JPH0714837Y2 - Temperature measuring device for high temperature melt such as silicon alloy - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a temperature measuring device for a high temperature melt such as a silicon alloy.

[Conventional technology]

Conventionally, the Czochralski method (hereinafter referred to as the CZ method) has been known as a method for single-crystallizing polycrystalline silicon, and the single-crystal silicon obtained by this method is used in ICs and LSIs. An apparatus as shown in FIG. 8 is used to carry out the CZ method. In the figure, 1 is a furnace, 2 is a quartz crucible, and 3 is a graphite heater. Into the quartz crucible 2, a silicon alloy in which a predetermined amount of a doping material (OC and other heavy metals) is added to polycrystalline silicon in which the same crystals are gathered in multiple directions is charged, and the furnace 1 is evacuated to a few mTorr. , 10 ~ 20Torr
Is replaced with an inert gas atmosphere such as Ar, and is melted while being radiantly heated by the graphite heater 3 (Max. 1470 ° C.) to be a silicon melt 4. The quartz crucible 2 is rotated in one direction by the rotating shaft 5, and the generated silicon crystal 6 is pulled from the quartz crucible 2 while being rotated in the opposite direction. If there is a temporal or local temperature fluctuation, crystal defects will occur during crystal growth. Therefore, control of temperature fluctuations in the silicon melt 4 becomes extremely important. Therefore, the temperature measuring device 7 is provided in the furnace, and the sensor part 8 of the device is immersed in the silicon melt 4 in the quartz crucible 2 to continuously measure the temperature in the silicon melt 4. Is being performed. [Problems to be Solved by the Invention] It is known that a thermocouple is used for the sensor part 8 of the temperature measuring device 7 described above, and as a protective material for the tip junction part of the thermocouple, the generated silicon single crystal is used. However, since it is required to have extremely high purity in terms of quality, it must be free from the concern of silicon contamination. Therefore, the technology of coating the tip junction of the thermocouple with boron nitride has been developed.
-38027 is proposed. However, as is well known, boron nitride is extremely expensive, and it is not preferable to add cost to the sensor unit 8 that is used consumably. In this respect, for example, the temperature measuring device 7 is divided into a sensor unit 9 and an outer shell unit 10, and the outer shell unit is made durable and can be used repeatedly, while the sensor unit is made expendable. It has been found that the cost problem can be solved by configuring the outer shell unit so that it can be used while replacing the sensor unit. This makes it possible to configure the sensor unit at a cost as low as possible away from the outer shell unit, and even if the outer shell unit itself becomes expensive, it is possible to reduce the total cost associated with ordinary temperature measurement. It is possible to reduce the cost. By the way, since the furnace 1 is exposed to a high temperature atmosphere, the temperature measuring device 7 must have a heat resistant structure. In this respect, if the sensor unit and the outer shell unit are formed as separate units as described above, the consumable sensor unit can have the minimum heat resistance necessary, but the durable outer shell unit that should be repeatedly used. Can be configured to have a cooling structure without being limited in cost. By adopting a cooling structure in the outer shell unit in this way, it is possible to prevent the occurrence of troubles at the connecting portion between the sensor unit and the outer shell unit. Since it can contribute, an advantageous result can be expected also in this respect. In spite of the demand for the proposal of such a unitized temperature measuring device, it has not been realized yet. Furthermore, in the above-mentioned CZ method, when the temperature measuring device 7 is introduced into the furnace by inserting it through the furnace wall, if outside air leaks into the furnace through the temperature measuring device 7, the silicon melt inside the furnace is There is a risk of oxidation and, at the same time, there is a risk of causing an explosion accident due to the combination of silicon vapor and oxygen in the furnace. Therefore, when performing the unitization as described above, this point must be solved. I have to. In addition, there are other issues to be studied in the specific structure for attaching and detaching the unitized sensor unit to the outer shell unit. [Means for Solving the Problem] The present invention provides a temperature measuring device that solves the above-mentioned problems, and is configured as a means thereof by inserting a high temperature molten material (4 ), And an airtight sealing means (59) for hermetically sealing between the outer peripheral surface of the outer shell unit and the outer surface of the furnace wall.
And a sensor unit (9) that is detachably attached to the outer shell unit (10) and has a sensor section (8) at the tip immersed in the high-temperature melt (4). A quartz tube (12) accommodating the thermocouple (11), and a holding tube (13) in which the vicinity of the tail end of the quartz tube is embedded and held via a filler (14) such as refractory cement.
A connector (20) arranged on the tail end side of the holding tube and electrically connected to the thermocouple via a compensating lead wire (21), and the outer shell unit (10) comprises the sensor unit (9). ) A tubular main body (22) having a storage chamber (19) for detachably inserting and holding the holding tube (13), and a connector (20) which is arranged in the storage chamber (19) and is detachable. The outer shell comprises an internal connector (34) to be connected and an external connector (35) arranged on the tail end side of the tubular main body (22) and electrically connected to the internal connector (34). The tubular main body (22) of the unit (10) includes a holding tube (13) of the sensor unit (9) inserted into the storage chamber (19) and a connector (20, 20) stored in the storage chamber (19). 34) is provided with a refrigerant passage (29, 30) for cooling the tubular main body (22) over the entire outer circumference of the tubular body (34), Body part (22)
