JPS63243722A - Monitor for liquid level in crucible - Google Patents

Abstract

PURPOSE:To enable a liquid level to be monitored in real time and avoid an empty crucible heating and an overflow by irradiating a light beam on a molten metal liquid surface to be measured and receiving reflected light by a photodetector. CONSTITUTION:The liquid surface of a molten metal in a crucible 12 is divided into two sections by a partition plate 22. The liquid surfaces in one and the other sections are made an evaporative surface 13a and a surface 13b to be measured, respectively. A light beam from a light source 25 provided on a side is irradiated on the surface 13b to be measured and reflected light from it is received by a photodetector 27. Therefore, the molten metal liquid surface in a severe atmosphere in the crucible can be monitored in real time by using an ordinary sensor and an empty crucible heating and an overflow are avoided to enable a smooth operation to be secured.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is applicable to, for example, liquid level measurement in metal evaporation crucibles of laser method uranium enrichment equipment and liquid level measurement of high-temperature molten metal in blast furnaces. The present invention relates to a liquid level monitoring device in a crucible used in a crucible, etc., and particularly relates to a liquid level monitoring device in a crucible that accurately measures the liquid level on the surface of molten metal in a harsh atmosphere.

(Prior Art) In recent years, an atomic laser uranium enrichment method using laser light has been considered as a method for recovering uranium with high efficiency. In this method, uranium 235 is used for isotope separation using laser light.
The separation takes advantage of the difference in the resonance absorption frequency of light between uranium-238 and uranium-238. Specifically, after putting unenriched uranium into a crucible inside a vacuumed uranium separation cell, this uranium is separated. The uranium vapor obtained by heating the uranium is irradiated with laser light to separate the uranium.

By the way, when this atomic laser uranium enrichment method is used, it is necessary to monitor the remaining amount of uranium in the crucible because the uranium in the crucible is vaporized by heating.

Therefore, conventionally, as a means for monitoring the uranium liquid level in the crucible, a viewing window is attached to the outer wall of the uranium separation cell to artificially monitor the remaining amount of uranium in the crucible.

In another method, a crucible is placed on a weighing device, and the weighing device measures the weight of the crucible to estimate the liquid level.

(Problem to be solved by the invention) However, with the former monitoring means, uranium vapor adheres to the glass of the viewing window, making it almost impossible to see inside the uranium separation cell, and artificially monitoring the uranium liquid level. difficult to do.

Furthermore, the latter liquid level monitoring means complicates the entire device, and it is extremely difficult to secure installation space for, for example, a uranium separation cell.

Therefore, from the above point of view, it is possible to monitor the metal liquid level in the crucible using methods other than artificial or mechanical methods. It is impossible to install sensors near the molten metal because the molten metal is in a very high and harsh atmosphere, and the evaporation rate of uranium metal is high and it forms a mist. It is difficult to monitor the liquid level using direct optical means.

As another technique, measurement using radiation or the like may be considered, but there is a problem that measurement is difficult due to the high metal density (19,8) and processing after measurement results takes time.

The present invention has been made in view of the above circumstances, and it is possible to monitor the liquid level of molten metal in a harsh atmosphere in a crucible in real time using a normal sensor, for example, to avoid emptying or overflow. It is an object of the present invention to provide a liquid level monitoring device in a crucible that can ensure smooth operation.

[Structure of the Invention] (Means and Effects for Solving the Problems) A liquid level monitoring device in a crucible according to the present invention divides the molten metal contained in the crucible into two, and monitors the molten metal in one of the crucibles. The metal liquid surface is formed as an evaporation surface, and the other molten metal liquid surface is formed as a measurement surface, and this measurement surface is irradiated with a light beam from the side, and the reflected light from the measurement surface is sent to a light receiving section. By receiving light at the evaporation surface, the liquid level on the evaporation surface is monitored in real time.

(Example) Hereinafter, as an example of the present invention, a case where the present invention is applied to, for example, an atomic method laser concentrator will be described with reference to FIGS. 1 to 3. FIG. 1 is a block diagram showing a part of such an apparatus in cross section, FIG. 2 is a diagram illustrating means for dividing uranium metal, and FIG. 3 is a diagram illustrating means for monitoring the metal liquid level.

In FIG. 1, reference numeral 11 denotes a uranium separation cell, which is evacuated by a pressure reducing means.

12 is a crucible containing uranium-13. Uranium 13 in this crucible is fired from an electron gun 14 and heated by an electron beam 1G deflected by a magnetic field device [15], thereby generating uranium vapor 17 from the uranium liquid surface. 18 is a steam encapsulant, 19 is an enriched uranium recovery plate, 20
is a depleted uranium recovery plate, and 21 is a bond.

In the uranium separation cell 11 as described above, a partition plate 22 is provided in the crucible 12 to divide the uranium 13, as shown in FIG. 13a, and the uranium surface in the other crucible is formed as the measurement surface 13b. This partition plate 22
has both sides fixed to the inner surface of the crucible 12, and
A predetermined gap is provided between the bottom surface of the partition plate 22 and the bottom surface of the crucible 12, so that the uranium 13 in the crucibles located on both sides of the partition plate 22 can mutually flow. Therefore, the uranium liquid levels on both sides of the partition plate 22 are maintained at the same level. In such a state, the electron beam 16 emitted from the electron gun 14 hits the uranium evaporation surface 1.
When it hits 3a, the uranium 13 reaches a high temperature, causing uranium evaporation 17, and as a result, the evaporation surface 13a often has a wavy or pitted appearance. However, partition plate 2
The communication portions of the uranium 13 in the grooves 12 located on both sides of the uranium 13 are constricted by the partition plate 22, so a damping effect works when the uranium 13 moves, and the electron beam on the evaporation surface 13a side It is not affected by waves etc.

On the other hand, the other side of the crucible with the seven partition plates 22 as a boundary is similarly molten uranium, but as mentioned above, it is not directly affected by the electron beam 16 and uranium vapor 17 is generated. Moreover, since the surface is in a vacuum container, there is no possibility of the surface being oxidized to form a compound (UO2), and the surface is silver-gray, so it is formed as a measurement surface 13b that is easy to optically measure.

Therefore, the measurement surface 13b formed by the partition plate 22
On the measurement surface 13b, highly convergent laser light, for example, is emitted from one side in a direction perpendicular to the path of the electron beam 16.
The uranium liquid level in the crucible 12 can be measured by providing an optical system that irradiates the laser beam and receives the laser beam or the like reflected from the measurement surface 13b on the side opposite to the light irradiation side.

That is, in this □ optical system, as shown in FIG. 3, a light entrance window 23 is provided on the enriched uranium recovery plates 19 to 21, and an optical path guide protrudes from the light entrance window 23 to the outside of the uranium separation cell. A light source 25 such as a laser emitter is installed at the end of the member 24 .

On the other hand, the enriched uranium recovery plate etc. 19-2 on the opposite side of the light source 25
Similarly, a first ti4 window 26 is provided on the lower side of the sensor 1, and an elongated light receiver 27 that receives reflected light from the measurement surface 13b is installed outside the light exit window 26. The reason why the elongated light receiver 27 is used is that it can receive the reflected light even if the reflection position changes as the liquid level on the measurement surface 13b changes, and it also allows the liquid level to be immediately detected from the receiving position of the spot-like reflected light. This is for the purpose of detection. In other words, when the reflection position changes as the measurement surface 13b of uranium 12 changes, the reception position of the reflected light changes depending on the reflection position. Detects liquid level. Further, when the remaining amount of uranium 13 in the crucible is low and the crucible is empty, an alarm can be output using the output of the light receiver 27 corresponding to the receiving position of the reflected light from the measurement surface 13b.

Therefore, according to the embodiment described above, the uranium 13 in the crucible is divided by the partition plate 22, and the uranium 13 in one of the crucibles is heated with the partition plate 2 in between to create a state in which it can be evaporated. Since the uranium liquid level in the other crucible is connected to the uranium in one crucible at the bottom of the partition plate 22, the same level can be maintained, and since the communicating part of the uranium 13 is constricted, the movement of the uranium 13 is prevented. At times, the damping effect works to form a stable liquid level state without being affected by the evaporation surface side, and the incident light from the light source 25 can be efficiently reflected. Further, the elongated light receiver 2 receives reflected light that is reflected according to changes in the liquid level on the measurement surface 13b.
7, the liquid level can be detected immediately from the output of the light receiver 27. Therefore, a complicated processing circuit is not required and measurement results can be obtained in a short time.

In the above embodiment, the optical system was installed at the bottom of the enriched uranium recovery plates 19 to 21 of the uranium separation cell 11, but it may be installed at an appropriate position taking into account the size of the uranium separation cell 11, light receiving sensitivity, etc. be.

Further, although a heat-resistant or heat-shielding transparent member such as glass is used for the light entrance window 23 and the light exit window 26, the material is not particularly limited. Further, the light source 25 and the light receiver 27 may be provided with a shutter for heat shielding. Further, as a means for dividing uranium 130, for example, as shown in FIG. 4, a concave connecting pipe 32 is connected from the outside to the lower part of the crucible 12 in the vacuum container 31, and the uranium supply port side at the end of the connecting pipe 31 is filled. The liquid level of the uranium is used as the measurement surface.
The uranium liquid level in the crucible 12 may be measured based on the same principle as shown in FIG. In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As detailed above, according to the present invention, the liquid level of the molten metal 1 can be detected in a stable state, dry boiling, overflow of the molten metal, etc. can be prevented, and It is possible to provide a liquid level monitoring device in a crucible that can quickly determine when to replenish new metal. Figures 1 to 3 are shown for explaining an embodiment of a liquid level monitoring device in a crucible according to the present invention. Figure 1 is a block diagram showing a part of the atomic laser concentrator to which the present invention is applied, Figure 2 is a schematic diagram illustrating the uranium splitting means in the crucible, and Figure 3 is a diagram showing the structure of the crucible. FIG. 4 is a schematic diagram illustrating another example of the device of the present invention.

11... Uranium separation cell, 12... Crucible, 13.
...Uranium, 13a... Evaporation surface, 13b... Measurement surface, 16... Electron beam, 17... Uranium evaporation, 22
... Partition plate, 25 ... Light source, 27 ... Light receiver,
31...Vacuum container, 32...Connecting pipe.

Applicant's agent: Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) In a liquid level monitoring device that continuously monitors the molten metal liquid level in a crucible, the molten metal is divided into two parts, and the molten metal liquid level in one of the crucibles is formed as an evaporation surface,
The liquid level on the evaporation surface is determined by forming the other molten metal liquid surface as a measurement surface, irradiating the measurement surface with a light beam from the side, and receiving the reflected light from the measurement surface with a light receiver. A liquid level monitoring device in a crucible characterized by monitoring. (2) A liquid level monitoring device in a crucible according to claim 1, wherein the means for dividing the molten metal contained in the crucible is performed by providing a partition plate in the crucible. (3) The means for dividing the molten metal housed in the crucible divides the molten metal between the inside of the crucible and the outside of the crucible via a molten metal supply connecting pipe, and fills the end of the connecting pipe outside the crucible. A liquid level monitoring device in a crucible according to claim 1, wherein the measuring surface is the liquid level of the molten metal.