JPH0647509A - Device for blowing gas - Google Patents

Abstract

PURPOSE:To easily measure the fall-down condition of a furnace wall and the remained height of a porous plug by including a waveguide bar body which the length can be measured with an ultrasonic wave, in the porous plug of a gas blowing device. CONSTITUTION:Plural notched parts 14b, 14c, 14d are arranged on the way of the waveguide bar body 14, and by inspecting reflecting wave with an ultrasonic wave length measuring instrument 19, the remained height of the porous plug 8, i.e., the exchanging time can be known. Ordinarily, the opening part 33 of a valve device 35 is made to closing condition and this measuring instrument is used as a device for blowing gas into the furnace from a gas hose 37 through the porous plug 8. At the time of detecting the height of the porous plug, the supply of the gas is stopped and a contact element is brought into contact with the waveguide bar body 14 from the opening part 33 in a change- over device A, and the prescribed frequency of the ultrasonic wave is transmitted to measure the length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas blowing device having a porous plug used for a molten metal container such as a ladle.

[0002]

2. Description of the Related Art In a gas blowing device arranged at the bottom of a molten metal container such as a ladle, a porous plug at the tip is exposed in the molten metal. Become shorter in sequence. If the porous plug becomes shorter than the limit value, problems such as leakage of molten metal from the mounting portion occur, and it is necessary to replace it as needed.

Such replacement of the porous plug is conventionally performed by inferring the melted state of the porous plug from the operating time, etc., since the melted state of the porous plug cannot be directly visually inspected. Therefore, it is difficult to accurately determine the replacement timing of the porous plug, that is, the amount of the porous plug that has been melted.

On the other hand, in various furnaces such as blast furnaces and heating furnaces,
A method to detect the falling of the furnace wall using the reflection of ultrasonic waves is
It is disclosed in JP-A-55-162593. In the method for detecting the falling of the furnace wall described in the publication, a detection rod is embedded in the furnace wall in the horizontal direction, ultrasonic waves are incident on the detection rod from outside the furnace, and a change occurs in the reflected signal, which is caused by the falling of the furnace wall. This is a method of detecting the bent state of the detection rod and knowing the falling state of the furnace wall from this.

[0005]

However, the above-mentioned method merely detects the falling state of the furnace wall, and does not suggest any means for detecting the melted state of the porous plug by using such ultrasonic waves. Further, since the same method detects the falling state of the furnace wall from the bent state of the detection rod, it is not possible to directly apply the furnace wall falling detection method described in the above publication to the detection of the residual height of the porous plug. Can not.

Therefore, the present invention further develops the ultrasonic technology used for detecting the falling of the furnace wall and applies it to the height detecting means of the porous plug, thereby making it possible to accurately determine the replacement time of the porous plug. The purpose is to do.

[0007]

In order to solve the above-mentioned problems, the gas blowing device of the present invention has a porous plug having a built-in waveguide rod-shaped body for ultrasonic measurement, and is substantially the same as the waveguide rod-shaped body. A gas blowing pipe connected on the axis, and a switching device having a pipe line connected to the gas blowing pipe and having a tip end formed with an opening facing the waveguide rod-shaped body, the switching device further comprising the pipe line. It has a valve device for opening and closing the opening, and a gas pipeline communicating with the middle of the pipeline.

Here, as the valve device, a two-way or three-way ball valve body, an opening / closing lid whose one end is axially supported, and a biasing means for biasing the opening / closing lid in the closing direction from the inside. Can be.

[0009]

According to the present invention, when the porous plug is melted down and its height is reduced during operation, the waveguide rod-shaped body for ultrasonic measurement is also melted and its length is shortened. Therefore, when the ultrasonic wave is applied to the waveguide rod-like body, the reflected ultrasonic wave changes depending on the length of the waveguide rod-like body. Therefore,
Insert a length measuring instrument equipped with a probe from the opening of the switching device and contact the probe with the waveguide rod to measure the state of reflected ultrasonic waves, thereby accurately determining the remaining height of the porous plug. Can be detected. Also, since the gas pipeline is formed in the switching device separately from the opening for inserting the length measuring device, it is possible to remove the gas hose and the like connected to the gas pipeline without removing it.
The remaining height of the porous plug can be measured simply by operating the valve device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially enlarged vertical sectional view showing a gas blowing device according to a first embodiment of the present invention attached to a bottom portion of a ladle.

