JP2935997B2 - Molten metal level detector - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a level detecting device for detecting the level of a molten metal contained in a container, and particularly to detecting abnormalities such as wear and poor connection of a detecting electrode. The present invention relates to an apparatus for detecting a level of a molten metal made possible.

(Prior art)

2. Description of the Related Art Usually, a melting furnace for melting a metal such as cast iron or aluminum to form a molten metal of the metal is provided with a level detecting device for detecting a liquid level of the molten metal in the melting furnace.

As shown in FIG. 4, the level detecting device 100 includes three connection terminals 102 to 104 fixedly disposed above a DC power supply 101 and a melting furnace 110, and upper ends of the connection terminals 102 to 104, respectively. Rod-shaped electrode 105 attached in the melting furnace 110
To 107 and the like.

The connection terminal 102 is connected to the plus terminal of the DC power supply 101, the connection terminal 103 is connected to the minus terminal of the DC power supply 101 via a lamp 108, and the connection terminal 104 is connected to the minus terminal of the DC power supply 101 via a lamp 109. It is connected.

On the other hand, the lower end of the electrode 105 is immersed in the molten metal 111,
The lower end of the electrode 106 is located above the lower end of the electrode 105 as shown by a solid line in FIG. 4, for example, at a first detection level 112 set as a liquid level at which the molten metal 111 can be discharged,
The lower end of the electrode 107 is located at the second detection level 113, which is the liquid level at which the molten metal 111 rises abnormally above the lower end of the detection electrode 106, as indicated by the dashed line in FIG.

The lamps 108 and 109 are provided on, for example, an operation panel or the like that can be visually recognized by an operator who operates and monitors the melting furnace 110.

By providing the level detection device 100 in this way,
When the molten metal 111 rises to the first detection level 112, the electrode
105 and the electrode 106 are energized through the molten metal 111, and the lamp 108
Lights up to inform the operator. When the molten metal 111 rises to the second detection level 113, the electrode 105 and the electrode 107 are energized, and the lamp 109 is turned on in addition to the lighting of the lamp 108 to notify the operator of the abnormality of the level of the molten metal 111. To let you know.

For reference, JP-A-53-113723 discloses a thermocouple-type movable electrode that can move up and down in addition to a plurality of thermocouple-type fixed electrodes to improve the accuracy of level detection of molten metal. A sensing device is described.

[Problems to be solved by the invention]

In the level detecting device 100, the high-temperature molten metal 1
When the electrodes 105 and 106 in contact with 11 are worn and shortened, the first
There is a problem that the detection level 112 cannot be detected accurately.

Further, when the connection between the electrodes 105 to 107 and the respective connection terminals 102 to 104 is disconnected, there is a problem that the liquid level of the molten metal 111 cannot be detected.

An object of the present invention is to provide a molten metal level detecting device capable of detecting an abnormality of an electrode.

[Means for solving the problem]

According to a first aspect of the present invention, there is provided a level detector for detecting a liquid level of a molten metal contained in a container, wherein a lower end is set to a liquid level detection level and connected to a first energizing circuit. A first electrode, a second electrode having a lower end set to a liquid level detection level and connected to a second energizing circuit, a first abnormality detection circuit connected to a lower end of the first electrode, A second abnormality detecting circuit connected to the lower end of the second electrode, and a closed circuit including a first energizing circuit, a first electrode, a molten metal, a second electrode, and a second energizing circuit when the liquid level is detected. On the other hand, when an abnormality is detected, a switch means for switching a circuit so as to form a closed circuit including a first energizing circuit and a first abnormality detecting circuit or a closed circuit including a second energizing circuit and a second abnormality detecting circuit. Are provided. According to a second aspect of the present invention, there is provided a level detector for molten metal.
According to the invention, in order to detect a plurality of liquid levels at different levels, the first electrode, the first abnormality detection circuit, the second electrode, and the second abnormality detection circuit are connected to a plurality of liquid levels at different levels. A plurality of sets are provided so as to correspond to the respective levels.

