JPH09166495A - Measuring device for molten metal temperature - Google Patents

Abstract

(57) Abstract: A temperature measuring device capable of measuring a temperature of a molten metal at a constant depth with time is obtained. A cylindrical holder having a through hole at its tip,
A molten metal temperature measuring device comprising a consumable metal tube-coated optical fiber which is inserted into the cylindrical holder and immersed in molten metal, and an optical fiber supply means for feeding the consumable metal tube-coated optical fiber into the molten metal. A double rod type air cylinder-10 in which the optical fiber supplying means is provided with a through hole for supplying an optical fiber-2 from one rod 8 to the other rod 9 at the center of the cylinder rod, and this air cylinder-10 A molten metal temperature measuring device comprising a chuck 11 for fixing the optical fiber-2 to the rod 9 at an end 9a of one rod 9. [Effect] The temperature of the molten metal can be accurately measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the temperature of molten metal using an optical fiber.

[0002]

2. Description of the Related Art In the steel industry, other refining industries, casting industries, etc., it is necessary to measure the temperature of molten metal in order to improve refining efficiency, reduce manufacturing costs, and guarantee quality.

The temperature of such molten metal is generally measured by using a consumable thermocouple. However, in the temperature measurement using the consumable thermocouple, the temperature measurement probe immersed in the molten steel melts and can be used only once. Therefore, it is necessary to replace the temperature measurement probe each time the temperature is measured. Therefore, there is a problem that the temperature measurement is expensive and it takes time to replace the probe.

In order to solve such a problem, in the technique disclosed in Japanese Patent Laid-Open No. 7-229791,
A molten metal temperature measuring device using an optical fiber has been proposed. As shown in FIG. 3, the molten metal temperature measuring device includes an optical fiber 41 and an optical fiber 41.
A tubular holder 42 made of steel for inserting and holding
Refractory cap 4 attached to the end of the cylindrical holder 42
3 and an optical fiber supply device 44 for feeding the optical fiber 41 into the molten metal. Note that FIG.
Reference numeral 45 is a handle for facilitating the handling of the cylindrical holder 42.

FIG. 4 shows a measuring method when the temperature of the molten metal is measured by using this temperature measuring device. The winding drum 46 of the optical fiber 41 having a built-in radiation thermometer is carried near the object to be measured, and the winding drum 4
The optical fiber 41 unwound from 6 is put into the cylindrical holder 4
2 and the cap 43, and the tip of the optical fiber 41 is exposed from the cap 43 by about 3 cm. Then, the worker 47 moves the tubular holder 42 and the handle 45.
Then, the tip of the optical fiber 41 is immersed in the molten metal.

Since the radiation thermometer built in the winding drum 46 is connected to the power source 49 by the cable 48,
Upon receiving the radiant light from the optical fiber 41, the temperature of the molten metal is detected. Then, the detected temperature is measured by the cable 50.
It is displayed on the temperature display panel 51 connected to.

As described above, in the temperature measuring device for molten metal using this optical fiber, only a part of the tip of the optical fiber immersed in the molten steel is consumed at every temperature measurement. By the optical fiber supply device 44,
There is an advantage that the temperature can be repeatedly measured if the optical fiber is supplied by the consumed length.

[0008]

However, in the above-mentioned conventional temperature measuring apparatus for molten metal, a mechanism for immersing the tip of the optical fiber to the position of the predetermined depth of molten steel is not disclosed. The immersion depth of the optical fiber differs depending on the temperature, and there is a problem that it is difficult to measure the temperature of the molten steel at the same depth position over time.

The present invention has been made in order to solve the above-mentioned problems of the prior art.
It is an object of the present invention to provide a molten metal temperature measuring device capable of constantly immersing the tip of the molten metal in a position of a predetermined depth of molten steel.

[0010]

A first molten metal temperature measuring device according to the present invention is a cylindrical holder having a through hole at its tip, and is inserted into the cylindrical holder and immersed in the molten metal. In a molten metal temperature measuring device comprising a consumable metal tube-coated optical fiber and an optical fiber supply means for feeding the consumable metal tube-coated optical fiber into the molten metal, the optical fiber supply means has one rod at the center of a cylinder rod. To the other rod, a double rod type air cylinder provided with a through hole for supplying an optical fiber, and a chuck for fixing the optical fiber to the rod at the end of one rod of this a cylinder. It is what is done.