The point is that a seal means is provided on the tail end side of the tubular main body (22) to insulate the storage chamber (19) from the outside air in an airtight manner.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings. (First Embodiment) In FIG. 1, a temperature measuring device 7 comprises a sensor unit 9 and an outer shell unit 10 for inserting and protecting the sensor unit 9. The sensor unit 9 is a U-tube single element type. That is, a U-shaped tubular quartz tube containing the thermocouple 11.
The sensor unit 8 is provided with the U-shaped bent portion facing the tip. Quartz tube 12 extending parallel to the sensor section 8
The portion near the tail end is inserted into a holding tube 13 made of metal such as stainless steel, and a filler 14 such as refractory cement filled in the holding tube 13
It is fixedly held by. AB at the tail end opening of the holding tube 13.
A cap 15 made of synthetic resin such as S resin is attached,
The cap 15 is provided with a positioning means 16 consisting of an annular groove or a pair of holes into which the tail ends of the quartz tubes 12 are fitted, and a pair of pins 17 project from the cap 15, and a pair of quartz is attached to each pin 17. The thermocouple 11 derived from the pipe 12 is connected. Further, a flange material 18 is fixed to the outer periphery of the tip of the holding tube 13 by welding or the like.
Irregularities such as iris knurling are formed on the outer circumference of.
A connector 20 is arranged on the tail end side of the holding tube 13, and the connector 20 is electrically connected to the pin 17 through a compensation lead wire 21. In this embodiment, the connector 20 is connected to the cap 15 in a free state by a compensating conductor 21. The outer shell unit 10 is a holding tube 13 for the sensor unit 9.
A cylindrical main body 22 having a storage chamber 19 for detachably storing the is formed. The tubular main body 22 has a triple pipe structure, and in each case, an inner pipe 23 made of metal such as stainless steel, a middle pipe 24,
The outer pipe 25 and the outer pipe 25 are concentrically arranged with a space therebetween in the inner and outer peripheral directions. The inner tube 23 and the outer tube 25 are connected and fixed to the annular cap 26 at the tip end by welding or the like. Inner pipe
23 and the middle pipe 24 are connected and fixed to the flange-shaped cap 27 at the tail end by welding or the like. The tail end of the outer tube 25 is the middle tube
The tail end of the outer pipe 25 is fixed by welding or the like to the annular spacer 28 that ends at the middle of 24 and is fixed by welding or the like on the outer periphery of the middle pipe 24. Therefore, an inner peripheral side refrigerant passage 29 is formed between the inner and outer circumferences of the middle pipe 24 and the inner pipe 23, and an outer peripheral side refrigerant passage 30 is formed between the inner and outer circumferences of the outer pipe 25 and the middle pipe 24. 29 and 30 are inserted near the annular cap 26. That is, the middle pipe 24
The tip of is spaced apart from the annular cap 26,
A communication passage 31 is formed by the space. An inlet port 32 communicating with the inner peripheral side refrigerant passage 29 is provided near the tail end of the middle pipe 24.
An outlet port 33 communicating with the outer peripheral side refrigerant passage 30 is provided in the vicinity of the tail end of the outer pipe 25, and the refrigerant such as the cooling liquid or the gas introduced from the inlet port 32 is supplied to the inner peripheral side refrigerant passage. Circulating 29, passing through the communication passage 31
After flowing through 30, the tail end of the inner peripheral side refrigerant passage 29 is sealed by the flange-shaped cap 27, and the tail end of the outer peripheral side refrigerant passage 30 is formed into the annular shape. The spacer 28 is hermetically sealed, and the communication passage 31 is hermetically sealed by the annular cap 26. An internal connector 34 is arranged in the storage chamber 19 of the cylindrical main body 22, and an external connector 35 is arranged on the tail end side of the cylindrical main body 22. The both connectors 34, 35 have a curl cord 36. Are conductively connected by. That is, the internal connector 34 is connected to the tip of the compensation lead wire in the curl cord 36,
The tail end of 37 is connected to the pin 38 of the external connector 35. On the tail end side of the tubular main body 22, a plug 39 is fitted into the opening of the inner pipe 23, and the flange 40 of the plug 39 is fitted to the flange of the flange cap 27 and a sealing member such as an O-ring.
They are fastened to each other by bolts 42 via 41. Stopper 39
Has a recessed portion 43 opening to the tail end side, the external connector 35 is screwed or fitted into the recessed portion, the tail end of the curl cord 36 is inserted into the bottom portion 44 of the stopper 39, and A sealant 45 such as an epoxy resin is filled in a recess 43 located between the bottom 44 and the external connector 35, and the compensating lead wire 37 and the pin 38 are embedded in the sealant 45. Therefore, the tubular body
At the tail end of 22, the storage chamber is formed by the plug 39, the flange-shaped cap 27, the seal member 41 and the sealant 45.
Sealing means is configured to insulate 19 from the outside air in an airtight manner. Thus, such a sensor unit 9 and an outer shell unit
