JP2539861B2 - Continuous temperature measuring tube for molten metal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement in a continuous temperature measuring tube for molten metal.

[Conventional technology]

Conventionally, for example, as a continuous temperature measuring tube for molten metal for measuring the temperature of molten steel in a tundish, it is described in JP-B-58-46692, JP-A-53-9585, JP-B-58-45653. Things are known. Each of these continuous temperature measuring tubes for molten metal has a structure as shown in FIG.

In FIG. 3, a protective tube 1 is internally provided with a porcelain tube 2, and a temperature measuring end of a thermocouple 3 is inserted inside the porcelain tube 2. The protective tube 1 and the porcelain tube 2 are integrally molded, or a graphite-based mortar is packed between the two. The upper part of the protective tube 1 is held by a metal holder 5 via a mortar 4, and this holder 5 holds a terminal 6
Has been fixed. The constant temperature end of the thermocouple 3 is connected to the terminal 6 and taken out to the outside. In each of the above publications, only the material of the protective tube 1 is different.

Using such a continuous temperature measuring tube for molten metal, the protrusion of the holder 5 is locked in the opening provided in the lid 7 of the tundish, and the tip of the protective tube 1 is immersed in the molten steel 8. And measure the temperature. During the temperature measurement, a cooling gas is flowing in the holder 5 as indicated by the arrow in the figure.

[Problems to be solved by the invention]

Since the continuous temperature measuring tube for molten metal has a tubular structure, its cost is almost proportional to its length. Therefore, it is conceivable to shorten the length in order to reduce the cost, but it is necessary to measure the temperature even when the amount of molten steel 7 in the tundish is small, so there is a limit to shortening the length. There is.
Therefore, it is reused to improve the cost / performance, but since slag etc. adhere to the molten steel immersion part of the temperature measuring tube that has been used once, the reliability of the measurement accuracy etc. will be improved after the second use. descend. Therefore, in order to maintain the measurement accuracy, it is desirable to replace the temperature measurement.

However, in the conventional continuous temperature measuring tube for molten metal, the protective tube 1
Also, since the porcelain tube 2 installed therein and at least the terminal 6 on the lid 7 of the tundish are integrated, replacing these integrated members each time the temperature is measured increases the cost. Leads to.

The present invention has been made to solve the above-mentioned problems, and in order to maintain the reliability of temperature measurement, even if the protective tube or the like is replaced, melting that does not significantly increase the cost required for the melting is performed. An object is to provide a continuous temperature measuring tube for metal.

[Means for solving problems]

The continuous temperature measuring tube for molten metal of the present invention is a refractory protection tube, a porcelain tube installed inside the protection tube, a thermocouple inserted into the porcelain tube, and detachable above the porcelain tube. A first connector attached to the thermocouple, an outer tube erected on the upper part of the protective tube, and an inner tube attached to the outer tube in a detachable manner and inserted into the outer tube. A pipe, a second connector attached to the lower end of the inner pipe and joined to the first connector, and connected to the second connector;
And a lead wire taken out to the outside through the inside of the inner tube.

In the present invention, the refractory forming the protective tube is at least one selected from alumina, zirconia or silica.
It is desirable to have a composition of 50 to 95% by weight and carbon 50 to 5% by weight. This is because at least one selected from alumina, zirconia, or silica is less than 50% by weight, and when carbon exceeds 50% by weight, corrosion resistance decreases,
This is because if at least one selected from alumina, zirconia or silica exceeds 95% by weight and carbon is less than 5% by weight, thermal shock resistance and heat transfer properties are deteriorated.

[Action]

In the continuous temperature measuring tube for molten metal according to the present invention, the protective tube, the porcelain tube and the outer tube are replaced as consumable parts each time the temperature is measured, and the other members are reused. The lengths of the protective tube and the porcelain tube can be made considerably shorter than conventional.

According to such a continuous temperature measuring tube for molten metal, unlike the conventional case, the reliability is not lowered due to reuse. Further, since the number of members to be replaced is smaller than in the conventional case, and the protection tube and the porcelain tube are shorter than in the conventional case, the cost is not so much increased. Therefore, the cost / performance can be improved much more than ever before.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, a refractory protective tube 11 is internally provided with a porcelain tube 12 made of alumina, and a thermocouple 13 is provided inside the porcelain tube 12.
The temperature measuring end of is inserted. Protective tube 11 and porcelain tube 12
Is about half the length of the conventional one. The protective tube 11 and the porcelain tube 12 are integrally molded, or graphite mortar is filled between the two. A connecting pipe 15 is attached to the upper portion of the protective pipe 11 via a mortar 14 with its central portion protruding upward. A ring 16 is detachably screwed to the protruding portion of the connecting pipe 15, and a first connector 17 is fixed to the ring 16, and the constant temperature end side of the thermocouple 12 is connected to the first connector 17. An outer pipe 18 is erected on the outer periphery of the upper portion of the connecting pipe 15 by being screwed. A holder 19 is pinned on the outer tube 18, and the outer tube 18 is attached to the holder 19.
An inner tube 20 inserted into 18 is attached. Therefore, the inner pipe 20 can be attached to and detached from the outer pipe 18. A second connector 21 is attached to the lower end of the inner pipe 20 and is engaged with the first connector 17. A lead wire 22 is connected to the second connector 21 and is taken out through the inside of the inner tube 20. Further, a cylindrical body 23 is attached to the inner pipe 20 so as to surround the first and second connectors 17 and 21 inside the outer pipe 18. The protection tube 11 is made of alumina,
At least one selected from zirconia or silica 50 to
It is composed of a refractory material having a composition of 95% by weight and 50 to 5% by weight of carbon. In addition, connecting pipe 15, ring 16, outer pipe
18, the holding tube 19, and the inner tube 20 are made of SS41 steel, SUS304 stainless steel, and other heat resistant steel.