A second molten metal temperature measuring apparatus according to the present invention comprises a cylindrical holder having a through hole at its tip,
A molten metal temperature measuring device comprising a consumable metal tube-coated optical fiber which is inserted into the cylindrical holder and immersed in molten metal, and an optical fiber supply means for feeding the consumable metal tube-coated optical fiber into the molten metal. The optical fiber supply means is composed of a pinch roll composed of a pair of rolls that advance with the optical fiber interposed therebetween, and a stepping motor for driving the pinch roll.

When dipping the tip of the optical fiber in the molten metal, in the case of an ordinary optical fiber, when the tip is brought close to the molten metal, the coating burns out and the optical fiber itself is easily broken during the dipping, so that the optical fiber is dipped in the molten metal. Is impossible. However, when the optical fiber is coated with a metal tube (stainless steel tube), the melting point of the metal tube is 1550.
Since the temperature is higher than 0 ° C., the optical fiber is protected from being melted for 1 to 2 seconds even if it is immersed in the molten metal, so that the optical fiber can be immersed in the molten steel.

Further, an optical fiber has a softening point of 160.
If it is made of quartz glass of 0 ° C. or higher, the heat resistance is improved.

When the tip of the metal tube-coated optical fiber is immersed in the molten metal in this way, the temperature of the metal tube and the tip of the optical fiber becomes the same as that of the molten metal, and the tip of the optical fiber satisfies the condition of a black body. ing. For this reason,
It emits radiant light only depending on temperature without being affected by the shape of the tip of the optical fiber. This radiant light is guided to a radiation thermometer through an optical fiber, and the temperature of the molten metal is detected by the radiation thermometer.

In actual temperature measurement, the tip of the holder is fixed in advance so as to be at a position separated from the molten metal surface by a predetermined distance, and then the metal tube-covered optical fiber is fed out from the tip of the holder by a predetermined length, and then the metal tube is attached. The coated optical fiber is immersed in the molten metal so that the tip of the optical fiber coated with a metal tube is located at a predetermined molten metal depth position.

Although the optical fiber immersed in the molten metal dissolves in a few seconds, it catches the light signal emitted up to that point and guides it to the radiation thermometer through the holder and the optical fiber arranged outside the holder, where the light is emitted. The temperature is converted and the temperature is detected. Then, after soaking for several seconds, the optical fiber is retracted and pulled out from the molten metal.

In the first temperature measuring apparatus for molten metal of the present invention, when the optical fiber is sent for temperature measurement, it is sent as follows. That is, an optical fiber is inserted from one end surface of one rod of a double rod type air cylinder, which is an optical fiber supply means, and is output from the end surface of the other rod.
Is manually fed to a predetermined position in the vicinity of the tip of the cylindrical holder connected to the exit side of the optical fiber of the double rod type air cylinder. A chuck that holds the optical fiber and prevents the optical fiber from freely advancing is attached to the end of the rod on the side where the optical fiber is inserted. Loosen and send by hand.

Then, after manually feeding the optical fiber by a predetermined length, the optical fiber is gripped by a chuck so that the optical fiber cannot be further advanced.

Compressed air is supplied to the air cylinder so that pressure is applied to the rod opposite to the rod fixed so that the optical fiber cannot be advanced.
The pressure inside the rod-side air cylinder to which the optical fiber is fixed is released. By doing so, the piston in the air cylinder moves in the direction opposite to the direction in which the optical fiber is sent out, by the stroke of the cylinder, and the tip of the optical fiber retracts accordingly. Then, in this state, the temperature measuring device is fixed so as to be at a position of a predetermined height from the molten metal surface to be measured.

After fixing the temperature measuring device, the optical fiber
Air pressure is applied to the rod side where is fixed, the optical fiber is advanced, and the tip of the optical fiber is immersed in the molten metal to a certain depth to measure the temperature.

After the temperature measurement, contrary to the case where the optical fiber was fed, pressure was applied to the air cylinder on the rod side opposite to the side where the optical fiber was fixed, and the optical fiber was fixed. Allow the pressure on the rod side to be released. By doing so, the piston in the air cylinder moves substantially by the stroke of the cylinder in the direction opposite to the direction in which the optical fiber is sent out, so the tip of the optical fiber remaining unmelted ( Since the immersed optical fiber is melted, the tip of the remaining optical fiber which is not melted is at the molten metal surface position) and is retracted from the molten metal molten metal surface by the stroke of the cylinder.

After retracting the optical fiber, the chuck is loosened to separate the optical fiber from the air cylinder,
Hand the optical fiber forward by the length of the melt,
The optical fiber is fixed to the rod with a chuck. And
As described above, air pressure is applied to the rod side to which the optical fiber is fixed, the optical fiber is advanced, and the tip of the optical fiber is immersed in the molten metal to a certain depth, and the next temperature measurement is performed.

