JPS6016453Y2 - Continuous casting mold - Google Patents

Description

[Detailed description of the invention] This invention relates to molds used in continuous casting equipment.
In particular, it relates to the improvement of continuous casting molds with embedded thermocouples for detecting the level of molten steel.

In recent years, continuous manufacturing methods have become rapidly popular in steel factories due to their advantages such as labor saving, automation, and cost reduction.However, there are some important casting conditions to improve the properties of ingots produced by continuous casting. These include the injection speed of molten steel and the casting withdrawal speed.

In order to control these speeds, it is necessary to detect and feed back the molten steel surface level, so the conventional method of detection is to operate a Geiger tube or scintillation counter to detect the gamma ray source. Typical methods include inserting a thermocouple near the mold surface in the mold and estimating the molten steel surface based on the temperature, but the latter method is mainly adopted from a practical and safety point of view. ing.

By the way, in order to detect the molten steel surface level during continuous casting using a thermocouple, the thermocouple is attached directly to the mold, but conventionally the thermocouple is inserted into a blind hole that reaches near the inner surface of the mold wall from the back side. As a result, the heat input from the molten steel to the sensor was indirect, resulting in poor detection accuracy and no hope of improving level measurement accuracy.

In addition, it has been proposed that a sensor block with thermocouples attached at equal intervals is embedded in the inner surface of the mold wall, and the sensor block is buried by electroforming. However, there is a problem in that there is a structural joint line between the sensor block and the mold wall, and there is a risk of cracks occurring in the electroformed layer from this joint boundary, and that it is difficult to replace the sensor block.

This idea was made to solve the above-mentioned conventional problems.It directly transfers the heat input from molten steel to the thermocouple, improves the heat flow near the thermocouple, and improves level measurement accuracy and response. In addition, the present invention provides a continuous casting mold which has no structural joining line between the plated part and the thermocouple, and which is designed so that the thermocouple can be easily replaced.

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

In a continuous casting mold, for example, a slab continuous casting mold 1 as shown in FIG. 1, a pair of wide mold walls 2 are used.
, 2', a pair of left and right narrow mold walls 3, 3' corresponding to the thickness dimension of the slab are connected to a movable member 4 that can move forward and backward, and move the narrow mold walls 3, 3' to the width dimension of the slab. After adjustment, fix.

A sensor for detecting the level of molten steel is embedded in one mold wall of the mold 1, for example, the narrow mold wall 3.

That is, as shown in FIGS. 2 and 3, the narrow mold wall 3 has cooling water passages 5° . 5. The above cooling water passage at a constant depth. . . . A long groove 6 in the longitudinal direction of the mold wall is cut to pass through the mold wall 5.

The long groove 6 has a small hole 7 that penetrates from the bottom of the long groove 6 to the inner surface 3b of the mold wall 3. ..., 7 in the longitudinal direction of the mold wall 3,
A large number of holes are drilled at required intervals in the direction of progress of the slab.

On the other hand, a thermocouple 8 for detecting the molten steel surface level,...
, 8 into the small hole 7. . . , the sensor holders 9 are arranged and supported at intervals of 7, and the thermocouples 8 of the sensor holders 9 are
．． ..., 8 into the small hole 7. ..., inserted into 7,
Thermocouple8. ..., the sensor holder 9 is inserted into the long groove 6 so that the tip of the sensor holder 8 slightly protrudes from the inner surface 3b of the mold wall 3.
Fixed inside.

Note that the thermocouples 8' and 8' for detecting the upper and lower limits are slightly different in position and spacing from the other thermocouples.

Each thermocouple 8 of the sensor holder 9. Wiring of δ (not specifically shown).

) are bundled into a watertight wiring pipe 10 from the back of the sensor holder 9 and pulled out to the outside, while on the back 3a of the mold wall 3,
A mounting plate 13 that covers the opening of the long groove 6 with a packing 11 and seals the wiring pipe 10 with a packing ring 12 is attached to the port 14. ..., 14, and the long groove 6 has a watertight structure.

Note that the sensor holder 9 holds each thermocouple 8. . . , and 8 are configured in advance to be waterproof.

Thus, the thermocouple 8. ..., with the tip of 8 slightly protruding from the inner surface 3b of the mold wall 3, using electroforming, that is, electrodeposition by electrolysis, onto the inner surface 3b of the mold wall 3, which is a cathode object. Metal plating such as copper alloy, nickel, chromium, etc. is applied to the inner surface 3b of the mold wall 3 and the protruding thermocouple 8. ....

8 is covered with a plating part 14.

If configured as described above, thermocouple 8. ..., 8, the heat input from the molten steel is directly transferred to the sensor holder 9 and the thermocouple 8. ..., 8
Heat removal from the vicinity of the tip is improved, and level measurement accuracy and response can be improved.

Also, thermocouple 8. . . . Since there is no structural joining line between the plated part 3 and the part 8, there is no need to worry about cracking, and furthermore, the cooling water passage 5 can be penetrated, so compared to the conventional thermocouple described above. Therefore, there are no restrictions on the position or range of attachment to the continuous casting mold, and by attaching and detaching the attachment plate 13, the sensor holder 9 can be replaced from the outside.

In the illustrated embodiment, the sensor is embedded in the narrow side mold wall 3 of the mold 1, but it may also be provided in the wide side mold wall 2, and the configuration of the mold 1 is also limited to an assembled mold. Of course, this is not something that can be done.

As is clear from the above explanation, this idea involves making a small hole in a long groove cut into the back surface of the mold wall, and the tip of the thermocouple that fits into the small hole protrudes slightly from the inside surface of the mold wall. The sensor holding frame is fixed in the long groove, and then the inner surface of the mold wall is coated by electroforming, so the heat input from the molten steel is directly transmitted to the thermocouple, improving level measurement accuracy and response. In addition, since there is no structural joining line between the plated part (sheathing part) and the thermocouple, cracks do not occur, and since the thermocouple can be attached and removed from the outside of the mold, replacement is easy. be able to.

In addition, if the long groove is inserted through the cooling water passage in the mold to make the sensor holder waterproof, the cooling water will improve the heat flow near the thermocouple, preventing temperature averaging in the thermocouple area and creating an appropriate temperature gradient. The above-mentioned level measurement accuracy can be further improved by showing the pattern, and the mounting of the thermocouple through the cooling water passage has various advantages such as there are no restrictions on position or range, and is of great practical value.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a continuous casting mold, Fig. 2 is a sectional view taken along the line A-A in Fig. 3, which is an enlarged view of the main parts of the continuous casting mold according to this invention, and Fig. 3 is a rear view of Fig. 2. It is a diagram. 1...Mold, 3...Mold wall, 5...
...Cooling water passage, 6...Long groove, 7...
・Small hole, end...Thermocouple, 9...Sensor holder, 10...Wiring pipe, mounting plate, 14...
...Plating section. 13...

Claims (2)

[Scope of utility model registration request] (1) Cut long grooves in the direction of slab movement on the back side of the mold wall. Small holes penetrating the inner surface of the mold wall are drilled at required intervals in the long grooves, and the level of molten steel in the mold is detected in the long grooves. A sensor holder having thermocouples arranged at intervals between the small holes is fixed so that the tips of the thermocouples slightly protrude from the inner surface of the mold wall, and then the inner surface of the mold wall is electroformed. A continuous casting mold characterized by being coated. (2) Continuous casting according to claim 1, characterized in that the long groove is cut so as to pass through a cooling water passage in the mold, and the sensor holder is of a waterproof type. template.