JPH1151880A - Moisture containing amount measuring unit of iron melting vessel inner lining refractory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture containing amount measuring unit capable of highly precisely measuring an amount of moisture containing in an inner lining refractory stuck on the surface of the iron plate of an iron melting vessel. SOLUTION: With regard to a moisture containing amount measuring unit 1, a thermal neutron tube 3 is disposed in a groove-like recess 2a at the side of being brought into contact with the surface of an iron plate 11 of an iron melting vessel of a block-like iron member 2, and a thermal neutron column 4 composed of a pair of graphite is disposed in a recess 22a and at a position of sandwiching the thermal neutron tube 3, and a neutron generation source 5 is fitted in the minute hole of the opening side of the recess 2a separated from the recess 2a. As a result, those which are decelerated and radiated from the neutron generation source 5, decelerated and scattered by moisture of an inner lining refractory 13 and returned as the thermal neutron, middle and fast neutrons are properly made the thermal neutrons by the thermal neutron column 4 to be counted by the thermal neutron tube 3, even such returned middle and fast neutrons are included without being converted to the thermal neutron.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water content measuring unit for measuring the amount of water contained in a test object by using neutrons, and more particularly, to a water content measuring unit stretched inside a steel shell of a molten metal container. It belongs to the technical field of a unit for measuring the water content of a refractory lining a molten metal vessel for measuring the amount of water contained in an irregular type refractory with high accuracy.

[0002]

2. Description of the Related Art As is well known, there is a moisture meter that measures the amount of moisture contained in a subject using neutrons. Such a moisture meter is disclosed, for example, in Japanese Patent Laid-Open No. 51-49.
No. 788 (Conventional Example 1) and Japanese Patent Application Laid-Open No. 49-64602 (Conventional Example 2), the outlines of these moisture meters and moisture measuring devices are described in these specifications. Description will be made sequentially using the same reference numerals and the same names.

First, the "ultra-low-level neutron transmission type moisture meter" according to Conventional Example 1 will be described with reference to FIG. A high-voltage power supply 7 and a preamplifier 8 are provided in an upper part of the inside. A neutron moderator 3 having a thermal neutron detection tube 4 embedded therein is provided below the inside of the head outer box 1.
The neutron moderator 2 is covered with the thermal neutron absorber 2. Further, the head outer case 1 has a configuration in which a source rod 5 penetrating downward from above and having a neutron source 6 of 100 microcuries or less embedded therein is attached to a tip thereof. The meter measures moisture in the ground.

When measuring moisture in the ground with the extremely low-level neutron transmission moisture meter having such a configuration, first, the head outer box 1 is set on the ground, and the source rod 5 is inserted into the ground. Then, fast neutrons emitted from the neutron source 6 at the tip of the source rod 5 are partially converted into thermal neutrons mainly due to the interaction with water molecules in the ground, and the other part is converted into medium neutrons. The neutrons reach the head outer box 1 with the fast or fast neutrons, but thermal neutrons are absorbed by the neutron absorbing material 2, so that only the medium or fast neutrons pass through the neutron absorbing material 2 and are decelerated by the neutron moderating material 3. As a result, thermal neutrons are detected by the thermal neutron detection tube 4. As described above, since what is detected by the thermal neutron detection tube 4 is a medium-speed or high-speed neutron that depends on the amount of moisture, the amount of moisture contained in the ground can be obtained by counting these neutrons. Can be.

Next, a "coke moisture measuring apparatus" disclosed in Japanese Patent Application Laid-Open No. 49-64602 will be described with reference to FIG. Source 3, thermal neutron counter 4,
A detection probe 2 having a built-in preamplifier 5 is provided. Fast neutrons emitted from the fast neutron source 3 to the coke hopper 1 are decelerated and scattered by hydrogen atoms to become thermal neutrons. Of these, those scattered in the direction of the detection probe 2 are converted into electric pulses by the thermal neutron counter 4, amplified by the preamplifier 5, and transmitted to the rate meter 7 via the cable 6. The amplified electric pulse signal is discriminated by a wave height discriminator 9, unnecessary noise is removed, and the pulse signal is made uniform by a waveform shaper 10. Further, the pulse signal is converted into a rectangular wave pulse by the counting rate meter 11 and converted into a DC voltage by the integrator 12.
The recorder 14 is operated through the switch 13.

When the empty signal of the coke hopper 1 is generated from the weighing device 15, the empty signal is transmitted to the switch 13.
And the DC output voltage of the rate meter 7 is applied only to the servo amplifier 17. The servo amplifier 17 drives the servo motor 18 until the difference between the DC output voltage and the output voltage of the feedback potentiometer 19 becomes zero, and operates the zero point adjuster 16 mechanically connected to the servo motor 18 to record. The pointer positions of the total 14 are set to zero. As described above, the recorder 1 receives the empty signal of the coke hopper 1 from the weighing device 15.
Since the pointer position of No. 4 becomes zero, even if moisture other than the coke moisture adheres to the vicinity of the high-speed neutron irradiation window of the detection probe 2, the occurrence of an error due to the shift of the zero point of the moisture measurement system is avoided. .

[0007]

The ultralow-level neutron transmission type moisture meter according to Conventional Example 1 has a configuration in which a source rod having a neutron beam embedded at the tip is inserted into a subject. For example, it cannot be used for measuring the amount of moisture contained in a refractory lining a molten metal container. Even if it could be applied to the measurement of the amount of moisture contained in the refractory lining a molten metal vessel, this extremely low-level neutron transmission moisture meter emits fast neutrons from a neutron source, Thermal neutrons due to interaction with water molecules are absorbed by a neutron absorbing material, and medium and fast neutrons that have passed through the neutron absorbing material are converted to thermal neutrons by a neutron moderator and counted by a thermal neutron detector tube. Since the thermal neutrons are not directly counted, there is a problem in the accuracy of measuring the amount of water in the subject.

Further, since the coke moisture measuring apparatus according to the conventional example 2 is configured to be attached to the side wall of the coke hopper, it is considered that it can be diverted to the measurement of moisture contained in the refractory lining the molten metal container. Then, among the fast neutrons irradiated from the fast neutron beam source to the coke hopper, those that have been decelerated and scattered by hydrogen atoms and become thermal neutrons are counted by a thermal neutron counter tube incorporated in the detection probe, It is thought that the amount of water can be measured with high accuracy, but only the thermal neutrons that are decelerated and scattered by water and returned are counted. Since the returned data is not counted, there is a problem in the measurement accuracy of the amount of water in the subject, similarly to the conventional example 1.

By the way, the purpose of measuring the amount of water contained in the refractory lining the molten metal container is to achieve the following. That is, when an inexpensive irregular-shaped refractory having excellent workability is used as the refractory, as shown in FIG. A core (not shown) is put inside the permanent brick 52, and a concrete-shaped refractory made of concrete kneaded with water is poured into a space between the permanent brick 52 and the core. It is taken out and dried to form a lining refractory 53 inside the permanent lining brick 52. In drying, a gas burner 55 that penetrates a lid 54 that closes the opening of the container 50 and blows a flame into the lining refractory 53 is used. It is performed by Drying of the lining refractory 53 by such a gas burner 55 is performed according to a drying pattern empirically created from past results. However, if the drying of the lining refractory 53 is insufficient, the molten metal is poured. As shown in FIG. 6 (b) in the explanatory diagram of the damage state between the permanent brick and the refractory lining, not only the refractory lining 53 peeled off, but also the explosion occurred in the permanent brick 52, The re-installation of the permanent brick and the refractory lining is required, so overdrying is performed to prevent steam explosion.

If the amount of moisture in the refractory lining during drying can be measured in real time and with high accuracy from outside the steel shell of the molten metal container, an appropriate drying pattern of the refractory lining can be established. . If so, the time required for overdrying can be reduced, and the construction cost of the refractory lining can be reduced.

Accordingly, an object of the present invention is to reliably capture thermal neutrons and medium / high speed neutrons which are decelerated and scattered by moisture and are contained in the refractory lining the molten metal container with high precision. An object of the present invention is to provide a unit for measuring the water content of a refractory lining a molten metal vessel, which makes it possible to measure the amount of water contained.

[0012]

Means for Solving the Problems In order to solve the above-mentioned problems, the feature of the means adopted by the unit for measuring the water content of a refractory lining a molten metal vessel according to the present invention is that the molten metal vessel has a feature.
On the side that comes into contact with the surface of the steel shell (11) of (10), a groove-shaped recess (2
a) A block-shaped iron member (2) provided with a), and a thermal neutron counter arranged in the recess (2a) of this iron member (2)
(3) and the thermal neutron counter in the recess (2a) and
(3) A pair of thermal neutron columns (4) arranged at positions sandwiching
And this recess (2a) deviated from the recess (2a) of the iron member (2)
And a neutron generation source (5) fitted in a minute hole (2b) provided on the opening side of the neutron source.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing the construction of a unit for measuring the water content of a refractory lining a molten metal vessel according to an embodiment of the present invention. 1 will be described with reference to FIG. 1. Reference numeral 1 shown in the figure denotes a container-shaped iron shell 11, a permanent brick 12 stretched inside the steel shell 11, and a permanent brick 12 The configuration described below for measuring the amount of water contained in the lining refractory 13 of the molten metal container 10 including the lining refractory 13 (which is an irregular-shaped refractory) stretched inside the brick 12. It is a moisture content measurement unit.

The water content measuring unit 1 includes a molten metal container 1
A block-shaped iron member 2 having a groove-shaped recess 2a provided on the side of the iron member 11 which is in contact with the surface of the iron shell 11, and a block-shaped iron member 2 having a concave cross section. A thermal neutron counter tube 3 disposed therein; a pair of thermal neutron columns 4 and 4 made of graphite disposed in the recess 2a and at positions sandwiching the thermal neutron counter tube 3; The neutron generating source 5 is separated from the recess 2a of the member 2 and is fitted into a minute hole 2b provided on the opening side of the recess 2a. Although not shown, the number of thermal neutrons counted by the thermal neutron counter 3 is converted into an electric signal and sequentially input to various electric meters for processing.

The neutron generating source 5 used in the water content measuring unit 1 according to this embodiment is californium (Cf) having an atomic number of 98, and is ²⁵² Cf of some radioisotopes produced. . Note that radium-beryllium in which beryllium is appropriately mixed with a natural α-radioactive element such as ²²⁶ Ra can also be used.

The configuration in which the thermal neutron counter tube 3 is disposed between the thermal neutron columns 4 and 4 made of graphite is intended to capture thermal neutrons with high efficiency. . In other words, if the thermal neutron columns 4 and 4 are sufficiently long and the directions of the neutron beams are well aligned, neutrons having an energy of 0.0018 eV or more are diffracted, and reflection is repeated by graphite crystals oriented in various directions. As a result, the amount of thermal neutrons that escape to the outside decreases, and graphite, which is the material of the thermal neutron columns 4 and 4, is also a moderator. This is because neutrons can be decelerated and converted to thermal neutrons and counted.

Hereinafter, a case of measuring the amount of water contained in the refractory lining the molten metal vessel by using the water content measuring unit 1 having the above structure will be described. First, the surface of the steel shell 11 of the molten metal vessel 10 is measured. The iron member 2 is attached to the steel shell 11 with the opening side of the recess 2a facing in the direction. Micro thermal neutron source 5
The high-speed neutrons radiated from the metal shell 11 of the molten metal container 10 through the shell 11 are decelerated and scattered by the moisture contained in the refractory lining 13 to become thermal neutrons.

