JP2970313B2 - Apparatus for measuring oxygen activity in molten material and measuring method using the apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an oxygen activity in molten iron slag or molten steel slag, an oxygen activity in iron, a non-ferrous metal, a glass, etc. More specifically, the present invention relates to an apparatus for measuring oxygen activity in a molten material, which can quickly and automatically measure the oxygen activity in a non-metal, and a measuring method using the apparatus. In addition to minimizing the work load of the measurer, the measurement of the measurer's experience is no longer required, and anyone can reliably measure the oxygen activity. And a measuring method using the device.

[0002]

2. Description of the Related Art In a metal refining process and a non-metal manufacturing process, it is important to measure the oxygen activity in these molten materials. For example, in the iron making process, steelmaking slag exists in a suspended 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 the oxygen activity measurement in the steelmaking slag is extremely important. The measurement of the oxygen activity in the molten material is not limited to the iron making process, but is also useful in the refining process of general metals, and is also useful in the process of manufacturing non-metals such as glass.

[0003] The applicant of the present invention has already filed many applications for measuring oxygen activity in slag from such a viewpoint.
For example, there are proposals 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 installed in a condensing type heating furnace a, and a heating section in the reaction tube b is provided. An iron crucible c was placed on a metal support d, and a thermocouple g for temperature measurement was placed in the support d, and the temperature-sensitive part of the thermocouple g was brought close to the lower surface of the iron crucible c. At the time of measurement, a specific metal M which does not form an alloy with iron at least under an inert atmosphere, hardly generates an oxide, and has a higher specific gravity than the slag S is used in the measurement. Along with the slag S to be measured is housed in a molten state together with the slag S, the solid electrolyte e having the standard electrode therein is immersed in the specific metal M and the slag S which have been brought into a molten state by heating the condensing type heating furnace a, Electromotive force between iron crucible c also serving as control electrode and 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. By knowing the iron oxide activity in the slag in this way, it has become possible to infer a reaction of phosphorus or sulfur which is not very desirable for products.

[0004] The present applicant has filed the above-mentioned application (Japanese Patent Application No. 1-271033).
Japanese Patent Application No. 3-5141 and Japanese Patent Application No. 3-181948 propose partial improvements of various parts while following the basic structure of the above-mentioned Japanese Patent Application.

[0005]

The oxygen activity measuring device proposed by the present applicant makes it possible to measure the oxygen activity in slag, and when the substance to be measured is an insulator, the same as in slag. It becomes possible to measure the oxygen activity in the molten material by following the above-mentioned principle as it is, and when the substance to be measured is a conductive material, the oxygen activity in the molten metal can be obtained without using the specific metal. Although it was possible to measure the quantity, the above-mentioned apparatus still had problems to be solved.

That is, in the oxygen activity measuring device,
Basically, all operations are performed by manual operation of the measurer or direct operation of the operation panel, and the measurement procedure is successful because the operation procedure and operation timing of each part of the device depend on the operation of the measurer. Whether or not the measurement is performed depends on the experience of the measurer, and no one can easily measure under the same conditions. Further, even an experienced measurer has difficulty in repeatedly performing measurement under the same conditions, and there has been a problem that measurement conditions are not stable. In addition, the above-described device requires complicated device operation, which may lead to an erroneous operation procedure. In addition, since the operation requires concentration, the operator is tired.

The present invention has been made in view of the above situation, and can automate almost all operations involved in oxygen activity measurement, and sets a metal crucible containing a substance to be measured at a predetermined position in the apparatus. By simply processing the subsequent work procedures sequentially, it is possible to automatically perform the calculation of the target oxygen activity value, so that anyone can always measure the oxygen activity under the same conditions regardless of experience. It is an object of the present invention to provide an apparatus capable of measuring the oxygen activity and a method for measuring oxygen activity using the apparatus.

[0008]

