JPH0426442Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a device for measuring the carbon content of molten steel and the temperature of molten steel.

(Prior Art) In order to measure the carbon content and molten steel temperature in a furnace such as a converter, it is generally known to use a measuring lance to measure the temperature. This is a method of measuring by immersing a consumable porobe into the scouring process once or twice using a thermocouple as the detection end.

Since this method provides intermittent information,
The company had to operate on the safe side in anticipation of errors in the final molten steel temperature, which was not sufficient in terms of operation and control. Furthermore, if the measuring lance was kept immersed in the molten steel for the required time during blowing, the measuring lance would be damaged by the heat in the furnace, making measurement practically impossible.

Also, in Utility Model Application Publication No. 57-9708, via a quartz tube,
Although it has been described that the amount of carbon and temperature of cast iron and molten metal can be measured, there are problems with the heat resistance of the objective lens and a problem with a large amount of noise, resulting in insufficient accuracy of the measurement results.

(Problems to be solved by the invention) This invention solves the above-mentioned problems, and in the furnace,
The present invention provides a device that continuously measures the carbon content and temperature of molten steel.

(Means for Solving the Problems) The gist of the present invention is to provide a device for measuring the carbon content and temperature of molten steel, in which a protective tube is provided at the tip of a measuring lance, and a void is formed on one side inside the protective tube. A quartz probe was installed, and two optical fibers were inserted into the measurement lance, one for measuring the carbon content and the other for measuring the temperature of the molten steel, connected to the radiation thermometer. This is a molten steel carbon content and molten steel temperature measurement device that continuously measures the carbon content and temperature by receiving radiant energy from molten steel with an optical fiber.

(Examples and effects) Hereinafter, the present invention will be explained in detail based on the drawings.

In the figure, 1 is a molten steel refining body such as a converter, 2 is a scouring lance, 3 is a measuring lance, 4 is molten steel, 5 is a radiation thermometer, 6 is an optical fiber, 7 is a quartz probe, 8
is a protective tube. Also, the state shown in the figure is under refinement and measurement.

During scouring, oxygen is injected from the scouring lance 2, and the molten steel 4 is stirred and oscillated. During measurement, the protective tube 8 at the tip of the measuring lance 3 is immersed into the molten steel.

This device is composed of a measuring lance 3, an optical fiber 6, a quartz probe 7, a protection tube 8, and a radiation thermometer 5, and is capable of continuous and highly accurate temperature measurement.

On the other hand, the carbon equivalent of the molten steel is measured using the molten steel adhering to the gap 9 between the protection tube 8 and the quartz probe 7. That is, when the protective tube 8 is initially immersed in molten steel and then pulled up slightly, a small amount of molten steel adheres to the cavity 9.

This molten steel is cooled by the protection tube 8 and solidifies. A radiation thermometer 5 connects to an optical fiber 6 for measuring the amount of carbon passed through the measuring lance 3 through a quartz probe 7 to measure the temperature change as the surface of the molten steel solidifies.
Measure continuously. Through this measurement, the temperature in the stagnation region of the cooling curve (solidification start temperature) is determined, and the carbon in the molten steel is measured based on the principle that the solidification start temperature varies depending on the carbon concentration in the molten steel.

In addition, when the quartz probe 7 comes into contact with the molten steel while measuring the carbon content, the radiant energy is received by the optical fiber 6 for temperature measurement through the quartz probe 7, allowing continuous and highly accurate measurement of the molten steel. It allows for warmth.

The quartz of the quartz probe 7 has excellent heat resistance and is less likely to be damaged during continuous measurement time, and also forms black body radiation to facilitate temperature measurement. This makes highly accurate temperature measurement possible. In addition, the lack of mechanical durability of the quartz probe 7 is solved by the protection tube 8, which protects the quartz probe 7 from wear and tear during the measurement period and enables continuous temperature measurement. It is also possible to prevent measurement disturbances caused by the shaking of molten steel, etc. in the furnace.

