasonic speed can be calculated to obtain a more accurate statistical average value.

[0089] According to the "sound velocity-temperature curve" of the sensor rod material at 100-1000°C, the average temperature of each section of the sensor rod can be obtained, that is, the average temperature of the softening section, volatilization section and sintering section of the self-baking electrode is 150°C, 310°C, and 690°C.

[0090] It should be noted that the above invention content and specific implementation methods are intended to demonstrate the practical application of the technical solution provided by the present invention and should not be interpreted as limiting the scope of protection of the present invention. Those skilled in the art can make various modifications, equivalent substitutions or improvements within the spirit and principles of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A multi-stage temperature measuring device for a self-baking electrode, characterized in that: The multi-stage temperature measuring device comprises a sensing rod (102), a transducer (103) and an operation control device; wherein: The sensing rod (102) is made of a non-ferromagnetic metal material, a graphite tube or a ceramic material with a high-temperature anti-oxidation coating on the surface. The non-ferromagnetic metal material is a single body or a mixture of iron alloy, tungsten, molybdenum, rhenium, iridium and lanthanum. The ceramic material is a single body or a mixture of zirconium oxide, silicon carbide and molybdenum silicide. The shape of the sensing rod (102) is filamentary or strip-shaped. The cross section of the sensing rod (102) is circular or square, so that the sensing rod (102) will not induce current under an alternating magnetic field, and is used to transmit ultrasonic waves. Two protrusions with a spacing of L are arranged at a distance D on a sensing rod (102) disposed outside the electrode (201) at the softening section, volatilization section and sintering section of the electrode (201) to reflect ultrasonic waves, thereby simultaneously obtaining the average temperature of multiple sections; the sensing rod (102) is in contact with the electrode (201) for temperature measurement, and the sensing rod (102) is covered with a strip of heat insulating cotton (114) to reduce heat conduction between the electrode (201) and the environment; The outer ring of the electrode (201) is provided with a copper washer (204), and the outer sleeve of the copper washer (204) is provided with a holding tube (205), so that the electrode (201) is coaxially arranged in the holding tube (205), the holding tube (205) is connected to the bottom of the lower brake (206), one end of the synchronization rod (115) is fixedly connected to the lower brake (206), and the other end of the synchronization rod (115) is connected to the sensing rod (102), the relative position of the copper washer (204) and the holding tube (205) remains unchanged, and the relative distance between the holding tube (205) and the lower brake (206) remains unchanged, so that when the electrode (201) moves up and down, the relative position of the sensing rod (102) and the copper washer (204) remains unchanged, thereby realizing synchronous acquisition of the temperatures of the softening section, volatilization section and sintering section of the electrode (201), and realizing temperature measurement; The transducer (103) is mounted on the upper end surface or the side surface of the sensing rod (102) and is used to emit ultrasonic waves, which are transmitted along the sensing rod (102); The operation control device is electrically connected and signal-connected to the transducer (103). The operation control device controls the transducer (103) to emit ultrasonic waves so that the ultrasonic waves are transmitted along the sensor rod (102). The transducer (103) receives reflected waves to obtain the ultrasonic reflection wave time T between each section of the protrusions, where T is in seconds (s). The operation control device calculates the average sound velocity of the first temperature measurement section according to the distance difference L between adjacent protrusions: The average sound velocity in the second temperature measurement section is The average sound velocity in the third temperature measurement section is The unit is meter / second (m / s); the units of L1, L2, and L3 are meter (m); the units of T1, T2, and T3 are second (s); and the average temperature of the softening section, volatilization section, and sintering section of the electrode (201) can be obtained based on the corresponding relationship between the sound velocity and temperature of the sensing rod (102) material.