Since the temperature measurement is repeated in this manner, the length of the optical fiber to be immersed is always constant.

In the second molten metal temperature measuring apparatus of the present invention, when the optical fiber is sent for temperature measurement, it is sent as follows. That is, when an optical fiber is sent out by a pinch roll which is an optical fiber supply means, the pinch roll is driven by a stepping motor, so that the feed amount of the optical fiber corresponding to the number of rotations of the pinch roll is displayed on a display board or the like. Can be grasped at. Therefore, the optical fiber can be immersed in the molten steel while confirming the feed amount on the display board or the like, and the immersion length of the optical fiber can always be made constant.

As an actual work, the tip of the optical fiber remaining unmelted is once retracted to a position separated from the tip of the holder by a predetermined distance. Then, when measuring the temperature, the temperature is sent while looking at the display panel or the like by a length equal to the total of the retracted distance and the melted length.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION A molten metal temperature measuring apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 (a)
Is a vertical sectional view of the temperature measuring device, and FIG. 1B is a vertical sectional view of a chuck used in the temperature measuring device. As shown in FIG. 1A, this temperature measuring device 1 includes a consumable metal tube-coated optical fiber (hereinafter, simply referred to as an optical fiber) 2 and a steel rear guide tube that holds the optical fiber 2 by inserting the optical fiber 2 inside. 3, an optical fiber supply device 4 connected to the tip of the rear guide tube 3, a first front guide tube 5 connected in front of the optical fiber supply device 4 for inserting the optical fiber 2, and an optical fiber 2 inserted The first front guide tube 5 and the second front guide tube 6 are moved forward and backward. In the case of this temperature measuring device 1, the rear guide tube 3
The double rod type air cylinder 10 of the optical fiber supplying device 4, which will be described later, the first front guide tube 5, and the second front guide tube 6 serve as the above-mentioned cylindrical holder.

FIG. 1 shows the optical fiber supply device 4 described above.
More specifically with reference to (a), this optical fiber-supplying device 4
Is composed of a double rod type air cylinder 10 having piston rods 8 and 9 on the front and back of the piston 7, and a collet chuck 11 for fixing the optical fiber 2 to the rear rod 9.

FIG. 1B is a sectional view showing the structure of the collet chuck 11.
The collet ring 12 screwed into the rear end 9a of the rear rod 9 and the optical fiber 2 inserted into the collet ring 12
Collet 13 for holding and fixing collet ring 12
And a cap nut 14 that is screwed into and presses the collet 13 into the collet ring 12.

A through hole is provided from the rear end 9a of the rear rod 9 to the tip 8a of the front rod 8 via the piston 7, and the optical fiber 2 is inserted into the rear guide tube 3 and then the through hole is formed. The first front guide tube 5 is passed through the first front guide tube 5, the second front guide tube 6 is passed through, and the tip is immersed in the molten metal to measure the temperature.

The first front guide tube 5 is directly connected to the air cylinder 10, and the front rod 8 is moved forward and backward while the optical fiber 2 is inserted through the first front guide tube 5. To do. Also, the second front guide tube 6
Is connected to the tip of the front rod 8 and moves forward and backward in the first front guide tube 5 together with the front rod 8.

When the temperature of the molten metal is measured by this temperature measuring device 1, the optical fiber 2 is passed through the front and rear guide pipes and the through holes of the front and rear rods of the air cylinder as described above, and manually fed so that the tip of the fiber is Predetermined position (position about 100 mm from the tip of the second front guide tube 6)
Try to come up. Then, the optical fiber 2 is gripped by the collet chuck 11 attached to the rear end portion of the rear rod 9 of the air cylinder 10 to prevent the optical fiber 2 from advancing any further.

Then, the temperature measuring device 1 is fixed at a position separated from the molten metal surface by a certain distance (it may be held by hand or fixed, or a fixing device may be used), and the front rod 8 is fixed.
The pressure is applied through the compressed air supply / exhaust hole 15 in the side air cylinder 10, and the pressure on the rear rod 9 side is released through the compressed air supply / exhaust hole 16. By doing so, the piston 7 in the air cylinder 10 is retracted by a stroke of the cylinder 10 in a direction opposite to the direction in which the optical fiber-2 is sent out.