The oxygen activity measuring apparatus of the present invention which has solved the above-mentioned problems has the following construction. A heating furnace provided with a cooling means; and exchangeably installed in the heating furnace;
A reaction tube filled with an inert gas inside; a metal crucible installed in the heating furnace and containing a molten substance to be measured inside; and immersed in the molten substance at the time of measurement,
An oxygen sensor for measuring the oxygen activity in the molten material, which is mainly composed of a solid electrolyte with a closed end and a standard electrode, and a temperature measuring means for directly or indirectly measuring the temperature of the molten material. Having a support for the metal crucible, and moving the support in a vertical and horizontal direction in a predetermined procedure with the metal crucible mounted thereon, and moving the metal crucible at a predetermined position inside the heating furnace and at a predetermined position outside the furnace; And a mechanism for setting and discharging the metal crucible to a fixed position by reciprocating between the two, and the mechanism relates to a signal obtained from a means for detecting a mounting state of the metal crucible on the support base. Controlled crucible moving means; a mounting portion for detachably holding a base end of the oxygen sensor, and moving the oxygen sensor held by the mounting portion vertically and horizontally in a predetermined procedure, A mechanism for setting and discharging the oxygen sensor to a fixed position by reciprocating the oxygen sensor between a predetermined position inside the heating furnace and a predetermined position outside the furnace, and the mechanism includes an oxygen sensor An oxygen sensor moving means controlled in association with a signal obtained from a means for detecting a mounting state; a refrigerant supply / discharge means for supplying / discharging a cooling medium into / from a heating furnace while controlling its timing; An inert gas supply means for supplying the inert gas while controlling the amount and timing thereof; a heating pattern corresponding to the substance to be measured is registered, and the heat source of the heating furnace is controlled based on the heating pattern A temperature control unit to perform; the metal crucible having a function as a reference electrode;
A support for a metal crucible, a molten substance, a solid electrolyte, disposed in the middle of a conductive path formed by a mounting portion of an oxygen sensor made of a conductive material, the conductive path being an electric closed circuit, and the electric closed circuit being An electromotive force detection unit for detecting an electromotive force generated in the apparatus; detecting a measurement start timing based on a temperature measurement result of the molten substance, and continuously monitoring a measurement value detected by the electromotive force detection unit; When the variation width of the time axis with respect to the time axis converges within a specified value, a measurement management control unit that calculates an oxygen activity value using the converged data group; a measurement value and an execution process monitored by the measurement management control unit Display means having a measurement content display section for displaying the calculated oxygen activity value while displaying the data in real time, and an operation content display section for visually displaying the operation procedure and operation items; 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 viewpoint of rapid temperature rise and easy temperature control.

The display means and the operation means may be provided independently. However, from the viewpoint of simplicity of operation, it is preferable to dispose a translucent touch panel on the front of the graphic display and integrate the display means and the operation means. It is preferable to use graphics that can easily recognize the contents displayed on the display.

[0011]

The oxygen activity measuring device having the above configuration is used as follows. First, when the power supply of the apparatus main body is turned on, a menu screen for selecting processing means of each means and each part constituting the oxygen activity measuring apparatus is displayed on the display means.
When the apparatus is used for the first time or when various setting conditions are changed, the initial setting is performed by inputting the number of service times of the semi-consumables such as the reaction tubes and the final temperature in the furnace.

Next, before starting the actual measurement, an operation test of each means and each part constituting the apparatus is forcibly performed to confirm that there is no abnormality in the apparatus. In addition, the thermocouple is continuously used without being replaced each time at the time of measurement, but needs to be replaced when it deteriorates. When replacing the thermocouple, confirm the accuracy of the thermocouple using a standard sample whose oxygen activity value is known,
Only those with an acceptable margin of error are used. The initial setting and the operation check are not performed every time the measurement is performed, but are performed once a day or performed as needed. At the same time as checking the accuracy of the thermocouple, the remaining usable number of semi-consumables is checked.
If it does, a warning will be issued to prompt the replacement of the corresponding semi-consumable item. The check of the remaining number of semi-consumables may be performed immediately after the mode shifts to the actual measurement mode described later.

When the above-mentioned preparation work is completed, actual measurement is started. The actual measurement is performed in the following procedure. First, a metal crucible containing a substance to be measured is placed on the support stand of the crucible moving means waiting outside the furnace, and an oxygen sensor is also mounted on 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. However, 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 addition, a specific metal which does not form an alloy with the material of the metal crucible under an inert atmosphere, hardly generates an oxide, and has a higher specific gravity than the substance to be measured is contained in a molten state. After the above operation, there is almost no manual operation by the measurer except for the key operation of the operation panel, and only the work of disposing of the metal crucible and the oxygen sensor at the end of the measurement is left.

Next, when the start key is operated to give an actual measurement start command to the measuring device, it is automatically determined whether or not the metal crucible and the oxygen sensor are set at a predetermined position and a predetermined posture. If detected, a warning is issued. On the other hand, if there is no abnormality, the metal crucible is moved vertically and horizontally by the crucible moving means and set 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, an inert gas is supplied for a predetermined time, and the reaction tube is filled with the inert gas. Next, the cooling medium is supplied into the heating furnace to start cooling the heating furnace, and at the same time, energization to the heat source of the heating furnace is started to start heating the metal crucible. The heating furnace prevents the furnace body from being excessively heated by the supply of the refrigerant.

The heating of the heating furnace is performed under the control of the temperature control means, and the temperature in the furnace is quickly brought to a specified temperature by maintaining the heating. During this time, the inside of the reaction tube is maintained in a state filled with the inert gas.

When the temperature in the reaction tube reaches a 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 the 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 to the predetermined depth is completed, and while the electromotive force data and the temperature measurement data that change every moment are stored in the storage means, the data contents are measured by the display means. Display in real time on the display.

