JP4113703B2 - Temperature sensor for packed bed in high temperature and highly corrosive atmosphere and method for installing the temperature sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a temperature sensor for a packed bed having a high temperature and a highly corrosive atmosphere and a method for installing the temperature sensor, and more particularly, filling a high temperature and highly corrosive atmosphere suitable for measuring the temperature in the blast furnace coke layer. The present invention relates to a temperature sensor for a layer and a method for installing the temperature sensor.
[0002]
[Prior art]
As is well known, in a high temperature state, in a coke layer, which is a packed bed of a blast furnace that generates highly corrosive gas, that is, blast furnace gas, heat removal information at the time of rest is extremely important.
In other words, from the heat removal information at the time of off-air, the amount of compensation heat required at the start-up of the off-air is quantified, and the coke ratio at the start-up and the air temperature are adjusted accordingly. It is because it becomes possible to make it. The heat removal during the blast furnace break can be determined by measuring the temperature distribution of the core for a long time and measuring the change in the temperature distribution of the measured core.
[0003]
The core temperature of the blast furnace is expected to be a high temperature of 1500 ° C to 1700 ° C even when there is no wind, but conventionally, the coke in the tuyere is sampled and the highest historical temperature is estimated from its structure. It was. However, such an estimation method has an essential drawback that even if the maximum temperature can be assumed, the temperature cannot be known in real time, and the change with time of the temperature cannot be grasped.
[0004]
Incidentally, techniques for measuring the temperature of a coke combustion zone (hereinafter referred to as a raceway) during blast furnace operation are disclosed in, for example, Japanese Patent Laid-Open Nos. 61-257405, 5-288480, and 7-305105. It is disclosed in the gazette. The outline of the technique for measuring the temperature of the raceway according to each conventional example will be described below.
[0005]
The technique disclosed in Japanese Patent Laid-Open No. 61-257405 is a technique for inserting a probe having a cooling function, in which glass fiber is incorporated, from the tip of a tuyere into the core body of a blast furnace.
Japanese Patent Laid-Open No. 5-288480 discloses an in-furnace monitoring device using an optical fiber at the tuyere of a coke-filling smelting reduction furnace. This is a technique for automatically monitoring a wide range of situations in the raceway by using a monitor and an image processing device.
Japanese Patent Laid-Open No. 7-305105 discloses that a radiation temperature camera is installed at the blast furnace tuyeres, the brightness of the raceway is measured in a non-contact manner, and the measured brightness is measured by an image analyzer. Convert to Then, based on the spectrum analysis of the time-series data of the converted temperature, the decay period θR, 0 of the blast furnace raceway is calculated from the reciprocal of the frequency at which the power density spectrum becomes maximum. On the other hand, the combustion of pulverized coal using the relational expression of the decay period of the raceway and the decay period θR, 0 from the mass balance around the raceway based on the elemental analysis values of tuyere wind speed, pulverized carbon, tuyere diameter, and pulverized coal This is a technique for evaluating the rate ηPC.
[0006]
[Problems to be solved by the invention]
According to each of the prior arts described above, the temperature of the raceway can be measured in real time, and also the change with time of the temperature can be known, which is considered to be extremely useful. However, none of these are intended to measure the core temperature deeper than the raceway. Therefore, with such conventional technology, it is not possible to grasp heat extraction information when the blast furnace is closed.
[0007]
Therefore, an object of the present invention is to provide a high temperature and highly corrosive atmosphere packed bed that makes it possible to stably measure the core temperature deeper than the raceway during a long period of time. It is to provide a temperature sensor and a method for installing the temperature sensor.
[0008]
[Means for Solving the Problems]
The inventors have considered inserting a temperature sensor into the core of a blast furnace in order to solve the above-described drawbacks of the conventional techniques. In order to insert the temperature sensor into the core of the blast furnace, a thrust of several tons is required, and therefore it is necessary to drive the temperature sensor using, for example, a forklift or a hydraulic hammering device. In that case, since the core temperature of the blast furnace exceeds the melting point of the metal protective tube only with the metal protective tube used in a normal thermocouple, such a metal protective tube cannot be used from the viewpoint of heat resistance. In addition, a protective tube made of ceramics cannot be used because it is damaged by an impact caused by impact during charging.