After setting as described above, the rear rod 9
Compressed air is supplied to the air cylinder 10 through the compressed air supply / exhaust hole 16 so that pressure is applied to the side.
The pressure in the air cylinder 10 on the front rod 8 side is released through the compressed air supply / exhaust hole 15. By doing so, the piston 7 in the air cylinder-10 is substantially moved in the direction in which the optical fiber-2 is sent out.
Of the optical fiber-2, the tip of the optical fiber-2 is immersed in the molten metal to a certain depth, and the temperature of the molten metal is measured.

After the temperature measurement, the air cylinder-1 on the side of the front rod 8 is reversed, as opposed to when the optical fiber-2 is fed.
The pressure is applied to the inside of 0, and the pressure on the rear rod 9 side is released. In this way, the air cylinder-10
Since the piston 7 inside moves in the direction opposite to the direction in which the optical fiber-2 is sent out by the stroke of the cylinder-10, the tip of the optical fiber-2 that remains unmelted (the immersed optical fiber- Is melted, the tip of the optical fiber that remains unmelted is at the melt level.)
Moves backward from the surface of the molten metal by about the length of the cylinder 10 and comes to a position (about 100 mm) away from the tip of the second front guide tube 6 by a predetermined distance.

After the optical fiber-2 is retracted, the collet chuck 11 is loosened to allow the optical fiber-2 to move back and forth, and then the optical fiber-2 is manually fed forward by the melted length. -2 again collet chuck 1
Grab 1 and fix. Then, as described above, the rear rod 9
Air pressure is applied to the side, the optical fiber-2 is advanced, the tip of the optical fiber-2 is dipped in the molten metal to a constant depth, and the next temperature measurement is performed.

Since the temperature measurement is repeated in this way, the length of the optical fiber-2 to be immersed is always constant. Therefore, the temperature of the molten metal at a certain depth from the molten metal surface can be measured with time, so that the temperature of the molten metal can be accurately controlled, the refining time can be shortened, and the metal having the intended component composition can be obtained. To be

Reference numeral 17 in FIG. 1 (a) is an N for supplying N ₂ gas for purging into the first front guide pipe 5.
₂ Gas supply port.

When the temperature of the molten metal is measured using the temperature measuring device 1, the whole measuring method is the same as the conventional measuring method described with reference to FIG. 4, except for the temperature measuring device. Therefore, it is omitted.

Next, a molten metal temperature measuring apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2A is a vertical sectional view of the molten metal temperature measuring device.
2B is a view taken along the line AA of FIG. As shown in FIG. 2A, the temperature measuring device 21 includes an optical fiber 22, a steel rear guide tube 23 for inserting and holding the optical fiber 22, and a rear guide tube 23.
An optical fiber feeding device 24 connected to the tip of the
A first front guide tube 25 which is connected to the front of the optical fiber supply device 24 and allows the optical fiber 22 to be inserted therethrough;
The second front guide tube 26 is connected to the first front guide tube 25 and allows the optical fiber 22 to be inserted therethrough. Reference numeral 27 in FIG. 2A is an N ₂ gas supply port for supplying a purge N ₂ gas into the first front guide pipe 25. In the case of this temperature measuring device 21, the rear guide tube 23, the support frame 29 of the optical fiber supply device 24, which will be described later, the first front guide tube 25, and the second front guide tube 26 are described above. It plays the role of a cylindrical holder.

The optical fiber supply device 24 described above is shown in FIG.
More specifically with reference to (b), this optical fiber-supplying device 2
Reference numeral 4 denotes a drive roll 30 rotatably supported by a support frame 29 via a bearing 28, and a rotary shaft 32 provided on a support member 31 slidable in the support frame 29, and freely rotatable via a bearing 33. The non-driving roll 34, which is supported by the driving roll 30 and which feeds the optical fiber 22 by sandwiching it together with the driving roll 30.
A stepping motor 35 for driving the drive roll 30 and a pressing mechanism 36 for pressing the non-drive roll 34 against the drive roll 30.

The pressing mechanism 36 will be described in detail. The pressing mechanism 36 is screwed into the disc spring 37 and the support frame 29, and a pressing bolt that applies a pressing force to the support member 31 via the disc spring 37. 38 and a fixing nut 39 for fixing the pressing bolt 38.

When the temperature of the molten metal is measured by the temperature measuring device 21, the optical fiber 22 is guided to the front and rear guide tubes and the optical fiber supplying device 24 as described above.
Through the drive roll 30 and the non-drive roll 34 of the optical fiber 22 by the pressing mechanism 36 described above.
It is sandwiched between 0 and the non-driving roll 34.

