JPS6133540Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a sensor for measuring temperature in the solidification process of molten steel using a thermocouple.

In order to perform optimal combustion control in a soaking furnace, it is necessary to accurately know the temperature of each part of the steel ingot that is fed into the soaking furnace. The temperature of each part of the steel ingot mentioned above cannot withstand the large shrinkage pressure when the molten steel solidifies, nor can it withstand the strong circulation flow when measuring the temperature in the center of the steel bath. It was impossible to actually measure it.

For this reason, conventional methods have been used to calculate the temperature of each part of molten steel during the solidification process using experimental formulas or computer models, but selecting various coefficients is troublesome and it is still difficult to obtain temperature values with the desired accuracy. There was a problem that the technique was not sufficiently developed.

This idea was made in view of the above-mentioned conventional problems, and it protects the tip of the thermocouple protection tube by holding it in a quartz tube so that it can be pulled out, and also protects the tip of the quartz tube. It is an object of the present invention to provide a sensor for temperature measurement during the solidification process that can directly measure the temperature of molten steel in the solidification process by having a structure that is housed in a pressure-resistant cylinder whose main component is silicon carbide.

An embodiment of this invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a thermocouple protection tube made of high-purity alumina, and a thermocouple wire 2 made of platinum-platinum rhodium is passed through a porcelain insulating tube 3 and housed at its tip. The protection tube 1 is inserted into the quartz tube 4 until its tip almost reaches the tip 4a of the quartz tube 4, and a ceramic fiber 3a is filled between the protective tube 1 and the quartz tube 4, and the protective tube 1 is held so that it can be pulled out upwards as shown in the figure. ing. 5 is a holding member for the protective tube 1.
Reference numeral 6 denotes a pressure-resistant cylinder made of silicon carbide as a main component, which is fitted onto the quartz tube 4 and fixed by filling the space between the two with alumina cement 7. However, the tip 4a of the quartz tube 4 is exposed from the pressure cylinder 6.
The wall thickness of the pressure cylinder 6 is set to be thick enough to withstand the solidification pressure of the molten steel 8. Reference numeral 9 denotes a cylindrical attachment body made of heat-resistant material, which receives the pressure-resistant cylinder 6 at its large-diameter end 9 a and is connected to the alumina cement 7 and a fixture 10 .

In the sensor constructed as described above, the mounting body 9 is inserted and held in the mold 11 from the inner wall side thereof, and a portion thereof is immersed in the molten steel 8, as shown in the figure. During immersion, insulating material 12 is placed at the boundary between the hot water surface and the atmosphere.
is fixed with water glass 13, for example, to prevent the generation of internal stress due to temperature differences and to prevent chemical instability of silicon carbide in the slag layer. Protection tube 1
Its body is protected by a quartz tube 4 and a pressure tube 6, and this pressure tube has a wall thickness that can withstand the solidification pressure of the molten steel 8, while its tip is only covered by the quartz tube 4. Therefore, even if the solidification process of the molten steel 8 progresses, it will not be crushed. Even if the pressure cylinder 6 is damaged, since the quartz tube 4 is present, the temperature of the molten steel 8 during solidification can be actually measured.

As solidification progresses, the entire sensor cannot be removed due to solidification pressure, but since the protection tube 1 is fixed in the quartz tube 4 so that it can be pulled out, the protection tube 1 can be collected and reused after temperature measurement. can be used. A portion of the pressure tube 6 and the like left in the steel ingot is a small amount when viewed from the steel ingot, and does not contain any components that would adversely affect subsequent processes.

As described above, according to this invention, a thermocouple protection tube is housed in a quartz tube, the tip of the quartz tube is exposed, and the other part is protected with a pressure-resistant cylinder whose main component is silicon carbide. Since the tip is protected by the tip of the quartz tube, it can withstand the high temperatures of molten steel, and by making the wall thickness of the pressure tube appropriate, it can be made pressure resistant enough to withstand the solidification pressure of molten steel. Because it is removable, it is possible to directly and continuously measure the internal temperature of molten steel, including its solidification process, making it easy to obtain accurate temperature values necessary for optimal combustion control in soaking furnaces. can.

[Brief explanation of the drawing]

The figure is a longitudinal cross-sectional view showing an embodiment of a sensor for measuring temperature during the solidification process of molten steel according to this invention. In the figure, 1... protection tube, 2... thermocouple wire, 4... quartz tube, 6... pressure cylinder.

Claims (1)

[Scope of utility model registration request] A protective tube containing a thermocouple is inserted so as to be able to be pulled out to the tip of the quartz tube, and the quartz tube, except for the tip, is housed in a pressure-resistant cylinder with a predetermined wall thickness and made of silicon carbide as a main component. A sensor for measuring temperature during the solidification process of molten steel.