At the same time when 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 stops the measurement when it is determined that the electromotive force data has been equilibrated. Calculate the amount. This method
With the current time as the reference time, while determining whether the measured value has converged within a predetermined value within a predetermined time, if the value has converged within a predetermined value, The oxygen activity value is calculated based on the measurement data obtained within the time period, and the measurement is terminated.On the other hand, when the measurement does not converge, the measurement is continued with the time when the value exceeds the specified value as a new reference time. The content is to do. When the total of the measurement time reaches a predetermined time limit without equilibrium of the electromotive force data, the measurement is terminated, and the variation range of the electromotive force converges within a specified value immediately before the end of the measurement. An oxygen activity value is calculated only for the measured data, and this value is used as a temporary oxygen activity value.

Then, the calculated oxygen activity value is recorded, and the counter of the number of times of use of the semi-consumable is added or subtracted by one to update the remaining number of times of use.

When the measurement is completed, the oxygen sensor and the metal crucible are taken out. The removal is performed in 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 cooling of 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. Subsequently, the crucible moving means is operated to discharge the metal crucible to the outside of the furnace. Then, the supply of the refrigerant to the heating furnace is stopped and the discharge operation of the metal crucible is completed.

Thereafter, the display content of the display means is returned to the initial menu screen, and at the same time, the available remaining number of semi-consumables is checked at this stage. If it does, a warning is issued to urge replacement of the corresponding semi-consumable.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The components constituting the apparatus of the present invention include 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 divided into display means, operation means, and a microcomputer for control. Hereinafter, these details will be described based on the embodiment of the illustrated example.

FIG. 1 is a front view of a main unit which is a central portion of the apparatus of the present invention, and FIG. 2 is a rear view. Although not shown, a coolant supply cylinder, an inert gas supply cylinder, a cooling water supply tank or a water source are provided outside the main unit A, and these are connected to the main unit A via a pipe to form an overall system. Make up the device.

The main unit A is arranged in a vertically long casing. The casing 1 has upper and lower boxes 2 and 3 in which various device groups are housed. The casing 1 is located between the boxes 2 and 3 and is suitable for performing a manual operation in a normal posture with the worker standing. The work space 4 is provided at the position where the work space is located. The bottom plate 5 that partitions the lower surface of the work space 4 is shared with the top plate of the box 3.

In the work space 4, a condensing type heating furnace 20 is arranged, and above the work space 4, an oxygen sensor moving means 30 is provided.
On the other hand, a 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 table 41 associated with the crucible move means 40 are mounted on the work space 4. Is located within. 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.

On the front panel of the upper box 2, a graphic touch panel 50 serving as a display means and an operation means is arranged, while on the front panel of the lower box 3, the supply and discharge amounts of cooling water, air and argon gas are adjusted. A regulator box 10, a main power switch 11, and a control power switch 12 are provided. In the figure, reference numeral 13 denotes 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 a front panel of the heating furnace controller 13 together with a level meter. In this embodiment, an ammeter is used as a 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 the lower portion of the rear surface of the casing. Ventilation device 19 is arranged. Hereinafter, the main components will be described.

As shown in FIG.
A furnace body 24 having a housing space 21 for housing a cylindrical reaction tube at the center thereof and having an infrared lamp 22 and an infrared reflecting plate 23 arranged around the housing space 21 is formed in half. One of the half-shaped furnace bodies is formed as a furnace body fixed side piece 24a fixed to the casing side wall, and the other is formed as a furnace body movable side piece 24b. The furnace body movable side piece 24b is attached to the furnace body fixed side piece 24a via a hinge or the like so as to be openable and closable, so that the internal maintenance and cleaning can be performed as necessary.

A water passage having a cooling water hose 25 exposed outside as a return path is formed inside the furnace body of the condensing type heating furnace 20, and a cooling water pipe attached to the back of the furnace body as shown in FIG. Cooling water supplied through the hose 26 is circulated through the furnace so that excessive heating of the furnace during heating can be prevented. Further, an air passage is also formed in the furnace body 24, and cooling air is directly blown from the outside of the furnace body to the infrared lamp 22 through a cooling air pipe 27, whereby
The infrared lamp 22 is prevented from being damaged due to excessive temperature rise. A power cable 28 for supplying power to the infrared lamp is also connected to the back of the furnace.

The condensing type heating furnace 20 has the advantages of being capable of rapidly raising the temperature, of being easy to control the temperature, of being less affected by noise and the like on the measuring system, and being capable of keeping the measuring environment clean. Although used, other heating furnaces such as a high-frequency induction heating furnace can be used.

