JPS58208649A - Method for detecting fusion of refractory wall - Google Patents

Abstract

PURPOSE:To carry out detection simply and certainly, by a method wherein the internal pressure of a fine metallic pipe of which the closed end is positioned in a refractory wall is defferentiated from the internal pressure of an apparatus to be detected and the change in the internal pressure of the fine metallic pipe caused by the opening of the closed end due to fusion is measured. CONSTITUTION:Fine metallic pipes 11 of which leading ends are closed and which have pressure gauges 12 provided to the trailing ends thereof and are held under atmospheric pressure are embedded in the lower side wall of a vacuum degassing tank 1 provided on a laddle 9 contg. molten steel 10 therein at three levels h1, h2, h3 while embedded at the level h1 in the vicinity of a gas blow-in port 8. In this constitution, the closed end of each fine pipe 11 is exposed as the refractory layer 3 of the tank 1 is lost by melting and instantaneously melted by molten steel to bring the internal pressure of the fine pipe 11 close to the vacuum degree of the tank 1. Therefore, the fusion of the layer 3 can be known by the pressure gauge 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for simply and reliably detecting melting damage on the wall of a large object.

In this case, "refractory wall" refers to molten metal containers (e.g., hot metal ladle, molten steel ladle, pig iron mixing car, etc.), smelting furnaces (e.g., top-blown, bottom-blown, top-bottom-blown converter furnaces, electric furnaces, etc.) , refers to a large-sized wall that is used in parts that come into contact with molten metal in vacuum processing equipment (for example, DI type, RH type vacuum processing equipment, etc.).

Accurately knowing the welding status of this type of refractory wall is extremely important from the viewpoint of improving the refractory unit consumption and preventing accidents.

Conventionally, methods for detecting corrosion damage in refractory walls include embedding thermocouples in refractory walls and estimating the temperature increase, or embedding RI in large refractory walls and detecting the RI's impact. A method of detecting the amount of radiation remaining or dissolved in the wall is known.

However, in the former case, the thermocouple deteriorates over time (wears out,
It is difficult to know the melting loss value accurately because it has a low durability due to ``thermal insulation'' and because it is estimated from temperature measurement results. On the other hand, in the latter case, not only is it necessary to take special measures to prevent the adverse effects of RI on the human body, but there are also problems in that evaluation of measurement results requires specialized knowledge and is complicated. ing.

The present invention solves the above-mentioned problems and provides a method for simply and reliably detecting the melting damage state of a refractory wall.

The method of the present invention uses one or more metal thin tubes having a closed end at the tip and a rear end connected to a pressure gauge, and positions the closed end at a predetermined neck in the thickness direction of the refractory wall. At least bury it. At this time, the pressure inside the metal cell shall be made different from the pressure inside the device or equipment to be detected. When the person-proof wall is gradually eroded by contact with the molten metal and the closed end of the metal tube is melted by the molten metal, the pressure inside the metal tube becomes close to the pressure inside the device or equipment being detected. Pressure i/co changes. By measuring the pressure change inside this thin metal tube with a pressure gauge, it is known that the closed end has been melted down to the buried position.

In this case, the shape ζ structure of the closed end is not limited to simply closing the tip of the metal tube, but may also be one in which a hollow annular chamber or a hollow plate-shaped chamber is provided at the tip of the metal tube, depending on the purpose of measurement. You can use the shape and structure selectively.

Examples will be described in detail below with reference to the drawings.

FIG. 1 shows a case in which the present invention is applied to a vacuum tank of an R-H type vacuum degassing apparatus, and FIG. 2 shows a case in which it is applied to the bottom and side walls of a bottom-blown converter.

First, in Fig. 1, reference numeral 1 denotes a vacuum degassing tank, which is composed of an iron skin 2 and a refractory layer 31 (therefore, has an exhaust port 4 connected to an exhaust system at the top, and an ascending pipe 5 and a descending pipe at the bottom). The riser pipe 5VC has a pipe 6, and an Ar gas blowing pipe 7 for suctioning molten steel is installed.
In order to improve the degassing efficiency, a gas inlet 8 is provided at the bottom of the degassing tank 1. In addition, 9 in the figure is a ladle, 10
is molten steel.

In such a vacuum degassing device, the III of the degassing tank 1 is
The present invention is implemented at the lower part of the wall and near the gas inlet 8.

Reference numeral 11 denotes a metal thin tube having a closed tip and a pressure gauge 12 at the rear end, and is buried at three levels of the lower part of the side wall f, h2 and h3, and placed near the gas inlet 8 and buried at 0 level. This metal thin tube 11 is made of stainless steel and has an outer diameter of 5 mm.
, with an inner diameter of 3mm.

Since atmospheric pressure is sealed inside the metal capillary tube 11, as the refractory layer 3 of the degassing tank 1 is eroded, the metal capillary tube 1
When the closed end of No. 1 is exposed and comes into contact with molten steel, it melts instantly. Since the inside of the degassing tank 1 normally has a degree of vacuum of 0:] to 0.5 Torr, the inside of the metal tube 11 also has a degree of vacuum similar to this, and the pressure change inside this tube 11 is reflected by the pressure gauge 12. From this display, it is possible to know to what level the refractory layer 3 has melted away. Incidentally, this pressure change may be further notified by a buzzer or the like.

Next, in FIG. 2, 13 is a converter, which is composed of an iron shell 14 and a refractory layer 15, and a gas injection plug 1 at the bottom of the furnace.
6 is attached. In order to detect the melting damage of this plug 16 and the surrounding refractory material, there are two levels: beam and h2 for the former, and hl and h2 for the latter.
Metal capillary tubes 11 similar to those shown in FIG. 1 are buried at three levels, i.e., h3 and h3.

The inside of the Queen's converter is normally at atmospheric pressure, so one gas cylinder
A metal capillary tube 11 is connected to 7 and filled with pressurized gas to maintain the pressure inside the metal capillary tube 11 at 0.5 kg/cilK. As the refractory and the plug 16 are welded, the closed end of the metal tube 11 is exposed and melts when it comes into contact with molten steel, causing the pressure inside the metal tube 11 to drop, and this change is detected by the pressure gauge 12.
are displayed (and alarmed), allowing you to know the status of each melting loss.

In this way, the present invention is a method for detecting the melting condition of a refractory wall by using the pressure change inside the metal tube due to the melting of the closed end of the metal tube. Compared to the method using radiation, it is possible to detect the state of melting damage more easily and reliably, and it has greatly contributed to the management of melting damage of refractory walls.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, with FIG. 1 being an explanatory diagram showing an example of application to a vacuum degassing apparatus, and FIG. 2 being an explanatory diagram showing an example of application to a bottom blowing converter. 11... Metal thin tube with a closed end 12... Pressure gauge 17... Gas cylinder No. 1 (21 Fig. 2

Claims (1)

[Claims] 1 Yoshii places the closed end of a metal capillary inside the refractory wall, makes the pressure inside this metal capillary different from the pressure inside the device to be detected, and measures the pressure change inside the metal capillary due to the melted opening of this closed end. A method for detecting erosion of a refractory wall, the method comprising measuring the corrosion damage of a refractory wall.