Then, the stepping motor 35 is rotated so that the tip of the optical fiber 22 reaches a predetermined position, and then the stepping motor 35 is temporarily stopped.

Then, the temperature measuring device 21 is fixed at a position distant from the molten metal surface by a certain distance (it may be held by hand or fixed, or a fixing device may be used), and the stepping motor 35 is turned on again. Is rotated, the optical fiber 22 is dipped in the molten metal for a predetermined length, and the first temperature measurement is performed. When immersing the optical fiber 22 in the molten metal, the feed length of the optical fiber 22 according to the rotation speed of the stepping motor 35 can be displayed on the display panel (not shown), so that the operator can see the required length while looking at the display panel. Can be soaked.

When the temperature measurement is completed, the stepping motor 35 is rotated in the reverse direction so that the tip of the optical fiber 22 is moved away from the surface of the molten metal, and the tip is about 10 from the tip of the second front guide tube 26.
Set it so that it is about 0 mm. This is done because it is sufficient to send the same length each time the temperature is measured next time. That is, the distance from this position to the molten metal surface plus the melting length of the optical fiber 22 may be fed.

Since the temperature measurement is repeated in this way, the length of the optical fiber 22 to be immersed is always constant. Therefore, since the temperature of the molten metal at a certain depth from the molten metal surface can be measured with time, the temperature of the molten metal can be accurately controlled in this case as well, the refining time can be shortened, and the target composition Can be obtained.

When the temperature of the molten metal is measured using the temperature measuring device 21, the whole measuring method is the same as the conventional measuring method described with reference to FIG. 4, except for the temperature measuring device. Therefore, it is omitted.

[0048]

According to the present invention, the temperature of a molten metal at a desired position can be accurately measured, so that the refining time can be shortened and a metal having a desired component composition can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a molten metal temperature measuring device according to a first embodiment of the present invention, (a) is a longitudinal sectional view of the temperature measuring device, and (b) is a chuck used in the temperature measuring device. FIG.

FIG. 2 is an explanatory view of a molten metal temperature measuring device according to a second embodiment of the present invention, (a) is a plan view of this temperature measuring device, and (b) is a view taken along the line AA of (a). It is a figure.

FIG. 3 is a vertical cross-sectional view of a conventional molten metal temperature measuring device.

FIG. 4 is an explanatory view showing a temperature measuring method using a conventional molten metal temperature measuring device.

[Explanation of symbols]

1 Temperature Measuring Device 2 Optical Fiber 3 Rear Guide Tube 4 Optical Fiber Supply Device 5 First Front Guide Tube 6 Second Front Guide Tube 7 Piston 8 Front Piston Rod 9 Rear Piston Rod 10 Double Rod Air Cylinder-11 Collet Chuck 12 Collet Ring 13 Collet 14 Cap nut 15 Compressed air supply / exhaust hole 16 Compressed air supply / exhaust hole 17 N ₂ Gas supply port 21 Temperature measurement device 22 Optical fiber 23 Rear guide pipe 24 Optical fiber supply device 25 First front guide pipe 26 Second front Guide tube 27 N ₂ gas supply port 28 Bearing 29 Support frame 30 Drive roll 31 Support member 32 Rotating shaft 33 Bearing 34 Non-drive roll 35 Stepping motor 36 Push mechanism 37 Disc spring 38 Push bolt 39 Fixing nut

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Maeda 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (2)

[Claims] 1. A cylindrical holder having a through hole at its tip,
In a temperature measuring device for a molten metal, which comprises a consumable metal tube-coated optical fiber which is inserted into the cylindrical holder and immersed in the molten metal, and an optical fiber supply means for feeding the consumable metal tube-coated optical fiber into the molten metal. A dual rod type air cylinder in which the optical fiber supply means is provided with a through hole for supplying an optical fiber from one rod to the other in the center of the cylinder rod, and the end of one rod of this air cylinder Part, a chuck for fixing the optical fiber to a rod, and a temperature measuring device for molten metal. 2. A cylindrical holder having a through hole at its tip,
In a temperature measuring device for a molten metal, which comprises a consumable metal tube-coated optical fiber which is inserted into the cylindrical holder and immersed in the molten metal, and an optical fiber supply means for feeding the consumable metal tube-coated optical fiber into the molten metal. A temperature measuring device for molten metal, wherein the optical fiber supply means comprises a pinch roll consisting of a pair of rolls for advancing with an optical fiber in between, and a stepping motor for driving the pinch roll.