JP2002107231A - Radiation thermometer for measuring molten metal inside temperature - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reuse an expensive consumptive immersion thermocouple in measuring a molten liquid temperature of a high temperature molten metal and to accurately measure a molten metal liquid inside temperature by means of a radiation thermometer. SOLUTION: A protective tube 4 having a metallic lid at the tip is mounted on a sensor 1 in the radiation thermometer via a pipe 2, and when the tip on the protective tube side is inserted into the inside of the molten metal, the molten metal inside temperature can be measured in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the measurement of the internal temperature of a molten metal performed in the steel industry or the metal refining industry, and more particularly, to the measurement of the internal temperature of a molten metal at a high temperature using a radiation thermometer. Related to the measurement method.

[0002]

2. Description of the Related Art Conventionally, a thermocouple or a radiation thermometer has been used for measuring the temperature of a molten metal of a high-temperature molten metal such as a steelmaking reaction. As for the method using a thermocouple, a method using a consumable immersion thermocouple has been used.

[0003]

However, in the case of using a consumable immersion thermocouple using a thermocouple method, an expensive thermocouple for high temperature is disposable, which is not only uneconomical but also increases the cost but also increases the cost. From the standpoint of effective use of resources, there was a problem that it was against the demands of the times. Also,
In the measurement with the radiation thermometer, while avoiding direct contact of the molten liquid with the high heat source and not being affected by noise etc. generated by the electric furnace, the molten metal surface temperature is detected from the measurement principle, There was a problem that the internal temperature of the molten metal liquid was not detected.

The present invention avoids the use of expensive consumable thermocouples and provides a method for accurately and economically measuring the temperature of a melt inside a molten metal by using a radiation thermometer. It is an object.

[0005]

In order to achieve the above object, in a radiation thermometer for measuring the internal temperature of a molten metal according to the present invention, a pipe is attached to a temperature detecting portion of the radiation thermometer in close contact with the pipe. At the other end of the pipe, a protective tube with a metal lid was attached.

The radiation thermometer for measuring the internal temperature of a molten metal according to the present invention is characterized in that the tip of a pipe having a protective tube with a metal lid attached thereto is inserted into the molten metal to be measured for a short time so that the molten metal liquid can be measured. It measures temperature. The metal lid is instantaneously melted by being inserted into the molten metal liquid, but at this time, since the inside of the pipe is sealed, the air pressure in the pipe prevents the melt from entering from the lid. Therefore, the surface of the melt temporarily appears at the position where the lid is placed, and the temperature at this time is measured. In this state, a black body furnace state appears almost for a short time. For this reason, the emissivity, which is a problem when using a radiation thermometer, can always be treated as being constant.

By using the radiation thermometer sensor in the present invention, the influence of noise and the like due to the electric induction of the electric furnace used for melting the metal can be avoided. Further, by using an optical fiber for the connection cable from the temperature sensor to the thermometer main body, electric noise picked up by the connection cable can be avoided.

By using a radiation thermometer whose focal length to be measured has a focal point on the surface of a metal lid attached to a protective tube attached to a pipe end, the metal lid after melting of the metal lid is used. The temperature of the molten metal liquid at the location can be measured.

The pipe connecting the radiation thermometer sensor and the protection tube serves to thermally separate the molten metal from the radiation thermometer sensor and to eliminate the influence of heat radiation from a position other than the position to be measured. This length ranges from 1 meter to 4 meters and is determined according to the situation of the measuring object. The pipe and the radiation thermometer sensor are in close contact.

The purpose of the protective tube with a metal lid attached to the end of the pipe is to insulate the molten metal for a short time and prevent the molten metal liquid from flowing when the distal end of the pipe on the protective tube side is inserted into the molten metal. I do. As the material, cardboard is mainly used, but ceramics, plastics and the like may be used if suitable for the purpose. The protective tube with a metal lid is a replaceable consumable item, but is inexpensive and economical.

[0011] The metal lid attached to the protection tube is
Must be of the same type as the molten metal or a material that does not affect it and that can be inserted into the molten metal liquid and melted in a short time. Further, when the protective tube is inserted into the molten metal liquid, the protective tube pushes the protective tube without melting into the slag layer covering the surface of the molten metal.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings based on embodiments. In FIG. 1, the radiation thermometer sensor 1 protects the molten metal from high temperatures,
Further, it is attached to the pipe 2 which plays a role of preventing heat radiation from entering from other than the object to be measured. At this time, the adhesiveness is maintained to secure the air pressure in the pipe for preventing the intrusion of the melt into the pipe, which is one of the aims of the present invention. Pipe length from 1 meter to 4
Between meters, depending on usage.