[Action]

In the metal molten metal level detecting device, when detecting the level of the molten metal in the container, the first energizing circuit, the first electrode, the second electrode, and the second energizing circuit are closed via the molten metal. The circuit is switched by the changeover switch means so as to constitute the circuit.

At this time, if the liquid level of the molten metal contained in the container is at a low level below the lower ends of the first electrode and the second electrode, the closed circuit is not formed, and thus no electricity is supplied.

When the liquid level of the molten metal rises to a predetermined liquid level detection level where the lower ends of the first electrode and the second electrode are located, the closed circuit is formed via the molten metal and electricity is supplied.

Therefore, by providing a lamp or a buzzer in the closed circuit, it is possible to detect that the metal melt has reached a predetermined liquid level detection level by turning on the lamp or sounding the buzzer.

On the other hand, when detecting the presence / absence of an abnormality in the electrode, a closed circuit including the first energizing circuit and the first abnormality detecting circuit or the second
The circuit is switched by the changeover switch means so as to form a closed circuit including the energizing circuit and the second abnormality detecting circuit.

If the first energizing circuit is disconnected, if the first energizing circuit and the first electrode are poorly connected, or if the lower end of the first electrode is worn, the first energizing circuit and the first abnormality detection circuit will No closed circuit is formed and no electricity is supplied. Similarly, if the second energizing circuit is disconnected, the second energizing circuit and the second electrode are poorly connected, or the lower end of the second electrode is worn,
No closed circuit is formed between the second energizing circuit and the second abnormality detection circuit, and no current is supplied.

Therefore, by providing a lamp or a buzzer in each closed circuit, an operator can detect the presence or absence of an abnormality in each electrode by turning on the lamp or sounding the buzzer. In the metal molten metal level detecting device according to the present invention, the first electrode, the first abnormality detecting circuit, the second electrode, and the second abnormality detecting circuit are used to detect a plurality of liquid levels having different levels. Are provided so as to correspond to a plurality of different liquid level detection levels, respectively, so that each liquid level detection level is set to the first energizing circuit, the first electrode, and the second electrode of each set. Detection can be performed through the two electrodes, the second energizing circuit, and the changeover switch means, and abnormality in the first electrode and its electric system or abnormality in the second electrode and its electric system in each set can be detected. .

〔The invention's effect〕

According to the apparatus for detecting the level of molten metal of claim 1, abnormalities such as wear of each electrode, disconnection of each energizing circuit, and poor connection between each electrode and each energizing circuit, as described in the above section, are explained. It can be detected by a simple changeover operation of the changeover switch means. Then, the liquid level of the molten metal can always be accurately detected.

In addition, since the lower end of the first electrode is set at the liquid level detection level, the wear of the first electrode can be reduced. According to the molten metal level detecting device of the second aspect, the first electrode, the first abnormality detecting circuit, the second electrode, and the second abnormality detecting circuit are respectively set to a plurality of different liquid level detection levels. Since a plurality of sets are provided so as to correspond to each other, a plurality of different liquid level detection levels can be respectively detected, and an abnormality in the first electrode or its electric system or a second electrode or its electric system for the detection can be detected. Abnormality can be detected.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In this embodiment, as shown in FIG.
The present invention is applied to a level detecting device 10 provided in a melting furnace 2 for producing the same.

The level detecting device 10 includes a pair of V-shaped electrodes 21 and 22 for detecting the first liquid level detection level 3 and a second liquid level detection level 4 higher than the first liquid level detection level 3. A pair of V-shaped electrodes 23 and 24 for detection, electrodes 21 and 22 and electrodes 23 and
Electromagnetic switch 30 for switching 24 to a level detection mode for detecting the liquid level of molten aluminum 1 and an abnormality detection mode for detecting abnormalities of electrodes and circuits, and a control box for operating and monitoring melting furnace 2 40 and electrodes 21-24
Connection terminals 51-58 for attaching
And the electromagnetic switch 30 and the like.

The electrode 21 has a predetermined length of electrode 21a and an abnormality detection electrode 21b.
As shown in FIG. 2, the electrodes 21a and 21b are joined at their lower ends, and the upper ends of the electrodes 21a and 21b are attached to connection terminals 51 and 52, respectively.

The electrode 22 includes an electrode 22a having a predetermined length and an abnormality detection electrode 22b.
The electrodes 22a and 22b are joined at the lower ends, and the upper ends of the electrodes 22a and 22b are attached to connection terminals 53 and 54, respectively.

The electrodes 21 and 22 are suspended in the melting furnace 2 and the electrodes 21 and 22 are suspended.
The lower end of 22 is located at the first liquid level detection level 3 at which the molten aluminum 1 can be discharged as shown by the solid line in FIG.

The electrode 23 includes an electrode 23a having a predetermined length and an abnormality detection electrode 23b.
The electrodes 23a and 23b are joined at lower ends, and upper ends of the electrodes 23a and 23b are attached to connection terminals 55 and 56, respectively.

The electrode 24 includes a predetermined length electrode 24a and an abnormality detection electrode 24b.
The electrodes 24a and 24b are joined at the lower ends, and the upper ends of the electrodes 24a and 24b are attached to connection terminals 57 and 58, respectively.

The electrodes 23 and 24 are suspended in the melting furnace 2 and the electrodes 23 and 24 are suspended.
The lower end of 24 is located at the second liquid level detection level 4 when the aluminum melt 1 rises abnormally as shown by the dashed line in FIG.

The electromagnetic switch 30 is a pair of single pole double throw type electromagnetic switches 31.
32, the electromagnetic switch 31 has a common terminal 31a and a switching terminal 3
1b and 31c, the electromagnetic switch 32 has a common terminal 32a and a switching terminal
It has 32b and 32c, and the common terminal 31a is the control box 4
0 is connected to the positive terminal of the DC power supply 40a and the common terminal 32a
Is connected to the negative terminal of the DC power supply 40a.

Next, the connection between the connection terminals 51 to 58 and the electromagnetic switches 31 and 32 will be described.

The connection terminal 51 is connected to a switching terminal 31b via a conductor 81, and the connection terminal 52 is connected to a switching terminal 32c via a conductor 82 having a lamp 61 and an electromagnetic switch 71 interposed in series. 53 is connected to the switching terminal 32b via a conductor 83 having a lamp 62, the connection terminal 54 is connected to the switching terminal 31c via a conductor 84 having an electromagnetic switch 72, and the connection terminal 55 is switched via a conductor 85. 31b, a connection terminal 56 is a conductor having a lamp 63 and an electromagnetic switch 73 interposed in series.
The switching terminal 32c is connected to the switching terminal 32c via 86, the connection terminal 57 is connected to the switching terminal 32b via a conducting wire 87 having a lamp 64,
The connection terminal 58 is connected to the switching terminal 31c via a conducting wire 88 having an electromagnetic switch 74.

The lamps 61 to 64 are attached to a display panel of the control box 40 so that the lamps can be visually recognized by an operator.

The control box 40 includes a programmable sequence controller having a timer, and a sequence set in advance is programmed in the sequence controller.

The electromagnetic switches 31 and 32 and the electromagnetic switches 71 to 74 are configured to be switched by a switching signal from the control box 40.
A changeover switch 41 for switching the sequence controller between the level detection mode and the abnormality detection mode is provided.

The operation of the level detection device 10 configured as described above will be described.

When setting the electrodes 21 and 22 and the electrodes 23 and 24 to the level detection mode, the operator switches the changeover switch 41 to the level detection mode. At this time, the common terminal of the electromagnetic switch 31 is switched by the switching signal from the control box 40.
31a and the switching terminal 31b are closed, the common terminal 32a and the switching terminal 32b of the electromagnetic switch 32 are closed, and the electromagnetic switches 71 to 74 are opened.

By setting the electrodes 21 and 22 and the electrodes 23 and 24 to the level detection mode in this way, the aluminum metal in the melting furnace 2 is dissolved, and the liquid level of the aluminum melt 1 is increased to the first liquid level detection level 3. When raised, the conductor 81 and the electrode 21
A closed circuit composed of a, the molten aluminum 1, the electrode 22a, and the conducting wire 83 is formed, energized, and the lamp 62 is turned on. After confirming that the lamp 62 is turned on, the operator stops melting and discharges the molten aluminum 1 in the melting furnace 2.

If the aluminum melt 1 rises to the second liquid level detection level 4 in addition to the above-mentioned closed circuit, the conductor 85 and the electrode 23a (or the conductor 81 and the electrode 21a), the aluminum melt 1, the electrode 24a and the conductor A closed circuit made up of a lamp 87 is formed and energized, and the lamp 64 is turned on in addition to the lamp 62 to notify the operator of the abnormality.

When the electrodes 21 and 22 and the electrodes 23 and 24 are set to the abnormality detection mode, for example, the molten aluminum 1 is placed in the melting furnace 2.
Then, the changeover switch 41 is switched to the abnormality detection mode side.

When the abnormality detection mode is set, the electromagnetic switches 31 and 32 and the electromagnetic switches 71 to 74 are switched according to the following sequence in accordance with a switching signal from the control box 40.

First, a switching signal is output from the control box 40 to the electromagnetic switch 32 and the electromagnetic switch 71, the common terminal 32a and the switching terminal 32c of the electromagnetic switch 32 are closed, and the electromagnetic switch 71 is closed.
Closes. In the electromagnetic switch 31, the common terminal 31a and the switching terminal 31b are closed, and the electromagnetic switches 72 to 74 are open.

When the electrode 21 is normal, a closed circuit including the conducting wire 81 and the electrode 21a, the abnormality detecting electrode 21b, and the conducting wire 82 is formed to energize the lamp 61 and the operator turns on the lamp 61. Can be confirmed.

On the other hand, if the electrode 21 is abnormal, that is, the electrode 21a and the connection terminal 5
When the connection with the electrode 1 is disconnected, or when the joint between the electrode 21a and the abnormality detection electrode 21b is worn and shortened due to contact with the high-temperature molten aluminum 1 and the joint is separated as shown in FIG. For example, the lamp does not have the closed circuit
Since 61 does not light, the operator can confirm the abnormality of the electrode 21.

Next, from the control box 40, the electromagnetic switches 71 and 73
A switching signal is output to the switch, and the electromagnetic switch 71 is opened and the electromagnetic switch 73 is closed. The electromagnetic switches 31 and 32 are in the same state as described above, and the electromagnetic switches 72 and 74 are open.

When the electrode 23 is normal, a closed circuit composed of the conductor 85, the electrode 23a, the abnormality detection electrode 23b, and the conductor 86 is formed and the lamp 63 is turned on and the operator turns on the electrode 23. Can be confirmed.

On the other hand, as in the case of the electrode 21, when the electrode 23 is abnormal, the above-described closed circuit is not formed and the lamp 63 is not turned on.

Next, from the control box 40, the electromagnetic switches 31 and 32
And a switching signal is output to the electromagnetic switches 72 and 73, and the common terminal 31
a and the switching terminal 31c are closed, the common terminal 32a and the switching terminal 32b are closed, the electromagnetic switch 72 is closed, and the electromagnetic switch 73 is opened. Note that the electromagnetic switches 71 and 74 are in an open state.

If the electrode 22 is normal, the conductor 84 and the abnormality detection electrode 22
Since a closed circuit including the electrode b, the electrode 22a, and the conductive wire 83 is formed and the lamp 62 is turned on by energization, the operator can confirm that the electrode 22 is normal.

On the other hand, as in the case of the electrode 21, when the electrode 22 is abnormal, the above-mentioned closed circuit is not formed and the lamp 62 is not turned on.

Next, from the control box 40, the electromagnetic switches 72 and 74
A switching signal is output to the switch, the electromagnetic switch 72 is opened, and the electromagnetic switch 74 is closed. The electromagnetic switches 31 and 32 are in the same state as described above, and the electromagnetic switches 71 and 73 are in the open state.

If the electrode 24 is normal, the conductor 88 and the electrode 24
Since a closed circuit including the electrode b, the electrode 24a, and the conducting wire 87 is formed and energized to turn on the lamp 64, the operator can confirm that the electrode 24 is normal.

On the other hand, similarly to the case of the electrode 21, when the electrode 24 is abnormal, the closed circuit is not formed and the lamp 64 does not turn on, so that the operator can confirm the abnormality of the electrode 24.

In this way, the confirmation of the presence or absence of abnormality in the electrodes 21 and 22 and the electrodes 23 and 24 is completed, and it is confirmed that there is no abnormality in the electrodes 21 and 22 and the electrodes 23 and 24. The operator sets the changeover switch 41 to the level detection mode. Switch to the control box
A switching signal is output from 40 to the electromagnetic switch 31 and the electromagnetic switch 74, the common terminal 31a and the switch terminal 31b are closed, and the electromagnetic switch 74
Is opened to set the electrodes 21 and 22 and the electrodes 23 and 24 to the level detection mode.

On the other hand, when abnormality is confirmed in the electrodes 21 and 22 and the electrodes 23 and 24, replacement of the electrodes or repair of the electric system is performed by the operator.

As described above, abnormalities such as wear and poor connection of the electrodes 21 and 22 and the electrodes 23 and 24 can be detected by a simple operation.
Then, the liquid level of the molten aluminum 1 in the melting furnace 2 can always be accurately detected.

The level detector 10 can of course be used to detect not only the liquid level of the molten aluminum 1 but also the liquid level of various molten metals such as cast iron and aluminum alloy. Although the electrodes 21 and 22 and the electrodes 23 and 24 are formed in a V-shape by bonding, they may be integrally formed in a V-shape.

Further, a buzzer or an ammeter can be used instead of the lamps 61 to 64. The lower end of the electrode 21 may be set at a level equal to or lower than the first liquid level detection level 3,
23 is not necessary and may be omitted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 3 show an embodiment of the present invention, FIG. 1 is a configuration diagram of a level detection device, FIG. 2 is an enlarged view of a lower end portion of an electrode, FIG. The figure is an enlarged view showing the worn state of the lower end of the electrode,
FIG. 4 is a configuration diagram of a level detection device according to the prior art. 1 ... Molten aluminum, 2 ... Melting furnace, 3 ... First liquid level detection level, 4 ... Second liquid level detection level, 21a to 24a ...
... electrodes, 21b to 24b ... abnormal detection electrodes, 31 and 32 ... electromagnetic switches, 40 ... control boxes, 81 to 88 ... lead wires.

Claims (2)

(57) [Claims] 1. A level detecting device for detecting a liquid level of a molten metal contained in a container, wherein a lower end is set to a liquid level detecting level and a first electrode connected to a first energizing circuit; A second electrode connected to a second energizing circuit, a first abnormality detecting circuit connected to a lower end of the first electrode, and a second electrode connected to a second energizing circuit; A second circuit for detecting abnormality connected thereto, and a closed circuit comprising a first energizing circuit, a first electrode, a molten metal, a second electrode, and a second energizing circuit when the liquid level is detected; Switch switch means for switching a circuit so as to form a closed circuit including one energizing circuit and a first abnormality detecting circuit or a closed circuit including a second energizing circuit and a second abnormality detecting circuit is provided. Metal melt level detector. 2. The method according to claim 1, wherein the first electrode, the first abnormality detecting circuit, the second electrode, and the second abnormality detecting circuit are connected to a plurality of liquids having different levels to detect a plurality of liquid levels having different levels. 2. The metal molten metal level detecting device according to claim 1, wherein a plurality of sets are provided so as to correspond to the surface detection levels, respectively.