JPH044214Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field of the invention) The measuring element of the molten metal measuring probe of the invention (for example, a temperature detection element, an oxygen concentration battery for measuring the amount of oxygen, and other components for measuring components in molten metal) This relates to a measuring element protector that protects the measuring element (elements, etc.).

(Background of the idea) In order to adjust the blow-off temperature and blow-off components to the right level in a refining furnace, such as a computer-controlled converter, it is necessary to provide control information such as temperature and components (mainly carbon content and oxygen content) at least during blowing. It is essential to know at any point in time (usually between 0 and 2 minutes before blow-off).

Conventionally, as shown in FIG. 6, there is a method in which a measuring probe 11 is attached to a sublance 9 and immersed in the molten metal 3 to measure the temperature, carbon content, oxygen content, etc. of the molten metal 3 in the converter 1 during blowing. is widely used.

In this case, as shown in Fig. 7a (for temperature detection) or Fig. 7b (for oxygen content measurement), the measuring element 14 at the lower end of the measuring probe 11 is protected by a metal cap 15 and melts after passing through the slag layer 2. When it reaches the metal 3, the cap 15 melts and the measuring element 1
4 will be exposed and the intended measurement will be performed.

However, molten metal 3 such as molten pig iron and scrap are charged into the converter 1, and if the scrap content ratio is high, damage to the measuring element 14 may occur due to the following reasons, and the converter may be damaged. There is a greater possibility that the temperature cannot be measured during blowing in the furnace 1: A. Physical damage (damage due to hard slag) If the scrap content is high, the slag formation into slag will be delayed and no reaction will occur when measured by the temperature probe 11. A large amount of lime or quicklime remains in the slag layer 2 to form a hard slag, and the cap 15 and the measuring element 14 collide with this and are damaged.

B Physical damage (damage due to undissolved scrap lumps) Due to the high proportion of scrap, the scrap is not completely dissolved when measuring during refining using an automatic insertion device such as Sublance 9, and such undissolved scrap The measuring element 14 exposed in the molten metal 3 collides with the scrap mass 5 and is damaged.

C Physical damage (damage due to flowing low-temperature slag, granulated iron, etc.) Hard low-temperature slag that has delayed slag formation due to the high scrap content and granulated iron present in large quantities in the slag layer 2 may cause damage to the main lance 7. It flows due to the stirring of the oxygen jet 8, collides with or comes into contact with the measuring element 14, and physically damages the measuring element 14.

D. Scientific erosion The slag adheres to the measuring element 14 and causes a chemical reaction, which destroys the elements (for example, SiO ₂ tube, Pt thermocouple wire, etc.) that constitute the element.

None of these examples poses a major problem in the case of a static bath after blowing, but when measuring during blowing, as mentioned above, the oxygen jet 8 of the main lance 7
The occurrence of these problems is further exacerbated by the agitation caused by this.

According to experience, the success rate of temperature measurement during blowing is usually more than 95% under conditions of scrap content of 0 to 15%, but when the scrap content is higher than this and the slag formation conditions are not good. , the temperature measurement success rate drops significantly to 60-90%.

For example, when the scrap rate is 25%, the measurement temperature is around 1540℃, and the carbon content is around 0.60%, the normal temperature success rate is 90%.
It is difficult to obtain more than that.

It is known that the higher the scrap content ratio, the higher the defect rate measured during blowing.

(Disclosure of publicly known documents, etc.) In order to prevent temperature detection elements and other component detection elements from being damaged during immersion due to hardened slag, conventional methods have been used such as Utility Model Publication No. 52-52625, Utility Model Application Publication No. 58-154461,
Utility Model Application Publication No. 58-178668 is publicly known.

(Purpose of the invention) The present invention improves the conventional method described above, and even when unmelted scrap lumps, hard slag, etc. are present during blowing, the melting method can more fully protect the metering element from damage. The purpose is to provide a measuring element protector for metal measuring probes.

(Embodiments of the invention) The protector of the invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 shows the protector of the present invention together with a measuring probe equipped with a measuring element, such as a temperature detecting element, and the measuring probe 11 has a support 19 made of ceramics or the like forming the lower end surface of the main body 12.

The support body 19 supports the measuring element 14 that projects downward.

The measuring element 14 is covered with a metal cap 15, and the cap 15 is covered with a protective block 22 constituting the protector of the present invention.

The protective block 22 is made of a heat-resistant material such as ceramics, shell mold, refractory cement, refractory brick, or cast metal.