As shown in FIG. 2, the first and second connectors 17 and 21 each have a heat-resistant ceramic 17a with a metal jack 17b attached, and a heat-resistant ceramic 21a with a metal plug 21b attached. It is a thing. Also,
The constant temperature end of the thermocouple 13 is crimped to the terminal of the jack 17b.

In the continuous temperature measuring tube for molten metal of the above-mentioned embodiment, similarly to the conventional one, the protruding portion of the holder 19 is provided with, for example, a tundish lid 24.
Is locked in the hole provided in the
Immerse in 25 and measure temperature. During the temperature measurement, as indicated by the arrow in the figure, the metal tube 20, the cylindrical body 23, the second and third support bodies 18,
Cooling gas (air, Ar, N _2, etc.) is flown into the inside of 19 to cool them so as not to be damaged by the heat of the molten steel 25.

In the continuous temperature measuring tube for molten metal of the above-mentioned embodiment, each member of the protective tube 11, the porcelain tube 12, the connecting tube 15 and the outer tube 18 is a consumable item and is replaced every time temperature is measured. Meanwhile, ring 16,
First connector 17, thermocouple 13, holding tube 19, inner tube 20, second
The respective members of the connector 21, the lead wire 22, and the cylindrical body 23 are reused.

When the continuous temperature measuring tube for molten metal in the above example was used for measuring the temperature of the molten steel in the tundish, the same accuracy as that of the conventional one was obtained. Further, when the consumable part consisting of the above-mentioned several members was replaced and the temperature was measured again, the measurement accuracy did not deteriorate. On the other hand, when the conventional continuous temperature measuring tube for molten metal was reused without replacement, the responsiveness decreased due to the influence of the slag adhering to the outer circumference of the protective tube. I had to replace almost everything. Therefore, in order to maintain the same measurement accuracy, the continuous temperature measuring tube for molten metal according to the present invention can significantly suppress the cost increase as compared with the conventional one. Further, in the continuous temperature measuring tube for molten metal according to the present invention, the attachment structure of the consumable part and the reusable part is simple, and the workability at the time of replacement hardly poses a problem.

In the above embodiment, the attachment structure between the consumable portion and the reused portion is, for example, screwed between the connecting pipe 15 and the ring 16 and pinned between the outer pipe 18 and the holding body 19.
In addition to this, bolting or bayonet type can be used, and the mounting structure and application site thereof are not limited at all. Further, it goes without saying that the joining method of the first and second connectors can be applied to those other than those used in the above embodiment. Further, the constituent members of the consumable part and the reusable part can be simplified as compared with the above embodiment. Furthermore, by covering the outer circumferences of the connecting pipe 15 and the outer pipe 18 with a heat insulating material such as ceramic fiber, the cooling effect inside the pipes can be further enhanced.

〔The invention's effect〕

As described above in detail, according to the continuous temperature measuring tube for molten metal of the present invention, there is no reduction in reliability due to reuse,
Moreover, even if the consumable part is replaced, the cost does not increase so much, so that its industrial value is extremely large.

[Brief description of drawings]

FIG. 1 is a sectional view of a continuous temperature measuring tube for molten metal in an embodiment of the present invention, FIG. 2 is a sectional view of first and second connectors used in the continuous temperature measuring tube for molten metal, and FIG. The figure is a cross-sectional view of a conventional continuous temperature measuring tube for molten metal. 11 …… Protection tube, 12 …… Porcelain tube, 13 …… Thermocouple, 14 …… Mortar, 15 …… Coupling tube, 16 …… Ring, 17 …… First connector, 18 …… Outer tube, 19… … Holder, 20 …… Inner tube, 21…
… Second connector, 22 …… Lead wire, 23 …… Cylinder.

Claims (2)

(57) [Claims] 1. A refractory protection tube, a porcelain tube installed inside the protection tube, a thermocouple inserted into the porcelain tube, and a detachably mounted above the porcelain tube, the thermocouple being attached to the thermocouple. A connected first connector, an outer pipe erected on the upper part of the protection pipe, an inner pipe detachably attached to the outer pipe and inserted into the outer pipe, and Attached to the bottom edge,
A molten metal, comprising: a second connector joined to the first connector; and a lead wire connected to the second connector and taken out through the inside of the inner pipe to the outside. Continuous temperature measuring tube. 2. The refractory material constituting the protective tube is at least one kind selected from alumina, zirconia and silica 50 to 95.
The continuous temperature measuring tube for molten metal according to claim 1, which has a composition of 50% by weight of carbon and 50 to 5% by weight of carbon.