JPH06185870A - Detection of deterioration of cooling wall of induction melting furnace - Google Patents

Abstract

PURPOSE:To detect the deterioration of the walls of a melting furnace before the leakage of cooling medium in order to safely stop the operation of the melting furnace by a method wherein the structure of the furnace is made up of double hollow walls, a temp. sensor, together with good heat and electricity conducting filler, is provided in the hollow part on the inner side of the walls and the deterioration of the walls is detected by the temp. sensor which senses a rise in the temp. of melt. CONSTITUTION:A temp. sensor 3, together with filler 4, is provided in a hollow part 2 on the inner side of a double hollow wall 1. Concerning the filler 4, filling powders are filled in the hollow part and outside air or helium is thereafter filled in spaces between the filling powders. If a hole is produced through the furnace wall in contact with melt 12 and the melt is moved therethrough and into contact with the cooled filling powders 7, it is instantaneously solidified and its further movement is stopped. Since the furnace is of induction type, however, the solidified melt again becomes molten and such a melt is moved through the spaces between the filling powders. When the melt 12 is further moved therethrough to reach a temp. sensor 3, this sensor senses a rise in the temp. of the melt and sends the temp. signal to a detector to indicate the existence of the through hole in the wall. Therefore, the operation of the furnace can be safely stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction melting furnace cooling wall deterioration detecting method for melting metal or ceramics.

[0002]

2. Description of the Related Art As shown in FIG. 5, an induction melting furnace is a melting furnace composed of a crucible composed of a working coil 31 and walls (a plurality of wall segments) 32. The characteristic of this melting furnace is the wall 32
Is hollow, and a cooling medium such as water is passed through the hollow portion to prevent damage to the wall 32 due to heating. Generally, the wall 32 is made of copper having a high thermal conductivity. The melting of metal or ceramics is performed in the crucible.

As described above, in a melting furnace using a cooling wall, the melt may come into contact with the cooling medium due to deterioration of the wall, causing a serious accident such as a steam explosion. Therefore, in this type of melting furnace, it is necessary to monitor the deterioration of the wall and prevent the leakage of the cooling medium such as water. For this reason, conventionally, the deterioration of the wall was visually checked, but it could not be sufficiently checked because the residue of the melt adhered to the wall surface.
As a countermeasure, there is a method of increasing the thickness of the wall on the side in contact with the melt, embedding a temperature sensor in the wall, and detecting the temperature rise due to the deterioration of the wall with this temperature sensor to detect the deterioration of the wall. is there.

[0004]

However, in this method, when the wall deteriorates and a through hole is instantaneously formed in the wall, even if the temperature rise is detected, the leakage of the cooling medium cannot be prevented. Further, if the thickness of the wall that is in contact with the melt is increased, thermal stress is generated in the wall, which may deform or damage the wall.

The present invention has been made in order to solve the above problems. The wall has a double hollow structure, a temperature sensor is arranged inside the wall, and a cooling medium is arranged outside the wall. It is an object of the present invention to provide an induction melting furnace cooling wall deterioration detecting method for detecting deterioration of a wall by flowing a gas and detecting a temperature rise by a temperature sensor arranged in a hollow inside.

[0006]

DISCLOSURE OF THE INVENTION The gist of the present invention is to provide an induction melting furnace for cooling a wall with a cooling medium, wherein the wall has a double hollow structure, and the inside of the wall has a temperature along with a good conductor of heat and electricity. This is a method for detecting deterioration of an induction melting furnace cooling wall in which a sensor is provided and a temperature rise is detected by this temperature sensor to detect deterioration of the wall.

[0007]

The deterioration of the wall is caused by cracks and wear, but these become large with the lapse of time and a through hole is formed in the wall. In the present invention, even if the wall deteriorates and a through hole is formed in the wall that comes into contact with the melt, the wall has a double hollow structure, so the melt does not come into contact with the cooling medium and causes a steam explosion or the like. There is no such thing.

When a through hole is formed in the wall that comes into contact with the melt, and the melt that has entered through the through hole moves through the filler and reaches the temperature sensor, the temperature sensor detects the temperature rise and deteriorates the wall. Can be detected. Since the movement of the melt is blocked by the intermediate wall of the double hollow structure, it is possible to safely shut down the furnace after detecting the deterioration of the wall.

Further, when a through hole is formed in the intermediate wall of the double hollow structure and the cooling medium enters the temperature sensor side, the temperature sensor detects the temperature decrease due to the movement of the cooling medium to detect the deterioration of the wall. be able to. In this case as well, the furnace can be safely shut down after the detection of wall deterioration.

Since the filler is a good conductor of heat, it exhibits a sufficient cooling effect in normal times, and since it is a good conductor of electricity, heat loss due to an induced current is also small.