As shown in FIG. 5, flanges 61, 61 are vertically arranged in the accommodation space 21 of the condensing type heating furnace 20.
Is inserted in a semi-fixed state, and the inside thereof can be filled with an inert gas such as argon gas through an inert gas inlet 67. The reaction tube 60 is made of a transparent heat-resistant material such as quartz, and has upper and lower openings. Through a lower opening 62, an iron crucible 64 with a crucible protection tube 63 is attached to the support base protection tube 65. It is configured to be able to appear and disappear with being placed on the crucible support table 41 that has been mounted. The first reason that the crucible protection tube 63 is configured differently from the support base protection tube 65 is that there is a remarkable difference in the degree of contamination between the peripheral portion of the iron crucible and the portion surrounding the crucible support base 41. This is because the service life of the support base protection tube 65 can be increased by allowing only the tube 63 to be appropriately replaced. Although the heating of the iron crucible 64 is necessary, it is not always necessary to heat the crucible support 41, and it may be more convenient to prevent the temperature of the crucible support 41 from rising. Is a crucible protection tube 6
Reference numeral 3 denotes a quartz tube having a high transmittance.
The heat generation can be controlled by selectively using a quartz tube having a low transmittance. This is the second reason for making the crucible protection tube 63 different from the support base protection tube 65. A thermocouple 66 for indirectly measuring the temperature of the sample in the iron crucible is provided inside the crucible support 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 a position in front of the condensing type heating furnace 20. The concentrating heating furnace 20 can be opened and closed, but does not open and close except when the reaction tube 60 is replaced or the furnace body 24 is adjusted. The insertion and discharge of the crucible performed for each measurement is performed by the condensing type heating furnace 20. The oxygen sensor 32 is inserted and ejected from below the heating furnace 20 while the oxygen sensor 32 is inserted and ejected from above the concentrating heating furnace 20.

The iron crucible 64 has a function of accommodating the substance to be measured and a function of a reference electrode at the time of measuring the electromotive force. Although an iron crucible is used here, other metal crucibles can be used. The iron crucible 64 covered by the crucible protection tube 63 is placed on the crucible support 41, and by operating the crucible moving means 40, a predetermined position outside the furnace is placed on the crucible support 41. From the furnace to a predetermined position in the furnace. Although not shown, a light emitting 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. It is configured so that you can check the right or wrong.

The oxygen sensor 32 is an oxygen sensor moving means 30
Is held in a suspended state by a cell chuck 31 attached to the furnace, and is moved from a stand-by position outside the furnace to a predetermined position in the furnace by the oxygen sensor moving means every time measurement is performed. 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 so as to sandwich the oxygen sensor 32, and an appropriate hanging position of the oxygen sensor 32 is used as an optical path, so that the oxygen sensor 32 It is configured to check whether the drooping condition is right or wrong. The standby position outside the furnace for the iron crucible 64 and the oxygen sensor 32 is set to a position in front of the condensing type heating furnace 20 so that manual operation by an operator is easy, but this position is another position. Well,
Alternatively, these may be automatically supplied sequentially from a stocker of an iron crucible or an oxygen sensor without manual setting.

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

The crucible moving means 40 comprises a horizontal moving device 42 and a vertical moving device 43, and the horizontal and vertical movement of the iron crucible 64 is enabled by combining the movements of these two devices. FIG. 7 is an explanatory side view schematically showing the crucible moving means 40 and its movement. Horizontal moving device 4
A linear drive mechanism associated with an air cylinder is used as the second and vertical movement devices 43, and these mechanisms are all housed below the bottom plate 5. When setting the iron crucible 64 at a predetermined position in the furnace, the iron crucible 64 is moved in the direction indicated by the outline arrow in the figure, while when the iron crucible 64 is discharged out of the furnace, along the direction indicated by the thin arrow in the figure. 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 41 is stopped at a position in front of the condensing type heating furnace 20. (II) Next, when the iron crucible 64 containing the sample is placed on the crucible support 41 and the operation button is operated, the crucible support 41 is lowered by the vertical moving device 43 to a position below the bottom plate 5. The iron crucible 64 is lowered. (III) Subsequently, the crucible support 4 is moved by the horizontal moving device 42.
1 is moved horizontally to position the iron crucible 64 immediately below the reaction tube 60 of the condensing type heating furnace 20. (IV) Finally, the crucible support 4 is moved by the vertical moving device 43.
Then, the iron crucible 64 is positioned at a predetermined position in the reaction tube and stopped. The discharge of the iron crucible 64 from the reaction tube 60 is performed by following the above procedure in reverse.

FIG. 8 shows a moving mechanism and a moving procedure of the oxygen sensor 32. Similarly to the crucible moving means 40, the oxygen sensor moving means 30 also includes a horizontal moving device 34 and a vertical moving device 35. The outline of the operation procedure is
It is as follows. (I) First, the oxygen sensor 32 is mounted on the cell chuck 31 stopped at a 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. (III) Next, the horizontal moving device 34 operates to move the oxygen sensor 32 in the horizontal direction and stop at the position above the reaction tube. (IV) Subsequently, the oxygen sensor 3 is moved by the vertical moving device 35.
2 is lowered into the reaction tube 60, and the oxygen sensor 32 is immersed in the substance to be measured and stopped.

