JPH06347442A - Measuring device for oxygen activity in molten material and measuring method employing the device - Google Patents

Abstract

PURPOSE:To let almost all works accompanying oxygen activity measurement be automated by computing oxygen activity value using convergent data groups as soon as measurement values detected by an electromotive force detecting section are converged. CONSTITUTION:The cooling of a heating furnace 20 is started with a coolant fed to the heating furnace, and the heating of a metallic crucible 64 is simultaneously started by energying heat source of the furnace 20. The furnace 20 is heated while being controlled by a temperature control means, so that temperature within the furnace is raised up to a specified temperature in an early stage. And when temperature within a reaction pipe is raised up to the specified temperature, an oxygen sensor 32 is moved in the furnace, so that it is immersed in molten material in a metallic crucible. After immersion has been over, reading the value of electromotive force out of the sensor 32 is simultaneously started, both data on electromotive force and data on measured temperature are stored in a memory means so as to be displayed on a measurement value display section. Simultaneously, a measurement control section cuts off the aforesaid measurement at the when it is judged that electromotive force is in an equilibrium, so that oxygen activity is thereby computed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, oxygen activity in hot metal slag and molten steel slag and oxygen activity in iron produced in the iron making process, oxygen activity in non-ferrous metals, and glass. Apparatus for measuring oxygen activity in a molten substance capable of quickly and automatically measuring oxygen activity in non-metals, and a measuring method using the apparatus, more specifically, automating measurement work This reduces the work load on the measurer as much as possible, and does not require the experience of the measurer to be taken into account when measuring, making it possible for anyone to measure the oxygen activity reliably. And a measuring method using the device.

[0002]

2. Description of the Prior Art In the refining process of metals and the manufacturing process of non-metals, it is important to measure the oxygen activity in these molten substances. For example, in the steelmaking process, steelmaking slag exists in a floating state on molten steel and indirectly controls the chemical reaction of the molten steel itself by causing a chemical reaction with the molten steel. It is important to control the slag component, and it is extremely important to measure the oxygen activity in the steelmaking slag. Further, the measurement of oxygen activity in a molten substance is not limited to the iron making process, but is useful in the refining process of metals in general, and is also useful in the non-metal manufacturing process such as glass.

From this point of view, the present applicant has already applied for a number of devices for measuring oxygen activity in slag,
For example, there are those proposed as Japanese Patent Application No. 1-271033, Japanese Patent Application No. 3-5141 and Japanese Patent Application No. 3-181948. For example,
In the apparatus proposed in Japanese Patent Application No. 1-271033, as shown in FIG. 22, a reaction tube b filled with an inert gas is vertically provided in a condensing type heating furnace a, and a heating section in the reaction tube b is provided. , The iron crucible c was placed on a metal support d, and a thermocouple g for temperature measurement was placed in the support d with its temperature sensing portion being close to the lower surface of the iron crucible c. In the iron crucible c, a specific metal M that does not form an alloy with iron and that does not easily form an oxide and has a higher specific gravity than the slag S is used in the measurement in the iron crucible c. While accommodating in a molten state together with the slag S to be measured, the solid electrolyte e containing the standard electrode is immersed in the specific metal M and the slag S that have been brought into a molten state by the heating of the converging type heating furnace a, Electromotive force between the iron crucible c that also serves as the control electrode and the standard electrode Measured by the instrument f, and were those thermoelectromotive force obtained from the thermocouple g by measuring the temperature of the metal crucible by detecting the instrument h actually measuring the oxygen activity of the slag S. In this way, by knowing the iron oxide activity in the slag, it became possible to estimate the reaction of phosphorus or sulfur, which is not so preferable for the product.

The present applicant has filed the above-mentioned application (Japanese Patent Application No. 1-271033).
Partial improvement of each part is proposed in Japanese Patent Application No. 3-5141 and Japanese Patent Application No. 3-181948 while following the basic structure of No. 1).

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention It becomes possible to measure the oxygen activity in the slag by the oxygen activity measuring apparatus proposed by the applicant of the present invention, and when the substance to be measured is an insulator, like the slag, It becomes possible to measure the oxygen activity in the molten substance by following the above principle as it is, and when the substance to be measured is a conductive substance, the oxygen activity in the molten metal can be obtained without using the specific metal. Although it has become possible to measure quantities, the device still has problems to be solved.

That is, in the above-mentioned oxygen activity measuring device,
Basically, all operations are performed by the operator's manual operation or direct operation of the operation panel, and the operation procedure and operation timing of each part of the device depend on the operator's operation, so the measurement is successful. Whether or not it depends on the experience of the measurer, and no one can easily measure under the same conditions. Further, even an experienced measurer has a problem that it is extremely difficult to measure repeatedly under the same conditions, and the measurement conditions are not stable. Further, since the above-mentioned device requires complicated device operation, there is a possibility that the operation procedure may be erroneous, and the concentration of the operation is required, which causes the operator to be tired.

The present invention has been made in view of the above situation, and it is possible to automate almost all the work involved in measuring oxygen activity, and set a metal crucible containing a substance to be measured at a predetermined position in the apparatus. By doing so, the subsequent work procedure can be sequentially processed to automatically calculate the target oxygen activity value, and regardless of experience, anyone can always measure oxygen activity under the same conditions. The present invention is intended to provide an apparatus capable of measuring the oxygen activity using the apparatus.