10 and 10 are detachably assembled as shown. That is, the holding tube 13 of the sensor unit 9 is inserted into the storage chamber 19 through the tip opening of the cylindrical main body 22 of the outer shell unit 10, and the flange material is inserted.
18 is brought into contact with the annular cap 26, and the holding tube 13 is fixed by screwing a set bolt 46 through a female screw hole formed in the annular cap 26 in the radial direction. When removing the worn sensor unit 9 from the outer shell unit 10 in order to replace it with a new sensor unit 9, loosen the set bolt 46,
The sensor unit 9 may be taken out from the outer shell unit 10 by gripping the flange member 18. In either case of attachment and removal, the connector 20 and the internal connector 34 are connected and disconnected by inserting the internal connector 34 through the extension of the curl cord 36 to the outside of the tip opening of the storage chamber 19, and then storing the storage chamber. You can easily work outside of. In the case of this embodiment, the connector 20 and the internal connector 24 may be non-directional contact type coaxial connectors. (Second Embodiment) FIG. 2 shows another embodiment of the refrigerant passage and the sealing means of the outer shell unit 10. The outer shell unit 10 includes an inner pipe 23, a middle pipe 24, and a tubular main body 22 having a triple pipe structure of an outer pipe 25, and forms an inner peripheral side refrigerant passage 29 and an outer peripheral side refrigerant passage 30. There is. The part which is broken and omitted in FIG. 2 (the part in the left direction in FIG. 2) has the same structure as the tip side part (the left side part in FIG. 1) of the tubular main body 22 shown in FIG. ． In the second illustrated embodiment, the tail end of the outer tube 25 is the middle tube 24.
Is extended to near the tail end of the outer pipe 25, and the tail ends of the middle pipe 24 and the inner pipe 23 are positioned so that the tail ends of the outer pipe 25 and the inner pipe 23 are sequentially projected toward the tail end. ． A cylindrical cap 27a is attached to the tail end of the outer pipe 25, and an inlet port 32a and an outlet port 33a are provided at the tail end of the cap 27a. The inlet port 32a is connected to the inner peripheral side refrigerant passage 29 through an inlet communication passage 29a formed in the cap 27a, and the inlet port 32a blocks the outer peripheral side refrigerant passage 30 by a blocking wall 32b. Has been done. On the other hand, the outlet port 33a is an outlet communication passage formed in the cap 27a.
The outlet port 33a is connected to the outer peripheral side refrigerant passage 30 through the opening 30a, but is blocked from the inner peripheral side refrigerant passage 29 by a blocking wall 33b. Therefore, the coolant such as the cooling liquid or the gas flowing from the inlet port 32a flows into the inner peripheral side refrigerant passage 29 from the inlet communication passage 29a, and the communication passage 31
After flowing through the outer peripheral side refrigerant passage 30 through (Fig. 1), it is discharged to the outlet port 33a via the outlet communication passage 30a. A plug 39a is screwed or fitted into the cap 27a from the tail end side, and the outer peripheral surface of the plug 39a and the inner peripheral surface of the cap 27a are sealed by a seal member 41a such as an O-ring. Plug 3
9a has a recessed portion 43a opening to the tail end side, the external connector 35 is screwed or fitted into the recessed portion, the tail end of the curl cord 36 is inserted into the bottom portion 44a of the stopper 39a, and the bottom portion 44a Between the external connector 35 and the external connector 35, the compensating lead wire 37 of the curl cord and the connector pin 38 are connected in the space of the recessed portion, and the space is filled with the sealing agent 45 such as epoxy resin,
The compensation lead wire 37 and the pin 38 are embedded therein. Therefore,
Also in this embodiment, the plug 39a, the cap 27a, the seal member 41a and the sealant 45 constitute a sealing means for the storage chamber 19, and the sealing means insulates the storage chamber 19 from the outside air in an airtight manner. (Third Embodiment) FIG. 3 shows a third embodiment in which the mounting structure of the internal connector 34 is different. Therefore, the tubular body of the outer shell unit 10
The technical configuration related to 22 is the same as that of the first or second embodiment. A short cylinder member 47 is inserted in the inner pipe 23.
47 has a holding wall 48 at the tip, and the internal connector 34 is fixed to the holding wall 48. A pair of cords 36a is introduced from the tail end side into the short tubular member 47, and a compensation lead wire 37a of the cord 36a is connected to the internal connector 34 inside the short tubular member 47. Sealing agent such as epoxy resin in 47
Is filled in, and the connecting portion of the internal connector 34 and the compensating lead wire 37a
Embedded in the sealant 49. A guide tube 50 is connected to the tail end of the short tubular member 47 and is tightly fitted in the inner tube 23 of the tubular main body 22 to position and fix the short tubular member 47 so as not to move in the inner tube 23. is doing. The outer shell unit 10 of the third embodiment is used in combination with a sensor unit 9 having a connector fixed to the tail end of a holding tube 13 as in the fourth and fifth embodiments described later. The storage unit 19 for the sensor unit 9 in the tubular main body 22
The connector 20 of the sensor unit 9 is automatically connected to the internal connector 34 when it is inserted to a predetermined position. Further, when the sensor unit 9 is pulled out from the tubular main body 22, the connector 20 of the sensor unit 9 is detached from the internal connector 34. (Fourth Embodiment) FIG. 4 shows a fourth embodiment in which the sensor unit 9 is a straight single element type. The quartz tube 12 includes a quartz outer tube 12a for accommodating the minus side thermocouple 11a and an inner quartz tube 12b for accommodating the plus side thermocouple 11b.