[0009]
Then, when a metal protective tube formed by inserting a protective tube made of ceramics incorporating a thermocouple was struck, this metal protective tube could be driven into the coke layer. However, in the measurement of the temperature in the coke layer of a blast furnace, it is necessary to measure the temperature continuously for several tens of hours to several tens of hours, whereas the actual temperature measurement time is about 1.5 hours. Could not be used.
[0010]
When it was pulled out from the coke layer and investigated, it was found that the protective tube made of ceramics was damaged by the impact at the time of driving, and that the thermocouple was carbonized by the furnace gas entering from the damaged part. Therefore, the inventors first place a high-strength metal cylinder on the coke layer. Then, a protective tube made of ceramics incorporating a thermocouple is inserted into the placed high-strength metal cylinder. In this case, since the impact force does not act on the protective tube, it is considered that the protective tube can be prevented from being damaged.
[0011]
Therefore, in order to solve the above problems, the means adopted by the temperature measuring sensor for the packed bed in the high temperature and highly corrosive atmosphere according to claim 1 of the present invention is closed at the tip and generates highly corrosive gas. A temperature sensor installed in a hot packed bed that protects the heat-resistant metal cylinder to be placed and the sensor body that is inserted into the heat-resistant metal cylinder and held in the insulating tube It is characterized by comprising a tube.
[0012]
The means employed by the temperature measuring sensor for the packed bed in a high temperature and highly corrosive atmosphere according to claim 2 of the present invention is installed in a high temperature packed bed that is closed at the tip and generates highly corrosive gas. Protective tube which is a temperature sensor, and includes a heat-resistant metal tube to be placed and a second protective tube which is inserted into the heat-resistant metal tube and houses a sensor body held by an insulating tube It is characterized by being comprised from these.
[0013]
The means employed by the temperature measuring sensor for the packed bed in a high temperature and highly corrosive atmosphere according to claim 3 of the present invention is installed in a packed bed at a high temperature where the tip is closed and a highly corrosive gas is generated. A plurality of second protections each comprising a heat-resistant metal cylinder to be placed and a sensor main body inserted in the heat-resistant metal cylinder and having different lengths held by an insulating tube. It is comprised from the protective tube in which a pipe | tube is accommodated, It is characterized by the above-mentioned.
[0014]
The means employed by the temperature sensor for the packed bed in the high temperature and highly corrosive atmosphere according to claim 4 of the present invention is the high temperature and high corrosion according to any one of claims 1 to 3. In the temperature sensor for the packed bed in the atmosphere, the protective tube is composed of a plurality of refractory tubes having different diameters, and a small-diameter refractory tube is inserted into the refractory tube in order, It is characterized by having a double or triple structure in which a refractory cement is interposed in the gap.
[0015]
The means employed by the temperature sensor for the packed bed in the high temperature and highly corrosive atmosphere according to claim 5 of the present invention is the high temperature and high corrosion according to any one of claims 1 to 4. In the temperature measuring sensor for the packed bed in the atmosphere, a heat-resistant thermal shock absorbing material is interposed between the heat-resistant metal tube and the protective tube.
[0016]
The means adopted by the temperature sensor installation method for a packed bed in a high temperature and highly corrosive atmosphere according to claim 6 of the present invention is that the tip is closed in the high temperature packed bed that generates highly corrosive gas. A heat-resistant metal cylinder is placed, and then a protective tube containing a sensor body held by an insulating tube is inserted into the heat-resistant metal cylinder.