2. The multi-stage temperature measuring device according to claim 1, characterized in that: The operation control device comprises an operation control module (110); wherein, The operation control module (110) is electrically and signal-connected to the high-power ultrasonic excitation module (105), so that the operation control module (110) sends a signal to the high-power ultrasonic excitation module (105) to generate a trigger signal; The high-power ultrasonic excitation module (105) is electrically and signal-connected to the sensor matching circuit (104), and the sensor matching circuit (104) is electrically and signal-connected to the transducer (103) and the band-pass filter circuit (107), respectively, so that the trigger signal acts on the transducer (103) through the sensor matching circuit (104), and the transducer (103) converts the first electrical signal into an ultrasonic signal, and the ultrasonic signal propagates to the lower end surface through the sensor rod (102) to generate a reflected echo, and the transducer (103) converts the reflected echo into a second electrical signal and transmits it to the band-pass filter circuit (107) through the sensor matching circuit (104); The bandpass filter circuit (107) is electrically and signal-connected to the gain adjustment circuit (108), so that the second electrical signal is transmitted to the digital acquisition circuit (109) for filtering and amplification after passing through the gain adjustment circuit (108); The gain adjustment circuit (108) is electrically and signal-connected to the digital acquisition circuit (109), and the digital acquisition circuit (109) is electrically and signal-connected to the operation control module (110), so that the second electrical signal is uploaded to the operation control module (110) via the digital acquisition circuit (109), and the operation control module (110) uses an ultrasonic temperature measurement algorithm to process the speed and distance constants to obtain temperature data; The operation control module (110) is electrically connected and signal-connected to the communication module (111), and the communication module (111) is electrically connected and signal-connected to the remote human-machine interaction module (112) and / or the local human-machine interaction module (113), so that the temperature data is transmitted to the remote human-machine interaction module (112) and the local human-machine interaction module (113) via the communication module (111).

3. The multi-stage temperature measuring device according to claim 1 or 2, characterized in that: The sensing rod (102) is placed inside the electrode (201); The sensing rod (102) is provided with a protective tube (101) on its outer sleeve. The protective tube (101) and the sensing rod (102) are pre-buried in the electrode paste of the electrode (201) to directly measure the internal temperature of the electrode paste. A cylindrical heat insulating cotton (114) is placed in the protection tube (101) to isolate the flow of gas. The heat insulating cotton (114) presses the temperature measuring part of the sensing rod (102) to make it contact with the wall of the protection tube (101).

4. The multi-stage temperature measuring device according to claim 3, characterized in that: The protection tube (101) is one or more of metal materials, graphite and / or ceramic materials, and the ceramic material is a single body or a mixture of aluminum oxide, zirconium oxide, magnesium oxide, silicon carbide, and molybdenum silicide; the shape of the protection tube (101) is a square tube or a round tube.

5. The multi-stage temperature measuring device according to claim 1, characterized in that: The thermal insulation wool (114) is composed of ceramic fibers, and the ceramic fibers are one or more of aluminum silicate fibers, aluminum oxide fibers and / or zirconium oxide fibers.

6. The multi-stage temperature measuring device according to claim 1, characterized in that: The transducer (103) is an electroacoustic converter, which acts as a transmitter to convert an electrical pulse signal into an ultrasonic signal, and acts as a receiver to convert an ultrasonic signal into an electrical pulse signal.

7. A method using the multi-stage temperature measuring device according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: Step S1: two protrusions with a spacing of L are arranged at a distance D on the sensing rod (102) corresponding to the softening section, volatilization section and sintering section of the electrode (201) to reflect ultrasonic waves; Step S2: the operation control device controls the transducer (103) to emit ultrasonic waves, so that the ultrasonic waves are transmitted along the sensor rod (102), and the transducer (103) receives the reflected waves to obtain the ultrasonic reflection wave time T between each section of the protrusion, where T is in seconds (s); Step S3: The operation control device calculates the average sound velocity of the first temperature measurement section according to the distance difference L between adjacent protrusions: The average sound velocity in the second temperature measurement section is The average sound velocity in the third temperature measurement section is The unit is meter / second (m / s); the unit of L1, L2, L3 is meter (m); the unit of T1, T2, T3 is second (s); Step S4: The average temperature of the softening section, volatilization section and sintering section of the electrode (201) can be obtained according to the corresponding relationship between the sound velocity and temperature of the sensing rod (102) material.

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