On the other hand, the radiation light to the radiation thermometer 5 is transmitted through the optical fiber 6, which makes it possible to measure temperature with high precision and high responsiveness, and to easily prevent the radiation thermometer 5 from being damaged by heat. It is something to do. That is, the present invention is based on the aforementioned Utility Model Application No. 57-9708.
With the configuration described in the publication, there is a problem with the heat resistance of the objective lens and the radiation thermometer. Therefore, an optical fiber is used to install the radiation thermometer in a position where it is less affected by heat, and to achieve measurement accuracy with less noise. The object of the present invention is to provide a measuring device that can obtain good measurement results.

In addition, measuring the molten steel temperature only with an optical fiber and a radiation thermometer without a quartz probe does not provide sufficient responsiveness, so this invention considers responsiveness and includes a quartz probe as one of the components. It is something.

Next, to describe the measurement procedure of the present invention, while the molten steel 4 is being refined by injecting oxygen from the scouring lance 2, the measuring lance 3 is lowered, and the tip of the measuring lance 3 is placed in the molten steel 4. Soak.

A protective tube 8 provided at the tip of the measuring lance 3
is first immersed up to point A in Figure 2, then immersed in point B.
raise it to the point.

When the protective tube 8 is pulled up to point B, the molten steel 4 adheres to the cavity 9, and the solidification temperature of the molten steel 4 is measured with the radiation thermometer 5 via the quartz probe 7 and the optical fiber 6 for measuring carbon content. measure quantity.

At the same time, the protection tube 8 is pulled up to point B where the quartz probe 7 contacts the molten steel 4, so the quartz probe 7 is immersed in the molten steel 4, and the quartz probe 7 is immersed in the molten steel 4.
The radiant energy is received by the optical fiber 6 through the molten steel, and the temperature of the molten steel is continuously measured.

Further, the time required for each temperature measurement is usually about several minutes, and if the temperature is continuously measured during that time, the accuracy of the measured temperature is sufficient.

The protective tube 8 used in the present invention is advantageously made of ceramic, refractory, metal, or other composite materials. Note that the quartz probe 7 and protection tube 8 are inexpensive compared to other components, and do not necessarily require long-term durability. The intent of this invention can be achieved. In this case, the purpose can be achieved by appropriately replacing only the quartz probe 7 and the protection tube 8 using a replacement device (not shown).

(Effects of the invention) According to the invention, continuous temperature measurement with good responsiveness is possible using a radiation thermometer and optical fiber, and mechanical durability is excellent by providing a protective tube on the quartz probe. It is now possible to prevent disturbances such as molten steel shaking inside the chamber, and by creating a gap between the protection tube and the quartz probe and measuring the solidification temperature of the molten steel adhering to the gap, it is also possible to measure the amount of carbon. This makes it possible to measure the carbon content and temperature of molten steel, and the effect is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a measuring lance used in a converter or the like, and FIG. 2 is a sectional view showing an apparatus for measuring the carbon content and temperature of molten steel according to the present invention. 1 is a molten steel refining body such as a converter, 2 is a refining lance,
3 is a measuring lance, 4 is molten steel, 5 is a radiation thermometer,
6 is an optical fiber, 7 is a quartz probe, 8 is a protection tube, and 9 is a cavity.

Claims (1)

[Scope of utility model registration request] In an apparatus for measuring the carbon content and temperature of molten steel, a protection tube is provided at the tip of a measuring lance, a quartz probe is placed inside the protection tube with a cavity on one side, and a radiation thermometer and a Two optical fibers are inserted into the measurement lance, one for measuring the amount of carbon and the other for measuring the temperature of the molten steel, and the optical fibers receive the radiant energy from the molten steel and detect the carbon Molten steel carbon content and molten steel temperature measurement device that continuously measures the amount and temperature of molten steel.