Of these thermal neutrons, those scattered in the direction of the water content measuring unit 1 penetrate through the iron shell 11 and are repeatedly formed of crystals of the thermal neutron columns 4 and 4 made of graphite oriented in various directions. The light is reflected and counted by the thermal neutron counter 3. Furthermore, medium and fast neutrons which return to the direction of the water content measuring unit 1 due to scattering without being converted to thermal neutrons due to being decelerated and scattered by moisture are also decelerated by the thermal neutron columns 4 and 4 to become thermal neutrons. Are counted by the thermal neutron counter 3.

[0019]

Next, an embodiment relating to the measurement of the amount of water in the refractory lining of a ladle by the water content measuring unit of the present invention will be described.
FIG. 2 of a perspective view of a ladle to which a water content measuring unit is attached.
This will be described with reference to (a), FIG. 2 (b) of a cross-sectional view of a ladle in which a mounting position of a thermocouple in a vertical direction is shifted, and FIG. 3 of a diagram illustrating a relationship between drying time and count number.

As shown in FIGS. 2 (a) and 2 (b), a water content measuring unit 1 is mounted on the surface of a steel shell 11 of a ladle 10 which is a molten metal container, and the temperature of the steel shell 11 is measured next to the unit. A thermocouple 6 to be measured is attached. This ladle 10
Is a new pot, and the thickness of the iron shell 11 at the measurement site is 3
The thickness of the permanent brick 12 is 90 mm, and the thickness of the refractory lining 13 which is an irregular refractory is 174 mm. Then, the count integration time of the water content measuring unit 1 is set to 10 minutes, and the amount of water in the lining refractory 13 is measured during the drying for 45 hours (2700 minutes), and in parallel with this, the thermocouple 6 is used. The temperature of the iron shell 11 was measured. The count number and the temperature of the steel shell recorded on the recorder are as shown in FIG.

According to FIG. 3, the count number gradually increases from the start of drying of the refractory lining 13 to 750 minutes.
After a lapse of 00 minutes, the value rapidly decreases, 2100 gradually decreases, and after 2500 minutes, it is almost constant. Such a process is as follows.

That is, from the start of drying the refractory lining 13,
It can be understood that the increase in the count number up to 50 minutes is because the air in the ladle 10 heated by the gas burner was cooled by the steel shell 11 and dew was formed. Actually, during this time, it was confirmed that water leaked from a steam vent (not shown) provided on the steel shell 11. It is understood that the rapid decrease in the count number after 1500 minutes is the evaporation period of water because the temperature of the steel shell 11 is almost constant at around 100 ° C. Further, it is considered that the decrease in the count number after 2100 minutes results in the crystallization water in the refractory lining 13 jumping and becoming anhydrous. In addition, it can be understood that the reason why the count number becomes constant after 2500 minutes is that the moisture in the refractory lining 13 is completely removed.

The molten metal was poured into the ladle 10 in order to confirm that the drying of the refractory lining 13 was completely completed when the count number became constant, but the refractory lining 13 caused a steam explosion. There was nothing to wake up. Therefore, the count number becomes constant when the refractory lining 13 is used.
Therefore, it is possible to establish an appropriate drying pattern of the lining refractory 13.

Conventionally, a refractory lining of a ladle 1
Despite the fact that the required drying time of 3 differs depending on the season (difference between atmospheric humidity and temperature), the drying pattern equivalent to that in winter was adopted even when the drying construction of the refractory lining 13 was performed in summer. However, the use of the water content measuring unit 1 makes it possible to reduce the time required for drying and to reduce fuel consumption, particularly in summer.

As described above, according to the water content measuring unit 1 according to the embodiment of the present invention, as described above, the thermal neutrons that are decelerated and scattered by moisture and returned are directed outward by the thermal neutron columns 4 and 4. In addition, medium and fast neutrons can be converted to thermal neutrons and counted by the thermal neutron counter tube 3 without escape, so that thermal neutrons are absorbed by the neutron absorbing material, and the medium and fast neutrons transmitted through the neutron absorbing material are removed. The measurement accuracy of the amount of water is better than that of Conventional Example 1 in which thermal neutrons are converted into thermal neutrons with a neutron moderator and counted by a thermal neutron detection tube (thermal neutron counter tube), and the amount of water is higher than that of Conventional Example 2 having no thermal neutron column Is excellent in measurement accuracy, and can greatly contribute to improvement in measurement accuracy of the amount of water in the refractory lining the molten metal vessel.

Further, according to the water content measuring unit 1 according to the embodiment of the present invention, as described above, thermal neutrons, medium-speed neutrons, and fast neutrons that are scattered and returned by moisture are captured and counted. Since it is possible to measure even with a smaller output, for example, using a neutron generating source 5 that does not require setting of a control area, the size of the iron member 2 of the water content measuring unit 1 for neutron shielding should be reduced. This has the effect that the management area can be reduced.

In the above, the case where the water content measuring unit 1 according to the present invention is applied to the measurement of the amount of water in the refractory lining a ladle has been described as an example. Is not particularly limited to ladle applications.

[0028]

As described above, according to the unit for measuring the water content of a refractory lining a molten metal vessel according to the present invention, thermal neutrons that are decelerated and scattered by moisture and returned are counted without escaping to the outside. In addition, medium and fast neutrons can be counted instead of thermal neutrons. Therefore, the thermal neutrons are absorbed by the neutron absorbing material, and the medium and fast neutrons that have passed through the neutron absorbing material are converted into thermal neutrons by the neutron moderator, and are counted by the thermal neutron detector tube, which is a thermal neutron counter tube. Since the measurement accuracy of the water content of the sample is excellent and the measurement accuracy of the water content of the test sample is superior to that of the conventional example 2 having no thermal neutron column, the measurement accuracy of the water content of the refractory lining the molten metal container is improved. There is an extremely excellent effect that it can greatly contribute to the improvement of.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of a unit for measuring the water content of a refractory lining a molten metal vessel according to an embodiment of the present invention (however, a part of the molten metal vessel is shown at a position away from the moisture content measurement unit). is there.

FIG. 2 (a) is a perspective view of a ladle to which a water content measuring unit is attached, and FIG. 2 (b) is a perspective view showing a thermocouple in which an attachment position in a vertical direction is shifted. It is sectional drawing of a pot.

FIG. 3 is a diagram illustrating a relationship between a drying time and a count number according to the embodiment of the present invention.

FIG. 4 is a cross-sectional configuration explanatory view of an extremely low-level neutron transmission moisture meter according to Conventional Example 1.

FIG. 5 is a block diagram of a coke moisture measuring device according to Conventional Example 2.

FIG. 6 (a) is an explanatory view of a drying state of a ladle, and FIG.
(B) is an explanatory diagram of a damaged state of the permanent brick and the lining refractory.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Water content measuring unit 2 ... Iron member, 2a ... Depression, 2b ... Micro hole 3 ... Thermal neutron counter tube 4 ... Thermal neutron column 5 ... Neutron generating radiation source 6 ... Thermocouple 10 ... Molten vessel, 11 ... Iron Leather, 12 ... Permanent brick, 1
3. Refractory lining

Claims (1)

[Claims] 1. A block-shaped iron member (2) provided with a groove-shaped recess (2a) on a side of a molten metal container (10) in contact with a surface of an iron shell (11); A thermal neutron counter tube (3) disposed in the recess (2a) of (2), and a thermal neutron counter tube (3) disposed in the recess (2a) and at a position sandwiching the thermal neutron counter tube (3). And a small hole (2) provided on the opening side of the recess (2a) which is separated from the recess (2a) of the iron member (2).
b) a neutron generating source (5) fitted to the molten metal vessel;