And a double tube structure, and the sensor section 8 is formed at the tip. The vicinity of the tail end of the quartz tube 12 is a holding tube 13 made of metal such as stainless steel.
It is fixedly held by a filler 14 such as refractory cement that is inserted into the holding tube 13 and is filled in the holding tube 13. A flange material 18 is fixed to the outer periphery of the tip of the holding tube 13 by welding or the like, and an uneven portion such as an iris knurling is formed on the outer periphery of the flange material 18. A cap 15 made of synthetic resin such as ABS resin is attached to the tail end opening of the holding tube 13, and the connector 20 is fixedly held by the cap 15. Tail end of quartz outer tube 12a and cap 15
A spacer 51 made of synthetic resin such as ABS resin is interposed between and, and the spacer 51 is fixed in the holding tube 13 by being hardened by the filler 14. The spacer 51 has a positioning means 16a for fitting the tail end of the quartz inner tube 12b on one side, and a recess for accommodating the pin 20a of the connector 20 on the other side, and the pin 20a is led out from the quartz inner tube 12b. Thermocouple 11b
Are connected. The thermocouple 11a derived from the quartz outer tube 12a is connected to the flange of the connector 20 through the outer peripheral side of the spacer 51. (Fifth Embodiment) FIG. 5 shows a fifth embodiment in which the sensor unit 9 is a straight 4-element type. In this embodiment, four quartz tubes 12 each accommodating a thermocouple are arranged in parallel. One of the four tubes makes the sensor portion 8a at the tip project more than the other three tubes, and the other three tubes. The book has the sensor part 8b at the other end aligned. The vicinity of the tail ends of these four parallel quartz tubes 12 is inserted into a holding tube 13 and fixed and held by a filler 14 such as refractory cement. A flange material 18 is fixed to the outer periphery of the tip of the holding tube 13 by welding or the like, and an uneven portion such as an iris knurling is formed on the outer periphery of the flange material 18. The tail end of each quartz tube 12 is a spacer 51a made of synthetic resin such as ABS resin.
Pins made of synthetic resin such as ABS resin, which are fitted and positioned in the quartz tube 12, and thermocouples derived from the quartz tubes 12 are superposed on the spacer 51a and fixed to the holding tube 13 by fixing means 52 such as pins or screws. Each of them is connected to the pin 53 held by the guide 51b. A cap 15 made of synthetic resin such as ABS resin is attached to the tail end of the holding tube 13.
Is attached, the connector 20 is inserted into the cap 15, and fixed and held by a fixing means 54 such as a pin or a screw.
The pin 53 of the pin guide and the pin 20b of the connector 20 are connected by a compensating conductor 21. (Sixth Embodiment) FIG. 6 shows an embodiment in which two sensor units 9 similar to the straight single element type shown in FIG. 4 are combined and used. However, each sensor unit 9 is slightly different from the fourth embodiment shown in FIG. That is, the flange member 18 is not provided at the tip of the holding tube 13, and instead of the connector 20 fixed to the tail end of each sensor unit, a connector 20a common to the two sensor units 9a and 9b is provided. 20
A is connected to the thermocouple of each sensor unit 9a, 9b by a compensating lead 21a. As shown in FIG. 6 and FIG. 7, the pair of sensor units 9a and 9b have their protective tubes 13a and 13b superposed in parallel and clamped and held by a clamp 55. The clamp tool 55 is composed of an upper clamp piece 55a and a lower clamp piece 55b, and the upper and lower clamp pieces 55a and 55b make the pair of protection tubes 13 together.
Hold a and 13b from above and below and bolt both clamp pieces 55a and 55b
Fastened by 56. Therefore, when sandwiched by the clasp tool 55, the pair of sensor units 9a, 9b are moved in the axial direction to be positioned arbitrarily, and as shown in FIG.
A pair of sensor parts according to the mounting inclination angle of the temperature measuring device 7
It is possible to set 8c and 8d so that they are located on the horizontal line, and in that state, they can be fixed and held by the clamp 55. The outer shell unit 10 to which the pair of sensor units 9a and 9b held by the clamp 55 is to be attached has the same structure as the outer shell unit 10 shown in the first illustration, but the cylindrical main body 22
The storage chamber 19 may be formed in an elliptical cross section so as to correspond to the outer shapes of the pair of superposed holding tubes 13a and 13b. (Example of Use of Temperature Measuring Device) The temperature measuring device 7 described above is a furnace 1 as shown in FIG.
Can be attached to. An insertion opening 57 is opened in the upper wall of the furnace 1, and the opening 57 is opened and closed by an opening / closing device 58 such as a butterfly valve. A bellows type cup material 59 is attached to surround the opening 57, and the lower opening edge of the cup material 59 is airtightly attached to the upper wall of the furnace 1. The temperature measuring device 7 is inserted from the upper opening of the cup material 59, the sensor part 8 at the tip is inserted into the quartz crucible 2 and immersed in the silicon melt 4. The temperature measuring device 7 and the upper opening of the cup member 59 are hermetically sealed by a sealing device 60. In this way, the temperature measuring device 7 is hermetically sealed between the outer peripheral surface of the outer shell unit 10 and the outer surface of the furnace wall by the hermetic sealing means constituted by the cup material 59.