[0011]

EXAMPLES Examples of the present invention will be described below. FIG. 1 is a conceptual diagram of the present invention, in which reference numeral 1 is a double hollow wall, and a temperature sensor 3 is arranged in a hollow 2 inside the double hollow wall 1 together with a filler 4. Cooling water 6 is passed through the hollow 5 outside the double hollow wall 1 to cool the double hollow wall 1. The end of the temperature sensor 3 is connected to a detector (not shown) to detect the temperature electrical signal. In the figure, 12 is a melt and 31 is an operating coil.

Example 1 FIG. 2 is an example in which the powder filling 7 was used as the filling, and the powder filling 7 was copper powder. After filling with the powder filling 7,
The space between the powder fillings is filled with air or helium. When a through hole is formed in the wall that contacts the melt 12 and the melt enters, it comes into contact with the cooled powder filling 7 and instantly solidifies to stop the entrance, but since the furnace is an induction furnace. , Melt again and move through the space between the fillings. When the melt moves in the space between the packings and reaches the temperature sensor 3,
Here, the temperature sensor 3 detects an increase in temperature, sends a temperature signal to the detector, and the detector can know that the through hole is formed in the wall. After detecting that the wall has a through hole,
Safely shut down the furnace.

Since the copper powder of the powder filling 7 is a good conductor of heat and the space between the copper powders is the atmosphere or helium, the inside of the hollow 2 has a good thermal conductivity under normal conditions and a sufficient cooling performance. Have Further, since the copper powders are good conductors of electricity, the heat loss due to the induced current flowing between the copper powders is small.

Example 2 FIG. 3 shows an example in which a low melting point metal filling 8 is used for the filling, and Na is used for the low melting point metal filling 8. When a through-hole is formed in the wall that contacts the melt 12 and the melt enters, it comes into contact with the cooled low-melting-point metal filler 8 and instantly solidifies to stop the entrance, but the furnace is an induction furnace. Therefore, the low melting point metal filling 8 is melted again, heated and melted, and mixed with the low melting point metal filling 8. This melt and low melting point metal filler 8
When the mixed material reaches the temperature sensor 3, the temperature sensor 3 detects the temperature rise here, sends a temperature signal to the detector, and the detector can know that the through hole is formed in the wall. After detecting the formation of a through hole in the wall, the furnace is safely shut down.

Since the low-melting-point metal filling 8 is a high-density Na metal, the inside of the inner hollow 2 has good thermal conductivity in normal times and has sufficient cooling performance. In addition to Na, K or the like can be used for the low melting point metal filling.
Further, the object of the present invention can be achieved by using a thermocouple instead of the temperature sensor.

Modified Embodiment FIG. 3 shows a structure in which the double hollow wall 1 is divided into two parts and is detachable, and the inner wall 9 in contact with the melt 12 is fixed to the water-cooled hollow wall 10 with bolts 11. In this way, by making the double hollow wall into a two-part structure, the temperature sensor 3 and the filling 4 can be easily replaced, and the inner wall 9 and the water-cooled hollow wall 10 can be visually checked.

As described above, it is possible to detect the deterioration of the wall and safely shut down the furnace by detecting the temperature rise by the temperature sensor arranged in the hollow inside the wall of the double hollow structure.

[0018]

INDUSTRIAL APPLICABILITY According to the present invention, in an induction melting furnace for cooling a wall by a cooling medium, the wall has a double hollow structure, and a temperature sensor is arranged in the hollow inside the wall together with a good conductor of heat and electricity. A method for detecting deterioration of a cooling wall of an induction melting furnace in which a temperature rise is detected by this temperature sensor to detect deterioration of the wall. According to the present invention, deterioration of the wall is detected before the cooling medium leaks due to the deterioration of the wall. And you can safely shut down the furnace.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of the present invention.

FIG. 2 is an explanatory diagram of Embodiment 1 of the present invention.

FIG. 3 is an explanatory diagram of a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a modified embodiment of the present invention.

FIG. 5 is an explanatory diagram of an induction melting furnace.

[Explanation of symbols]

1 ... Double hollow wall, 2 ... Inner hollow, 3 ... Temperature sensor, 4
... filling, 5 ... outer hollow, 6 ... cooling water, 7 ... powder filling, 8 ... low melting point metal filling, 9 ... inner wall, 10 ... water cooling hollow wall, 11 ... bolt, 12 ... melt, 31 ... Operating coil, 32 ...
wall.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F27D 11/06 A 7141-4K

Claims (1)

[Claims] 1. In an induction melting furnace for cooling a wall with a cooling medium, the wall has a double hollow structure, and a temperature sensor is provided in the hollow inside the wall together with a good conductor of heat and electricity, and this temperature sensor is used. A method for detecting deterioration of a cooling wall of an induction melting furnace, which comprises detecting a temperature rise to detect deterioration of a wall.