JPH09243459A - Optical temperature-measuring apparatus for hightemperature solution and measuring method by the apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously correctly measure the temperature of a solution by providing a function of inserting a leading end of an optical fiber into the high-temperature solution intermittently and properly cutting a devitrified part of the leading end of the optical fiber when the optical fiber is pulled up. SOLUTION: This optical temperature-measuring apparatus is provided with a compression means 10 having a compression rod 11, an optical fiber-storing means 20 moving together with the compression rod 11, and an optical fiber-cutting means 30. In order to measure the temperature of a high-temperature solution, e.g. copper solution, the compression rod 11 is lowered by the compression means 10 to insert a leading end of an optical fiber 40 into the solution 50. The light radiated from the solution 50 enters from the leading end part of the optical fiber 40 and is transmitted to an optical temperature detector. The temperature is detected based on a luminance of the radiated light. After the measurement, the leading end of the optical fiber is pulled up from the solution 50. If the leading end of the optical fiber is devitrified, the devitrified part is cut by the cutting means 30. Although it is enough to cut the optical fiber generally after the optical fiber is used four or five times in the case of the copper solution, the optical fiber may be cut each time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical temperature measuring device capable of easily and accurately measuring the temperature of a high temperature molten material in a copper making furnace or the like.

[0002]

2. Description of the Related Art Thermocouples have been conventionally used to measure the temperature of molten metal, and there are consumable thermocouples that are directly charged into molten metal and those stored in a ceramic protective tube. Are known. However, in the consumable thermocouple, the sensor probe must be replaced for each measurement, and the measurement operation is complicated. In addition, the cost is inevitable because it is disposable. On the other hand, the one having a protective tube has a problem in corrosion resistance and thermal shock resistance of its material, and the measuring time can be maintained only for about 5 to 20 hours.

In addition to such a thermometer using a thermocouple, a temperature measuring method using an optical fiber is also practiced.
For example, a method is known in which the tip of a ceramic protective tube that houses the detection end of an optical fiber is immersed in molten metal, and the radiant heat of the immersed portion is transmitted as an optical signal to a radiation thermometer through the optical fiber to measure the temperature. (JP-A-4-348236
No., JP-A-4-329323, etc.). However, this method has a problem that the immersion accuracy at the tip of the optical fiber is contaminated and the measurement accuracy is lowered. In addition, as a countermeasure against this, a gas for preventing dirt from adhering to the tip portion is also made to flow (Japanese Patent Laid-Open No. Sho 61-135).
No. 60-231126), but in this case, the temperature of the tip part is lowered by the gas flow, and there is a limit to improving the measurement accuracy.

Further, there is also practiced a method in which the tip of an optical fiber is immersed in a high-temperature liquid, and the radiation of the liquid is directly detected to measure the temperature (Japanese Patent Laid-Open No. 62-19729). In this method, when the temperature of the melt reaches 1350 ° C or higher, as in an iron-making furnace, the tip of the SUS pipe that covers the optical fiber melts during the immersion of the melt, so a new fiber end surface is constantly in contact with the melt for continuous measurement. It is possible, but the copper melt is 1200
In the case of around ℃, there is a problem that the temperature cannot be continuously measured like the iron melt due to the temperature of the melt and the measurement error is large. SUMMARY OF THE INVENTION It is an object of the present invention to provide a temperature measuring device that solves the above-mentioned problems in the conventional immersion consumable temperature measuring method using an optical fiber.

[0005]

In the present invention, the reason why continuous measurement cannot be performed in the conventional temperature measurement of copper melt is that the temperature of copper melt is SU.
It is lower than the melting point of S, and the tip of the SUS tube inserted into the melt does not immediately melt like an iron melt, so the optical fiber coated on the SUS tube is not consumed and devitrification occurs due to heat. Yes, in order to eliminate this, intermittently pull up the fiber to cut the devitrified tip, insert a new fiber tip into the copper melt, and remove the measurement peak that occurs during fiber insertion and pulling up. However, it was found that accurate and continuous temperature measurement can be performed by measuring the temperature with a steady value sandwiched between the measurement peaks. The present invention is based on the above findings, and a specific device configuration of an optical thermometer having a function of intermittently inserting the tip of an optical fiber into a high temperature melt and appropriately cutting the devitrified tip of the optical fiber when the optical fiber is pulled up. I will provide a.