Thus, since the sensor portion 8 faces the silicon melt 4 at a predetermined inclination angle, the cup material 59 is deformable via the bellows portion 59a. The tail end of the outer shell unit 10 of the temperature measuring device 7 is inserted into the outside of the cup member 59, and a coolant circulation pipe such as cooling water or cooling air is connected to the inlet port 32 and the outlet port 33, respectively. ． Further, the external connector 35 is connected to a temperature detection device such as an electromotive force display via a lead wire. [Advantage of the Invention] According to the present invention, the temperature measuring device 7 is connected to the sensor unit 9
The sensor unit 9 is divided into an outer shell unit 10 and the both units are detachably assembled, and the quartz tube 12 is used as the thermocouple protection means of the sensor unit 9.
Can be constructed at low cost. As a result, the sensor unit 9 can be made expendable, and the outer shell unit 10 can be made durable, so that the worn out sensor unit 9 can be replaced at any time, while the outer shell unit 10 can be used repeatedly to make It is possible to reduce the overall cost associated with accurate temperature measurement. In addition, when the unit is assembled, the holding tube 13 of the sensor unit 9 is removably inserted into the storage chamber 19 of the tubular main body 22 of the outer shell unit 10 to facilitate the assembly. While attempting to realize the same, the tail end of the storage chamber 19 is sealed by means (sealing means 39 and cap 27, sealing member 41, sealant 45, etc. or other means for closing the tail end opening of the storage chamber in an airtight manner). Since it is insulated from the outside air in an airtight manner, it is possible to prevent the outside air from leaking into the furnace 1 through the temperature measuring device 7, prevent the oxidation of the silicon melt inside the furnace and the explosion accident inside the furnace. It is excellent in the prevention of. Further, since the outer shell unit 10 is formed with the cooling medium passages 29, 30 to have a cooling structure, the durability of the outer shell unit 10 itself can be improved, and the above repeated use can be ensured. Due to the cooling effect, the compensating lead wire in the sensor unit 9 in use, the connection part of the connector, and the like are preferably protected from the high temperature in the furnace, and troubles during temperature measurement can be prevented. With respect to this cooling structure, according to the present invention, the vicinity of the tail end of the quartz tube 12 accommodating the thermocouple 11 is filled with a filler such as refractory cement.
The sensor unit 9 is configured by the holding tube 13 which is embedded and held via 14, and the tubular main body portion 22 of the outer shell unit 10 is
A configuration is provided that includes a holding pipe 13 of the sensor unit 9 inserted into the storage chamber 19 and refrigerant passages 29 and 30 for cooling the tubular main body portion 22 over the entire outer circumferences of the connectors 20 and 34 stored in the storage chamber 19. Therefore, it is particularly excellent in the following effects.