The temperature detected by the radiation temperature sensor is connected to the thermometer body 6 through a connection cable. At this time, if electrical induction of the melting furnace becomes a problem, an optical fiber connection cable is used.

A protective tube 4 with a metal lid 3 is attached to the temperature measuring side of the pipe 2. This protective tube with a lid is mainly made of corrugated cardboard, is a heat insulating material for a short time, prevents inflow of molten metal, and is a consumable product. It is easily replaceable with the pipe 2 and is attached with good adhesion.

[0015] Metal lid 3 attached to the tip of the protection tube
Has a shape and dimensions that can be melted in a short time by being inserted into a molten metal. Although there are various methods for attaching the protective tube 4 to the protective tube 4, FIG. 2 shows an example in which the protective tube 4 is attached to the protective tube 4 with a high-temperature ceramic adhesive. In addition, there is a method in which the end of the protective tube is covered by the periphery of the lid, and a method in which the end of the protective tube covers the periphery of the lid.

When the temperature of the molten metal is very high, or when the insertion dimension of the pipe is large, the air pressure in the pipe is unnecessarily high due to the expansion of the air in the pipe by a sudden insertion operation into the molten metal liquid. May be. In this case, a pressure adjusting plug 7 for adjusting the pressure is attached to the side surface of the pipe 2. FIG. 7 shows an example of the mounting state. The pressure adjusting plug may be a simple leaf spring type in addition to the spring spring type as shown in the figure.

[0017]

The temperature of the cast iron melt was measured using the radiation thermometer for measuring the internal temperature of the molten metal according to the present invention. When the protective tube portion with the metal lid was inserted into the melt for a short time, the lid portion was pushed out of the slag layer and inserted into the melt without melting to the required size, and then melted rapidly. At this time, the protective tube prevented the inflow of the melt, and a sufficient time was maintained for the measurement. Therefore, the measurement of the internal temperature of the metal melt within a short time was achieved as intended.

By the way, the temperature of the molten iron was measured 25 times under various conditions, and the results of the comparative measurement between the present invention and the conventional thermocouple were comparable. Atsuta.

As described above, according to the radiation thermometer for measuring the internal temperature of a molten metal according to the present invention, it is possible to measure the temperature of a molten metal at a high temperature simply by replacing the protective tube with a metal cover every temperature measurement. The economic effect is large. According to the method of using the radiation thermometer according to the present invention, the conventional use of the radiation thermometer in this direction has a drawback that the temperature of the melt surface is measured so that the slag floats. Thus, the temperature inside the melt can be measured.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a radiation thermometer for measuring the internal temperature of a molten metal according to the present invention.

FIG. 2 is a longitudinal sectional view showing an embodiment of a protection tube with a metal lid.

FIG. 3 is a longitudinal sectional view showing an embodiment in which a pressure adjusting plug is attached to a pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radiation thermometer sensor 2 Pipe 3 Metal lid 4 Protection tube 5 Optical fiber cable 6 Thermometer main body 7 Pressure control plug

Claims (4)

[Claims] 1. A protective tube (4) having a metal lid (3) at the tip thereof is attached to a temperature detecting portion of a sensor (1) of a radiation thermometer via a pipe (2). A radiation thermometer for measuring the internal temperature of molten metal that can measure the temperature of molten metal in a short time by inserting the tip of the side into the molten metal. 2. The melting pipe according to claim 1, wherein a portion of the protection tube with the metal lid is easily replaceable, and the portion is attached to a tip of the pipe. Radiation thermometer for measuring internal metal temperature. 3. A lid (3) attached to the protective tube (4),
3. The radiation thermometer for measuring the internal temperature of a molten metal according to claim 2, comprising a metal that is melted in and does not harm the molten metal to be measured. 4. The radiation for measuring the internal temperature of a molten metal according to claim 1, wherein a pressure regulating plug (7) is attached to the pipe (2) in case the air pressure inside the pipe (2) becomes unnecessarily high. thermometer.