[0017]
The means adopted by the temperature sensor installation method for the packed bed in the high temperature and highly corrosive atmosphere according to claim 7 of the present invention is the measurement for the packed bed in the high temperature and highly corrosive atmosphere described in claim 6. In the temperature sensor installation method, when the protective tube is inserted into the heat-resistant metal cylinder, a heat-resistant thermal shock absorbing material is provided on the outer periphery of the protective tube.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a temperature sensor for a packed bed in a high temperature and highly corrosive atmosphere according to Embodiment 1 of the present invention will be described with reference to the accompanying drawings. A case of a layer will be described as an example. FIG. 1 is an explanatory diagram of the state of installation of a temperature sensor in a blast furnace, FIG. 2 (a) is a schematic cross-sectional view of the tip, and FIG. 2 (b) is an A- It is A sectional view.
[0019]
Reference numeral 1 shown in FIG. 1 is a temperature measuring sensor having a configuration to be described later. The temperature sensor 1 is driven from a tuyere 102 attached to the iron skin 101 of the blast furnace 100 to a coke layer 103 which is a packed bed in the blast furnace 100. As shown in FIG. 1, the temperature sensor 1 includes a heat-resistant metal cylinder 2 made of SUS304 that is driven from a tuyere 102 into a coke layer 103 in a blast furnace 100. The tip of the heat-resistant metal cylinder 2 is closed and sharpened by a conical body so that it can easily enter the coke layer 103. By the way, what is stacked between the inner periphery of the tuyere 102 and the outer periphery of the temperature sensor 1 is a fluffy alumina fiber (trade name; kao wool) 6, which is used for air flow into the blast furnace 100. This is to prevent inflow.
[0020]
Next, a protective tube 3 having a configuration which will be described later is inserted into the heat-resistant metal cylinder 2 driven into the coke layer 103. The protective tube 3 is composed of three types of refractory tubes 31, 32, and 33 having different diameters. More specifically, a refractory tube having a small diameter is sequentially inserted into the refractory tube, and a triple structure is formed as shown in FIGS. 2 (a) and 2 (b). These three types of refractory tubes 31, 32, 33 are all formed from recrystallized alumina (melting point 2015 ° C.). Each of the three types of refractory pipes 31, 32, 33 constituting the protective pipe 3 is composed of a plurality of pipes connected by a heat resistant cement 8. And the connection part of these pipe | tubes overlaps so that it may not mutually overlap as shown to Fig.2 (a).
[0021]
Further, the gap between the refractory tube 31 and the refractory tube 32 and between the refractory tube 32 and the refractory tube 33 is filled with the heat-resistant cement 8 in the same manner as the connection portion of the tube. With such a configuration of the protective tube 3, even if the heat-resistant metal tube 2 is melted, the time required for the in-furnace gas to penetrate to the position of the thermocouple 5 can be greatly extended, and stable for a long time. Temperature measurement is possible.
[0022]
As refractories other than recrystallized alumina, for example, silicon carbide, zirconia, cermet cermotherm and the like can also be employed for the protective tube 3.
By the way, the material of the protective tube may be a refractory material that is airtight, resistant to thermal shock, and resistant to a reducing atmosphere. The reason why the protective tube 3 made of recrystallized alumina is used is that it has the above characteristics, is inexpensive, and is easily available.
[0023]
In the protective tube 3, three thermocouples 5, which are sensor bodies that are passed through and held by two parallel through holes of an insulating tube 4 made of recrystallized alumina, are inserted. The lengths of these three thermocouples 5 are different from each other, and the three thermocouples 5 are configured to be able to individually measure the temperatures at three locations shifted by a predetermined distance in the longitudinal direction of the protective tube 3. These thermocouples 5 are all B thermocouples, that is, platinum / 30% rhodium / platinum / 10% rhodium thermocouples, and these are all calibrated in advance. In this case, three pairs of thermocouples 5 are inserted in the protective tube 3, but the number of thermocouples may be one pair, two pairs, or four or more pairs. . In other words, the number of inserted thermocouples 5 is determined by the inner diameter of the protective tube 3 that can be inserted into the heat-resistant metal cylinder 2 that can be inserted into the tuyere 102. In addition to a platinum / rhodium thermocouple, for example, a tungsten / rhenium thermocouple can be used.