[0008]

The oxygen activity measuring device of the present invention, which has solved the above problems, has the following constitution. A heating furnace provided with a cooling means; replaceably installed in the heating furnace,
A reaction tube filled with an inert gas therein; a metal crucible installed in the heating furnace and containing a molten substance to be measured; and a metal crucible immersed in the molten substance at the time of measurement,
An element for measuring oxygen activity in a molten substance, an oxygen sensor mainly composed of a one-end closed tube type solid electrolyte containing a standard electrode; a temperature measuring means for directly or indirectly measuring the temperature of the molten substance Having a support for the metal crucible and moving the support vertically and horizontally in a predetermined procedure with the metal crucible placed on the metal crucible so that the metal crucible has a predetermined position inside the heating furnace and a predetermined position outside the furnace. And a mechanism for setting and discharging the metal crucible to a fixed position by reciprocating between and, and the mechanism relates to the signal obtained from the means for detecting the mounting state of the metal crucible on the support base. A controlled crucible moving means; and a mounting portion that detachably holds the base end of the oxygen sensor, and the oxygen sensor held by the mounting portion is moved in a predetermined procedure in vertical and horizontal directions to obtain the oxygen sensor. The oxygen sensor has a mechanism for reciprocating between a predetermined position inside the heating furnace and a predetermined position outside the furnace to set and discharge the oxygen sensor to a fixed position, and the mechanism is provided for connecting the oxygen sensor to the mounting portion. Oxygen sensor moving means controlled in association with the signal obtained from the means for detecting the mounting state; Refrigerant supplying / discharging means for supplying / discharging the cooling medium into / from the heating furnace while controlling its timing; An inert gas supply means for supplying an inert gas while controlling its amount and timing; a temperature rise pattern corresponding to a substance to be measured is registered, and a heat source of a heating furnace is controlled based on the temperature rise pattern. A temperature control part for controlling; a metal crucible having a function as a contrast electrode,
The conductive path is formed in the middle of the conductive path formed by the support of the metal crucible, the molten substance, the solid electrolyte, and the mounting portion of the oxygen sensor made of a conductive material, and the conductive path forms an electrically closed circuit. An electromotive force detection unit for detecting electromotive force generated in the electromotive force; a measurement start timing is detected based on a temperature measurement result of the molten substance, and a measurement value detected by the electromotive force detection unit is continuously monitored, and the measurement value is A measurement management control unit for calculating an oxygen activity value by using the converged data group when the variation width of the above with respect to a specified value converges within a specified value; the measurement value and the execution process monitored by the measurement management control unit. And a display unit having a measurement content display unit for displaying the calculated oxygen activity value in real time and an operation content display unit for visually displaying the operation procedure, operation items, and the like; Operation means for providing a manually input or start command or the like of operating conditions for each unit and each unit; is characterized by comprising; a microcomputer for controlling said each means, and each part of the operating procedure.

It is preferable to use a condensing type heating furnace as the heating furnace from the viewpoints of rapid temperature rise and easy temperature control.

The display means and the operating means may be provided independently, but it is preferable to arrange a translucent touch panel on the front surface of the graphic display to integrate the display means and the operating means from the viewpoint of facilitating the operation. It is preferable to use a graphic whose contents displayed on the display are easy to recognize.

[0011]

The oxygen activity measuring device having the above construction is used as follows. First, when the power of the apparatus main body is turned on, a menu screen for selecting the processing contents of each unit and each unit constituting the oxygen activity measuring apparatus is displayed on the display unit.
When the equipment is used for the first time or when various setting conditions are changed, initial settings are made by inputting the service life of semi-consumables such as reaction tubes and the final temperature reached in the furnace.

Next, before starting the actual measurement, the operation test of each means and each part constituting the apparatus is forcibly performed to confirm that there is no apparatus abnormality. Further, the thermocouple is used continuously without replacement at each measurement, but it needs to be replaced when it deteriorates. When replacing the thermocouple, check the thermocouple accuracy using a standard sample with a known oxygen activity value,
Only those with an acceptable error range are used. The initial setting and operation check work are not performed every time measurement is performed, but are performed once a day or as needed. At the same time as confirming the accuracy of the thermocouple, the remaining usable number of semi-consumables is also checked.
If so, issue a warning and encourage replacement of the relevant semi-consumable. The check of the number of remaining semi-consumables may be performed immediately after the shift to the actual measurement mode described later.

When the above-mentioned preparation work is completed, the actual measurement is started. The actual measurement is performed by the following procedure. First, the metal crucible containing the substance to be measured is placed on the support table of the crucible moving means waiting outside the furnace, and the oxygen sensor is also attached to the mounting portion of the oxygen sensor moving means waiting outside the furnace.

When the substance to be measured is a conductive substance, only the substance to be measured is accommodated in the metal crucible, but when the substance to be measured is an insulating substance such as slag or non-metal, it is put together with the substance to be measured. In the inert atmosphere, a metal of the metal crucible is not alloyed, an oxide is not easily generated, and a specific metal having a specific gravity larger than that of the substance to be measured is contained in a molten state. After the above work is completed, there is almost no manual work by the measurer other than the key operation on the operation panel, and the rest is only the work of discarding the metal crucible and the oxygen sensor at the end of the measurement.

Next, when the start key is operated to give an actual measurement start command to the measuring device, it is automatically judged whether or not the metal crucible and the oxygen sensor are set at a predetermined position and a predetermined posture, and an abnormality is detected. When it is detected, a warning is issued. On the other hand, if there is no abnormality, the crucible moving means moves the metal crucible vertically and horizontally to set it at a predetermined position in the reaction tube.

When it is confirmed that the metal crucible is set at a predetermined position in the reaction tube, the inert gas is supplied for a predetermined time to fill the reaction tube with the inert gas. Next, the refrigerant is supplied into the heating furnace to start cooling the heating furnace, and at the same time, to start energizing the heat source of the heating furnace to start heating the metal crucible. The heating furnace prevents excessive temperature rise of the furnace body by supplying the refrigerant.

The heating of the heating furnace is performed under the control of the temperature control means, and by continuing the heating, the temperature inside the furnace reaches the specified temperature early. During this time, the inside of the reaction tube is kept filled with the inert gas.

When the temperature inside the reaction tube reaches the specified temperature registered in the temperature control means, the oxygen sensor moving means is operated to move the oxygen sensor waiting outside the furnace into the furnace. Immerse in molten material in a metal crucible.
The reading of the electromotive force from the oxygen sensor is started at the same time when the immersion in the predetermined depth is completed, and the electromotive force data and the temperature measurement data which change from moment to moment are stored in the storage means, while the data content is measured by the display means. Real time display on the display.

