JPS6294790A - Molten-metal leakage detector for induction furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] When metal in the furnace is melted by induction heating in an induction furnace, if the melting temperature of the metal is low or contains a low melting point metal, the molten metal will evaporate. conductive vapor is generated.

The present invention relates to a hot water leak detection device for an induction furnace that can prevent malfunction of the detection device due to conductive steam.

[Prior art and its problems]

A conventional example of a field leak detection device for an induction furnace will be explained based on Figure 2. In this figure, crucible-shaped refractory lining 1
A water-cooled induction heating coil 6 is wound around the outer periphery of a furnace body 8 made of asbestos 2 surrounding the outer surface of the furnace body 8 through a plurality of cylindrical insulators 4.5 shown in FIG. A molten metal 7 heated and melted by the electromagnetic induction action of a coil 6 is housed. The insulator 4 is formed of a mica sheet or the like,
The insulator 5 is formed inside the coil 6 from a heat-resistant fluororesin sheet or the like. The coil 6 is provided with a water passage 6a in its conductor, and cooling water is passed through the water passage 6a for cooling. A leak detection electrode 8 made of a high melting point metal such as stainless steel is buried in the bottom of the furnace body 8 with its tip in contact with the molten metal 7, and a number of strip electrodes 9 are also arranged between the insulators 4 above and below. They are arranged in parallel in the direction and wound in the circumferential direction. The reason why the electrode 9 is divided into a large number of strips is to prevent damage to the electrode 9 by escaping the force accompanying the expansion even if the furnace body 3 expands in the vertical and radial directions due to the molten metal 7. When the detecting means 12 detects a current flowing through the furnace body 3 due to the leaking molten metal 7 passed through each of the electrodes 9, a display means 13 such as a lamp or a buzzer warns of the occurrence of a leak.

When the induction furnace is used for a long period of time, the furnace body 8 may be eroded by the molten metal 7 or cracks may occur due to heat cycles, penetrating the furnace body 3 and leaking the molten metal 7. If the molten metal 7 in the coil 3 is discharged, the insulator 4.5 can prevent the coil 6 from melting. Thereafter, the furnace body 3 is dismantled or repaired.

In such a structure, there are many pinholes that allow gas to pass through the furnace body 3 and the insulator 4 made of mica sheet, etc., but not the molten metal 7. Therefore, when conductive vapor is generated due to evaporation of the molten metal 7, the pinholes It penetrated into the furnace body 3 and the insulator 4 through the hole and made the current detection circuit conductive, and as a result, the display means 13 did not issue an alarm distinguishing it from a latent leak. In such a case, even if the furnace body 8 is normal, the furnace body 8 has to be dismantled because it is determined that a leak has occurred, which is uneconomical.

[Purpose of the invention]

In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a hot water leak detection device for an induction furnace that can prevent malfunctions caused by conductive steam and reduce expensive furnace dismantling costs. .

[Key points of the invention]

In order to achieve the above-mentioned object, this invention has a cylindrical shape using adhesive tape made of fluororesin, etc., which has heat resistance and has no pinholes, on the inside of the electrode for detecting hot water leakage arranged around the outer periphery of the crucible-shaped furnace body. An insulator is formed to prevent electrical conduction caused by conductive vapor.

[Embodiments of the invention]

FIG. 1 shows an embodiment of the present invention, and parts indicated by the same reference numerals as in FIGS. 2 and 3 are the same parts. In this figure, a plurality of cylindrical insulators 4 are arranged around the outer periphery of a crucible-shaped furnace body 8.
．． An induction heating coil 6 is wound through the wire 5, and a band-shaped hot water leakage detection electrode 9 is placed between the insulator 4 made of mica sheet or the like.
are installed in large numbers. A cylindrical insulator 21 is formed on the inside of the pole 9 using an adhesive tape made of a fluororesin or the like that is heat resistant and has no pinholes.

According to the embodiment, even if conductive vapor enters through the pinholes in the furnace body 8 and the insulator 4, the insulator 2 has no pinholes.
1, the current detection circuit is not electrically connected to the lt electrode, and the occurrence of a false alarm on the display means 13 can therefore be prevented.

〔Effect of the invention〕

According to this invention, in a hot water leak detection device for an induction furnace, an adhesive tape made of a heat-resistant and pinhole-free fluororesin or the like is attached to the inside of an electrode for detecting elevating subsidence arranged around the outer periphery of a crucible-shaped furnace body. Since we formed a cylindrical insulator using
It is possible to prevent conduction due to conductive steam in the bath, and to reduce the cost of dismantling the furnace due to malfunction 1.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of a conventional example, and FIG. 3 is an enlarged vertical cross-sectional view of a main part of FIG. 8... Furnace body, 4.21... Insulator, 6... Coil, 7... Molten metal, 9... Riit pole. Figure 1 Figure 2 Figure 3 Procedural amendment (voluntary) 1. Indication of case Patent application Sho≦Q-7e? Otsu//f Lord
Location Month 1-::+ 7:I Month 1:'
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Claims (1)

[Claims] 1) An induction heating coil is wrapped around the outer periphery of a crucible-shaped furnace body through a plurality of cylindrical insulators made of mica sheets, etc., and an electrode for detecting leaking molten metal penetrating the furnace body is arranged between the insulators. A hot water leak detection device for an induction furnace, characterized in that a cylindrical insulator is formed inside the electrode using an adhesive tape made of fluororesin or the like that has heat resistance and no pinholes. Detection device.