That is, according to the present invention, there is provided an optical temperature measuring device having the following configuration. (1) A device for measuring the temperature of a high temperature liquid by immersing the tip of an optical fiber in the high temperature liquid and converting an optical signal transmitted through the optical fiber into a temperature amount,
(A) Optical temperature detector that converts the radiant light of the high temperature liquid into a temperature amount, (b) Expansion and contraction means equipped with a rod that expands and contracts toward the high temperature liquid in order to put the optical fiber tip into and out of the high temperature liquid, ( C) An optical fiber storage means that moves integrally with the rod, and (d) an optical fiber cutting means attached to the tip of the expansion / contraction means, and the cutting means cuts the optical fiber tip at the position where the optical fiber is pulled up from the high temperature melt. And a clamp means for gripping an optical fiber extending from the tip of the rod.

Further, according to the present invention, there is provided an optical temperature measuring device having expansion / contraction means having the following structure. (2) The expansion / contraction means is formed by a cylinder means provided with an expansion / contraction rod, and the optical fiber storage means is connected to the rear end of the expansion / contraction rod. A guide frame is provided at the rear end of the cylinder means in the longitudinal direction, and the carriage moves integrally with the telescopic rod along the guide frame and is pulled out from the winding portion of the carriage. The optical temperature measuring device according to (1), wherein the optical fiber penetrates the inside of the telescopic rod and projects from the tip of the rod.

Further, according to the present invention, there is provided an optical temperature measuring device having a cutting means having the following structure. (3) The optical temperature measuring device as described in (1) or (2) above, wherein the optical fiber cutting means is formed integrally with the expansion / contraction means. (4) The optical fiber cutting means is formed by a cutter and a clamp means which are arranged to face each other with an optical fiber extending from the end of the telescopic rod, and the clamp means is reciprocally movable in the telescopic direction of the telescopic rod. The optical temperature measuring device according to any one of (1) to (3) above, wherein the clamping means and the cutter are provided so as to be able to move forward and backward toward the optical fiber.

Further, according to the present invention, there is provided an optical temperature measuring device having the following structure with respect to the optical fiber, the winding portion thereof, the pinch roller, and the measurement control system. (5) An optical temperature detector is built in the optical fiber winding section provided on the carriage, and a correction roller for removing the optical fiber reliance is provided on the carriage together with the pinch roller forming the winding section and the optical fiber feeding means. And in addition,
The optical temperature measuring device according to any one of (1) to (4) above, wherein a guide tube that prevents the optical fiber from hanging down is provided at the end of the telescopic rod. (6) The optical temperature measuring device according to any of (1) to (5) above, which uses an optical fiber having no resin coat on the outer circumference. (7) The pinch roller tightening pressure can be adjusted (1) ~
The optical temperature measuring device according to any one of (6). (8) The above-mentioned (1) which has a control circuit that automatically extinguishes the heating burner around the measuring device during measurement and re-ignites after measurement
The optical temperature measuring device according to any one of to (7).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to illustrated embodiments. FIG. 1 is a schematic diagram showing the overall structure of the optical temperature measuring device of the present invention. In addition, a partial schematic view in which the optical fiber storage portion is enlarged from the side surface is additionally shown. 2 is a partially cutaway perspective view showing the configuration of the optical fiber storage portion of the device, FIG. 3 is a partial view showing the configuration of the cutting means at the tip of the device, FIG. 4 is an explanatory view showing the operation of the cutting means, and FIG. Schematic sectional view of the tip of the optical fiber, FIG. 6 (a)
(b) is an explanatory view showing an operating state of the apparatus.

I. Structure of the device The optical temperature measuring device of the present invention is a high temperature liquid by immersing the tip of the optical fiber in the high temperature liquid and transmitting the radiated light due to the thermal radiation of the high temperature liquid to the optical temperature detector through the optical fiber to convert it into a high temperature. A device for measuring the temperature of the melt, which is an expanding / contracting means 10 having an expanding / contracting rod, an optical fiber accommodating means 20 moving integrally with the expanding / contracting rod 11 of the expanding / contracting means, and an optical fiber cutting means 3 located at the tip of the expanding / contracting means.
0 is provided.

A preferred configuration example of the expansion / contraction means 10 is shown in FIGS. As shown in the figure, the expansion / contraction means 10 is formed by a cylinder means having an expansion / contraction rod 11, and a guide frame 12 extending in the longitudinal direction is integrally formed at the rear end of the cylinder means. A carriage 21 is slidably provided on the guide frame 12, and the carriage 21 is connected to the rear end of the telescopic rod 11 and reciprocates integrally with the telescopic rod 11 on the guide frame.

The carriage 21 is provided with a winding part 22 around which an optical fiber 40 is wound and a feeding means 23 for pulling out the optical fiber 40. The optical fiber storage means 20 comprises a carriage 21 and a winding portion 22 mounted on the carriage.
The optical fiber 40 formed by the feeding means 23 and drawn from the winding portion 22 of the carriage 21 penetrates the inside of the telescopic rod 11 and projects outward from the rod tip 11a.

FIG. 2 shows a specific structural example of the optical fiber storage means 20. As shown in the figure, rollers 12 rolling on the upper and lower surfaces of the guide frame 12 are provided on both sides of the carriage 21.
a, 12b and a roller 12c rolling on the inner surface of the guide frame 12 are provided.
2 is slidably engaged. A bobbin 22 that winds an optical fiber 40 is provided at the rear of the carriage 21, and a light temperature detector 23 that converts radiation light transmitted by the optical fiber into a temperature amount is built in the bobbin 22.

Further, the carriage 21 is provided with a pair of pinch rollers forming a feeding means 23 for the optical fiber 40, and a straightening roller 24 for removing the reliance of the optical fiber 40 between the pinch roller 23 and the bobbin 22. Is provided. In the configuration shown in the figure, the straightening roller 24 is composed of three rollers rollingly contacting each other, and the optical fiber 40 extending from the bobbin 22 is wound around these rollers and sandwiched between the pinch rollers 23, and is pulled out by the pinch rollers 23, so that the telescopic rod is extended. Rod end 11 penetrating inside 11
a is projected. Optical fiber 40 pinch roller 23
The length pulled out by is adjusted according to the cutting length of the tip. Here, it is preferable that the tightening pressure of the pinch roller 23 can be appropriately adjusted according to the diameter of the optical fiber or the like. If this tightening pressure is too small, the pinch roller 23 slips, and if it is too large, the optical fiber may be deformed to prevent light transmission.

On the other hand, preferably, as shown in FIGS. 1 and 3, a guide tube 13 for preventing the optical fiber from hanging down is provided at the end of the telescopic rod 11a.
The guide tube 13 extends in the longitudinal direction of the telescopic rod 11, and an optical fiber 40 is inserted into the guide tube 13 and protrudes from the tip. The cutting means 30 is provided at the tip of the expansion / contraction means.

The cutting means 30 comprises a cutter 31 for cutting the tip portion of the optical fiber 40 and a clamp means 32 for gripping the optical fiber 40, and is preferably formed integrally with the expanding / contracting means 10. A suitable configuration example of the cutting means 30 is shown in FIGS. 3 and 4. As shown in the drawing, a frame 33 in the shape of a cross girder is fixed to the tip of the cylinder of the expansion / contraction means 10, and the cutter 31 and the clamp means 32 are attached to the frame 33. The cutter 31 and the clamp means 32 are arranged so as to face each other with the optical fiber 40 therebetween, and can be moved forward and backward toward the optical fiber 40, and at least the clamp means 32 can be reciprocated along the longitudinal direction of the optical fiber 40. It is provided in.

The cutter 31 includes a rotary blade 31a, a drive motor 31b for the rotary blade 31a, and an optical fiber 40 for integrating them.
It is formed by a cylinder means 31c that reciprocates toward the frame.
The rotary blade 31a is mounted on the tip of the cylinder means 31c together with the drive motor 31b with the blade end facing the optical fiber 40. The cylinder means 31c may be provided so as to move the frame 33 up and down. On the other hand, the clamp means 32 includes a claw portion 32a that holds the optical fiber 40 and can be opened and closed, a cylinder means 32b that reciprocates the claw portion 32a toward the optical fiber 40, and a claw portion 32a and a cylinder means 32b that are integrated along the optical fiber 40. It is formed by vertically moving cylinder means 32c.

When cutting the tip of the optical fiber, the telescopic rod 11 is retracted and the tip of the optical fiber is pulled up to the vicinity of the guide tube 13 at the tip of the telescopic rod, and then the clamp means 32 is raised toward the guide tube 13. With the claw portion 32a open, it advances toward the optical fiber 40 and loosely grips the optical fiber 40. Continuing, optical fiber 4
The clamping means 32 holds the optical fiber 4 while holding 0.
Then, the cutter 31 at the standby position is advanced to cut the optical fiber tip by the rotary blade 31a. After cutting, the cutter 31 retracts and returns to the standby position, the clamp means 32 retracts with the claw portion 32a opened, and waits until the next cutting. The operations of the cutter 31 and the clamp means 32 at the time of cutting are not limited to the above order. It suffices that the operation sequence is such that the optical fiber is gripped by the clamp means and can be stably cut by the cutter 31.

The optical fiber 40, as shown in FIG.
Quartz fiber 4 usually consisting of core glass and clad
1 is the core wire, and the resin coat (UV coat) 43 on the outer circumference
The metal coating 42 is reinforced by a metal coating 42 made of an extremely thin stainless tube, and a resin coat 44 is provided on the outer periphery of the metal coating 42. As the optical fiber 40, the one having the above structure which is commonly used for optical communication can be used. However, the resin coat is burned when the optical fiber 40 is inserted into the high-temperature melt to temporarily generate a flame, and this flame causes a measurement error in the temperature measurement of the copper melt. The optical fiber 40 does not have a resin coat 44 on the outer periphery of the metal coating.
It is preferable to use

In general, a smelting furnace is provided with a heating burner around the furnace in order to prevent the temperature of the molten material from lowering, and the molten material is heated. To prevent measurement error due to the flame of the heating burner installed around the, the heating burner is automatically extinguished during measurement,
It is advisable to provide a control circuit that automatically ignites again after the measurement.

II. Measuring Method ( Operation ) As shown in FIG. 6, the optical temperature measuring device has a support frame 52 in which the device is slightly inclined from the side of the melting furnace 51 toward the melt 50 so as not to hinder the melting work. It is good to fix to. In order to measure the temperature of the high temperature liquid 50 such as a copper melt, the expansion / contraction means 10 lowers the expansion rod 11 and inserts the tip of the optical fiber 40 into the high temperature liquid 50. The emitted light of the high-temperature melt enters from the tip of the optical fiber 40 and is transmitted to the optical temperature detector through the inside. The light temperature detector detects a temperature amount based on the luminance of the emitted light. The immersion time of the optical fiber is about 2 to 3 seconds.

After the measurement, the telescopic rod 11 is raised to pull up the optical fiber tip from the high temperature melt 50. When devitrification occurs at the fiber tip, the devitrification portion of the fiber tip is cut by the cutting means 30 as described above.
In the case of a copper melt, it may be cut after usually measuring 4 to 5 times, but may be cut every time if necessary. The cut length is based on the length of the devitrified portion, but is generally about 5 to 7 cm. After cutting the tip of the fiber, the length corresponding to the cut length is pulled out by the pinch roller 13, and then the telescopic rod 11 is lowered to insert the tip of the optical fiber 40 into the high temperature melt 50, and the measurement is repeated.

When the temperature of the optical fiber tip is intermittently taken in and out from the high temperature liquid, the temperature is measured as described above.
When the optical fiber 40 is inserted into the high temperature liquid, the resin coat burns to form a flame, and a temperature peak different from that of the high temperature liquid to be measured is recorded. Furthermore, even when the tip of the optical fiber is pulled out of the melt, the oxygen concentration in the open air is higher than the oxygen concentration in the melt, so violent combustion occurs at the moment the tip of the optical fiber touches the open air, and the temperature measurement chart shows A prominent temperature peak similar to the beginning is recorded. Therefore, it is advisable to exclude the measurement peaks at the time of immersion and pulling up and set the measurement temperature based on the steady value sandwiched between these measurement peaks so that this does not cause a measurement error. Further, as described above, if the optical fiber 40 having no resin coating on the outer periphery of the metal coating is used, the above influence can be reduced.

[0025]

The optical temperature measuring device of the present invention described above has a function of intermittently inserting the tip of an optical fiber into a high temperature melt and appropriately cutting the devitrified tip of the optical fiber when the optical fiber is pulled up. In addition, it is possible to continuously and accurately measure the melt temperature of a melt such as a copper melt having a melt temperature considerably lower than the melting temperature of quartz. In addition, since the optical fiber storage part moves together with the telescopic rod, the fiber pull-out length is minimal when inserting the optical fiber into the melt, and also when the optical fiber is pulled up from the melt, the fiber does not loosen. It does not cause any inconvenience.

Further, in the case where the optical fiber storage section is mounted on the carriage continuously provided at the rear end of the expansion rod, the expansion rod and the optical fiber storage section can be smoothly moved integrally and the operability is excellent. By penetrating and projecting the optical fiber from the tip thereof, the expansion / contraction means and the optical fiber housing portion are compactly integrated, and the expansion / contraction means can also serve as a protective case for the optical fiber extension portion.

Further, since the cutting means has the clamp means and the cutter, the optical fiber can be grasped and stably cut at the time of cutting, and the one in which the clamp means and the cutter are integrally formed with the expansion / contraction means is a device. Excellent in operability because there is no need to adjust the cutting position when changing the overall orientation. If the clamping means and the cutter move forward and backward with respect to the optical fiber, and the clamping means moves to the cutting position after gripping the optical fiber near the tip of the guide tube, even if the tip of the optical fiber hangs down, It can be accurately grasped and cut in the vicinity.

Further, by incorporating a light temperature detector in the optical fiber winding portion, the device can be made more compact, and by further providing a straightening roller in the optical fiber storage portion and a guide tube at the end of the telescopic rod, the optical fiber is provided. Since the bending, sagging, and sagging are eliminated, the operability of the device is further improved.

In addition to this, by using an optical fiber having no resin coat on the outer periphery, and by providing a control circuit for automatically extinguishing and re-igniting the heating burner around the optical temperature measuring device, combustion and heating of the resin coat are performed. The influence of the burner can be eliminated and more accurate temperature measurement can be performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the overall structure of an optical temperature measuring device of the present invention.

FIG. 2 is a partially cutaway perspective view showing a configuration of an optical fiber storage means of the above device.

FIG. 3 is a partial view showing a configuration of cutting means at the tip of the device.

FIG. 4 is an explanatory view showing the operation of the cutting means.

FIG. 5 is a schematic cross-sectional view of the tip of an optical fiber.

FIG. 6 is an explanatory diagram showing an operating state of the above apparatus, (a)
Indicates before measurement, and (b) indicates during measurement.

[Explanation of symbols]

10-Expansion / contraction means, 11-Expansion / contraction rods, 12-Guide frame, 20-Optical fiber storage means, 21-Carriage, 22-Winding part, 23-Feeding means, 30-Cutting means, 31-Cutter, 32-Clamping means , 40-
Optical fiber

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nozomu Hasegawa Nozomi Hasegawa 449 1 Naoshima-cho, Kagawa-gun, Kagawa Mitsubishi Materials Corporation Naoshima Smelter (72) Inventor Takashi Funamizu 1-2-2 Marunouchi, Chiyoda-ku, Tokyo No. Nihon Steel Pipe Co., Ltd. (72) Inventor Yoshiro Yamada 1-2 1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (8)

[Claims] 1. An optical fiber tip is immersed in a high temperature liquid,
A device for measuring the temperature of a high-temperature liquid by converting an optical signal transmitted through the optical fiber into a temperature amount, wherein (a) an optical temperature detector for converting radiant light of the high-temperature liquid into a temperature amount, ( (B) Expansion / contraction means equipped with a rod that expands / contracts toward the high-temperature liquid in order to put the optical fiber tip in and out of the high-temperature liquid, (c) optical fiber storage means that moves integrally with the rod, (d) at the tip of the expansion / contraction means. An equipped optical fiber cutting means is provided, and the cutting means is provided with a cutter for cutting the tip of the optical fiber at a position where the optical fiber is pulled up from the high temperature melt, and a clamping means for holding the optical fiber extending from the tip of the rod. An optical temperature measuring device for high temperature liquids, characterized by: 2. The extensible means is formed by a cylinder means provided with an extensible rod, and the optical fiber storage means is connected to the rear end of the extensible rod, a trolley, an optical fiber winding part attached to the trolley, and the optical fiber is pulled out. A guide frame is provided at the rear end of the cylinder means in the longitudinal direction, and the carriage moves integrally with the telescopic rod along the guide frame, and at the same time from the winding portion of the carriage. The optical temperature measuring device according to claim 1, wherein the drawn optical fiber penetrates the inside of the telescopic rod and projects from the tip of the rod. 3. The optical temperature measuring device according to claim 1, wherein the optical fiber cutting means is formed integrally with the expansion / contraction means. 4. The optical fiber cutting means is formed by a cutter and a clamp means which are arranged to face each other with an optical fiber extending from the end of the telescopic rod, and the clamp means reciprocates in the telescopic direction of the telescopic rod. The optical temperature measuring device according to any one of claims 1 to 3, wherein the clamp means and the cutter are provided so as to be movable forward and backward toward the optical fiber. 5. An optical temperature detector is built in an optical fiber winding portion provided on the carriage, and a correction roller for removing the reliance of the optical fiber together with a pinch roller forming a feeding means of the winding portion and the optical fiber is provided on the carriage. The optical temperature measuring device according to any one of claims 1 to 4, further comprising a guide tube protruding from the end of the telescopic rod to prevent the optical fiber from hanging down. 6. The optical temperature measuring device according to claim 1, wherein an optical fiber having no resin coat on the outer periphery is used. 7. The optical temperature measuring device according to claim 1, wherein the tightening pressure of the pinch roller is adjustable. 8. The optical temperature measuring device according to claim 1, further comprising a control circuit for automatically extinguishing a heating burner around the measuring device during measurement and re-igniting after the measurement.