At the same time as the electromotive force data and the temperature measurement data are stored and displayed, the measurement management control unit continues to monitor the electromotive force data, and when the electromotive force data is judged to be in equilibrium, the measurement is terminated and the oxygen activity is stopped. Calculate the amount. This method
With the current time as the reference time, while judging whether or not the measured value has converged within the predetermined specified value within the specified fixed time, if the value converges within the specified value, When the oxygen activity value is calculated based on the measurement data obtained within the time and the measurement ends, on the other hand, when it does not converge, the time when the specified value is exceeded is set as the new reference time and the measurement is continued. It is the content to do. When the cumulative measurement time reaches the predetermined time limit without the equilibrium of the electromotive force data, the measurement is ended and the variation range of the electromotive force converges within the specified value immediately before the end of the measurement. The oxygen activity value is calculated only for the measured data being measured, and this value is used as the temporary oxygen activity value.

Then, the calculated oxygen activity value is recorded, and the remaining number of useful lives is updated by adding or subtracting the counter of the number of useful lives of semi-consumables by one.

When the measurement is completed, the oxygen sensor and the metal crucible are taken out. The removal is performed by the following procedure. First, the oxygen sensor moving means is operated to discharge the oxygen sensor, and then the power supply to the heat source of the heating furnace is stopped, and at the same time, the supply amount of the inert gas into the reaction tube is increased to promote the cooling in the reaction tube. The supply of the inert gas is stopped when the temperature in the reaction tube becomes equal to or lower than the predetermined temperature. Then, the crucible moving means is operated to discharge the metal crucible to the outside of the furnace, and then the supply of the refrigerant to the heating furnace is stopped to complete the discharge work of the metal crucible.

After that, the display content of the display means is returned to the initial menu screen, and at the same time, the remaining usable number of the semi-consumables is checked, and the remaining number of the semi-consumables is 0 when the remaining number is 1. If so, issue a warning and encourage replacement of the relevant semi-consumable.

[0023]

EXAMPLES Each part constituting the apparatus of the present invention comprises a heating furnace, a reaction tube, a metal crucible, an oxygen sensor, a temperature measuring means, a crucible moving means, an oxygen sensor moving means, a refrigerant supply / discharge means, an inert gas supply means, and a temperature. Control unit, electromotive force detection unit, measurement management control unit,
It can be roughly classified into a display means, an operating means, and a control microcomputer. Hereinafter, these details will be described based on the embodiment shown in the drawings.

FIG. 1 shows a front view of a main body device which is a central part of the device of the present invention, and FIG. 2 shows a rear view thereof. Although not shown, a refrigerant supply cylinder, an inert gas supply cylinder, and a cooling water supply tank or water source are provided outside the main body apparatus A, and these are connected to the main body apparatus A via a pipe, so that Configure the device.

The main unit A is assembled in a vertically long casing. The casing 1 has boxes 2 and 3 accommodating various device groups at the top and bottom, and is a position sandwiched by the boxes 2 and 3, and is suitable for a worker to perform manual work in a normal posture in a standing state. A work space 4 is provided at the open position. The bottom plate 5 that partitions the lower surface of the work space 4 is shared with the top plate of the box 3.

A concentrating heating furnace 20 is arranged in the work space 4, and an oxygen sensor moving means 30 is provided above the work space 4.
On the other hand, on the other hand, the crucible moving means 40 is arranged below the work space 4, and the cell chuck 31 which is the tip of the oxygen sensor moving means 30 and the crucible support base 41 related to the crucible moving means 40 are provided in the work space 4. It is located inside. Further, a cell chuck opening / closing switch 33 is arranged at a front position on the bottom plate 5, and a collective display lamp 7, a floppy disk drive 8 and a program reset switch 9 are arranged on a panel 6 adjacent to the work space 4.

The front panel of the upper box 2 is provided with a graphic touch panel 50 which also serves as a display means and an operating means. On the other hand, the front panel of the lower box 3 adjusts the supply / discharge amount of cooling water, air and argon gas. A regulator box 10, a main power supply switch 11, and a control power supply switch 12 are arranged for this purpose. In the figure, 13 is a heating furnace controller for controlling the temperature of the condensing type heating furnace 20, and a furnace body power switch 14 is arranged on the front panel of the heating furnace controller 13 together with a level meter. In this embodiment, an ammeter is used as the level meter.

As shown in FIG. 2, an argon gas inlet 15, a dry air inlet 16, a cooling water outlet 17 and a cooling water inlet 18 are provided adjacent to each other on the lower portion of the rear surface of the casing, and an electric fan is used at the upper position. A ventilation device 19 is installed. The main parts will be described below.

As shown in FIG. 3, the condensing type heating furnace 20 has:
A furnace body 24 having a housing space 21 for housing a tubular reaction tube in the center thereof and an infrared lamp 22 and an infrared reflection plate 23 arranged around the housing space 21 is formed in a half-divided form. In this embodiment, one of the half-divided furnace bodies is a furnace body fixed side piece 24a fixed to the casing side wall, and the other is a furnace body movable side piece 24b. The movable-body-side piece 24b of the furnace body is openably and closably attached to the fixed-side piece 24a of the furnace body via a hinge or the like, so that the internal maintenance and cleaning can be performed as necessary.

Inside the furnace body of the condensing type heating furnace 20, a water channel is formed by using the exposed cooling water hose 25 as a return path, and as shown in FIG. 4, the cooling water pipe attached to the back surface of the furnace body. Cooling water supplied through the hose 26 is circulated in the furnace body to prevent excessive temperature rise of the furnace body during heating. Further, an air passage is also formed in the furnace body 24, and by directly blowing cooling air from the outside of the furnace body to the infrared lamp 22 through the cooling air pipe 27,
The infrared lamp 22 is prevented from being damaged due to excessive temperature rise. An electric power cable 28 for supplying electric power to the infrared lamp is also connected to the rear surface of the furnace body.

The condensing type heating furnace 20 is capable of rapid temperature rise, easy temperature control, little influence of noise and the like on the measuring system, and has the advantage that the measuring environment can be kept clean. Although used, other heating furnaces such as a high frequency induction heating furnace can also be used.

