JPS5857673B2 - Starting mold for channel induction furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a starting mold embedded in the refractory in the form of a groove, which dries and heats the refractory and then decomposes it by applying electricity to generate heat during startup. This relates to a starting mold for a channel induction furnace.

Conventionally, this type of channel induction furnace has been manufactured so that the molten duct refractory 1 and the groove refractory 2 are in close contact with each other, as shown in FIGS. 1 to 3 of the accompanying drawings. 3 and a ditch runner 4 are designed to hold a fortress bath.

The groove refractory 2 is provided so as to surround an electromagnetic induction circuit formed by an iron core 5 and a coil 6 forming a closed circuit, and causes the hot water in the groove runner 4 to generate heat by applying voltage to this electromagnetic induction circuit. Based on this heat generation, the temperature of the bath water is increased or increased.

In this case, the method of forming the groove runner 4 is to
For example, a starting mold 7 as shown in FIG. 2 is embedded in a refractory to form a groove refractory 2 adjacent to the groove runner 4, and upon starting,
By energizing the coil 6 of the electromagnetic induction circuit, the starting mold 7 is heated, and this heat heats and dries the groove refractories 2, and finally the starting mold 7 is also sintered to dry the groove. Road 4 and Liaotang are formed to complete the channel induction furnace.

Since the starting mold 7 of the groove-shaped induction furnace formed in this way also thermally expands when heated, a gap corresponding to the extension of the starting mold 7 is provided between the groove refractory 2 and the starting mold 7. Since it is necessary to provide the groove refractory 2 by wrapping a combustible material 8 such as paper tape or cloth tape around the outer periphery of the starting mold 7,
By embedding it in the furnace and burning it during the temperature rise, a gap is created between the starting mold 7 and the groove refractory 2, and this gap is made to be a gap corresponding to the extension. There is.

That is, the volume of the hollow part within the groove refractory '2 is larger than the volume of the starting mold.

Conventional channel induction furnaces are configured like this, so
When the coil 6 is energized to heat the starting mold 7, since the starting mold 7 is generally complex in shape, the conductance is not necessarily uniform and the amount of heat generated is also different. Since there is also a difference in the amount of heat transfer, the temperature of the starting mold 7 cannot be raised uniformly and becomes non-uniform.

Furthermore, since the electrical conductivity of metal decreases as its temperature increases, the amount of heat generated in the high-temperature portion of the starting mold 7 is greater than the amount of heat generated in its low-temperature portion. The high-temperature part due to this becomes even hotter, and the difference between the high and low temperatures widens, and therefore, the temperature non-uniformity continues to widen as the temperature of the starting mold 7 rises.

The highest temperature reached in this way reaches the melting point, although there is still a low-temperature part, and then it absorbs the latent heat of melting and begins to undergo acid melting, but metals generally change from a solid state to fermentation melting. In this state, the conductivity rapidly decreases, so that the conductivity also decreases rapidly in the molten part of the starting mold 7, and the conductance becomes small.

In addition, the molten metal of the starting mold 7 that has partially melted in this way fills the gap between the part of the starting mold 7 that has not yet melted and remains solid and the groove refractory. However, since the molten metal flows down in the fermentation and melting part of the metal, the remaining cross-sectional area is small, and the conductance decreases.

Due to the synergistic effect of these two conductance reductions,
A very large amount of heat is generated, and as a result, the starting mold 7 may be disconnected at the heat generating part, but since the starting mold 7 is buried in the groove refractory 2, this disconnection occurs. Therefore, no induced current is generated in the disconnected starting mold 7, and it is impossible to disconnect the starting mold 7 by increasing the temperature. It becomes impossible.

As described above, the conventional apparatus had a serious drawback that caused the inability to start.The present invention eliminates such a drawback and provides a starting mold for a channel induction furnace that does not cause the inability to start. This is its purpose.

In order to achieve this object, the present invention provides that certain parts of the starting mold which are not buried in the groove refractories, for example, the part of the mold metal that is not buried in the groove refractory, for example, if the fermented water falls into the gap below due to melting, the mold metal of that part is The cross-sectional area of the unbroken part is smaller than other parts, or the metal bar has a smaller decapitation area than other parts and has a melting point higher than that of the starting mold metal in that part. By embedding and filling the wire, even if the hot water caused by melting in that part falls off and breaks the wire, the current can still be supplied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings showing one embodiment thereof.

In FIG. 4, the starting mold 11 is a part that is not buried in the groove refractory 2 and is not cut off by falling of the boiling water downward due to melting.
In this embodiment, a relatively long part of the upper horizontal part, for example, between the dots, has a cross-sectional area smaller than the other part of the starting mold 11, for example, another part. The cross-sectional area is V2 of the cross-sectional area of the part.

Since the starting mold 11 of the present invention is configured like this,
When the primary current is applied to the coil 6, this starting mold 1
A secondary current is generated at 1, but since the cross-sectional area between the points is 1/2 of that of other parts, the conductance is also 1/2, so the amount of heat generated is equal to that of other parts. This is approximately twice the portion of .

On the other hand, the area in contact with the refractory is also other parts, i.e.
'-N and L part-M in the vertical part, and lower horizontal part M-N
Because it is smaller than the K-L section, there is less heat propagation, and by preventing heat dissipation due to radiation and air convection in the section exposed to the atmosphere above, the large amount of heat generated by the K-L section and Starting mold 1 based on a small amount of heat dissipation
The highest temperature region of 1 occurs in the −L region over a relatively long range.

In this state, if the conductance of other parts of the starting mold 11 is the same, the amount of heat generated by the generation of secondary current in that part will be the same, but the heat from the -L part, which is the hottest part, will be the same. Due to the propagation, the temperature distribution of the starting mold 11 is highest at the K-L section, and decreases from K to H, and from L to L and M.
The lowest temperature occurs at the midpoint of the M-N section.

In this embodiment, the starting mold 11 is heated by electrical current.
The highest temperature part occurs in the upper Himi part, that is, in the K-L part, so even if a relatively large amount of metal that has smelted here falls off downward, it will remain in the upper horizontal groove. Road 4-1
wide, sequentially on the upper horizontal part of the starting mold 11 /
The L part melts, and then the vertical parts '-N part and L part-
The M part melts from the top to the bottom to form a vertical runner 4-2.
Finally, the lower horizontal portion M-N is fermented and melted to fill the lower horizontal groove runner 4-3 to form the groove runner 4, and the other groove runner 4 is also filled with the open water.

As described above, according to the present invention, the starting die 11 is connected to the groove refractory 2 in the part of the starting die 11 that does not cause rupture, or in the part where the fused part can be connected even if it occurs. Start-up mold 11 so that the part that is not buried in the
As a result, the starting mold 11 does not melt in the area surrounded by the groove refractories 2, and therefore molten molten water is always formed in the groove runner by heating the starting mold by energizing the coil 6. However, the channel induction furnace has the effect of not being unable to start.

In the case of swelling, rapid heating, or if there is not enough fermented water to reach the melting part, the starting mold 11 may melt at the -L part in the upper horizontal part. Yes, but
In this case, since the upper part is open, it is possible to connect the fused parts from the outside by using a metal rod or the like, and it is also possible to connect by pouring fermented water. This has the effect of eliminating the risk of inability to start due to melting.

In this embodiment, the highest temperature generating part of the starting mold 11 is made into a continuum with a smaller cross-sectional area than other parts, that is, a -L part having a certain length, but it does not necessarily have a certain length. It is not necessary to use a U-shaped cutout 12 as shown in FIG. 5, or a square cutout 13 as shown in FIG. 6 or other shapes.

Furthermore, in order to deal with fusing that may occur due to the rapid heating, etc., a section with a reduced cross-sectional area for the generation of the highest temperature is heated to a temperature higher than the melting point of the starting mold metal, as shown in Figure 6. By burying and filling the metal rod 14 with a high melting point, it is possible to prevent the electrical circuit of the starting mold from being disconnected even after the starting mold is cut.

As described above, according to the present invention, it is possible to make the desired part the highest temperature part and cause the starting mold to stagnate from there. This has the effect of completely eliminating the possibility that the channel induction furnace will be unable to start.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a channel induction furnace, Fig. 2 is a longitudinal cross-sectional view of a conventional starting mold, and Fig. 3 is a cross-sectional view taken along the line ■-■.
FIG. 4 is a longitudinal cross-sectional view of one embodiment of the present invention, and FIGS.
The figure is a longitudinal sectional view of another embodiment. 2... Groove refractory, 4... Groove runner, 7
, 11... Starting mold, 8... Flammable material, 14... Metal rod.

Claims (1)

[Claims] 1. A starting mold is buried in the groove refractory in advance,
In a groove-type induction furnace that melts the starting metal by heating with electricity to form a groove runner during startup, the cross-sectional area of a specific part of the starting metal that is not buried in the groove refractory is made larger than other parts. A starting mold for a groove-shaped induction furnace, which is characterized by a smaller size. 2. Bury the starting mold in advance in the groove refractory,
In a groove induction furnace in which a groove runner is formed by melting the starting metal by heating with electricity at startup, the cross-sectional area of a specific part of the starting metal that is not buried in the groove refractory can be made smaller than other parts. What is claimed is: 1. A starting mold for a groove-shaped induction furnace, characterized in that it is made smaller and at least this portion is filled with a metal rod having a higher melting point than that of the starting mold metal.