As for the moving procedure of the crucible moving means 40 and the oxygen sensor moving means 30, other methods can of course be considered as long as they can reciprocate between a predetermined position outside the furnace and a predetermined position inside the furnace. The supply path of the air that is the driving 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
One is supplied to a crucible moving means (crucible drive) and an oxygen sensor moving means (cell drive) via a manual valve 71 and an electromagnetic valve 72 arranged in the regulator box 10, and the other is supplied to the furnace body. The air is supplied to the condenser heating furnace 20 as cooling air.

FIG. 10 is an argon gas circuit showing a supply path of the argon gas into the reaction tube set in the condenser heating furnace 20. The argon gas is used for both the purpose of preparing the measurement environment by making the inside of the reaction tube inert and to increase the supply amount after the measurement is completed, thereby rapidly cooling the inside of the reaction tube. The supply route is 2 corresponding to these two types of applications.
It is divided into strains. That is, after the gas path supplied from the gas cylinder installed outside the main device is branched into two systems, one is supplied into the reaction tube via the manual valve 80 and the flow meter 81 in the regulator box 10,
The other is configured to be introduced into the reaction tube via another path via another electromagnetic valve, and that the cooling of the reaction tube can be promoted by supplying a large amount of argon gas through both paths at the end of the measurement.

The above has been a description of the main parts of the mechanical configuration of the apparatus of the present invention. The electrical system diagram of the apparatus of the present invention is shown in FIG. The electrical system of the device of the present invention is configured by connecting various device groups around a microcomputer (hereinafter, referred to as a computer). Computers have
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 /
On the other hand, a sequencer, a relay unit for controlling contact points of various driving 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 of the heat source of the condensing type heating furnace 20 based on data from the thermocouple 66. Further, the computer determines the measurement start timing based on the data from the thermocouple 66, and continuously monitors 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 has the function of the measurement management control unit.

The computer has a ROM for storing programs such as a monitor program and a startup program, and a RAM for making the control program resident and for temporarily storing data.
Equipped. It also has a floppy disk drive (FDD) and IC card for 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 a display device, a liquid crystal display device (LC
A graphic touch panel formed by laminating a translucent touch panel on the front surface of D) is used. The graphic touch panel displays the current processing content and measurement data graphically so that it is easy to confirm visually.
Various operation instructions can be directly specified on the screen by touching the corresponding portions on the surface. In this embodiment, a color liquid crystal is used from the viewpoint of abundant display information amount and visibility of display contents.

The present invention has a special feature in the display contents on the display device. The display device has a measurement content display function for displaying data measured by an oxygen sensor or a thermocouple and a calculation result, and an operation content display function for visually displaying operation procedures, operation items, and the like. Corresponds almost to the contents of the work process. Hereinafter, the measurement method using the apparatus of the present invention will be described while explaining the display examples shown in FIGS. 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 at the time of starting up the apparatus, in which various modes that can be selected immediately after the power is turned on are displayed. When a corresponding item is selected on this screen, the screen is switched to the corresponding mode screen, and various operations are displayed and guided in an interactive manner on a graphic screen. 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 product, is set in the condensing type heating furnace 20, and the thermocouple and the support base protection tube 65 are placed outside the furnace in the crucible support 41. Then, when "initial setting" is selected, the screen is switched to an "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 allowable error of the equilibrium reading of the electromotive force obtained by the oxygen sensor, the reaction tube which is a semi-consumable, the thermocouple (in the figure, The number of durable times of the “thermocouple for temperature control” and the support base protection tube (displayed as “crucible base protection tube” in the figure) is set. The figure shows a state in which the temperature increase patterns of 1400 ° C. and 1450 ° C. are registered, and also shows a state in which a prescribed value is displayed on the left side and the remaining number is displayed on the right side as the number of times the semi-consumables are used. When the registration of each initial value is completed, "menu" is selected and the screen returns to the "start screen".

<Operation Test Step> When "operation check" is selected in the "start screen", the screen switches to the "operation check" screen as shown in FIG. This screen mode is a mode for forcibly performing an operation test on whether or not each unit and each unit normally operates before the actual measurement. In this operation check mode, in addition to the driving test of the oxygen sensor moving means (shown as “elevating device” in the figure) and the crucible moving means (shown as “elevating device” in the figure), supply and discharge of cooling water, cooling air, and argon gas Control is also performed. The supply / discharge control is performed, for example, by touching the “furnace cooling water / air” button, inverting the display item in yellow, starting the supply of these items, and displaying the “cooling air pressure” displayed beside the display item. The operation is performed by operating a manual valve or a main valve in the regulator box 10 while monitoring the gauges of "" and "Cooling water pressure". It is recommended that this “operation check” is always performed prior to the actual measurement. In this mode, the normal state of all parts of the apparatus is checked, and then the process proceeds to the next work process.