As shown in FIG. 5, the upper and lower flanges 61, 61 are provided in the accommodation space 21 of the condensing type heating furnace 20.
The reaction tube 60 to which is attached is inserted in a semi-fixed state, and the inside thereof can be filled with an inert gas such as argon gas through the inert gas inlet 67. The reaction tube 60 is made of a transparent heat-resistant material such as quartz, has an upper portion and a lower portion opened, and an iron crucible 64 that covers the crucible protection tube 63 through the lower opening 62 and a support base protection tube 65. It is configured so that it can appear and disappear in a state of being mounted on the crucible support base 41 that is externally mounted. The first reason why the crucible protection pipe 63 is configured differently from the support base protection pipe 65 is that there is a significant difference in the degree of pollution between the peripheral part of the iron crucible and the part surrounding the crucible support base 41, so that the crucible protection with significant pollution is protected. This is because it is possible to increase the service life of the support base protection tube 65 by allowing only the tube 63 to be replaced as appropriate. Further, although it is necessary to heat the iron crucible 64, it is not always necessary to heat the crucible support base 41, and it may be more convenient to prevent the temperature of the crucible support base 41 from being raised. Is a crucible protection tube 6
3 uses a high transmittance quartz tube, while the support base protection tube 65
It is possible to control each heat generation by selectively using a quartz tube having a low transmittance. This is the second reason why the crucible protection tube 63 is configured separately from the support base protection tube 65. A thermocouple 66 for indirectly measuring the sample temperature in the iron crucible is provided inside the crucible support base 41 on which the iron crucible 64 is placed.

FIG. 6 shows the iron crucible 64 and the oxygen sensor 32 waiting outside the furnace at the front position of the concentrating heating furnace 20. The concentrating heating furnace 20 can be opened and closed, but it is not opened and closed except when the reaction tube 60 is replaced or the furnace body 24 is adjusted, and the crucible insertion and discharge performed for each measurement are concentrating. The heating is performed from below the heating furnace 20, while the oxygen sensor 32 is inserted and discharged from above the converging heating furnace 20.

The iron crucible 64 has a function of accommodating a substance to be measured and a function of a reference electrode when measuring an electromotive force. Although an iron crucible is used here, other metal crucibles can be used. The iron crucible 64, which is covered by the crucible protection tube 63, is placed on the crucible support base 41. By operating the crucible moving means 40, the iron crucible 64 is placed on the crucible support base 41 and is positioned outside the reactor at a predetermined position. Can be moved to a predetermined position in the furnace. Although not shown, a light projecting portion and a light receiving portion are provided on one side and the other side of the casing side wall so as to sandwich the iron crucible 64, and the iron crucible 64 is placed at the mounting position by forming an appropriate optical path for the iron crucible 64. It is structured so that you can check the pros and cons of.

The oxygen sensor 32 is the oxygen sensor moving means 30.
It is held in a suspended state by the cell chuck 31 attached to the cell chuck 31 and is moved from the standby position outside the furnace to a predetermined position inside the furnace by the oxygen sensor moving means for each measurement. Further, although not shown, a light projecting portion and a light receiving portion are provided on one side and the other side of the casing side wall so as to sandwich the oxygen sensor 32, and the oxygen sensor 32 has a proper hanging position as an optical path. It is configured so that you can check whether it is hanging or not. The outside positions of the iron crucible 64 and the oxygen sensor 32 are both in front of the concentrating heating furnace 20 so that a worker can easily perform a manual operation, but this position is other position. Well,
Alternatively, these may be sequentially and automatically supplied from the iron crucible or the stocker of the oxygen sensor without manual setting.

When the oxygen sensor 32 is immersed in the substance to be measured, the crucible support 41, the iron crucible 64 having a function as a reference electrode, the molten substance, the oxygen sensor 32, the cell chuck 31 made of a conductive material, An electric closed circuit that passes through the oxygen sensor moving means 30 and the electromotive force detection unit (not shown) is formed, and the electromotive force generated in the electric closed circuit is measured by the electromotive force detection unit to be measured. It becomes possible to measure the oxygen activity of a substance.

The crucible moving means 40 is composed of a horizontal moving device 42 and a vertical moving device 43. By combining the movements of these devices, the iron crucible 64 can be moved horizontally and vertically. FIG. 7 is an explanatory side view showing the outline of the crucible moving means 40 and its movement. Horizontal movement device 4
A linear drive mechanism associated with an air cylinder is used as the vertical movement device 43 and the vertical movement device 43, and these mechanisms are all housed under the bottom plate 5. When the iron crucible 64 is set at a predetermined position in the furnace, it is moved in the direction indicated by the white arrow in the drawing, while when the iron crucible 64 is discharged outside the furnace, it is moved in the direction indicated by the thin arrow in the drawing. To move.

The procedure for positioning the iron crucible 64 at a predetermined position in the furnace will be briefly described as follows. (I) First, in the initial state, the crucible support base 41 is stopped at a position in front of the concentrating heating furnace 20. (II) Next, when the iron crucible 64 containing the sample is placed on the crucible support base 41 and the operation button is operated, the crucible support base 41 is lowered by the vertical movement device 43 to a position below the bottom plate 5. The iron crucible 64 is lowered. (III) Subsequently, the crucible support base 4 is moved by the horizontal movement device 42.
1 is moved horizontally, and the iron crucible 64 is positioned immediately below the reaction tube 60 of the condensing type heating furnace 20. (IV) Finally, the crucible support 4 is moved by the vertical movement device 43.
1 is raised to position the iron crucible 64 at a predetermined position in the reaction tube and stop it. The discharge of the iron crucible 64 from the reaction tube 60 is performed by reversing the above procedure.

The moving mechanism and moving procedure of the oxygen sensor 32 are shown in FIG. Like the crucible moving means 40, the oxygen sensor moving means 30 is also composed of a horizontal moving device 34 and a vertical moving device 35. The outline of the operating procedure is
It is as follows. (I) First, the oxygen sensor 32 is attached to the cell chuck 31 stopped at the side position of the condensing type heating furnace 20. (II) When the operation button is operated in this state, the vertical movement device 35 operates to raise the oxygen sensor 32 to a predetermined height and stop it. (III) Next, the horizontal movement device 34 operates to move the oxygen sensor 32 in the horizontal direction and stop it at the position above the reaction tube. (IV) Subsequently, the oxygen sensor 3 is moved by the vertical movement device 35.
2 is dropped into the reaction tube 60, and the oxygen sensor 32 is immersed in the substance to be measured and stopped.