On the ladle bottom plate 1, a perm brick 2 and a ladle bottom brick 3 are laminated. The ladle bottom plate 1, the perm brick 2 and the ladle bottom brick 3 are formed with through holes 4 for penetrating a porous plug, and the portion corresponding to the through hole 4 of the ladle bottom brick 3 has a conical through hole. A brick 6 having 5 is provided. Further, a receiving member 7 for attaching / detaching a porous plug is fixed to the lower surface of a portion of the ladle bottom plate 1 corresponding to the through hole 4 by welding or the like.

The porous plug 8 comprises a round rod-shaped porous element 9 made of a refractory material such as high-alumina brick having high air permeability, a substantially conical castable element 10 provided on the outer periphery of the porous element 9, and a castable element 10. A substantially conical metal case 11 that covers in an airtight state except the upper end portion
And a gas injection pipe 13 is connected to the bottom surface of the metal case 11.

Furthermore, the waveguide rod-shaped body 14 for ultrasonic length measurement, which has good propagation characteristics for ultrasonic waves and is melted away at the same degree as the porous plug 8, has a porous structure inside the porous plug 8. It is embedded in the element 9 on the same axis as the gas blowing pipe 13, and the base end portion is the porous element 9
Protruding from. The waveguide rod 14 is made of steel,
SUS, non-ferrous metals, alloys, fine ceramics (dense), molten ceramics (including glass, quartz, etc.) can be used.

The waveguide rod 14 is shown in FIGS. 2 (a) and 2 (b).
As shown in FIG.
Small triangular notches 14b, 14c, 1 at mm intervals
4d is formed and is closest to the base end side, that is, the measurement end surface 14
The cut 14d on the e side is formed at the limit position of the remaining height of the porous plug 8.

A plug receiving brick 15 is provided below the plug body 12, and the pressing metal 1 is attached to the plug receiving brick 15 through a desired number of height adjusting disks 16.
7 is pressed down.

As shown in FIG. 1, the plug receiving brick 15 has a through hole 15a formed in the center thereof for allowing the gas blowing pipe 13 to pass therethrough. The gas blowing pipe 13 has a plug receiving brick 15 and a high height. The penetrating adjustment disk 16 and the pressing metal 17 are pulled out to the outside of the container.

The pressing metal 17 and the receiving metal 7 have a bayonet structure, and the wing portion 1 provided on the pressing metal 17 is
7a is aligned with a notch (not shown) formed in the receiving metal 7 and the plug body 12 and the plug receiving brick 1
5, the porous plug 8 composed of the height adjusting disk 16 and the pressing metal 17 is pressed against the brick 6 and rotated, whereby the porous plug 8 is attached to the ladle.

A male screw 13a is formed on the outer periphery of the tip of the gas blowing pipe 13, and a switching device A is connected by a pipe joint 31 having a female screw 31a screwed onto the male screw 13a.

The switching device A is provided with a pipe line 34 formed on the same axis as the gas blowing pipe 13 and having an opening 33 through which the waveguide rod 14 can be exposed. Reference numeral 35 denotes a valve device in which a part of the pipe line 34 is bulged and arranged, and an insertion hole 35a having the same size as the pipe line 34 is formed in a part thereof to form a two-way spherical valve. The opening / closing operation of the opening 33 can be performed by rotating the valve device 35 in the direction of the arrow. Further, a gas pipeline 36 is made to communicate with a substantially intermediate position of the pipeline 34 from a direction perpendicular to the axis of the pipeline 34. A taper screw 36a is formed at the tip of the gas pipeline 36, and a gas hose 37 having a male screw 37a screwed to the taper screw 36a is connected.

In the above structure, the valve device 35 is normally rotated 90 ° from the state shown in FIG. 1 to close the opening 33, and gas is supplied from the gas hose 37 through the porous plug 8 into the furnace to blow a normal gas. Used as a device.

When the porous plug 8 is estimated to be melted after being used for a certain period of time, the residual height of the porous plug is detected as described below.

FIG. 3 is a vertical sectional view of a length measuring device 50 used for detecting the height of a porous plug. A probe spring 52 urges a tip end of a cylindrical body 51 having a through hole 51a in the axial direction. Probe 53 consisting of an ultrasonic transducer
The probe 53 is installed by the wiring 54 in FIG.
It is connected to the ultrasonic length measuring device 19 shown in FIG.

Upon detection, the gas supply is stopped,
The valve device 35 is rotated as shown in FIG. 1 so that the waveguide rod 14 can be exposed from the opening 33 of the switching device A through the gas blowing pipe 13. Then, the length measuring device 50 is inserted into the conduit 34 and the gas blowing pipe 13 through the opening 33, and the probe 53 is brought into contact with the waveguide rod-shaped body 14 embedded in the porous plug 8.

In this state, when an ultrasonic wave of a predetermined frequency is transmitted from the probe 53 to the waveguide bar 14, the reflected wave from the waveguide bar 14 is detected by the probe 53 and the ultrasonic wave shown in FIG. It is sent to the sound wave length measuring device 19. In the ultrasonic measuring device 19,
The reflection state is displayed on the cathode ray tube 19a in which the horizontal axis is the time axis and the vertical axis is the reflection intensity.

At this time, the ultrasonic waves transmitted to the waveguide rod 14 travel along the waveguide rod 14 and mainly end face 14a.
However, a part of the light will be reflected by the notches 14b, 14c, 14d formed in the waveguide rod-shaped body 14.

More specifically, in the initial state, the ultrasonic waves are mainly reflected by the initial end face 14a of the waveguide rod-shaped body 14, so that the position corresponding to the initial end face 14a of the waveguide rod-shaped body 14 as shown in FIG. A reflected wave P _T with a large amplitude is observed at the same time, and small reflected waves P _b , P _c , P _d generated at the cuts 14b, 14c, 14d are also observed.

When the tip of the porous plug 8 is melted and the tip of the waveguide rod 14 is also melted with the start of operation, the reflection time of ultrasonic waves is shortened, and the waveguide rod 14 is cut as shown in FIG.
The position of the reflected wave P _{T having} a large amplitude generated at the end of the point moves to the transmitting end side (left side in the figure). This reflected wave P _T
The remaining height of the porous plug 8, that is, the porous plug 8 by observing the position of
You can know when to replace.

As described above, in addition to the reflected wave P _{T having} a large amplitude generated at the end of the waveguide rod 14, the notches 14b, 1
Since the reflected waves P _b , P _c , and P _d (see FIG. 5) having a small amplitude generated at 4 c and 14 d at regular intervals are also observed, the remaining height of the porous plug 8 is set by using these reflected waves as check points. You can know exactly.

When it is found that the position of the reflected wave P _T reaches the position of the reflected wave P _d and the remaining height of the porous plug 8 reaches the limit, the porous plug 8 is replaced.

As described above, in the gas blowing device of the present embodiment, the length of the porous plug melted by the length measuring instrument equipped with the waveguide rod-shaped body and the ultrasonic oscillator incorporated in the porous plug was maintained in the molten metal container. The lost state can be detected, and the time to replace the porous plug can be accurately determined. Further, since the switching device A is provided, the valve device 35 can be used without removing the gas connection pipe or the like.
The detection work can be easily carried out by simply rotating and operating the and inserting the length measuring device 50 through the opening 33 of the switching device A.

FIG. 7 is a sectional view of a second embodiment of the switching device shown in FIG. In the following embodiments, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the switching device B of this embodiment, the valve device 40 is provided at a substantially intermediate position of the pipe 34, that is, on the axis of the gas pipe 36.
It is arranged so that the center of is located. The valve device 40 has a first insertion hole 4 for communicating the conduit 34 with the opening 33.
0a and a second through hole 40b extending in a perpendicular direction at an intermediate position of the first insertion hole 40a to form a T-shaped three-way spherical valve.

FIG. 7 shows a state in which the gas pipe line 36 side is closed and the opening 33 side for inserting the length measuring device 50 is communicated with the pipe line 34. In this state, the length measuring device 50 is inserted through the opening 33,
The length of the porous plug 8 is measured in the same manner as described in the first embodiment.

When the work is completed, the opening 33 is closed by rotating the valve device 90 degrees to the right from the state of FIG. 7, and at the same time, the gas pipeline 36 is closed by the first and second through holes 40.
The a and 40b are in communication with the pipe 34, and gas can be supplied into the furnace.

As described above, in this embodiment, as the valve device 40, a three-way spherical valve is used which can simultaneously open the communication between the opening 33 and the conduit 34 and close the gas conduit 36. Therefore, as described in the first embodiment,
There is no need to stop the gas supply during the length measurement work, which can improve work efficiency and completely prevent gas leaks due to forgetting to stop the gas supply. Can be improved.

FIG. 8 is a sectional view of a third embodiment of the switching device shown in FIG.

The switching device C of this embodiment is provided with an opening / closing lid 46 which has a stepped receiving port 33a formed in the opening 33 of the conduit 34 and which is fitted as a valve device 45 into the receiving port 33a. A mounting plate 47 is fixed to one end of the opening / closing lid 46, and the mounting plate 47 is rotatably supported by a supporting portion 48a provided in a housing 48 of the switching device by an opening / closing shaft 48b. Also the mounting plate 47
A plate spring 49 is connected to the other end of the plate spring 49, and the other end of the plate spring 49 is attached to the housing 48.

In the above structure, the opening / closing lid 46 is normally biased in the closing direction by the plate spring 49, and the receiving port 3
3a, and at the same time, it is pressed in the closing direction by the pressure of the supplied gas, so that the airtightness of the opening 33 is secured. During the length measurement work, the gas supply is stopped, and the opening 33 is opened at the tip of the length measurement device 50 shown in FIG.
By slightly pressing the opening / closing lid 46 that closes the door, the opening / closing lid 46 rotates counterclockwise about the opening / closing shaft 48b, and the length measuring device 50 can be inserted into the conduit 34. After that, the work is performed in the same manner as in the first embodiment. When the length measuring device 50 is pulled out from the inside of the conduit 34 with the completion of the work, the lid is automatically closed by the urging force of the plate spring 49.

As described above, according to this embodiment, it is not necessary to rotate the valve device at the time of the length measuring work as in the first and second embodiments, and the length measuring device can be obtained by merely pressing the opening / closing lid 46 from the outside. 50 can be attached, and the efficiency of length measurement work can be improved.

[0040]

According to the present invention, the following effects can be obtained.

(1) Since the waveguide rod-shaped body for ultrasonic measurement that is melted by heat is used, it is possible to accurately know the remaining height of the porous plug provided at the bottom of the container, and replace the porous plug. The time can be accurately judged.

(2) Since the switching device provided with the opening for inserting the length measuring device is provided independently of the gas supply path, the length measuring work can be easily performed in the operating state without removing the gas hose or the like. be able to.

[Brief description of drawings]

FIG. 1 is a partially enlarged vertical sectional view showing a state in which a gas blowing device according to a first embodiment of the present invention is attached to a bottom portion of a ladle.

FIG. 2 is a perspective view of the waveguide rod-shaped body shown in FIG.

FIG. 3 is a vertical cross-sectional view of a length measuring device used for detecting the height of a porous plug.

FIG. 4 is an explanatory diagram showing a connection relationship between a length measuring device and an ultrasonic length measuring device.

FIG. 5 is an explanatory diagram showing an example of measurement by an ultrasonic length measuring device in an initial state.

FIG. 6 is an explanatory diagram showing an example of measurement by an ultrasonic length measuring device when a porous plug is melted.

7 is a cross-sectional view showing a second embodiment of a switching device incorporated in the gas blowing device shown in FIG.

8 is a cross-sectional view showing a third embodiment of the switching device incorporated in the gas blowing device shown in FIG.

[Explanation of symbols]

1: Ladle bottom plate, 2: Permanent brick, 3: Ladle bottom brick,
4: Through hole, 5: Through hole, 6: Receiving brick, 7: Receiving material, 8: Porous plug, 9: Porous element, 1
0: Castable, 11: Metal case, 11a: Through hole, 12: Plug body, 13: Gas blowing pipe, 1
4: waveguide rod-shaped body, 14a: initial end face, 14b, 14c,
14d: notch, 14e: measuring end surface, 15: plug brick, 15a: through hole, 16: height adjusting disk,
17: Presser hardware, 17a: Wing portion, 19: Ultrasonic measuring device, 19a: CRT, 31: Pipe joint, 33: Opening, 33a: Receptacle, 34: Pipe line, 35: Valve device, 35
a: insertion hole, 36: gas pipeline, 37: gas hose, 4
0: valve device, 40a: first insertion hole, 40b: second insertion hole, 45: valve device, 46: open / close lid, 47: mounting plate, 48: housing, 48a: support portion, 48b:
Open / close shaft, 49: plate spring, 50: length measuring device, 51: cylindrical body, 51a: through hole, 52: probe spring, 53: probe, 54: wiring, A, B, C switching device

Claims (3)

[Claims] 1. A porous plug containing a waveguide rod-shaped body for ultrasonic measurement, a gas blowing pipe connected on substantially the same axis as the waveguide rod-shaped body, and a tip connected to the gas blowing pipe. A switching device having a pipe line having an opening facing the waveguide rod body, the switching device further comprising a valve device for opening and closing the opening of the pipe line, and a gas pipe line communicating with the middle of the pipe line. And a gas blowing device having. 2. The gas blowing device according to claim 1, wherein the valve device comprises a two-way or three-way spherical valve. 3. The gas blowing device according to claim 1, wherein the valve device includes an opening / closing lid whose one end is pivotally supported, and an urging means for urging the opening / closing lid from the inside toward the closing direction.