JPH0629672Y2 - Jiro furnace with hearth monitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a jiro furnace having a hearth bottom electrode and a hearth monitoring device.

[Prior Art] In the hearth, for example, when the electrode is broken, the contact between the hearth and the electrode is poor, or the contact between the electrode and the electrode holder is poor, the power consumption increases, the melting time increases, and the furnace condition increases. Abnormality in the hearth was recognized due to a malfunction or water leakage from the electrode holder, and we were working on restoration work according to the state at that time.

[Problems to be Solved by the Invention] However, in some cases, until the abnormality in the furnace body is recognized, the abnormality may be recognized only by the operation of 10 charges or more. In the meantime, an abnormal situation has progressed, and there has been a possibility that it will cost a lot of money to restore the abnormal situation.

This invention was made in view of such circumstances. When an abnormality occurs in the furnace, it is immediately discovered and necessary recovery work is carried out to prevent the abnormal situation from proceeding and to recover at the minimum cost. It is an object of the present invention to provide a jiro furnace having a hearth monitoring device capable of performing the above.

[Means and Actions for Solving the Problems] The present invention is directed to a jiro furnace having a furnace bottom electrode, which is formed inside the furnace bottom electrode penetrating the bottom of the furnace body and a part of the furnace shell. A furnace wall that electrically insulates the iron shell and the furnace bottom electrode, a furnace body lining formed inside the furnace wall and the iron shell where the furnace wall is not formed, and having conductivity, and the iron shell And a voltmeter for measuring the voltage between the bottom electrode and the bottom electrode.

In a jiro furnace under operation, for example, if the polarity of the electrode (hereinafter referred to as the upper electrode) provided on the upper part of the furnace is positive, the current will flow from the upper electrode to the molten metal in the furnace, and the stamp with the conductivity from the molten metal. It is normal for the furnace body lining made of paste to flow from the furnace body lining to the furnace bottom electrode embedded therein. If the polarity is negative, the route is simply reversed, and the following points do not change. At this time, a furnace wall made of insulating refractory brick is provided between the furnace body lining having electric conductivity and the iron skin,
The furnace wall does not cover the entire iron shell, and a part of the iron shell contacts the furnace body lining, so that the furnace body lining and the iron shell are electrically connected. Therefore, during operation, the furnace lining and the iron skin have almost the same potential. Since the iron shell and the bottom electrode are insulated from each other, normally no voltage is generated between the bottom electrode and the bottom electrode, but there is an abnormality such as breakage of the bottom electrode or crack of the furnace wall. When a condition occurs, a voltage will be generated here.
An abnormal situation can be recognized by detecting this with a voltmeter.

In this invention, it does not matter whether the power source used for the Jiro furnace is AC or DC.

[Embodiment] An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a vertical sectional view of the Jiro furnace of the present invention. The furnace body 10 of the Jiro furnace is a furnace body lining 1 made of a stamp paste mixed with electrically conductive carbon on the inside, a furnace wall 2 made of alumina brick with good electrical insulation on the outside thereof, and an outside It is composed of the iron skin 3.
The furnace wall 2 is formed inside the furnace body except the upper part of the iron shell. Further, the furnace body lining 1 is formed so as to cover the inside of the furnace wall 2 and the inside of the iron shell 3 on the upper part of the furnace body, and the furnace body lining 1 and the iron shell 3 having conductivity are in contact with each other at the upper part of the furnace body. , Both are electrically connected. During operation, the furnace body lining is in contact with the molten metal 9 that serves as a flow path for a current flowing between the upper electrode 7 and the furnace bottom electrode 5, so that the molten metal 9
And the iron skin 3 are electrically connected. Therefore, in the normal case, the molten metal 9 and the iron shell 3 have almost the same potential. A furnace bottom electrode 5 held by an electrode holder 4 is provided on the furnace bottom so as to penetrate the iron shell 3 and the furnace wall 2, and the tip of the furnace bottom electrode 5 reaches the furnace body lining 1. The electrode holder 4 penetrates the iron casing 3 together with the furnace bottom electrode 5, and an insulating sleeve 6 is provided between the electrode holder 4 and the iron casing 3. The upper electrode 7 is provided above the furnace body 10.
And a power source 8 for generating a voltage between the upper electrode and the furnace bottom electrode 5. Further, voltmeters 11 and 12 for measuring the voltage between the iron shell 3 and the furnace bottom electrode 5 and the upper electrode 7, respectively, are provided.

The operation of the Jiro furnace configured as described above will be described. A voltage is supplied from the power source 8 between the furnace bottom electrode 5 and the upper electrode 7, and an arc 13 is formed between the upper electrode 7 and the molten metal or the molten material (hereinafter simply referred to as the molten metal 9). An electric current flows between the two electrodes through the arc 13, the melt and the furnace body lining 1. The furnace wall 2 is an electrical insulator, but the iron shell 3 and the furnace body lining 1 are in electrical contact with each other at the upper part of the furnace body, and the furnace bottom electrode 5 has a tip portion of the furnace body lining 1 If the hearth is normal, the voltmeter 11 does not detect any voltage other than that due to the electric resistance of the current flow path, since it is in contact with the lower part of the. On the other hand, between the upper electrode 7 and the iron shell 3, the voltage supplied from the power source 8 appears in the voltmeter 12 as it is in a normal state. Therefore, the voltages shown on the voltmeters 11 and 12 are set to V ₁ and
And it has a _{V 1} "V ₂ in the normal state and the V _2. However, when the bottom electrode 5 is broken or the contact between the furnace body lining 1 and the bottom electrode 5 is poor,
Since this becomes a large resistance in the current flow path, the voltmeter 11 also detects the voltage. That, _{V 1} is larger than the same extent or _{V 2} and _{V 2,} the _{V 1 ~V 2, V 1>} V 2. The voltmeter 11 is equipped with a meter relay, and when V ₁ exceeds the control limit, an alarm is issued. Therefore, an abnormal situation of the hearth is immediately discovered and restoration work is started, and the progress of the abnormal situation is advanced. Can be prevented.

[Effect of the Invention] According to this invention, since the voltmeter for measuring the voltage between the iron shell and the bottom electrode provided on the outside of the furnace body of the Jiro furnace is provided, it is possible to immediately detect the occurrence of an abnormal situation. I can.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of the Jiro furnace of the present invention. 1 ... Furnace lining, 2 ... Furnace wall, 3 ... Iron skin, 4 ... Electrode holder, 5 ... Furnace bottom electrode, 6 ... Insulation sleeve, 7 ... Upper electrode,
8 ... power source, 9 ... molten metal, 10 ... furnace body.

Claims (1)

[Scope of utility model registration request] 1. In a jiro furnace having a furnace bottom electrode, the furnace bottom electrode penetrating the bottom of the furnace body and the iron shell and the furnace bottom electrode formed inside the furnace body except for a part of the shell are provided. An electrically insulating furnace wall, a furnace body lining having electrical conductivity formed inside the furnace wall and the iron shell where the furnace wall is not formed, and a voltage between the iron shell and the bottom electrode A Jiro furnace having a hearth monitoring device, which has a voltmeter for measuring.