As for the procedure for moving the crucible moving means 40 and the oxygen sensor moving means 30, other methods can naturally be considered as long as they can reciprocate between a predetermined position outside the furnace and a predetermined position inside the furnace. The air supply path for the drive source of the crucible moving means 40 and the oxygen sensor moving means 30 will be described with reference to the air circuit shown in FIG. That is, the air supplied from the outside of the main unit is filtered by the filter 70, and then 2
It is branched into a system, one of which is supplied to a crucible moving means (crucible driving) and an oxygen sensor moving means (cell driving) through a manual valve 71 and an electromagnetic valve 72 arranged in the regulator box 10, and the other is supplied to a furnace body. It is supplied to the condensing heating furnace 20 as cooling air.

Further, FIG. 10 is an argon gas circuit showing the supply path of the argon gas into the reaction tube set in the condensing type heating furnace 20. Argon gas is used for both the purpose of rapid cooling in the reaction tube by inactivating the reaction tube and preparing the measurement environment, and by increasing the supply amount after the measurement is completed. The supply route is 2 for two types of applications such as
It is divided into lines. That is, the gas path supplied from the gas cylinder installed outside the main unit is branched into two systems, and one is supplied into the reaction tube via the manual valve 80 and the flow meter 81 in the regulator box 10,
The other one is configured to be introduced into the reaction tube through another path via another electromagnetic valve, and when the measurement is completed, a large amount of argon gas is supplied through both paths to promote cooling in the reaction tube.

The main part of the mechanical structure of the device of the present application has been described above. An electric system diagram of the device of the present application is shown in FIG. The electric system of the device of the present application is configured by connecting various device groups around a microcomputer (hereinafter, referred to as a computer). The computer has
The electromotive force of the thermocouple, the electromotive force obtained from the oxygen sensor, and the analog signal output collected from various other sensors are A /
The signal is input via the D converter, and on the other hand, a sequencer, a relay unit for controlling contacts of various drive mechanisms, various displays, and various sensors for controlling the operation of these mechanisms are connected via an I / O interface. The computer has a function of a temperature control unit that controls energization to the heat source of the concentrating heating furnace 20 based on the data from the thermocouple 66. The computer also determines the measurement start timing based on the data from the thermocouple 66 and continues to monitor the electromotive force measurement value obtained from the oxygen sensor 32, detects the equilibrium portion of the measurement data, and calculates the oxygen activity value. It also functions as a measurement management control unit.

The computer has a ROM for storing programs such as a monitor program and a starting program, and a RAM for resident a control program and temporarily storing data.
Are equipped with. In addition, it is equipped with a floppy disk drive (FDD) and an IC card to support data storage and program version upgrades, and a serial communication interface so that measurement data can be collected by the host computer as needed. ing.

As the display device, a liquid crystal display device (LC
A graphic touch panel having a translucent touch panel laminated on the front surface of D) is used. The graphic touch panel graphically displays the current processing contents and measurement data for easy visual confirmation, and at the same time,
It is possible to directly specify various operation instructions on the screen by touching the corresponding portion on the surface. In this embodiment, a color liquid crystal is used from the viewpoint of abundance of display information amount and visibility of display contents.

The present invention is also characterized by the contents displayed on the display device. The display device has a measurement content display function that displays the data measured by the oxygen sensor or thermocouple and the calculation result, and an operation content display function that visually displays the operation procedure and operation items, and displays the operation procedure. Corresponds to the content of the work process. Hereinafter, the measurement method using the device of the present invention will be described while explaining the display examples shown in FIGS. 12 to 19. In the following description, measurement of oxygen activity in steelmaking slag will be described as an example.

<Menu Screen Display Step> FIG. 12 shows a start screen when the apparatus is started up, and displays each mode that can be selected immediately after the power is turned on. When the corresponding item is selected on this screen, the mode screen is switched to, and various operations are interactively and graphically displayed and guided. On each mode screen, a "menu" button for instructing a return to the "start screen" is set on the screen.

<Initial Setting Step> First, the reaction tube 60, which is a semi-consumable item, is set in the condensing type heating furnace 20, and the thermocouple and the support table protection tube 65 are on standby outside the furnace. When the "Initial setting" is selected after mounting on the screen, the screen is switched to the "Initialization menu" screen as shown in FIG. On this screen, the temperature rise pattern such as the final temperature in the furnace corresponding to the sample to be measured, the tolerance of the reading equilibrium value of the electromotive force obtained by the oxygen sensor, the reaction tube which is a semi-consumable item, the thermocouple (in the figure Set the number of times of service of the "temperature control thermocouple") and the support base protection tube (indicated as "crucible base protection tube" in the figure). The figure shows a state in which temperature rise patterns of 1400 ° C. and 1450 ° C. are registered, and a semi-consumable product life count is displayed on the left side with a specified value and on the right side with the remaining number. When the registration of each initial value is completed, select "Menu" to return to the "Startup screen".

<Operation test process> When "operation confirmation" is selected on the "start screen", the screen is switched to the "operation confirmation" screen as shown in FIG. This screen mode is a mode for forcibly performing an operation test of whether or not each means and each part operate normally prior to actual measurement. In this operation confirmation mode, in addition to the drive test of the oxygen sensor moving means (indicated as "elevator" in the figure) and crucible moving means (indicated as "elevator" in the figure), supply / discharge of cooling water, cooling air, and argon gas It also controls. For supply and discharge control, for example, touch the "Reactor cooling water / air" button to invert the relevant display items in yellow, start supplying these, and display "Cooling air pressure side by side" under the relevant display items. While monitoring the gauges for “and cooling water pressure”, the manual valve and the main stopper in the regulator box 10 are operated. This "operation check" is always encouraged to be performed prior to the actual measurement. In this mode, the normal state of all parts of the device is confirmed before proceeding to the next work step.

<Thermocouple Good / Failure Judging Step> When "Standardize" is selected on the "Startup screen", the screen is switched to the "Standardized sample measurement" screen as shown in FIG. "Standardization"
Can be rephrased as the thermocouple pass / fail judgment step. "Standardization" is a process of inspecting whether or not the accuracy of this thermocouple is within a specified value when the thermocouple, which is a semi-consumable item, is replaced prior to actual measurement. The inspection method is a method of inspecting the accuracy of the thermocouple by measuring the oxygen activity of a standard sample with a known oxygen activity and inspecting how far the value deviates from the standard value.
"Standardization" does not only judge the quality of thermocouples,
Up to calibration of the thermocouple may be included. Note that the measurement procedure using the standard sample is the same as the actual measurement described later, and is therefore omitted here. At this stage, the remaining number of lifespans of the semi-consumables is also checked, and if any of the semi-consumables has reached its lifespan, the "semi-consumables check" screen is automatically displayed as shown in FIG. Then, the worker is prompted to replace the semi-consumable item. The service life check of each semi-consumable item may be performed immediately after the actual measurement step described below.

When "Measurement" is selected on the "Startup screen", the screen switches to the screen shown in FIG. 16 and shifts to the "measurement mode". On the "Measurement" screen, first enter a data name in alphabets and numbers to distinguish the measurement results of each sample. This data name is also used as the file name when writing to the floppy disk. Also on this screen,
The remaining number of life of each of the reaction tube, the crucible support (which is indicated as “support” in the figure) and the support protection tube, which are semi-consumables, is displayed.

<Setting Process of Metal Crucible and Oxygen Sensor> When the input of the data name is completed, the screen is switched to the screen shown in FIG. At this stage, the iron crucible 64 accommodating the sample to be measured is placed on the crucible support base 41 waiting outside the furnace, while the oxygen sensor 32 is attached to the cell chuck 31. When the sample to be measured is a metal, only the sample to be measured is contained in the iron crucible, but when the sample to be measured is a nonmetal such as slag or glass and is an insulator, the sample to be measured is A specific metal that, together with the substance, does not form an alloy with iron at least in an inert atmosphere and that does not easily generate an oxide and has a higher specific gravity than the sample to be measured,
For example, it contains silver or the like.

In this embodiment, the iron crucible 64 is mounted and the oxygen sensor 32 is mounted manually by the measurer, but these may be automatically supplied from a separately provided stocker. When the automatic supply mechanism is used, the placing of the iron crucible 64 and the mounting of the oxygen sensor 32 are completed only by the measurer giving an automatic supply command through the operation button. On the other hand, even in the case of manual work, the work is easy because the placement of the metal crucible and the mounting of the oxygen sensor are performed outside the furnace.

When the mounting of the iron crucible 64 on the crucible support base 41 and the mounting of the oxygen sensor 32 on the cell chuck 31 are completed, "START" at the lower left of the display screen is selected,
Start the actual measurement. When "START" is selected, it is first determined whether or not the iron crucible 64 and the oxygen sensor 32 are properly set before movement, and when an abnormality is detected, a warning such as a lamp blinking or a buzzer sounding is issued, while If it is normal, the iron crucible 64 is moved to a predetermined position in the furnace and stopped, and the setting is displayed graphically on the right side of the screen.

<Argon gas supply step, step of energizing heat source of heating furnace, step of maintaining argon gas filled state>
When the setting to the predetermined position in the furnace is completed, the electromagnetic valve is automatically opened and the argon gas is supplied into the reaction tube 60 for a predetermined time to fill the reaction tube 60 with the argon gas and at the same time to supply the cooling water and the cooling air. It is supplied to the furnace body 24 to prepare a cooling system for the heating furnace, and then the heat source of the concentrating heating furnace 20 is energized.

Then, under the control of the temperature controller, the heating is continued to bring the temperature in the furnace to a prescribed temperature based on the registered temperature rising pattern. Then, during the temperature raising process, the argon gas is continuously supplied into the reaction tube 60 to maintain the inside of the reaction tube 60 filled with the argon gas.

<Oxygen Sensor Inserting Step> When it is detected that the temperature has reached the specified measurement temperature, the oxygen sensor moving means 3
0 is activated to immerse the oxygen sensor 32 in the molten material in the metal crucible. This state is also graphically displayed on the screen.

<Step of displaying the measurement contents in real time while measuring> Simultaneously with the completion of immersion of the oxygen sensor 32, reading of the electromotive force from the oxygen sensor 32 is started, and the electromotive force data from the oxygen sensor 32 and the thermocouple are read. While storing the oxygen activity value and the sample temperature obtained by calculating the thermoelectromotive force data by the computer in the RAM, a graph showing changes in the oxygen activity value and the sample temperature is displayed in real time on the left side of the screen. Then, the end time of the measurement is automatically determined by the computer.

<Oxygen activity calculation step> The determination of the measurement end time and the calculation of the oxygen activity value are all processed by a computer, and this specific processing method is also a feature of the present invention. In calculating the oxygen activity value, it is important to find out the equilibrium portion as quickly as possible. However, the present invention is devised to find the equilibrium portion. 20 and 21 are explanatory views showing a method for reading an electromotive force detected by the oxygen sensor. This method is a method of evaluating the change width of the electromotive force for each measurement unit time having a constant time width with the current time as the reference time for the electromotive force curve that changes with the passage of time. As shown in FIG. 20, with an area Q divided by a constant time width ΔT and an allowable specified variation width ΔE of electromotive force being a unit,
While sequentially shifting this area Q in time, it is determined whether or not the change in the vertical axis of the electromotive force curve is within this area. If the measured value converges in the area Q, the oxygen activity value is calculated based on the measured data obtained in the area and the measurement is ended.

Depending on the measurement, the measured values may not converge within the area. In such cases, it is necessary to terminate the measurement at some stage. In the present invention, the maximum cumulative time of measurement time is set in advance, and when the cumulative total of measurement time reaches this time limit, the measurement work is forcibly aborted regardless of the content of the measured value. Even if the data does not fall within the specified value in this way, all the data is not meaningless and may be used if the assumption that the accuracy is poor is accepted. In order to handle such cases,
In the present application, when the measured value reaches the time limit without converging within the specified value, the oxygen activity value is targeted only at the measured data in which the variation width of the electromotive force converges within the specified value immediately before the end of measurement. Is calculated, and this value is used as the oxygen activity value for the retention.