[0024]
Further, a heat resistant thermal shock absorbing material 7 is interposed between the inner surface of the heat resistant metal cylinder 2 and the outer surface of the protective tube 3. The heat-resistant thermal shock absorbing material 7 is made of an alumina sleeve or alumina fiber (trade name: kao wool). The heat-resistant thermal shock absorbing material 7 is packaged on the outer periphery of the protective tube 3 when the protective tube 3 is inserted into the heat-resistant metal cylinder 2. As described above, the heat-resistant thermal shock absorbing material 7 is provided on the outer periphery of the protective tube 3 because the inner wall surface of the heat-resistant metal cylinder 2 is at a high temperature and may be damaged by the thermal shock at the time of charging. Because there is.
[0025]
Hereinafter, the operation mode of the temperature sensor 1 having the above-described configuration will be described. When the temperature sensor 1 is driven from the tuyere 102 of the blast furnace 100 to the coke layer 103, the heat-resistant metal cylinder 2 is first driven into the coke layer 103 until it reaches the furnace core having a predetermined depth.
Next, after heat-resistant buffer material 7 is sheathed on the outer periphery of protective tube 3 into which thermocouple 5 is inserted, protective tube 3 is pushed together with heat-resistant buffer material 7 to be inserted into heat-resistant metal tube 2. The temperature measuring sensor 1 is configured by the procedure described above.
[0026]
According to such a procedure, the impact due to the impact does not act on the protective tube 3 and the thermal shock does not act on the protective tube 3, so that the protective tube 3 is not damaged in the heat resistant metal cylinder 2. The temperature sensor 1 can be configured by charging.
[0027]
Since the temperature in the coke layer 103 is high, the heat-resistant metal cylinder 2 placed on the coke layer 103 is melted down after a predetermined time. However, the temperature sensor 1 is configured as follows as described above.
(1) The connecting portions of the three types of refractory pipes 31, 32, 33 of the protective pipe 3 are connected by a heat resistant cement 8.
(2) The connection parts of the three types of refractory pipes 31, 32, 33 of the protective pipe 3 are overlapped so as not to overlap each other.
(3) The gaps between the refractory pipe 31 and the refractory pipe 32 of the protective pipe 3 and between the refractory pipe 32 and the refractory pipe 33 are filled with the heat-resistant cement 8.
[0028]
Therefore, according to the temperature measuring sensor 1 according to the first embodiment, it takes a long time for the gas in the furnace to enter the position of the thermocouple 5, so the temperature in the coke layer 103 is measured for a long time. You can continue. And after temperature measurement is completed, the blast furnace operation can be continued without any trouble by pulling out the temperature sensor 1 and removing it from the tuyere 102.
[0029]
Next, a temperature sensor for a packed bed in a high temperature and highly corrosive atmosphere according to Embodiment 2 of the present invention will be described with reference to FIG. However, since the temperature sensor according to the second embodiment is similar to the temperature sensor according to the first embodiment, the same reference numerals are given to the same and the same functions as those in the first embodiment. The same name is used for explanation.
[0030]
The protective tube 3 of the temperature measuring sensor 1 according to the second embodiment has a double structure of a refractory tube 31 and a refractory tube 32 made of recrystallized alumina. The protection tube 3 is loaded with three second protection tubes 34, 34, 34 having different lengths, in which the thermocouples 5 having different lengths held in the insulating tube 4 are loaded. ing.
[0031]
That is, the temperature measuring sensor 1 according to the second embodiment also individually adjusts the temperatures at three locations that are shifted by a predetermined distance in the longitudinal direction of the protective tube 3 as in the case of the temperature measuring sensor 1 according to the first embodiment. The temperature can be measured. And the connection part of two types of refractory pipe | tubes 31 and 32 of the protection pipe 3 is connected with the heat-resistant cement 8, and it overlaps so that it may not mutually overlap. Further, the gap between the refractory tube 31 and the refractory tube 32 of the protective tube 3 is filled with the heat-resistant cement 8.
[0032]
Therefore, according to the temperature sensor 1 according to the second embodiment, since it takes a long time for the in-furnace gas to enter the position of the thermocouple 5, it is equivalent to the temperature sensor 1 according to the first embodiment. There is an effect. However, in the temperature measuring sensor 1 according to the second embodiment, as described above, the thermocouple 5 is inserted into the second protective tube 34 having a different length. 1 is superior to the temperature sensor 1 according to FIG.
[0033]
For example, when the protective tube 3 is damaged, in the temperature measuring sensor 1 according to the first embodiment, the in-furnace gas penetrates to the positions of all the thermocouples 5 and becomes platinum carbide (having a low melting point). Since the strand of 5 melts, it becomes impossible to measure temperature at the same time. On the other hand, in the temperature sensor 1 according to the second embodiment, the probability that the three second protective tubes 34 are damaged at the same time is small. That is, even if one second protective tube 34 is damaged, the temperature measurement can be continued with the thermocouple 5 in the remaining second protective tube 34, and thus there is an effect of extending the temperature measurement time. It is superior to the temperature sensor 1 according to the first embodiment.
[0034]
【Example】
Hereinafter, a temperature sensor according to an embodiment of the present invention will be described. The specifications and the like of each part constituting this temperature sensor are as follows.
(1) Heat-resistant metal cylinder Material: SUS304
Total length: 6000mm (excluding sharp edges)
Outer diameter / inner diameter: 34 mm / 28 mm (thickness: 3 mm)
(2) Protection tube (triple structure)
Material: Recrystallized alumina Outer diameter / Inner diameter: 20mm / 16mm, 15mm / 11mm, 10mm / 6mm
(3) Insulating tube material: Recrystallized alumina Number of through-holes: 2
Number used: 1
(4) Thermocouple Material: Platinum, 30% rhodium / Platinum, 10% rhodium Wire diameter: 0.5 mm
Number used: 1 pair
A temperature sensor 1 composed of each part having such specifications was placed in the coke layer from the tuyere, and the temperature of the furnace core at a depth of 4000 mm from the tip of the tuyere was measured. As a result, it was possible to continuously measure the temperature distribution of the core during resting for about 16 hours. In addition, in the temperature sensor 1 which concerns on a present Example, the above-mentioned kao wool was employ | adopted as a heat resistant thermal shock buffer material.
[0036]
In the above embodiment, the case where the thermocouple supported by the insulating tube is directly accommodated in the protective tube having the triple structure has been described. On the other hand, for example, as described in the temperature measuring sensor according to the second embodiment, the thermocouple supported by the insulating tube is accommodated in the second protective tube, and the second protective tube in which the thermocouple is accommodated. May be accommodated in a protective tube having a triple structure. With such a configuration, it takes an even longer time for the in-furnace gas to reach the position of the thermocouple, so there is an effect that it is possible to measure the temperature for an even longer time.
[0037]
Moreover, in the above embodiment and Example, all demonstrated the example in the case of measuring the temperature of the coke layer in a blast furnace with a temperature sensor. However, the temperature measuring sensor according to the present invention can be applied to temperature measurement in a packed bed such as a direct reduction furnace or an alloy iron manufacturing furnace. Therefore, the temperature sensor according to the present invention is not limited to the temperature measurement of the coke layer in the blast furnace.
[0038]
【The invention's effect】
As described above, in the temperature sensor according to claims 1 to 5 of the present invention or the temperature sensor installation method according to claims 6 and 7 of the present invention, until the heat-resistant metal cylinder reaches a predetermined depth. Punch into packed bed in high temperature and highly corrosive atmosphere. Next, after the heat-resistant thermal buffer material is packaged in the protective tube into which the sensor body is inserted, the protective tube is pushed together with the heat-resistant thermal buffer material, and is inserted into the heat-resistant metal cylinder that is driven into the filling layer. To do. Therefore, at the time of insertion into the heat-resistant metal cylinder, impact due to impact does not act on the protective tube, and thermal impact does not act.
[0039]
Therefore, according to the temperature sensor according to claims 1 to 5 of the present invention or the temperature sensor installation method according to claims 6 and 7 of the present invention, the protection tube is not damaged and is mounted in the heat-resistant metal cylinder. The temperature sensor can be configured. The heat-resistant metal cylinder melts, but the sensor body is inserted in the protective tube , and it takes a long time for the high temperature and highly corrosive atmosphere to enter the position of the sensor body. Therefore, the temperature in the packed bed can be continuously measured for a long time.
[0040]
In the temperature measuring sensor according to claim 3 of the present invention, a plurality of second protective tubes each containing a sensor body having a different length are stored in the protective tube, and these second protective tubes are damaged at the same time. There is no such thing. Therefore, even if the protective tube is damaged, the temperature measurement can be continued with the sensor body housed in another second protective tube. Therefore, according to the temperature measuring sensor according to claim 3 of the present invention, the temperature in the packed bed of the high temperature and highly corrosive atmosphere is higher than that in the case where the sensor main body is directly accommodated in the protective tube. There is an effect of extending the temperature measurement time that the temperature can be measured for a longer time.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a state where a temperature sensor is installed in a blast furnace according to the first embodiment of the present invention.
2 (a) is a schematic cross-sectional view of a tip portion of a temperature sensor, and FIG. 2 (b) is a cross-sectional view taken along line A- of FIG. 2 (a) according to the first embodiment of the present invention. It is A sectional view.
FIG. 3 is a schematic cross-sectional view of a tip portion of a temperature sensor according to Embodiment 2 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Temperature sensor, 2 ... Heat-resistant metal cylinder, 3 ... Protection tube, 31, 32, 33 ... Refractory tube, 34 ... 2nd protection tube, 4 ... Insulation tube, 5 ... Thermocouple, 6 ... Alumina fiber, 7 ... heat-resistant thermal shock absorbing material, 8 ... heat-resistant cement 100 ... blast furnace, 101 ... iron skin, 102 ... tuyere, 103 ... coke layer

Claims (7)

A temperature measuring sensor installed in a high-temperature packed bed that closes the tip and generates highly corrosive gas, and is inserted into the heat-resistant metal cylinder and the heat-resistant metal cylinder for insulation. A temperature measuring sensor for a packed bed in a high temperature and highly corrosive atmosphere, characterized by comprising a protective tube containing a sensor main body held in a tube. A temperature measuring sensor installed in a high-temperature packed bed that closes the tip and generates highly corrosive gas, and is inserted into the heat-resistant metal cylinder and the heat-resistant metal cylinder for insulation. A temperature measuring sensor for a packed bed having a high temperature and a highly corrosive atmosphere, characterized in that the temperature sensor is composed of a protective tube in which a second protective tube containing a sensor main body held by the tube is accommodated. A temperature measuring sensor installed in a high-temperature packed bed that closes the tip and generates highly corrosive gas, and is inserted into the heat-resistant metal cylinder and the heat-resistant metal cylinder for insulation. A high temperature and highly corrosive atmosphere packed bed comprising: a protective tube containing a plurality of second protective tubes each housing a sensor body of different length held by the tube Temperature sensor. It said protective tube consists of refractory pipes in which a plurality of diameters are different, sequentially fitted to the small diameter of the refractory tube to refractory tube, double or interposed refractory cement into the gap between the adjacent refractories tube temperature measuring sensor hot, and filling layer of highly corrosive atmosphere according to any one of of the preceding claims 1 to 3, characterized in that a triple configuration.   The high temperature according to any one of claims 1 to 4, wherein a heat resistant thermal shock absorbing material is interposed between the heat resistant metal tube and the protective tube. A temperature sensor for packed beds in highly corrosive atmospheres.   A heat-resistant metal cylinder whose tip is closed is placed in a high-temperature packed bed that generates a highly corrosive gas, and then the protective tube containing the sensor body held by the insulating pipe is connected to the heat-resistant metal cylinder. A method of installing a temperature sensor for a packed bed in a high temperature and highly corrosive atmosphere, characterized by being inserted into the inside.   The high temperature and highly corrosive atmosphere according to claim 6, wherein a heat resistant thermal shock absorbing material is sheathed on an outer periphery of the protective tube when the protective tube is inserted into the heat resistant metal cylinder. How to install temperature sensor for packed bed.

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