In the configuration in which the sensor unit 9 is detachably attached to the outer shell unit 10 as described above, when the temperature measuring device 7 is inserted into the high temperature atmosphere in the furnace, the holding tube 13 and the tubular body portion 22 are There is a risk that the insertion / bonding point will be heated and seizure will occur. If seizure occurs, it becomes impossible or difficult to replace the consumable sensor unit 9 with the durable outer shell unit 10.

In this regard, according to the present invention, the insertion joint portions of the holding tube 13 and the tubular main body portion 22 are suitably cooled by the refrigerant passages 29 and 30, so that seizure can be prevented, so that a durable shell. The intended purpose of replacing the consumable sensor unit 9 with the unit 10 can be achieved.

In addition, when the sensor unit 9 is heated, the holding tube
In the interior of 13, the quartz tube 12 and the filler 14 such as refractory cement have different expansion coefficients, which causes various inconveniences. The tube 13 can be suitably cooled to prevent expansion differences as much as possible.

For example, when high alumina is selected as the refractory cement that constitutes the filler 14, the expansion coefficient (volume%) of high alumina is 8 ¹ × 10 ^-6 / ° C, while the expansion coefficient of quartz ( (Volume%) is 5 × 10 ⁻⁷ / ° C., so that the expansion coefficient is in the relationship of refractory cement> quartz tube. Therefore, in the configuration of the sensor unit 9 in which the periphery of the quartz tube 12 is filled with the refractory cement 14, when the temperature rises, a gap is created between the quartz tube 12 and the refractory cement 14, and as a result, the gap is generated. There is a risk that the gas in the furnace will enter the storage chamber 19 of the outer shell unit 10 via the and will contaminate the electrical system such as the connectors 20, 34 and the compensating lead wire 21 there. In this regard, according to the present invention, the sensor unit 9 is cooled at least in the portion inserted into the outer shell unit 10 to prevent the expansion difference between the quartz tube 12 and the refractory cement 14 as much as possible. By preventing the occurrence of the gap as described above, it becomes possible to measure the temperature for a long time while protecting the electric system.