<Thermocouple Pass / Fail Judgment Step> When "Standardization" is selected in the "Start screen", the screen is switched to the "Standardized sample measurement" screen as shown in FIG. "Standardization"
Can be said to be a thermocouple pass / fail determination step. “Standardization” is a step of checking whether or not the accuracy of the thermocouple is within a specified value when the thermocouple, which is a semi-consumable, is replaced, before the actual measurement. The inspection method is a method for measuring the accuracy of a thermocouple by measuring the oxygen activity of a standard sample whose oxygen activity is known, and inspecting how far the value deviates from the standard value.
"Standardization" does not just determine the quality of a thermocouple,
It may include even thermocouple calibration. Note that the measurement procedure using the standard sample is the same as the actual measurement described later, so that the description is omitted here. At this stage, a check is also made on the remaining number of times of use of the semi-consumables. If any of the semi-consumables has reached the number of uses, the "Semi-consumables check" screen is automatically displayed as shown in FIG. As a result, the operator is prompted to replace the semi-consumables. The service life check of each semi-consumable item may be performed immediately after shifting to the actual measurement process described later.

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

<Setting Step 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 containing the sample to be measured is placed on the crucible support 41 waiting outside the furnace, and the oxygen sensor 32 is attached to the cell chuck 31. When the sample to be measured is metal, only the sample to be measured is stored 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 Along with the substance, a specific metal that does not form an alloy with iron at least under an inert atmosphere and hardly generates an oxide and has a higher specific gravity than the sample to be measured,
For example, silver is stored.

In this embodiment, the placing of the iron crucible 64 and the attachment of the oxygen sensor 32 are manually performed by the measurer, but they may be automatically supplied from a separately provided stocker. When the automatic supply mechanism is used, the placement of the iron crucible 64 and the attachment of the oxygen sensor 32 are completed only by the measurer giving an automatic supply command using the operation buttons. On the other hand, even when the work is performed manually, 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 placement of the iron crucible 64 on the crucible support 41 and the attachment of the oxygen sensor 32 to the cell chuck 31 are completed, "START" at the lower left of the display screen is selected.
Start actual measurement. When “START” is selected, it is first determined whether or not the iron crucible 64 and the oxygen sensor 32 are correctly set before moving, and when an abnormality is detected, a warning such as a lamp blinking or a buzzer is sounded. In the normal case, the iron crucible 64 is moved to a predetermined position in the furnace and stopped, and the setting is graphically displayed on the right side of the screen.

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

Next, under the control of the temperature control unit, the heating is continued to make the furnace temperature reach a specified temperature based on the registered temperature rising pattern. Then, during this heating process, the argon gas is continuously supplied into the reaction tube 60, and the state where the inside of the reaction tube 60 is filled with the argon gas is maintained.

<Oxygen sensor insertion step> If it is detected that the specified measurement temperature has been reached, the oxygen sensor moving means 3
Activate O to immerse the oxygen sensor 32 in the molten material in the metal crucible. This situation is also graphically displayed on the screen.

<Step of Real-Time Display of the Measurement Contents While Measuring> Simultaneously with the completion of the 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 data are read. 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 while storing the oxygen activity value and the sample temperature obtained by arithmetically processing the thermoelectromotive force data by the computer in the RAM. 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 how to find the equilibrium portion quickly, but in the present invention, a method for finding the equilibrium portion is devised. FIGS. 20 and 21 are explanatory diagrams illustrating a method of reading an electromotive force detected by an oxygen sensor. This method is a method of evaluating an electromotive force curve that changes with the passage of time, and evaluating a change width of the electromotive force for each measurement unit time having a certain time width with the current time as a reference time. As shown in FIG. 20, an area Q defined by a fixed time width ΔT and a prescribed change width ΔE of an allowable electromotive force is used as 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 falls within this area. If the measured value converges in the area Q, the oxygen activity value is calculated based on the measurement data obtained in the area Q, and the measurement ends.

Also, depending on the measurement, the measured value may not converge in the area forever. In such a case, it is necessary to terminate the measurement at a certain stage. In the present invention, the maximum total time of the measurement time is determined in advance, and when the total of the measurement time reaches the time limit, the measurement operation is forcibly terminated regardless of the content of the measurement value. Even if the data does not fall within the specified value, all data are not meaningless and may be used if the premise that accuracy is poor is accepted. To deal with such cases,
In this application, when the measured value reaches the time limit without converging within the specified value, the oxygen activity value is measured only for the measurement data in which the variation range of the electromotive force converges within the specified value immediately before the end of the measurement. Is calculated, and this value is used as the oxygen activity value for keeping the retention.