In this way, all the measured data are stored in the RAM and can be recorded on a floppy disk or IC card as required. In addition, the measurement data may be transferred to the host computer using the serial communication interface. The measurement data recorded in the RAM or the floppy disk can be appropriately inquired by selecting "Data Inquiry" on the "Startup screen". FIG. 18 shows a case where the latest 30 measurement data items stored in the RAM are displayed in a list format.

<Oxygen sensor discharging step, reaction tube cooling step>
When the measurement is completed, if you return to the "start screen" and instruct "end", the oxygen sensor is automatically discharged from the inside of the furnace by the oxygen sensor moving means, returns to a predetermined position outside the furnace, and then stops. The operator manually removes these. Next, the power supply to the heat source of the heating furnace is stopped, and the electromagnetic valve is automatically opened to increase the supply amount of the argon gas into the reaction tube, thereby promoting the cooling of the reaction tube.

<Step of Discharging Iron Crucible, Supply of Cooling Water and Cooling Air> When the temperature in the reaction tube becomes lower than a predetermined temperature, the supply of argon gas is stopped and the crucible moving means 40 is operated to remove the iron crucible 64. All the work steps are completed by discharging and stopping the supply of cooling water and cooling air to the heating furnace.

[0063]

According to the present invention, the oxygen activity in the molten substance can be measured quickly and automatically. The automation of the measurement work significantly reduces the work load on the measurer, and the experience of the measurer is not required for the measurement, so that anyone can measure the oxygen activity. Further, since the work content and the operation content are displayed on a graphic screen that is easy to visually recognize, the work procedure can be easily understood, and by following the screen instructions, each step in the measurement work can be proceeded without error.

When a condensing type heating furnace is used as the heating furnace, the temperature can be rapidly raised, the temperature can be easily controlled, and impurities and the like are not scattered in the furnace.

When the remaining number of times the semi-consumable product has been used is checked, occurrence of measurement failure due to the degree of consumption of the semi-consumable product is prevented.

When a translucent touch panel is provided on the front surface of the graphic display to integrate the display means and the operating means, and the display content is made easy-to-recognize graphic information, the operation content and the processing content can be more easily grasped. And the operability is significantly improved.

[Brief description of drawings]

FIG. 1 is a front view of a main body device which is a central part of the device of the present invention.

FIG. 2 is a rear view of the main body device.

FIG. 3 is a perspective view of an open concentrating heating furnace viewed from the front side.

FIG. 4 is a perspective view of the closed condensing heating furnace seen from the back side.

FIG. 5 is an explanatory cross-sectional view showing a reaction tube installed in a concentrating heating furnace.

FIG. 6 is a main part explanatory view showing a main part of the main body device and showing a relationship between a concentrating heating furnace and a metal crucible waiting outside the furnace at a position in front of the concentrating heating furnace.

FIG. 7 is a side view illustrating an outline of crucible moving means and a movement path of a metal crucible moved by the crucible moving means.

FIG. 8 is a front explanatory view showing a moving path of the oxygen sensor by the oxygen sensor moving means.

FIG. 9 is an explanatory diagram of an air circuit

FIG. 10 is an explanatory diagram of an argon gas circuit.

FIG. 11 is a block diagram showing the electrical hardware configuration of the main device.

FIG. 12 is an explanatory diagram of a start screen

FIG. 13 is an explanatory diagram of an initialization menu screen

FIG. 14 is an explanatory diagram of an operation confirmation screen

FIG. 15 is an explanatory diagram of a standardized sample measurement screen.

[Figure 16] Illustration of the measurement screen

[Figure 17] Illustration of the measurement screen

FIG. 18 Explanatory diagram of data inquiry screen

FIG. 19 is an explanatory diagram of a semi-consumables check screen.

FIG. 20 is an explanatory diagram showing a method for reading an electromotive force.

FIG. 21 is an explanatory diagram showing a method for reading an electromotive force.

FIG. 22 is a cross-sectional explanatory view showing a principle diagram of an apparatus for measuring oxygen activity in slag, which the applicant has already proposed.

[Explanation of symbols]

S Slag M Specified metal a Concentrated heating furnace b Reaction tube c Iron crucible d Metal support stand e Solid electrolyte f Meter g Thermocouple h Meter A Main unit 1 Casing 2, 3 Box 4 Working space 5 Bottom plate 6 Panel 7 Collective display lamp 8 Floppy disk drive 9 Program reset switch 10 Regulator box 11 Main power switch 12 Control power switch 13 Heating furnace controller 14 Furnace power switch 15 Argon gas inlet 16 Dry air inlet 17 Cooling water outlet 18 Cooling water inlet 19 Ventilator 20 Concentrated heating furnace 21 Housing space 22 Infrared lamp 23 Infrared reflector 24 Furnace body 24a Furnace body fixed side piece 24b Furnace movable side piece 25 Cooling water hose 26 Cooling water piping hose 27 Cooling air piping 28 Electric power cable 30 Oxygen sensor Move Step 31 Cell chuck 32 Oxygen sensor 33 Cell chuck open / close switch 34 Horizontal moving device 35 Vertical moving device 40 Crucible moving means 41 Crucible supporting base 42 Horizontal moving device 43 Vertical moving device 50 Graphic touch panel 60 Reaction tube 61 Flange 62 Lower opening 63 Crucible protection Tube 64 Iron crucible 65 Support tube protection tube 66 Thermocouple 67 Inert gas inlet 70 Filter 71 Manual valve 72 Electromagnetic valve 80 Manual valve 81 Flow meter

Claims (5)

[Claims] 1. A heating furnace equipped with a cooling means, a reaction tube exchangeably installed in the heating furnace and filled with an inert gas therein, and a reaction tube installed in the heating furnace inside the object to be measured. A metal crucible containing a molten substance and an element for measuring the oxygen activity in the molten substance by being immersed in the molten substance at the time of measurement, which mainly comprises a solid electrolyte of a closed end type with a standard electrode. And an oxygen sensor, a temperature measuring means for directly or indirectly measuring the temperature of the molten substance, and a support base for the metal crucible, and the support base is vertically and horizontally mounted with the metal crucible placed. In a predetermined procedure, the metal crucible is reciprocated between a predetermined position in the heating furnace and a predetermined position outside the furnace to have a mechanism for setting and discharging the metal crucible to a fixed position, and the mechanism is To the support Has a crucible moving means which is controlled in association with the signal obtained from the means for detecting the placement state of the genus crucible, a mounting portion for detachably holding a proximal end of the oxygen sensor,
Further, the oxygen sensor held by the mounting portion is moved in a vertical and horizontal direction in a predetermined procedure, and the oxygen sensor is reciprocated between a predetermined position inside the heating furnace and a predetermined position outside the furnace to a fixed position of the oxygen sensor. And a mechanism for performing setting and discharging of the oxygen sensor, and the mechanism relates to an oxygen sensor moving means controlled in association with a signal obtained from a means for detecting the mounting state of the oxygen sensor on the mounting portion, Refrigerant supply / discharge means that supplies and discharges the cooling medium while controlling the timing, inert gas supply means that supplies the inert gas into the reaction tube while controlling the amount and timing, and supports the measurement target substance The temperature control pattern for controlling the heat source of the heating furnace based on the temperature increase pattern is registered, and the metal ruler having a function as a control electrode is registered. A crucible, a support for a metal crucible, a molten material, a solid electrolyte, and an oxygen sensor made of a conductive material. The conductive path is formed in the middle of the conductive path to form an electrically closed circuit. An electromotive force detection unit that detects the electromotive force generated in the closed circuit, and detects the measurement start timing based on the temperature measurement result of the molten substance, and continues to monitor the measurement value detected by the electromotive force detection unit. When the variation width of the measurement value with respect to the time axis converges within the specified value, the measurement management control unit that calculates the oxygen activity value using the converged data group, and the measurement value monitored by the measurement management control unit and A display having a measurement content display section for displaying the execution process in real time and the calculated oxygen activity value, and an operation content display section for visually displaying the operation procedure, operation items, etc. And a means for manually inputting operating conditions and inputting a start command to each means and each part, and a microcomputer for controlling the operation procedure of each means and each part. Inside oxygen activity measuring device. 2. The apparatus for measuring oxygen activity in a molten substance according to claim 1, wherein a condensing type heating furnace is used as the heating furnace. 3. The number of times of service life of a semi-consumable product such as a reaction tube is registered in advance, and a measurement executability judging unit is provided for comparing the number of times of measurement with the number of service times to judge whether or not the measurement can be performed. 1. An apparatus for measuring oxygen activity in a molten substance according to 1 or 2. 4. The melt according to claim 1, 2 or 3, wherein a translucent touch panel is arranged on the front surface of the graphic display to integrate the display means and the operating means, and the display content is made easy-to-recognize graphic information. Device for measuring oxygen activity in substances. 5. The oxygen activity measuring apparatus according to claim 1, wherein the step is to select the processing means of each unit and each unit constituting the oxygen activity measuring apparatus as a display means after the power of the apparatus body is turned on. Steps for displaying the start-up menu screen, initial setting step for registering condition settings or condition changes such as the service life of semi-consumables such as reaction tubes, final reached temperature in the furnace, and each means constituting the oxygen activity measuring device And the operation confirmation process in which the operation test of each part is forcibly performed before the actual measurement, and when the thermocouple is replaced, the accuracy of the thermocouple is checked using a standard sample with a known oxygen activity value. The judgment process, the process of checking the number of times the semi-consumables have been used, and issuing a warning if the remaining number is 0, and the metal crucible containing the substance to be measured on the support table of the crucible moving means waiting outside the furnace. The oxygen sensor is placed and is waiting outside the furnace. The step of mounting the oxygen sensor on the mounting part of the moving means, and when the start key is operated to give an actual measurement start command to the measuring device, the metal crucible and the oxygen sensor are moved to the predetermined position,
It is judged whether or not the robot is standing by in a predetermined posture, and if an abnormality is detected, a warning is issued, and if there is no abnormality, the crucible moving means is activated to set the metal crucible at a predetermined position in the reaction tube, and After confirming that the metal crucible has been set, an inert gas is supplied for a predetermined time to fill the inert gas in the reaction tube, and at the same time, a refrigerant is supplied into the heating furnace to start cooling the heating furnace, Further, under the process of energizing the heat source of the heating furnace and under the control of the temperature control means, the heating is continued so that the temperature inside the furnace reaches the specified temperature and the inside of the reaction tube is maintained filled with the inert gas. After detecting the process and reaching the specified measurement temperature, operate the oxygen sensor moving means to immerse the oxygen sensor in the molten substance in the metal crucible, and at the same time as the immersion is completed, the electromotive force from the oxygen sensor Starting the sampling, storing the electromotive force data and the temperature measurement data in the storage means, and displaying the content in real time on the measurement content display section of the display means. While judging whether the measured value has converged within the predetermined specified value within the time, if the value converges within the specified value, based on the measurement data obtained during the time When the oxygen activity value is calculated and the measurement is terminated, on the other hand, if it does not converge, the step of continuing the measurement with the time when the specified value is exceeded as the new reference time, and the cumulative measurement time are set in advance. When the time limit is reached, the measurement is terminated, and the oxygen activity value is calculated only for the measurement data in which the variation range of the electromotive force converges within the specified value immediately before the measurement ends. Value of temporary acid The step of setting the activity value, the step of recording the calculated oxygen activity value, and the step of incrementing or decrementing the counter of the number of lives of semi-consumables by one, and operating the oxygen sensor moving means to activate the oxygen sensor. The step of discharging, the step of stopping the energization of the heat source of the heating furnace, the step of increasing the supply amount of the inert gas into the reaction tube to promote the cooling in the reaction tube, and the temperature in the reaction tube below the predetermined temperature. At this stage, the supply of inert gas is stopped, the crucible moving means is activated to discharge the metal crucible, and the supply of refrigerant to the heating furnace is stopped, and the reset key is operated to display the display means. A method of returning the contents to the initial menu screen, and a method of measuring the oxygen activity in the molten substance, which comprises the steps of