Furthermore, according to the present invention, the holding tube of the sensor unit 9 is
Not only 13 but also the connectors 20, 34 and the compensating lead wire 21 housed in the housing chamber 19 of the tubular main body 22 are suitably cooled by the refrigerant passages 29, 30 in the same manner, so an electric system vulnerable to high heat Can be suitably protected.

For example, when a compensation type (JIS C 1610-1981) is used as the core wire of the compensating lead wire 21 of the thermocouple, the temperature error when exposed to high temperature is remarkable, and the operating condition at an upper limit of 150 ° C or less is required. , 50 ° for highly accurate temperature measurement
Use below C is desirable. In this regard, according to the present invention, the temperature rise of the compensating lead wire 21 in combination with the connectors 20 and 34 is prevented, so that it is possible to perform highly accurate temperature measurement for a long time, and also to use repeatedly. By protecting the connector 34 of the outer shell unit 10 from heat, durability is guaranteed.

[Brief description of drawings]

1 is a vertical sectional view showing a temperature measuring device according to a first embodiment of the present invention, FIG. 2 is a vertical sectional view showing an essential part of an outer shell unit according to a second embodiment, and FIG. FIG. 4 is a vertical cross-sectional view showing an essential part of an outer shell unit according to a third embodiment, and FIG.
FIG. 5 is a vertical sectional view showing a sensor unit according to an embodiment, FIG. 5 is a vertical sectional view showing a sensor unit according to a fifth embodiment,
FIG. 6 is a side view showing a temperature measuring device according to a sixth embodiment,
FIG. 7 is a front view of the same device as seen from the front, and FIG. 8 is a vertical cross-sectional view illustrating a state in which the temperature measuring device is mounted in a CZ furnace. 1 ... Furnace, 2 ... Crucible, 4 ... Silicon melt, 7 ... Temperature measuring device, 8 ... Sensor part, 9 ... Sensor unit, 10 ... Outer shell unit, 11 ... Thermocouple, 12 ... Quartz tube, 13 ... Holding tube , 19… Storage room, 2
0… Connector, 22… Cylindrical body, 23… Inner tube, 24… Middle tube, 25…
Outer pipe, 27 ... Cap, 29 ... Inner peripheral side refrigerant passage, 30 ... Outer peripheral side refrigerant passage, 32 ... Inlet port, 33 ... Outlet port, 34
… Internal connector, 35… External connector, 39… Stopper, 41… Seal member, 45… Sealant.

Claims (1)

[Scope of utility model registration request] 1. An outer shell unit (10) which is inserted through a furnace wall and exposed to a high temperature melt (4) in the furnace, and between an outer peripheral surface of the outer shell unit and an outer surface of the furnace wall. An airtight sealing means (59) for airtightly sealing, and a sensor unit (9) detachably attached to the outer shell unit (10) so that the sensor part (8) at the tip is immersed in the high temperature melt (4). The sensor unit (9) comprises a quartz tube (12) accommodating a thermocouple (11), and a portion near the tail end of the quartz tube embedded with a filler (14) such as refractory cement. The outer shell unit, which comprises: a holding tube (13) which is held; and a connector (20) which is arranged on the tail end side of the holding tube and is electrically connected to the thermocouple through a compensation lead wire (21). (10) is a storage for detachably inserting the holding tube (13) of the sensor unit (9). A tubular body (22) having (19), an internal connector (34) arranged in the storage chamber (19) and detachably connected to the connector (20), and the tubular body (22) ) Is disposed on the tail end side of the outer shell unit (10) and is connected to the inner connector (34), and the cylindrical main body part (22) of the outer shell unit (10) is the storage chamber. The tubular main body (22) is cooled over the entire outer circumference of the holding pipe (13) of the sensor unit (9) inserted in the (19) and the connectors (20, 34) housed in the housing chamber (19). The tubular main body (22) is provided with a refrigerant passage (29, 30), and the storage chamber (19) is insulated from the outside air in a hermetic manner at the tail end side of the tubular main body (22). A temperature measuring device for a high-temperature melt such as a silicon alloy, characterized by comprising: