JP4146420B2 - Blast furnace tapping temperature and hot metal / molten slag mixing ratio measurement method - Google Patents

Description

  The present invention relates to a method for measuring the temperature of a blast furnace discharge and a mixture ratio of molten iron / molten slag for measuring the mixing ratio and temperature of a mixture of molten iron and molten slag flowing out from the outlet of the blast furnace. Is.

  In blast furnace operation, the temperature of the effluent from the tap is one of the important indicators for judging the heat condition in the furnace. When this temperature fluctuates, it is considered that the heat distribution is not uniform, which is not preferable. For this reason, various methods for measuring the temperature transition of the hot metal flowing out from the outlet of the blast furnace have been devised.

  The hot metal and molten slag flow out from the blast furnace outlet, and after that, the hot metal and molten slag are separated by the skinmer device, and the molten iron flows into the molten iron. Hereinafter, the mixture of molten iron and molten slag flowing out from the outlet is referred to as “depot”. In addition, the temperature of the output flowing out from the output port is referred to as “output temperature”.

  First, a method of measuring hot metal temperature intermittently in a skinmer device using an immersion consumable thermocouple is used as a method of measuring the hot metal temperature used conventionally. Although it is possible to measure temperature with high measurement accuracy and reliability, it is limited to intermittent measurement several times during output due to limitations such as the cost of the precious metal thermocouple probe to be disposable and the labor of manual input. In addition, heat removal from the hot metal to the refractory is large for several tens of minutes from the start of the brewing, and the hot metal temperature measured by the skinmer device must be lower than the brewing temperature at the time of the brewing. The output temperature itself is important in grasping the blast furnace conditions, and the difference between the hot metal temperature in the skinmer device and the output temperature at the outlet is an error factor.

  Radiation temperature measurement can be used as a method for measuring the temperature of a hot object in a non-contact manner. If the emissivity of the object is known, the temperature of the object can be measured based on the measured radiance and emissivity. There are a method of measuring based on a radiance measurement result of a specific wavelength and a known spectral emissivity at that wavelength, or a method of measuring based on total radiant energy and total emissivity.

  Hot metal and molten slag coexist in the spout from the outlet, and the emissivity differs between hot metal and molten slag. For this reason, when radiation temperature measurement is performed at the blast furnace outlet, and the hot metal temperature is measured using the emissivity of the hot metal, an erroneous temperature is measured because the emissivity is different in the molten slag portion.

  In the case of performing radiation temperature measurement on an object whose emissivity is not constant, it is known that the temperature measurement error is reduced by performing temperature measurement using a wavelength as short as possible within the wavelength range in which the radiant energy can be detected. Yes. This point can be derived from Planck's blackbody radiation theory. For this reason, in the temperature range of 1400 to 1600 ° C., a wavelength band of about 0.5 to 0.9 μm is used for radiation temperature measurement.

  In the radiation temperature measurement, a method of measuring the spectral radiance at two or more observation wavelengths is known in order to cope with the problem that the emissivity of the temperature measurement object fluctuates, and is called a two-color method. When the relationship between the two spectral emissivities having different wavelengths varies in a proportional relationship, the ratio of the two spectral radiances depends only on the temperature, so that the temperature can be accurately obtained.

  However, it has been found that even if the above-described two-color method is used for measuring the radiation temperature of the output, it is difficult to measure the temperature of the output with the necessary accuracy. Since the wavelength dependence of the hot metal spectral emissivity is completely different from the wavelength dependence of the molten slag spectral emissivity, the two spectra with different wavelengths are varied in the variation of the spectral emissivity when the mixing ratio of the hot metal and molten slag changes. This is because the emissivity relationship cannot be a constant constant proportional relationship.

  In the hot metal after the hot metal and the molten slag are separated by the skinmer apparatus, a method of continuously measuring the hot metal temperature by radiation temperature measurement is known. However, even in the hot metal part, molten slag and the like are floating on the hot metal, and the suspended matter has become a noise source, causing a sudden change in the temperature measurement value, making accurate temperature measurement difficult. In Patent Document 1, when measuring the temperature of hot metal with a non-contact thermometer, a specific temperature measurement pattern according to the hot metal surface state is detected and classified, and noise removal processing is performed according to the pattern. A temperature detection method is described. Further, in Patent Document 2, in the method of measuring the temperature of the hot metal flowing through the blast furnace tuna with a radiation thermometer, if there is a hot metal having a different emissivity from the hot metal surface, the hot metal and the hot metal are determined on the measurement data. A method is described in which the measurement error due to the iron slag is automatically corrected by distinguishing and the hot metal temperature is measured with high accuracy.

  Patent Document 3 describes a method of measuring radiation temperature by immersing an optical fiber in hot metal ejected from a spout. A consumable metal tube-coated optical fiber connected to an optical fiber radiation thermometer is fed into the hot metal jet and receives heat radiation directly inside the hot metal.

  Patent Document 4 describes a method of estimating the hot metal temperature based on the relationship between the hot metal temperature and the slag temperature obtained separately by causing only the slag to flow out and performing radiation temperature measurement. This method is a method for measuring the temperature of the hot metal contained in a refractory container or the like of a kneading vehicle, and is a temperature measuring method when only slag can be poured out from the container. In order to measure the temperature of the hot metal flowing out from the tap outlet, it flows out in the state where hot metal and molten slag coexist at the outlet of the blast furnace, and slag or hot metal cannot be selected intentionally. This method cannot be applied.

JP-A-1-233329 JP-A-1-185422 JP-A-8-82553 JP 2001-115208 A

  Conventionally, when measuring the hot metal temperature of a blast furnace by radiation temperature measurement, the hot metal temperature measurement in hot metal after separating hot metal and molten slag with a skinmer device has been performed for the purpose of eliminating measurement errors due to molten slag as much as possible. It was broken. However, with this method, the hot metal temperature drops from the hot metal outlet to the hot metal, and the temperature drop is not constant, so it is difficult to accurately measure the hot metal temperature at the hot metal outlet. Further, even in the hot metal, the molten slag is floating on the hot metal, and even if the methods described in Patent Documents 1 and 2 are used, it is difficult to sufficiently reduce the temperature measurement error caused by the floating slag. Met.

  The method described in Patent Document 3 requires an elevating device at the tip of an optical fiber and a delivery mechanism composed of a measure roll. The apparatus becomes large, and hot metal or molten slag is caused by gas ejection from the spout. May scatter, and there is concern about the durability of the device placed near the tap.

  A first object of the present invention is to provide a blast furnace tapping temperature measuring method for simply and continuously accurately measuring the temperature of the tapping outflow from a blast furnace tapping outlet.

  The slag outflow condition evaluated by the mixing ratio of the molten iron and molten slag flowing out from the blast furnace outlet is one index for estimating the soundness of the blast furnace bottom reservoir. Therefore, if the mixing ratio of hot metal and molten slag can be measured, it becomes valuable information for evaluating the soundness of the blast furnace.

  As described above, the soot mixed stream is separated into hot metal and molten slag by a skinmer apparatus. The hot metal is poured into a torpedo car (chaotic car), and the amount of hot metal produced is weighed together with the torpedo car. On the other hand, the molten slag is solidified by water cooling and pulverized and carried out, but since it is weighed after pulverization, it takes several hours until the outflow amount is known. Therefore, it was impossible to know online the mixing ratio of hot metal and molten slag in the outflow flowing out from the outlet.

  The second object of the present invention is to provide a method for measuring the mixing ratio of the molten iron and molten slag flowing out from the outlet of the blast furnace.

That is, the gist of the present invention is as follows.
( 1 ) Spectral radiance is measured in the far-infrared band (hereinafter referred to as “long wavelength band”) for the outflow flowing out from the blast furnace outlet, and hot metal and molten slag are measured based on the measured spectral radiance. A method for measuring the mixing ratio of molten iron and molten slag in the blast furnace
Measuring spectral radiance L _meas, and _LW, black body radiance of Planck of the wavelength at any temperature in the range of 1,500 to 1,600 ° C. L _b, the long-wavelength spectral emissivity epsilon _LW of tapping slag from the _LW The hot metal spectral emissivity ε _{m, LW} and the molten slag spectral emissivity ε _{s, LW} and the long wavelength spectral emissivity ε _LW of the iron blast furnace tapping slag molten iron-molten slag mixture ratio measurement method characterized Rukoto issuing calculate the mixture ratio R.
(2) Long wavelength spectral emissivity of output from measured spectral radiance L _{meas, LW} and plank's black body radiance L _{b, LW of the} wavelength at any temperature in the range of 1500-1600 ° C. ε _LW is obtained by equation (1),
ε _LW = L _{meas, LW} / L _{b, LW} (1)
From the long-wavelength spectral emissivity ε _LW , the long-wavelength spectral emissivity ε _{m, LW} of the molten iron and the long-wavelength spectral emissivity ε _{s, LW} of the molten slag,
_{R = (ε s, LW -} ε LW) / (ε s, LW - ε m, LW) (2)
The method for measuring the hot metal / molten slag mixing ratio of the blast furnace feed described in the above (1), characterized by estimating.
( 3 ) The method for measuring the mixing ratio of molten iron / molten slag in the blast furnace as described in ( 1 ) or ( 2 ) above, wherein the long wavelength band is a wavelength band of 8 to 12 μm.
( 4 ) By the method for measuring the hot metal / molten slag mixing ratio of the blast furnace feed as described in one of (1) to (3 ) above,
Based on the measured spectral radiance L _{meas, LW} in the long wavelength band, the mixing ratio R of the hot metal and molten slag is obtained, and the obtained mixing ratio R, the spectral emissivity ε _{m, SW} of the hot metal in the short wavelength band and melting A method for measuring a blast furnace outlet temperature, wherein the temperature T of the slag is determined based on the spectral emissivity ε _{s, SW of} the slag and the measured spectral radiance L _{meas, SW} in a short wavelength band.
( 5 ) When determining the temperature T of the molten iron, from the mixing ratio R of the molten iron and molten slag and the spectral emissivity ε _{m, SW} of the molten iron in the short wavelength band and the spectral emissivity ε _{s, SW of the} molten slag, The output emissivity ε _SW of the output in the short wavelength band is obtained, and the output temperature T is determined by comparing this with the measured spectral radiance L _{meas, SW} in the short wavelength band. The blast furnace discharge temperature measuring method according to (4) above.
( 6 ) The blast furnace output as described in (4) or (5) above, wherein the short wavelength band is a wavelength of 0.5 to 1.5 μm and the long wavelength band is a wavelength of 8 to 12 μm. Temperature measurement method.

In the present invention, the spectral emissivity ε _{m, SW} of the hot metal in the short wavelength band and the spectral emissivity ε _{s, SW} of the molten slag are obtained in advance prior to measurement.

  According to the present invention, it is possible to perform radiation temperature measurement while measuring the emissivity that determines the accuracy of the radiation temperature measurement on-line. Therefore, since the hot metal and slag are mixed at an unknown ratio, the emissivity varies. The temperature of the jet can be measured with high accuracy.

  As a feature of radiation temperature measurement, there is no need to install a device near the tap and remote measurement is performed from a remote location, so environmental measures such as hot metal / slag thermal radiation and splash are simple. In addition, continuous measurement is possible, and it becomes possible to grasp the heat condition inside the blast furnace more quickly and accurately than the change and transition of the tapping temperature, so that the operation of the blast furnace can be made more stable.

  Moreover, since the present invention can evaluate the mixing ratio of the molten iron and molten slag flowing out from the outlet of the blast furnace online, it is possible to accurately estimate the soundness of the blast furnace bottom reservoir layer. .

  First, problems in measuring the temperature of the brewery using a conventional radiation temperature measurement method will be described.

  As described above, the molten iron and the molten slag are ejected from the tap outlet in a mixed state. Although there are cases where only the hot metal or molten slag is used for a short period of time between the beginning and the end of the brewing process, the molten iron and the molten slag flow out in a mixed state as a liquid during normal brewing. The mixing ratio of hot metal and molten slag always fluctuates, and it is not possible to obtain this mixing ratio online near the tap. As described above, the emissivity is different between hot metal and molten slag. For this reason, when radiation temperature measurement is performed using the emissivity of the hot metal as the emissivity, an error occurs in which the measured temperature deviates from the actual temperature at the moment when molten slag is present in the radiation temperature observation field of view. .

  Conventionally, the spectral emissivity for each wavelength of hot metal and molten slag has not been examined in detail. In particular, the wavelength dependence in the infrared region of the spectral emissivity of blast furnace slag in a high-temperature molten state has not been known. Therefore, the present inventor investigated the spectral emissivities of hot metal and molten slag by experiments. As a result, as shown in FIG. 1, the spectral emissivity of the hot metal gradually decreases as the wavelength becomes longer, while the spectral emissivity of the molten slag has a local minimum value near the wavelength of 1.3 μm and is longer than that. Then, it became clear that it gradually increased as the wavelength increased.

  The reason why accurate temperature measurement was not possible even when the two-color method was used for the radiation temperature measurement of the hot metal was due to the above-mentioned characteristics of the wavelength dependence of the spectral emissivity of the hot metal and molten slag. For example, it is assumed that the dichroic method is used with a wavelength of 2 μm as the short wavelength side and a wavelength of 10 μm as the long wavelength side. When the output is 100% hot metal and the emissivity is the lowest, the short wavelength spectral emissivity is larger than the long wavelength spectral emissivity. On the other hand, when the output is 100% molten slag and the emissivity is the highest, the short wavelength spectral emissivity is smaller than the long wavelength spectral emissivity. That is, when the mixing ratio of hot metal and molten slag changes and the emissivity fluctuates, the ratio between the spectral emissivity on the short wavelength side and the spectral emissivity on the long wavelength side is not kept constant, and the proportional relationship is maintained. There is no. This makes it impossible to measure the output temperature by the two-color method.

  When the emissivity of the measurement target is not constant, it is known that the temperature measurement error of the radiation temperature measurement is reduced by making the observation wavelength as short as possible within the range in which the amount of the emitted light can be detected. This point is derived from Planck's blackbody radiation theory. Since the blast furnace temperature range is 1500-1600 ° C., a wavelength of about 0.5-0.9 μm was used for radiation temperature measurement. Further, as can be seen from FIG. 1, since there is a region where the spectral emissivity difference between the hot metal and the molten slag is the smallest in the vicinity of the wavelength of 1.5 μm, the measurement wavelength range with little temperature measurement error is expanded to the wavelength of 1.5 μm. be able to.

However, even if there are few temperature measurement errors in radiation temperature measurement in the short wavelength region, it is difficult to achieve the accuracy required as the temperature measurement accuracy of the blast furnace output. FIG. 2 is a graph in which the temperature change of the spectral radiance of hot metal and molten slag at a wavelength of 0.6 μm is calculated based on Planck's blackbody radiation theory. Since the temperature of the brewery is approximately in the range of 1500-1600 ° C., this temperature range is shown. For example, it is assumed that the spectral radiance obtained by measuring radiation at a wavelength of 0.6 μm at a certain moment is 1700 (W / sr / μm / m ² ). The temperature is calculated to be 1580 ° C. if the molten iron at that moment is assumed to be 100% molten iron, but the temperature is calculated to be 1500 ° C. if the molten iron is assumed to be 100% molten slag. In other words, depending on the assumption of the mixing ratio of the molten iron slag and the molten slag, a measurement temperature error of 80 ° C. exists. This does not provide the accuracy required to control the hot metal temperature.

  By the way, in the long wavelength region (far infrared region) having a wavelength of 10 μm, the horizontal axis is the temperature (1500 to 1600 ° C.) as in FIG. 2, and the spectral radiances of the hot metal and the molten slag are calculated and illustrated. become that way. From FIG. 3, it is assumed that the radiance is obtained by measuring the temperature of the actual brewery, and the measured temperature fluctuates greatly depending on the assumption of the mixing ratio of the molten iron and molten slag. it is obvious. This is also why the long wavelength region was not used when measuring the temperature of an object whose emissivity varies.

  As is clear from FIG. 3, in the long wavelength region with a wavelength of 10 μm, the variation in the radiance of the hot metal and molten slag in the temperature range of 1500 to 1600 ° C., which is the temperature range of the brewing, is slight, at most ± 5 %. On the other hand, in this temperature region, the radiance is greatly different between the case where the molten iron is 100% molten iron and the case where the molten iron is 100% molten slag. This is much larger than the difference in radiance. From this fact, if the spectral radiance of the ferment (temperature is in the range of 1500 to 1600 ° C.) is measured in the far-infrared band, the mixing ratio of the hot metal and molten slag is within a slight error range. It is derived that it can be calculated.

  Based on the radiance measurement in the long wavelength band, the mixing ratio R (hereinafter also simply referred to as “mixing ratio R”) of the molten iron and molten slag can be calculated as described above. From this, it is clear that the mixing ratio of the molten iron and molten slag flowing out from the outlet of the blast furnace, which is the second object of the present invention, can be measured.

  On the other hand, since the emissivity of the molten iron and the emissivity of the molten slag are known in the short wavelength band, if the mixing ratio R is known, the emissivity of the molten iron in the short wavelength band can be calculated. . Therefore, secondly, using the mixing ratio R calculated as a result of the measurement of the long wavelength band, the emissivity of the output in the short wavelength band is calculated, and at the same time as the measurement of the long wavelength band, If the radiance measurement in the wavelength band is performed, the output of the output which is the first object of the present invention is calculated from the calculated emissivity of the output in the short wavelength band and the measured radiance measurement result of the output. It can be seen that the temperature can be accurately measured.

The present invention has been made on the basis of the above-described knowledge, and when measuring the temperature of the brewery flowing out from the blast furnace outlet by the radiation temperature measurement method, the visible or near infrared band (short wavelength band). And the spectral radiance at two wavelengths in the far-infrared band (long wavelength band), and the mixing ratio R of hot metal and molten slag is obtained based on the measured spectral radiance L _{meas, LW} in the long wavelength band , mixing was determined ratio R, measured spectral radiance L _meas in spectral emissivity epsilon _{s, SW} spectral emissivity epsilon _{m, SW} of molten slag, and short wavelength band of hot metal in a short wavelength _band, based on the _SW A method for measuring the temperature of a blast furnace discharge, characterized in that the temperature T of the discharge is determined.

Spectral radiance is measured at the far-infrared band (long wavelength band) for the outflow flowing out of the blast furnace outlet _, and the hot metal and molten slag are measured based on the measured spectral radiance L _{meas and LW} . A mixing ratio R is obtained, which is a method for measuring the mixing ratio of hot metal / molten slag in the blast furnace.

Here, the spectral emissivity ε _{m, SW} of the hot metal in the short wavelength band and the spectral emissivity ε _{s, SW} of the molten slag are obtained in advance prior to measurement.

  This will be specifically described below.

When obtaining the mixing ratio R of the hot metal and molten slag based on the measured spectral radiance L _{meas, LW} in the long wavelength band, one of two methods can be used. _Firstly, the long-wavelength spectral emissivity ε _LW of the _output is obtained from the measured spectral radiance L _{meas, LW} , and the molten iron spectral emissivity ε _{m, LW} and the molten slag spectral radiation in the long-wavelength band obtained in advance. This is a method of calculating the mixing ratio R of hot metal and molten slag from the rate ε _{s, LW} and the long-wavelength spectral emissivity ε _{LW of the} above iron. The second example is a reference example, in which the spectral radiance L _{m, LW} of the hot metal in the long wavelength band, the spectral radiance L _{s, LW of the} molten slag _, and the measured spectral radiance L _{meas, This} is a method of calculating the mixing ratio R of hot metal and molten slag from _LW .

In the first method, first, the long-wavelength spectral emissivity ε _LW is calculated from the measured long-wavelength spectral radiance L _{meas, LW} using the following equation (1). At this time, the temperature may be any temperature in the range of 1500 to 1600 ° C., but here it is assumed to be 1550 ° C., which is an intermediate value from 1500 ° C. to 1600 ° C.
ε _LW = L _{meas, LW} / L _{b, LW} (1550 ℃) (1)
Here, L _{meas, LW} is a measured value of radiance at a long wavelength, L _{b, LW} (1550 ° C.) is a long wavelength observation wavelength, and Planck's black body radiance at 1550 ° C.

In the present invention, it has been known in advance that the output temperature is in the range of 1500 to 1600 ° C. Therefore, the black body radiances L _{b and LW} used for calculating the long wavelength spectral emissivity ε _LW are determined. The temperature can be defined as a constant temperature within the expected range of the output temperature. In the above formula (1) _, the temperatures of L _{b and LW} are 1550 ° C. As a result, as described above, even if the actual temperature of the output is outside the range of ± 50 ° C. from the assumed 1550 ° C., the long-wavelength spectral luminance falls within ± 5% of the fluctuation. The spectral emissivity is also preferable because it can be obtained with an accuracy within ± 5%.

The long-wavelength spectral emissivity ε _LW of the molten iron is based on the molten iron spectral emissivity ε _{m, LW} , the molten slag spectral emissivity ε _{s, LW} and the mixing ratio R of the molten iron and slag in the long wavelength band,
ε _LW = ε _{m, LW} · R + ε _{s, LW} · (1-R)
It is related as follows. Conversely, the hot metal / slag mixing ratio R is calculated from the long-wavelength spectral emissivity ε _{LW of} the hot metal, the long-wavelength spectral emissivity ε _{m, LW} of the hot metal, and the long-wavelength spectral emissivity ε _{s, LW} of the molten slag. It can be estimated by the following equation (2).
R = (ε _{s, LW} −ε _LW ) / (ε _{s, LW} −ε _{m, LW} ) (2)
Here, ε _{s, LW is} a spectral emissivity of slag in a long wavelength band measured in advance _, and ε _{m, LW} is a spectral emissivity of hot metal in a long wavelength band measured in advance. Further, the mixing ratio R is determined as the ratio of hot metal during the cooking.

In the above-described second method, firstly, the spectral radiance L _m of hot metal in the long wavelength _{band, LW} spectral radiance L _s of the molten _slag, is obtained in advance and _LW. These values, temperature assuming 1550 ° C. which is an intermediate value of 1600 ° C. from 1500 ° C., determined from the long-wavelength spectral emissivity epsilon _{s, LW} of molten slag and the long-wavelength spectral emissivity epsilon _{m, LW} of hot metal be able to. Based on these values and the measured spectral radiance L _{meas, LW} , the hot metal / slag mixing ratio R can be estimated by the following equation.
R = (Ls _{, LW- Lmeas, LW} ) / (Ls _{, LW-} Lm _{, LW} )

After obtaining the mixing ratio R by the first method or the second method, the mixing ratio R, the spectral emissivity ε _{m, SW} of the hot metal in the short wavelength band, and the spectral emissivity ε _{s, SW of the} molten slag are obtained. And the temperature T of the output is determined based on the measured spectral radiance L _{meas, SW} in the short wavelength band.

Here, even in the short wavelength band of visible or near infrared, it is considered that the value of the spectral emissivity of the output is determined by the mixing ratio R of hot metal and slag. Therefore, in determining the temperature T of the molten iron, the mixing ratio R of the molten iron and the molten slag and the spectral emissivity ε _{m, SW} of the molten iron in the short wavelength band and the spectral emissivity ε _{s, SW of the} molten slag are calculated spectral emissivity epsilon _SW of tapping slag in a wavelength band, and to define the temperature T of the tapping slag measuring spectral radiance L _meas in spectral emissivity epsilon _SW and short wavelength _band, by comparing the _SW It is preferable.

That is, the output spectral emissivity ε _SW in the short wavelength band is obtained based on the following equation (3).
ε _SW = ε _{s, SW} −R ・ (ε _{s, SW} −ε _{m, SW} ) (3)
Here, ε _{s, SW is} a spectral emissivity of molten slag in a short wavelength band measured in advance _, and ε _{m, SW} is a spectral emissivity of hot metal in a short wavelength band measured in advance.

The relationship between the spectral radiance measurement value L _{meas, SW} at a short wavelength and the temperature T is expressed by the following equation.
L _{meas, SW} = ε _SW · L _{b, SW} (T) (4)
L _{b, SW} (T) = c ₁ λ _SW ^-5 · exp (−c ₂ / λ _SW / T) (5)
Here, λ _{SW is a} visible or near-infrared observation wavelength, c _{1 is} a first constant of Planck, and c ₂ is a second constant of Planck.

Solving equations (4) and (5) for temperature T,
T = − (c ₂ / λ _SW ) / ln {(L _{meas, SW} / ε _SW ) / (c ₁ λ _SW ⁻⁵ )} (6)
It becomes.

  In the present invention, the short wavelength band is preferably a wavelength band of 0.5 to 1.5 μm, and the long wavelength band is preferably a wavelength of 8 to 12 μm. If the short wavelength band is a wavelength range of 0.5 to 1.5 μm, the measurement error after the emissivity is estimated is sufficiently small. In addition, when obtaining spectral emissivity in the long wavelength band, light with a longer far-infrared wavelength is better. However, in practice, a wavelength range of 8 to 12 μm and a light absorption path on the optical path called an atmospheric window is suitable. ing.

If the spectral emissivity ε _SW in the visible or near infrared can be estimated with an accuracy of ± 5%, the error due to the emissivity of the temperature T is about ± 5 ° C., and sufficient accuracy can be obtained for the output temperature management. .

  The present invention was carried out for the purpose of measuring the temperature of the brewery flowing out from the blast furnace outlet and the mixing ratio R of the molten iron and molten slag. For the short wavelength band of visible or near infrared, radiance was observed at a wavelength of 0.6 μm. For the far-infrared long wavelength band, radiance was observed at a wavelength of 10 μm.

  As shown in FIG. 4, the tap 2 flowing out of the tap 1 was observed from the lateral direction. A short wavelength detection radiometer 4 that detects a wavelength of 0.6 μm and a long wavelength detection radiometer 5 that detects a wavelength of 10 μm are arranged side by side, and the optical axis is set so that both capture the same observation point 7 of the output 2 . The output signals of the short wavelength detection radiometer 4 and the long wavelength detection radiometer 5 are input to the calculation device 6, where emissivity calculation based on the above-described equations (1) to (5), calculation of the mixing ratio R, Temperature calculation is performed. Specifically, the arithmetic unit 6 used a personal computer. The calculation result of the tapping temperature T is displayed in a graph on a personal computer screen and saved in a storage device inside the personal computer.

  The temperature transition of the output 2 in the middle of the output was measured by the method of the present invention, and compared with the measured value obtained by performing a manual immersion / consumable thermocouple near the output port (FIG. 5). It was confirmed that the radiation temperature measurement by the method of the present invention (dotted line in the figure) and the conventional thermocouple measurement (■ in the figure) agree well. The radiation temperature measurement according to the present invention is characterized in that a continuous temperature transition can be observed.

  The transition of the mixing ratio R between the hot metal of the hot metal 2 and the molten slag in the middle of the hot spring was measured by the method of the present invention, and is shown by a solid line in FIG. The mixing ratio R represents the area ratio between the hot metal and the molten slag that appears on the surface of the molten iron, and this corresponds to the volume ratio of the molten iron and the molten slag at the same time. In addition, the broken line in FIG. 6 is the result of calculating the volume ratio of hot metal and molten slag based on the hot metal weighing value weighed after pouring into the torpedo car and the slag weighing value weighed after water cooling. The conversion from mass to volume was calculated as the specific gravity of hot metal 6.8 and the specific gravity of slag 2.8. As a matter of course, the broken line is an average value of the total amount of output in one output, and the evaluation result is found after several hours have passed since the output.

It is a figure which shows the wavelength dependence of the spectral emissivity of hot metal and molten slag. It is a figure which shows the temperature dependence of the radiance of hot metal and slag in wavelength 0.6micrometer (short wavelength) and the temperature of 1500-1600 degreeC. It is a figure which shows the temperature dependence of the radiance of hot metal and slag in wavelength 10micrometer (long wavelength) and the temperature of 1500-1600 degreeC. It is a perspective conceptual diagram which shows the condition which measures the temperature of the tapping using this invention. It is a figure which shows the temperature measurement result of the brewing by this invention. It is a figure which shows the hot metal / molten slag mixing ratio measurement result of the brewery by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outlet 2 Outlet 3 Outgoing 4 Short wavelength detection radiometer 5 Long wavelength detection radiometer 6 Arithmetic unit 7 Observation point

Claims (6)

Spectral radiance is measured at the far-infrared band (hereinafter referred to as “long wavelength band”) for the outflow flowing out from the blast furnace outlet, and the mixture of hot metal and molten slag is based on this measured spectral radiance. A method for measuring the mixing ratio of molten iron / molten slag in a blast furnace to obtain a ratio,
The long-wavelength band obtained in advance by calculating the long-wavelength spectral emissivity of the output from the measured spectral radiance and the plank black radiance of the wavelength at any temperature in the range of 1500 to 1600 ° C. hot metal blast furnace tapping slag it characterized Rukoto issuing calculate the mixing ratio of the hot metal spectral emissivity and the molten slag spectral emissivity and long wavelength spectral emissivity of the tapping slag and molten iron and molten slag in・ Measuring method of molten slag mixing ratio. Measuring spectral radiance L _meas, and _LW, black body radiance of Planck of the wavelength at any temperature in the range of 1,500 to 1,600 ° C. L _b, the long-wavelength spectral emissivity epsilon _LW of tapping slag from the _LW Obtained by equation (1),
ε _LW = L _{meas, LW} / L _{b, LW} (1)
From the long-wavelength spectral emissivity ε _LW , the long-wavelength spectral emissivity ε _{m, LW} of the molten iron and the long-wavelength spectral emissivity ε _{s, LW} of the molten slag,
_{R = (ε s, LW -} ε LW) / (ε s, LW - ε m, LW) (2)
The method for measuring the mixing ratio of hot metal / molten slag in the blast furnace feed according to claim 1, wherein the estimation is performed. The long wavelength band blast tapped slag molten iron-molten slag mixture ratio measuring method according to claim 1 or 2, characterized in that a wavelength 8~12μm band. By the method for measuring the hot metal / molten slag mixing ratio of the blast furnace feed according to claim 1,
Obtain the mixing ratio of hot metal and molten slag based on the measured spectral radiance in the long wavelength band, find the mixing ratio, the spectral emissivity of molten iron and the spectral emissivity of the molten slag in the short wavelength band, and the short wavelength band A method for measuring a blast furnace output temperature, wherein the temperature of the output is determined on the basis of the measured spectral radiance in the furnace. When determining the temperature of the molten iron, the spectral emissivity of the molten iron in the short wavelength band is determined from the mixing ratio of the molten iron and molten slag, the spectral emissivity of the molten iron in the short wavelength band and the spectral emissivity of the molten slag. The method for measuring a blast furnace output temperature according to claim 4 , wherein the temperature of the output is determined by comparing the measured spectral radiance with the measured spectral radiance in the short wavelength band. 6. The blast furnace discharge temperature measurement according to claim 4, wherein the short wavelength band is a wavelength band of 0.5 to 1.5 μm, and the long wavelength band is a wavelength band of 8 to 12 μm. Method.

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