FIG. 2 shows a protection block 22 divided into multiple parts.
showed that.

The protection block 22 is connected to the main body 12 by being supported by side walls 13 and a bottom cover 23 made of combustible material such as paper (the bottom cover 23 may be omitted if it can be supported only by the side walls 13). ).

Further, a cavity 25 is formed in the side wall 13 at the outer periphery of the joint between the protection block 22 and the lower end surface of the main body 12.

The action of the protector of the present invention shown in the above embodiments is as follows.

That is, as shown in FIG. 6, a measuring probe 11 is attached to an automatic insertion device such as a sublance 9, and the measuring probe 11 is lowered into the converter 1 during blowing.

As a result, the protector at the lower end of the measurement probe 11 is immersed in the slag layer 2.

In the slag layer 2, the surface of the side wall 13 is carbonized due to the high temperature, but the bonded state with the main body 12 is maintained.

Therefore, while passing through the slag layer 2, the measuring element 14 is protected by the protective block 22 of the protector.

Next, when the protective body reaches the molten metal 3, the side wall 13 is exposed to the cavity 25, which is most likely to burn due to its high temperature.
is burned and cut.

Furthermore, since convection and agitation flows of molten metal exist, the protective block 22 and the side wall 13 housing it are removed by the action of the molten metal flow.

This separates the protection block 22 from the main body 12.

As a result, the cap 15 is exposed in the molten metal 3 and immediately melts away.

As a result, the measurement element 14 is exposed in the molten metal 3 and starts measurement.

The protector of the present invention may have the following configuration other than that shown in the above embodiments.

That is, the measurement element 14 is a concept in a broad sense, and for example, when a sample introduction tube (not shown) is arranged on the lower end surface of the main body 12 of the measurement probe 11 to collect a sample of molten metal, the sample introduction tube, etc. is also a measurement element. shall be interpreted as 14.

Further, as shown in FIG. 3, the protective block 22 may be divided into three parts instead of four, and the cap 15 shown in FIG. 1 may be omitted since it is covered with the protective block 22.

Furthermore, as shown in FIG. 4, the protection block 22 may be made to protrude downward.

Additionally, a spring 28 as shown in FIGS. 4 and 5 may be housed within the protective block 22 to facilitate division of the protective block 22.

Although the protection block 22 of the split type was used in the above embodiment, the protection block 22 does not necessarily have to be of the split type.

For example, the protection block 22 may be formed by casting a refractory or baked into one piece, or if the tip is to be completely sealed, a shell molded block or the like may be used.

(Effects of the Invention) The measuring element protector of the molten metal measuring probe of the present invention has the following effects in the configuration and operation shown in the above embodiments.

(1) The protector of the present invention has the structure described in the claims for utility model registration, and since the measuring element is covered with a protective block made of a particularly heat-resistant material, hard slag, low-temperature slag, particles, etc. It is well protected from iron and unmelted scrap lumps and there is no risk of damage from these.

(2) The protector of the present invention has the same structure as above, and in particular, a cavity is formed in the side wall at the outer periphery of the joint between the protective block and the lower end surface of the main body, so that the side wall is reliably burned and cut in molten metal. measurement is performed.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional front view showing the protector of the present invention together with a measurement probe, Fig. 2 is a perspective view of a protection block of the same protector, Fig. 3 is a perspective view of another protection block same as the above, and Fig. 4 is the same as the above. 5 is a perspective view of a spring used in the protector of FIG. 4, FIG. 6 is a conceptual diagram showing a conventional measurement probe for official use, and FIGS. 7a and 7b. The figure is a cross-sectional front view of the cap of a conventional measurement probe. 1... Converter, 2... Slag layer, 3... Molten metal, 5... Unmelted scrap lump, 7... Main lance, 8... Oxygen jet, 9... Sublance,
11...Measuring probe, 12...Main body, 13...
Side wall, 14...Measuring element, 15...Cap, 1
9... Support body, 21... Lead wire, 22... Protection block, 23... Bottom cover, 25... Blank space, 28...
...Spring.

Claims (1)

[Scope of utility model registration request] A protective block made of a heat-resistant material that covers the measuring element protruding downward on the lower end surface of the main body of the measuring probe, a side wall made of a combustible material that supports the protective block and connects it to the main body, and a protective block. A measurement element protector for a molten metal measurement probe consisting of a cavity formed in the side wall of the outer periphery of the joint on the lower end surface of the main body.