The data thus measured are all stored in the RAM, and can be recorded on a floppy disk or an IC card as needed. In some cases, measurement data is transferred to a host computer using a serial communication interface. The measurement data recorded in the RAM or on the floppy disk can be queried as appropriate by selecting "Data query" on the "Start screen". FIG. 18 shows a case where the latest 30 measured data stored in the RAM are displayed in a list format.

<Oxygen sensor discharging step, reaction tube cooling step>
When the measurement is completed, returning to the "start screen" and instructing "end", the oxygen sensor is automatically discharged from the furnace by the oxygen sensor moving means from the inside of the furnace, returns to a predetermined position outside the furnace, and stops. These are manually removed by the operator. 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 argon gas into the reaction tube, thereby promoting 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 equal to or lower than the predetermined temperature, the supply of argon gas is stopped, and the crucible moving means 40 is operated to remove the iron crucible 64. Discharge and stop the supply of cooling water and cooling air to the heating furnace to complete all work steps.

[0063]

According to the present invention, the oxygen activity in a molten material can be measured quickly and automatically. In addition, since the measurement work is automated, the work load of the measurer is remarkably reduced, and the experience of the measurer is not questioned at the time of measurement, so that anyone can measure the oxygen activity. In addition, since the work contents and operation contents are displayed on an easily visible graphic screen, it is easy to understand the work procedure, and each step in the measurement work can be performed without error by following the screen instructions.

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 no impurities or the like are scattered in the furnace.

When the remaining number of the service life of the semi-consumable is checked, the occurrence of measurement failure due to the degree of consumption of the semi-consumable is prevented.

When a translucent touch panel is arranged on the front of the graphic display to integrate the display means and the operation means, and the display contents are easily recognizable graphic information, it is easier to grasp the operation contents and processing contents. And the operability is significantly improved.

[Brief description of the 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 unit.

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

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

FIG. 5 is an explanatory sectional view showing a reaction tube installed in a condensing type heating furnace.

FIG. 6 is an explanatory view of a main part of a main body device, showing a relationship between a concentrating heating furnace, a metal crucible standing outside the furnace at a position in front of the concentrating heating furnace, and an oxygen sensor;

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

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

FIG. 9 is an explanatory diagram of a pneumatic circuit.

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

FIG. 11 is a block diagram showing an electrical hardware configuration of a 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 check screen.

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

FIG. 16 is an explanatory diagram of a measurement screen.

FIG. 17 is an explanatory diagram of a measurement screen.

FIG. 18 is an explanatory diagram of a data inquiry screen.

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

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

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

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

[Explanation of symbols]

S Slug M Specific metal a Concentrated heating furnace b Reaction tube c Iron crucible d Metal support base e Solid electrolyte f Meter g Thermocouple h Meter A Main unit 1 Casing 2, 3 Box 4 Work space 5 Bottom plate 6 Panel 7 Collective indicator 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 DESCRIPTION OF SYMBOLS 20 Condensing type heating furnace 21 Housing space 22 Infrared lamp 23 Infrared reflector 24 Furnace body 24a Furnace body fixed side piece 24b Furnace body movable side piece 25 Cooling water hose 26 Cooling water piping hose 27 Cooling air piping 28 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 support 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 base protection tube 66 thermocouple 67 inert gas inlet 70 filter 71 manual valve 72 solenoid valve 80 manual valve 81 flow meter

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-94673 (JP, A) JP-A-4-331364 (JP, A) JP-A-3-131748 (JP, A) 58360 (JP, U) Hira 4-97837 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) G01N 27/411

Claims (5)

(57) [Claims] 1. A heating furnace provided with a cooling means, a reaction tube which is exchangeably installed in the heating furnace and is filled with an inert gas, and a reaction tube which is installed in the heating furnace and has a measurement object therein. A metal crucible containing a molten substance, and an element that is immersed in the molten substance at the time of measurement to measure the oxygen activity in the molten substance. An oxygen sensor, a temperature measuring means for directly or indirectly measuring the temperature of the molten substance, and a support for the metal crucible, and the support with the metal crucible placed on the support in vertical and horizontal directions. In a predetermined procedure, the metal crucible has a mechanism for reciprocating between a predetermined position in the heating furnace and a predetermined position outside the furnace to set and discharge the metal crucible to a fixed position, and the mechanism, 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,
And the oxygen sensor held by the mounting portion is moved in a predetermined procedure in the vertical and horizontal directions, and the oxygen sensor is reciprocated between a predetermined position in the heating furnace and a predetermined position outside the furnace to a fixed position of the oxygen sensor. An oxygen sensor moving means controlled in association with a signal obtained from a means for detecting a state of attachment of the oxygen sensor to the mounting portion, and Refrigerant supply / discharge means for supplying / discharging the cooling medium while controlling its timing, inert gas supply means for supplying the inert gas into the reaction tube while controlling its amount and timing, and corresponding to the substance to be measured A temperature control unit that controls the heat source of the heating furnace based on the temperature increase pattern, and a metal control unit that has a function as a control electrode. A pot, a support for a metal crucible, a molten substance, a solid electrolyte, and a conductive path formed by a mounting portion of an oxygen sensor made of a conductive material. An electromotive force detection unit for detecting an electromotive force generated in the closed circuit; and detecting a measurement start timing based on a temperature measurement result of the molten substance and continuously monitoring a measurement value detected by the electromotive force detection unit. When the variation width of the measured value with respect to the time axis converges within a specified value, a measurement management control unit that calculates an oxygen activity value using the converged data group, and a measurement value monitored by the measurement management control unit and A display unit having a measurement content display unit for displaying the execution process in real time and displaying the calculated oxygen activity value, and an operation content display unit for visually displaying the operation procedure and operation items, etc. A molten substance, comprising: an operating means for manually inputting an input of an operating condition, a start command, and the like to each of the means and each part, and a microcomputer for controlling an operation procedure of each of the means and each part. Oxygen activity measurement device inside. 2. The apparatus for measuring oxygen activity in a molten material according to claim 1, wherein a condensing type heating furnace is used as the heating furnace. 3. The use count of a semi-consumable such as a reaction tube is registered in advance, and a measurement execution availability determination unit is provided for comparing the measurement count with the use count to determine whether the measurement can be executed. 3. The apparatus for measuring oxygen activity in a molten substance according to 1 or 2. 4. The melting device according to claim 1, wherein a translucent touch panel is arranged on the front of the graphic display to integrate the display means and the operation means, and the displayed contents are easily recognizable graphic information. A device for measuring oxygen activity in substances. 5. An apparatus for measuring oxygen activity according to claim 1, wherein in the step, after turning on the power supply of the apparatus main body, the processing means of each means and each part constituting the oxygen activity measuring apparatus are selected on a display means. A step of displaying a start menu screen, an initial setting step of registering a condition setting or a condition change such as a service count of semi-consumables such as a reaction tube, and a final temperature in a furnace, and various means constituting an oxygen activity measuring apparatus. And an operation check step of forcibly performing an operation test of each part prior to actual measurement, and a thermocouple quality check for checking the accuracy of the thermocouple using a standard sample whose oxygen activity value is known when the thermocouple is replaced A judgment step, a step of checking the service life of the semi-consumables and issuing a warning if the remaining number is zero, and a step of placing the metal crucible containing the substance to be measured on the support stand of the crucible moving means waiting outside the furnace. With the oxygen sensor mounted and waiting outside the furnace Mounting the oxygen sensor on the mounting portion of the moving means, and operating the start key to give an actual measurement start command to the measuring device, the metal crucible and the oxygen sensor are positioned at predetermined positions,
It is determined whether or not the vehicle is standing by in a predetermined position, and if an abnormality is detected, a warning is issued.If there is no abnormality, the crucible moving means is operated to set the metal crucible to a predetermined position in the reaction tube. After confirming that the metal crucible has been set, an inert gas is supplied for a predetermined time to fill the reaction tube with the inert gas, and at the same time, a coolant is supplied into the heating furnace to start cooling the heating furnace, And a step 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 in the furnace reaches a predetermined temperature, and the inside of the reaction tube is maintained in a state filled with an inert gas. After detecting that the specified measurement temperature has been reached, the oxygen sensor moving means is operated to immerse the oxygen sensor in the molten material in the metal crucible, and simultaneously with the completion of the immersion, the electromotive force from the oxygen sensor is reduced. Starting the sampling, storing the electromotive force data and the temperature measurement data in the storage means, and displaying the contents in real time on the measurement content display section of the display means, While determining whether the measured value has converged within a predetermined value within a time, if the value has converged within a predetermined 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 the measurement does not converge, the process of continuing the measurement with the time when the value exceeds the specified value as a new reference time, and the total measurement time is predetermined. 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 is completed. Value of the temporary acid A step of setting an elementary activity value; a step of recording the calculated oxygen activity value; and a step of adding or subtracting a counter of the number of times of use of the semi-consumable item by one, and operating the oxygen sensor moving means to activate the oxygen sensor. Discharging, stopping the energization of the heat source of the heating furnace, and increasing the supply of inert gas into the reaction tube to promote cooling in the reaction tube, and reducing the temperature in the reaction tube to a predetermined temperature or less. Stopping the supply of the inert gas at the stage, activating the crucible moving means to discharge the metal crucible, and stopping the supply of the refrigerant to the heating furnace, and operating the reset key to display the display means A method for returning the contents to the initial menu screen; and a method for measuring the oxygen activity in the molten material, comprising the steps of: